At this point it may be noted that the investigations conducted by Mr. Swan before referred to and those by the writer and the resultant observations of each were substantially alike. Many of the writer's, however, preceded those of Mr. Swan's, for during the years 1885 and 1886, having had the custody of part of the Archives of the City of New York there were many opportunities to study this subject which were taken advantage of, before and after which time frequent examinations were made of writings much more ancient than those pertaining to New York.

Assuming a second premise was to assert that the inks employed in the writing of these documents were "straight" or possessed some "added" pigment or color. Again, the vehicles to hold the particles or possibly preserving substances, might be factors.

All literature possible referring to ink formulas was examined to ascertain the names of materials recommended or formerly "added" to gall inks, because if the pristineness of the blacker inks was due to the added pigment it was a safe proposition that it was still existent in the ink, and that if it could be discovered part at least of the problem would be, simplified.

The "added" color compounds, excluding those of the aniline family which pertain to the more modern ink compositions, are of two classes: those possessing tannin and color-yielding materials and those containing only a color-yielding material. Many of the first class have been used in the manufacture of ink both with infusions of nut-galls or alone, while but very few of the second class have been used for either purpose. The decomposing action of light, oxygen and moisture on many of each class placed them beyond the purview of consideration, while the dates of the discovery and the fact of the small percentage of tannin contained in others permitted them also to be discarded. For instance: vanadium, which is fairly permanent, was discovered only in 1830; chanchi, the ink plant of New Granada discovered in the sixteenth century, possessing excellent lasting qualities, does not assimilate perfectly with other constituents used in the manufacture of ink, but is best when used alone; Berlin blue (prussian blue) is well spoken of, but was only discovered by accident in 1710 by Diesbach, a preparer of colors at Berlin; logwood, more used for this purpose than any other material, was first imported into Europe in the sixteenth century and causes a deterioration of the durable qualities of the tanno-gallate of iron; Brazil-wood and archil, and their allies, are exceedingly fugitive; bablah, the fruit of the acacia arabica, myrabolams, of Chinese growth, catechu, and sumac which though used in the time of Pliny, each contains a percentage of gallic acid too small to meet the requirements. Divi-divi, a South American product, came into use only at the end of the sixteenth century and has not stood the test of time.

This sifting process completely eliminated all but lampblack, madder and indigo in some form as a permanent "added" color pigment. Lampblack, which is we know forms the basis of "Indian" ink, is not soluble and requires a very heavy gummy vehicle to prevent its immediate precipitation, and while it could have been used in combination with tanno-gallate of iron as an ink, the fact that it was possible to chemically remove the ancient inks which remained black, was a sufficient demonstration that this carbon substance, which is not affected by chemicals, either as contained in the fluid ink or as dusted on after writing, could have formed no part of the ancient tanno-gallate of iron inks.

Madder is mentioned as of very ancient times and was cultivated in Europe as early as the tenth century; its addition to an iron and gall ink is said to be an invention of the year 1855; it is certain, however, that it was used for a like purpose as early as 1826, and a fair presumption that it was frequently employed in some form during the preceding four centuries. It has under certain conditions very lasting properties as the madder-dyed cloths found wrapped around Egyptian mummies demonstrates, but does not assist the tanno-gallate of iron to retain its black color; on the contrary it seems to lessen this quality.

That indigo for added color was employed by ink manufacturers in the eighteenth century is shown by the formulas appearing in the literature of that time. It was used alone as an ink long before, as well as contemporaneously with, those of the tanno-gallate of iron family. Its lasting properties are most remarkable if it be true that, used as a dye, there is still in existence specimens of it on cloth five thousand or more years old. The history of its use ALONE as an ink is difficult to ascertain back of a certain period; the writer has several specimens of it, one written in 1692 whose color is a green blue; another written about a century ago is believed to be as bright blue as the day it was placed on the paper; from 1810 to 1850 it was in common use particularly in hot climates where it was "home-made." Consequently if the old "gall" inks contained a lasting added color, indigo must have been the one, Dr. Stark whose investigations along this line for twenty-three years have already been cited has said that he preferred for his own use an ink composed of galls, sulphate of indigo and copperas (sulphate of iron); this means a tanno-gallate of iron ink with indigo for "added" color. Like formulas calling for different proportions of constituents both before and after his time in England and the continents of Europe and America are to be found in considerable number, proving that its use was more or less constant in this respect. To determine, then, whether or not the blacker specimens of the ancient writings contained indigo in any of its forms was most important, and the plan adopted most simple. Specimens of writing in ink of which the manufacturer's name was known as well as his formula and only thirty years old showed evidence of considerable "browning;" some of them when tested in juxtaposition with those of from fifty to one hundred years old which had turned completely brown, gave approximately the same results, and differentiated largely from the results obtained from jet black specimens of eighty to five hundred or more years of age. In a number of the browner ones indigo was found to be present while in many of the black ones it was not, demonstrating that the reason for the continuing blackness of the older inks is not due to an added color or pigment of any kind and furthermore that the "Stark" and corresponding ink formulas after the test of TIME did not retain their original blackness but deteriorated to a brown color; moreover, that their purpose as in the present day was to give an agreeable and immediate color result, a free-flowing ink, and to cheapen the cost of manufacture when compared with that of an unadulterated tanno-gallate of iron ink.

No disagreement being now possible as to the lasting color virtues of a properly proportioned tanno- gallate of iron ink WITHOUT an "added" color or pigment, there remained the sole question as to the vehicle utilized to hold this combination in suspension and whether or not it had to do with the continuing blackness of the older inks.

The answer must lie between the vegetable product known as gum and the animal product known as gelatine. The first disintegrates, quickly absorbs moisture and gradually disappears, while gelatine (isinglass) "contains under conditions 50% carbon, although its molecular formula has not yet been determined. It cannot be converted into vapor and does not form well-defined compounds with other bodies; it is insoluble in alcohol which precipitates it in flakes from its aqueous solution. It is also precipitated by tannin, which combines with it to form an insoluble non-putrescible compound. Gallic acid, however, does not precipitate it." (Bloxam.)

Possessing an undisturbed and complete history it was the very substance employed long before the discovery of gall ink, and is found present in the earliest specimens of the "Indian" inks which remain to us.

It must now be evident that there can be no material difference of opinions as to what has been so clearly and conclusively established, viz. that ink which contains a base of tanno-gallate of iron (without "added" color) is a permanent ink, and the length of its durability and continuing pristineness can be disturbed only by inferior quality of constituents, wrong methods of admixture and its future environment. Hence any black ink with this combination missing is of no practical value whatever either for record or commercial uses.

"Indian" ink, except for specific purposes, belongs to the great past and will so continue with its virtues unchallenged and proven, until some solvent is discovered for the carbon which forms nearly the whole of its composition, at which time THE perfect ink can be said to have been discovered.



CHAPTER XVII.

INK PHENOMENA.

CONDITION OF INK WHEN FIRST PLACED ON PAPER—ITS METAMORPHOSIS AND AFFINITIES—IGNORANCE OF THE FORGER AS TO ITS ORIGINAL ENVIRONMENT—TREATMENT OF OLD INK MARKS—HOW PAPER MAY DISCOLOR INK—THE USES OF ACID IN INK—VEHICLES TO HOLD INK PARTICLES AND PRESERVE THEM—INKS FIVE CENTURIES OLD DO PRESERVE THEIR GLOSS—SOME CAUSES OF INK DISINTEGRATION—WHEN INK BECOMES IRRESPONSIVE TO THE ELEMENTS— DEMONSTRATED TRUTHS ABOUT INK CONSTITUENTS AND COLOR PHENOMENA—NATURAL EVOLUTION OF AN INK MARK—LENGTH OF TIME REQUIRED TO BECOME BLACK—FIRST INDICATIONS OF AGE—DISAPPEARANCE OF INK QUALITIES—ARTIFICIAL AGING OF INK—TESTS FOR IT AND HOW TO CONFIRM THEM—BLEACHING AND REMOVAL OF INK FROM PAPER CRIMINALLY CONSIDERED— CHEMISTRY OF SUCH MARKS—THEIR RESTORATION— VARIATIONS IN METHODS WHICH CAN BE EMPLOYED.

ALL inks when first placed on paper are of course in a fluid state. Gradual evaporation of moisture causes a change not only in color but in the case of the iron and gall inks, in their chemical constitution, being immediately affected by their environment, whether due to the character of the paper on which they rest, the kind or condition of the pen used, or most important of all, the elements. Those who use the black inks and chemical writing fluids will have noticed these characteristics. The pale brown, blue or green as first written, and the gradual change after a short period to an approaching blackness, are reactions due largely to atmospheric conditions, the oxygen uniting with that for which it has affinity and instantly beginning with TIME to make its march, producing natural phenomena, which can be only superficially imitated but never exactly reproduced. When we further take into consideration that the forger cannot always know of the circumstances which surround the placing of original ink on paper and that be cannot manufacture the TIME which has already elapsed, it is not strange that attempted fraud can often be made evident and complete demonstrations given of the methods employed.

With the passage of time, the particles in some inks which are held together on the paper by gummy vehicles, commence to disintegrate and change from intense black to the brown color of iron rust, the "added" color which of itself is fugitive in character, soon departs; the vegetable astringent separating from the iron salt decays gradually and disappears and finally terminates in a mere stain or dust mark which can be blown off the paper. Sometimes, the written surface of such paper can be treated by carefully moistening it with a decoction of nut-galls or its equivalent in the presence of a weak acid, then if any iron be present, a measurable degree of restoration of color will ensue and remain for a short period.

Again, the discoloration of an iron ink may be due to the character of the paper; if of the cheaper grades and the bleaching compounds employed in their manufacture are not thoroughly washed out, then the ink not only begins to absorb oxygen from the atmosphere but the chlorine in the paper attacks it and the process of destruction is thereby hastened.

The introduction of acid into ink has two purposes, one to secure more limpidity, and the other to cause it to penetrate the paper and in this way bind together the constituent particles of both ink and paper. Most of the chemical writing fluids of this decade carry a superabundance of acid in their composition, which in time will burn through the paper and ultimately destroy it.

All tanno-gallate of iron inks require some vehicle to hold their particles in a state of suspension, otherwise there would be precipitation and such an ink could not be used. To meet this requirement a variety of gums are employed by manufacturers, gum acacia being the principal one. Its purpose is threefold—as before stated, to hold the ink particles in suspension—to prevent the ink from flowing too rapidly, and after drying WITHOUT blotting, to act as an envelope to encase the now fixed ink and prevent or interfere with its absorption of an excess of oxygen. The longer these latter conditions obtain the longer will the ink retain its pristineness, its durability and permanence. The "time proved" ink-written specimens of five hundred years or more ago which continue to retain their original intense black color and "glossy" appearance, do not, however, yield any evidence of the use of vegetable gums in their composition. Where such instances have been noticed the gloss is invariably missing. But, where ANY gloss is present, it was and is because of the employment of isinglass (fish-glue) as the vehicle to hold the ancient ink particles.

Hence the variations of color seen in ancient paper writings, as already stated, were due not only to possible imperfect admixtures of the component parts of the inks, but to the use of vegetable gums in their preparation. In the course of time these have been absorbed by moisture which hastened disintegration, causing a gradual disappearance of their original blackness and gloss and finally a return to the rusty color of oxidized iron.

It therefore follows, my observations and deductions being correct, the older a writing made with tanno-gallate of iron ink, where isinglass is the binder, and which has not been "blotted," the harder and more impervious and irresponsive it becomes to the action of the natural elements or of chemical reagents.

The truths demonstrated in this proposition cannot be denied. They fortify as certain that a properly proportioned mixture in water of an infusion of nut- galls or gallo-tannic acid and sulphate of iron, with isinglass as the vehicle to bold the particles in a state of suspension, if written with on good paper and allowed to dry without blotting, in a short time becomes encased or enveloped in such vehicle, which is thereby rendered substantially insoluble and absolutely prevents any extensive oxidation. Also, as a further consequent result, there is chemically created an unchangeable and continuing black color more permanent and durable than the substance on which it appears.

With a sample of standard commercial chemical writing fluid, write on "linen" paper without blotting it; in thirty hours, if exposed to the air and from three to five days if kept from it, the writing should have assumed a color bordering on black; it becomes black at the end of a month under any conditions, and so continues for a period of about five or six years, when if examined under a lens of the magnification of ten diameters, there will be a noticeable discoloration of the sides or pen tracks which slowly spreads during a continuing period of from ten to fifteen years, until the entire pen marks are of a rusty brown tint. A species of disintegration and decay is now progressing and when approximately forty years of age, has destroyed all ink qualities.

If, however, "chemical writing fluid" is first treated by exposure to the fumes of an ammoniacal gas, a "browning" of the ink occurs, not only of the pen tracks but of the entire ink mark. If examined now with a lens, the ink is found to be thin enough to permit the fibre of the paper to be seen through it, thus indicating artificial age. Furthermore, if a 20 per cent strength of hydrochloric acid be applied, the "added" color (usually a blue one) is restored to ITS original hue; alike experiment on "time" aged ink gives only the yellow brown tint of pure gall and iron combinations, the "added" color having departed caused by its fugitive characteristics. Again, if a solution of chlorinate of lime or soda be applied, the ink mark is instantly bleached, where in the case of honest old ink marks, it takes considerable time to even approximate a like result.

To confirm the chemical tests which may be employed in the determination of the artificial aging of ink marks, photographs made by permitting light to transmit through the paper and to interfere with its rays by filtering them through a "color" screen containing orange and some green, will indicate the presence of a fugitive substance in the ink, usually the "added" color employed in its manufacture.

The process of bleaching or "removal" of ink marks from paper is frequently employed in the attempted eradication of words or figures and the substitution of others on monetary instruments, commonly called "raising." Its purpose is usually a criminal one and some observations as to the modus operandi and its chemistry are not out of place here.

Ink marks made with a compound consisting of the combination of iron and an infusion of galls or its equivalent (a tanno-gallate of iron ink), as treated with certain chemicals, change from a compound with color to a chemical compound, with no color. Nothing has in fact been absolutely removed or eradicated, but it is a mere change of form, a sort of re-arrangement of the particles, the ingredients which formed the original color being still present, but in such a condition that they are invisible to the eye. A restoration of the invisible ink marks so that they can be observed, becomes possible by the use of chemical reagents and is the reverse of the one of erasure or bleaching, and changes the constituents again into a compound which has color from the one which had none. It does, not, however, reproduce the exact composition originally existing. Such a reagent simply goes to the basis of the material as first used, takes up what was left and reforms the particles sufficiently to make them abundantly recognizable. An apt illustration of these chemical changes of color is found in what is known as the phenolphtalein test solution, which is colored deep purplish-red by alkali hydrates or carbonates, and then by the addition of an acid rendered colorless, to be again reddened by an over- plus of the alkali and so on ad infinitum.

A popular material for the purpose of making chemical erasures is chlorinated lime or soda, which becomes more active by first touching the ink mark to be removed with a one half strength solution of acetic acid; this hastens the liberation of chlorine gas, THE active agent which causes the "bleaching" to take place. Hydrogen peroxide, also a bleaching compound, is less rapid in its action than chlorinate of soda; the same may be said of combinations of oxalic and sulphurous acids.

The most effective re-agent for the restoration of a chemically "bleached" iron ink mark is the sulphide or sulphuret of ammonia (it has several names). This penetrating chemical blackens metals or their salts, whether visible or not, if brought together. It must not be used by direct contact, the best and safest plan being to place a quantity in a small saucer, to be set on the floor of a closed box; to fasten to the box lid the specimen to be operated on; in this way the restoration is due to the fumes of the chemical and a possible danger of destruction of the specimen much lessened, especially if the marks are very light or delicate ones. The restoration of color under particular conditions may also be obtained by treatment with tannic acid, potassium ferro-cyanide (acidulated) or a weak solution of an infusion of galls.



CHAPTER XVIII.

INK CHEMISTRY.

SOME OBSERVATIONS AS TO CHEMICAL EXAMINATION OF INK MARKS BY ALLEN—ERASING OF INKS BY CHEMICAL MEANS—APPROVED CHEMICAL TESTS IN THE ASCERTAINMENT OF INK CONSTITUENTS.

A COMPILATION of the methods of Robertson, W. Thompson (Lord Kelvin), Irvine, Wislar, Hoffman and others, relative to the chemical examination of ink marks, is to be found in "Allen's Commercial Organic Analysis." Their experiments, however, date back many years ago, a few of them before the time of the use of the "anilines" for added color. The so-called "alizarin" ink referred to has now become obsolete. The following is the citation in part:

"In chemico-legal cases it is sometimes of importance to ascertain the nature of the ink used, to compare it with specimens of writing of known history, and to ascertain the relative ages of the writings. A minute inspection should first be made with a magnifying power of about 10 diameters, and any peculiarities of color, lustre, shade, etc., duly noted, and where lines cross each other which lie uppermost. The examination is often facilitated by moistening the paper with benzine or petroleum spirit, whereby it is rendered semi- transparent. The use of alcohol or water is inadmissible.

"Valuable information is often obtainable by treating writing or other ink-marks with reagents. Some inks are affected much more rapidly than others, though the rate of change depends greatly on the age of the writing. Normal oxalic acid (63 grammes per litre), or hydrochloric acid of corresponding strength, should be applied to a part of the ink marked with a feather or camel-hair brush (or the writing may be traced over with a quill pen), and the action observed by means of a lens, the reagent being allowed to dry on the paper. Recent writing (one or two days old) in gallic inks is changed by one application of oxalic acid to a light gray, or by hydrochloric acid to yellow. Older stains resist longer, in proportion to their age, and a deeper color remains. Log-wood ink marks are mostly reddened by oxalic acid, and alizarin marks become bluish, but aniline inks are unaffected. With hydrochloric acid, logwood ink marks turn reddish or reddish-gray, alizarin marks greenish, and aniline ink marks reddish or brownish-gray. The treatment with acid should be followed by exposure to ammonia vapors, or blotting paper wet with ammonia may be applied. Thus treated, marks in logwood ink turn dark violet or violet-black. The age of ink marks very greatly affects the rate of their fading when treated with dilute ammonia, the old marks being more refractory. The behavior of ink marks when treated with solution of bleaching powder is often characteristic, the older writings resisting longer; but unless the reagent be extremely dilute, writings of all ages are removed almost simultaneously. Hydrogen peroxide acts more slowly than bleaching solution, but gives more definite results. After bleaching the mark by either reagent, the iron of the ink remains mordanted on the paper, and the mark may be restored by treatment with a dilute solution of galls, tannic acid, or acidulated ferro- cyanide. The same reagents may be used for restoring writing which has been faded from age alone.

"When ink marks have been erased or discharged by chemical means, traces of the treatment are often recognizable. After effecting the erasure the spot is often rubbed over with a powdered alum or gum sandarac, or coated with gelatin or size. The bleaching agents most likely to have been used are oxalic, citric, or hydrochloric acid, bleaching powder solution, or acid sulphite of sodium. Moistened litmus paper will indicate the presence of a free acid, and in some cases treatment with ammonia fumes will restore the color. The presence of calcium, chlorides, or sulphates in the water in which the paper is soaked will afford some indication of bleaching powder or a sulphite having been used. Potassium ferro-cyanide will detect any iron remaining in the paper. Exposure to iodine vapor often affords evidence of chemical treatment, and other methods of examination readily suggest themselves."

M. Piesse, in the Scientific American, is authority for a method of removing ink, found on "patent" check paper:

"Alternately wash the paper with a camel's- hair brush dipped in a solution of cyanide of potassium and oxalic acid; then when the ink has disappeared wash the paper with pure water."

Inks of the tanno-gallate of iron family, whether containing "added" color or not, can be more or less "erased" by chlorinate of lime or soda, in the presence of a weak acid. These chemicals do not, however, materially affect the prussian blue inks, which require solutions of hydrate of potash or soda. Real indigo can be removed by chloroform, morphine or an aniline salt (indigo and aniline both owe their names to the same Portuguese source), which possess the rare property of dissolving pure indigo. Such combination, if refractory in the presence of permanganate of potash with sulphuric acid, must be followed by an application of sulphurous acid. In like manner, inks composed of by-products of coal tar, can be effectively treated, when irradicable with plain water or soap and water.

The erasure and removal of most inks from paper can be accomplished by the application of the chemicals heretofore enumerated. The requirements in this direction of some inks, however, though of rare occurrence, are to be met by the employment of other and particular reagents.

Many of the tests specified in the Allen citation to determine the character of ink constituents, if made alone are practically valueless, because the same behavior occurs with different materials employed in the admixture of ink. To avoid error in judgment the operator should verify if possible by confirmatory tests. Thus, in the one for logwood, sulphurous acid will cause a logwood ink mark to turn yellow; mercuric chloride, orange; tartar-emetic, red; and if the marks are faded ones, solutions of sulphate of iron or bichromate of potash will restore them respectively to a violet or blue-black color.

Prussian blue, aniline blue and indigo blue are to be tested as follows: Solution of chloride of lime, no change of color for prussian blue; decoloration or faint yellow for aniline blue or indigo. To discriminate between the two latter, test with solution of caustic soda, when decoloration or change of color will indicate aniline blue and permanence will indicate presence of indigo blue.

In the manufacture of the blue-black inks, a variety of violets have been and are still employed. Among them are aniline violet, iodine violet, madder, alkanet, orchil and logwood.

(a) Apply chloride of lime solution: 1. No change of color indicates alkanet. 2. Any change, one of the other five.

(b) Apply lemon juice: 1. The violet becomes brighter if it is one of the aniline violets, to be distinguished from each other by applying one part of hydrochloric acid to three parts of water, when it will become violet-blue, changing to red if it is common aniline-violet, but blue changing to a green hue and upon adding plain water to a lilac or pearl gray if it is iodine-violet (Hoffman's). It will also turn from red to yellow in lemon juice. To test for the other three violets: (a) Apply chloride of lime, to be followed by a solution of yellow prussiate of potash: absence of a blue coloration leaves orchil and logwood to be considered. To distinguish between them apply solution of hydrate of lime, whereby a change to gray, followed by complete decoloration indicates logwood, and a change to violet-blue, orchil.

The substances utilized with but few exceptions for red ink are the "eosins," possessing different names like erythrosine, as well as different hues. Antecedent to about thirty-five years ago, cochineal (known as "carmine"), madder, Brazil wood and saffron formed the basis of most of the red inks.

Make a soap solution adding a small quantity of ammonia, lemon juice, muriate of tin, all in water: 1. No change upon application indicates madder. 2. Any change, the presence of one of the three other reds: (a) thus a complete decoloration with a return of the color indicates saffron; (b) reappearance of the red color though weaker, aniline-red: (c) production of a yellowish red or light yellow color, cochineal or Brazil wood, to be distinguished from each other by the application of concentrated sulphuric acid, when Brazil wood will at once give a bright cherry-red, and cochineal a yellowish orange.

No yellow inks are in commercial use. Documents do, however, often contain yellow marks about which information is required as to their origin. As a rule they are iron rust, picric acid, turmeric, fustic, weld, Persian berries or quercitron. In order to recognize the different colors, the presence or absence of iron rust and picric acid must first be determined.

Apply a warm sample of a slightly acid solution of yellow prussiate of potash; iron rust will be indicated by a blue coloration.

Apply a weak solution of cyanide of potassium; picric acid will yield a blood-red coloration.

If picric acid and iron rust are both absent, apply a bit of ordinary wetted soap: 1. It turns reddish-brown and becomes yellow again with hydrochloric acid— turmeric; 2. It turns quite dark—fustic; 3. It is unaffected—weld, Persian berries or quercitron. To distinguish between these three, apply sulphuric acid, the color of weld will disappear, and of the others remaining apply tin-salt solution, when a change to orange indicates Persian berries, and no change or a very slight one, quercitron.

Inks containing also logwood, fustic, Brazil wood, or madder, were all of them more or less employed some years ago. Their color phenomena, following long periods of time, is much the same. Tests as prescribed in the accompanying table for such inks will serve to classify them preliminary to subsequent and more certain ones.



LOGWOOD. FUSTIC.

Concentrated Hydrochloric Acid Red-yellow Red Dilute " " Reddish Yellow-Brown

Concentrated and dilute Nitric Acid Red Red-Yellow " Sulphuric Acid . . Black Dark Purple Dilute " " Red Brown Purple Potassium Chromate . . . . Black Stannous Chloride Violet Yellow Tartaric Acid . . . . . Gray-Brown Yellow Sulphate of Copper . . . . Dark Gray Tannin . . . . . . Yellow-Red Yellow Potash Dark Red Yellow Potassium Permanganate Light-Brown Yellow " Iodide . . . . . Red-Yellow Pyrogallic Acid . . . . Yellow-Brown Yellow Chrome-yellow . . . . . Dark Violet Sodium (Salt) Violet Red Sulphate of Iron Gray to Black Alum . . . . . . . Violet Red,Brown. Faint Red

BRAZIL WOOD. MADDER.

Concentrated Hydrochloric Acid Light Red Pale Yellow Dilute " " Light Red Pale Yellow

Concentrated and dilute Nitric Acid Dark Purple Pale Yellow " Sulphuric Acid . . Red Pale Yellow Dilute " " Purple Pale Yellow Potassium Chromate . . . . - - Stannous Chloride Light Red Light Red Tartaric Acid . . . . . Red Yellow Pale Yellow Sulphate of Copper . . . . - - Tannin . . . . . . No Change Pale Yellow Potash Crimson Light Red Potassium Permanganate - - Iodide . . . . . - - Pyrogallic Acid . . . . - - Chrome-yellow . . . . . - - Sodium (Salt) - Red Sulphate of Iron Dark Violet - Alum . . . . . . . - Faint Red

CHAPTER XIX.

FRAUDULENT INK BACK GROUNDS.

DETECTION OF ALTERATIONS IN DOCUMENTS BY CHEMICAL TESTS WHICH APPLY SOLELY TO THE PAPER—ACCURACY OF RESULTS OBTAINED BY USE OF IODINE EXCELS THAT OF ALL OTHER CHEMICALS—IT APPLIES BEST TO LINEN PAPER—MODERN HARD PAPER DOES NOT GIVE COMPLETE INFORMATION—EFFECT OF IODINE ON MARKS MADE BY A STYLUS OR GLASS PEN.

FIFTY years ago and long before the employment of the fugitive "anilines" for ink uses, and "wood pulp" as a material for paper, two French chemists, Chevallier and Lassiagne, published in the Journal de Chimie Medical, an article "On the Means to be Employed for Detecting and Rendering Perceptible Fraudulent Alterations in Public and Private Documents," which as translated is valuable enough to quote in full:

"The numerous experiments which have been already tried at various times, have made known the processes which may frequently be put in practice for causing the reappearance of traces of writing effaced by chemical reactions, and for throwing light on the work of the guilty. But there are cases in which all the means proposed for this purpose fail, and then the criminal may escape justice from the want of conclusive material proofs. If, as has already been proved, it is not always possible to cause the reappearance of the effaced writing, for which written words have with a fraudulent intent been substituted, at least, as our experiments demonstrates, we may recognize, by some effects which are manifest on the surface of the altered paper, the places where the criminal act has been performed, circumscribe them by a simple chemical reaction visible to the least practiced eye, and even measure their extent. In a word, the visible alterations produced on a deed are susceptible, owing to the partial modifications which the surface of the paper has undergone, of being differently affected by certain chemical actions, and of being rendered visible. The following experiments, made in a judicial investigation, furnish us with the following facts:

"1st. The surface of paper sized in the ordinary way, or letter paper, no longer presents with certain reactions, the same uniformity where it has been either accidently moistened in several places by various liquids, or left in contact for a certain time with agents capable of removing or destroying the characters which have been traced on it with ink.

"2d. The application of a thin layer of gum, of starch, or farina, of gelatine, or fish-glue, with a view of sizing certain parts of the paper, or of causing certain bodies to adhere to it momentarily, is detected by an action similar to that which shows paper to have lately been wetted by the contact of liquids.

"3d. The heterogeneousness of the pulp of the papers, and the kind of size with which they are impregnated, lead to differences in the results which are observed with the same chemical reagents. We shall now examine each of these propositions, and describe the means which we have employed in endeavoring to solve questions of so high a degree of interest.

"1st. The homogeneousness of sized paper not partially altered by the contact of liquids (water, alcohol, salt-water, vinegar, saliva, tears, urine, acid salts, and alkaline salts) is demonstrated by the uniform coloration which this surface takes on being exposed, if not wholly, at least in various parts, to the action of the vapor of iodine disengaged at the ordinary temperature from a flask containing a portion of the metalloid. When the surface of paper not stained by any of the above mentioned liquids is exposed to the action of this vapor for three or four minutes in a room the temperature of which is about 60 degrees F., a uniform yellowish, or light-brownish yellow, coloration is noticed on the whole extent exposed to the vapor of iodine; in the contrary case, the surface which has been moistened, and afterwards dried in the open air, is perfectly distinguished by a different and well circumscribed tint. On the papers into which paste starch and resin have been introduced, the stains present such delicate reactions that we may sometimes distinguish by their color the portion of paper which has been moistened with alcohol from that which has been moistened with water. The stain produced by alcohol takes a bistre-yellow tint; that formed by water is colored of a more or less deep violet blue, the desiccation having been effected at the ordinary temperature. For the stains occasioned on these same papers by other aqueous liquids, the tint, apart from its intensity, resembles that of the stains of pure water. The feeble or dilute acids act like water on the surface of the same paper containing starch in its paste; but the concentrated mineral acids, by altering more or less the substances which enter into the composition of the latter, give test to the stains which present differences. We are always able to recognize by the action of the vapor of iodine the parts of the paper which have been put in contact with chemical agents, the energy of which has been arrested by washing in cold water. We are able, on several ancient deeds, written on stamped paper, and a few words of which had been removed by us with chemical agents, to recognize the places where their action was exerted, to see and to measure the extent which they occupied on the surface of the paper.

"The testing of a paper with the vapor of iodine will present this double advantage over the methods hitherto practiced for detecting falsifications in writings, that it points out at once the place in the paper in which any alteration may be suspected, and that, on the other hand, it enables us to act afterwards with the reagents proper for causing the reappearance of the traces of ink, when that is possible. If the means which we now propose cannot always make the former writing appear, they demonstrate the places where the alterations must have been made, when, however, the want of uniformity presented by the surface of the paper is not explained by any circumstance. This proof becomes, therefore, a weapon which the guilty person cannot avoid. But might not the presence of a stain, or several stains, developed by the vapor of iodine, in different parts of a public or private deed, give rise to a suspicion, where these stains have, perhaps, been occasioned by the spilling of some liquid on the surface of the paper? and would it not be rash and unjust to raise an accusation from such a fact? There would indeed be great temerity in drawing such a conclusion from a fortuitous circumstance; but the inference which may be drawn from the place occupied by these stains on the surface of the paper, from the more or less significant words found in those places, would not permit an accusation to be so lightly brought, where simple reasoning would be sufficient to destroy its basis. Besides, the subsequent reactions which would be made would certainly never revive words formerly written and effaced; whilst the latter effects may be often produced, more or less visibly, on those parts of the paper on which falsification has been practiced, figures or words being substituted for other figures or words.

"2d. The applications made to the surface of a sheet of paper, with a view of covering it again at certain parts with a fine layer of gum, gelatine, starch or flour paste, or in other places to cause other sheets of paper to adhere, may be recognized not only by the reflection of light falling upon the paper inclined at a certain degree of obliquity, and by the transmission of light through the paper, but also by the varying action which the vapor of iodine exerts on the surface which is not homogeneous. Papers containing starch and resin are more powerfully acted upon by this vapor than papers of a less complex composition. Both in the parts covered with starch, or paste flour, are colored in a few minutes of a violet blue; but with starched papers alone a more intense coloration is manifest on the places covered again with a thin layer of gum arabic, size or gelatine. By looking, then, on the surface of the paper, held somewhat obliquely to incidental light, we distinguish clearly, by their different aspects, the parts on which these various substances have been applied. The vapor of iodine, in condensing at the ordinary temperature on the surface of the papers to which any kind of size has been applied in various places, produces differences which are most commonly well recognized by the greater or less transparence of the paste of the paper.

3d. The heterogeneousness of the pulp of the various papers of commerce, and the nature of the size with which they are penetrated, cause differences, either in the coloration which the surface of these papers takes when exposed to the vapor of iodine, or in the tint which is manifested in the portions of the size deposited in certain portions of that surface; thus, papers with starched pulp generally turn brown, or blue, according to the amount of water that remains in their interstices; other papers turn yellow only under the influence of the vapor of iodine, and the parts which have received superficially a layer of another agglutinative body resist this action for a certain time, and are distinguished from the parts of the paper which are not covered with it."

My own investigations confirm to a great extent the value of these experiments and the accuracy of the deductions, in so far as they relate to "linen" paper; but they do not always obtain when made in connection with paper of inferior grades.

It is also true that dry paper is affected differently under the influence of the vapor of iodine, as would be paper which had been moistened and then dried; but the part which had been moist assumes the color of blue-violet, while unaltered paper assumes a yellow- brown color. Even when the paper thus treated is moistened all over with water, there will be a difference, for those parts which had been before moistened, will appear a dark violet-blue, while the other parts will show a plain blue coloration.

In cases where pencil writing has been removed with a soft rubber or fresh bread, the parts thus erased will assume, when subjected to iodine fumes, a brown color trending towards violet and much darker than the undisturbed portions of the paper. Lines impressed upon paper with a "stylus," a glass or ordinary dry pen, can be made visible by the fumes of iodine, the lines showing with a stronger coloration than the surrounding paper.



CHAPTER XX.

FUGITIVE INK.

SOME OBSERVATIONS ABOUT "ADDED" COLOR TO INK— INVENTION OF COAL TAR COLORS—CHRONOLOGICAL HISTORY OF THE "ANILINES" EMPLOYED AS INK—OTHER SUBSTANCES USED FOR THE SAME PURPOSE.

THE term "added color," as applied to ink, is the popular phraseology for a multitude of materials which have been more or less utilized for a period of centuries, in adulterating and coloring ink. In olden times they were introduced into ink with an honest belief that it would also improve and ensure its lasting qualities, but latterly more often to cheapen the cost of its manufacture. Reference has been made to a large variety of these substances used for this purpose and the story told of the effect of the test of time upon them as indicative of their supposed value. Attention has also been directed to the discovery during the nineteenth century of the colors which owe their origin to by-products of coal tar.

Generically these colors are classified as "anilines." They have worked a revolution in all the arts in which colors are used. Employed without a mordant, with few exceptions, they are measurably affected by both light, heat, moisture, or other changes and as made into inks are never permanent. Hence they should not be used for records, because if obliterated from any cause whatever, there are no known means to render them again legible.

The origin and history of the "anilines" are known. Viewed from an ink standpoint they are of vast interest. So extended in number are the "anilines" (they run into the thousands) that they include every shade of black and all possible tints or hues of the colors of the rainbow.

The chronological history of such of these artificial colors which appertain to ink or its manufacture is important as locating the dates of their invention and commercial use.

The first discovery of "aniline" is credited to Helot in 1750. In 1825 Faraday in rectifying naphtha discovered benzole, which by the action of strong nitric acid be converted into nitro-benzole; and this latter, when agitated with water, acetic acid and iron filings produced aniline. Unverdorben in 1826 discovered an analogous material in products obtained by the destructive distillation of indigo. Runge in 1834 claims to have detected it in coal tar and called it kyanol, which after oxidation became an insoluble black pigment and known as aniline black. It could not, however, be used as an ink. Zinan in 1840, experimenting along the same lines, produced another compound terming it benzidam. Fritsche in the same year by the distillation of indigo with caustic potash developed a product which he also called aniline, the name being derived from the Portuguese word anil, meaning indigo. Shortly afterwards A. W. Hoffman established the identity of these substances.

Aniline when pure is a colorless liquid, possessing a rather ammoniacal odor. It soon becomes yellow and yellow-brown under the influence of light and air. It does not affect litmus paper.

In 1856 Perkins accidentally discovered the violet dye called mauve, which acquired considerable commercial importance besides its utility for ink purposes.

Nicholson in 1862 succeeded in producing the first of the soluble blue anilines.

The discovery of induline, one of the modifications of aniline black, was made known in 1864.

Nigrosine, produced by the action of concentrated sulphuric acid on the insoluble indulines, was discovered in 1868.

The soluble indulines and nigrosines differentiate in appearance, the first a bronzy powder and the latter a black lustrous powder. When made into ink they possess about equal color values.

In 1870 the German chemists, Graebe and Liebermann, announced that they had succeeded in producing artificial alizarin,—the coloring matter of the madder root. Commercial value was not given to this discovery until it was put on the market in 1873, although it did not meet all the requirements.

Springmuhl in 1873 obtained an accessory product in the artificial manufacture of alizarin out of anthracene, from which a beautiful blue was made, superior in many respect to the aniline blues. It differed from aniline in having the same color in solution. Alkalis destroyed the color but acids restored it. The process was kept a secret for a long time. This product was originally sold as high as $1,500 for a single pound.

Caro, a German chemist, invented in 1874 the red color known as eosine, which was brought to this country in the following year and sold for $125 per pound. Its color is destroyed by acids.

Orchil or archil (the red color) was discovered in 1879. The commercial use of the so-called "orchil substitutes" (purples) began, however, in the years 1885 and 1887.

Artificial indigo, as the result of many years of experimenting, came into commercial use under the name of "indigo pure" only in 1897. It had previously been produced synthetically in a variety of ways, but the cost of the production was far above that of the natural product. Baeyer and Emmerling in 1870, Suida in 1878, Baeyer in 1878, Baeyer and Drewsen in 1882, and Heumann in 1890, can be said to have been the pioneers in the production of artificial indigo.

The intensity of some of the aniline colors may be indicated by the fact that a single grain of eosine in ten millions of water exhibits a definite rose-pink color.

It is asserted that in the last three years many improvements have been made in the permanent qualities of some of the soluble anilines, but no material which is soluble in plain water should ever be employed as an ink for record purposes.

Preceding the discovery of the "anilines," as already related, other substances had been employed for "added" color in the admixture of ink, principally madder, Brazil wood, indigo, and logwood.

Only a casual reference has heretofore been made to Brazil wood and logwood.

Brazil wood, also called peach wood, is imported from Brazil. Its employment as a dyestuff is known to be of great antiquity, antedating considerably the discovery of South America. Bancroft states, "The name 'Brazil' was given to the country on account of the extensive forests of the already well-known 'Brazil wood,' which was found by its Portuguese discoverers. The dyestuff thus gave its name to the country from which it was afterwards principally obtained. The word 'Brazil' appears to have been originally used to designate a bright red or flame color. Thus in a contract between the cities of Bologna and Ferrara, in 1194, the dyestuff kermez is referred to as grana de Brazile and Brazil wood, both dyestuffs at that time being obtained from India." For "added" color to ink and alone it was much used in the seventeenth and eighteenth centuries.

Logwood, employed more extensively for "added" color than any other color compound, was introduced into Europe by the Spaniards, A. D. 1502. In England it does not appear to have been much used until about 1575. In 1581 the Parliament prohibited its use "because the colours produced from it were of a fugacious character." Its use was legalized in 1673 by an act, the preamble of which reads, "The ingenious industry of modern times hath taught the dyers of England the art of fixing, the colours made of logwood, alias blackwood, so as that, by experience, they are found as lasting as the colours made with any sort of dyeing wood whatever." It is obtained principally from the Campeachy tree, which grows in the West Indies and South America.

The practical utility of logwood as the base for an ink was a discovery of Runge in 1848, who found that a dilute solution of its coloring matter, to which had been added a small quantity of neutral chromate of potassium, produced a deep black liquid which apparently remained clear and did not deposit any sediment. This composition became very popular on account of its cheapness and dark purple color. It is of a fugitive character, though, and has passed almost entirely out of commercial use.



CHAPTER XXI.

ANCIENT AND MODERN INK RECEIPTS.

"INDIAN" INK—SPANISH LICORICE—BITUMEN—CARBON FROM PETROLEUM—PROCESS TO OBTAIN GALLIC ACID—EFFECT OF SUGAR IN INK—DARK COLORED GALLS BEST FOR INK MAKING—SUBSTITUTES FOR GALLS—RELATIVE PROPORTIONS OF IRON AND GALLS—ANECDOTE OF PROFESSOR TRIALL— ESTIMATION OF SULPHATE OF COPPER—QUAINT INK RECIPE—RIBAUCOURT'S INK—HORSELEY'S INK— ELSNER'S INDELIBLE MARKING INK—BLACK INK FOR COMMON AND COPYING USES—COMMON BLACK INK—SHINING BLACK INK—PROCESS FOR "BEST" INK—INDELIBLE BLACK INK WITHOUT GALLS OR IRON—INK POWDER—STEEL PEN INK—SOME EARLY LITERATURE OF THE COAL TAR PRODUCTS—INK PLANT OF NEW GRANADA—"IMPERISHABLE" INK—FIRE- PROOF INK—"INERADICABLE" INK—EXCHEQUER INK—"PERMANENT" RED INK—SUBSTITUTE FOR "INDIAN" INK—TO PREVENT INK FREEZING—BACTERIA IN INK—GOLD AND OTHER INKS USED FOR ILLUMlNATING.

INNUMERABLE receipts and directions for making inks of every kind, color and quality are to be found distributed in books more or less devoted to such subjects, in the encyclopaedias, chemistries, and other scientific publications. If assembled together they would occupy hundreds of pages. Those cited are exemplars indicating the trend of ideas belonging to different nations, epochs, and the diversity of materials. They can also be considered as object lessons which conclusively demonstrate the dissatisfaction always existing in respect to the constitution and modes of ink admixture. Many of them are curious and are reproduced without any amendments.

"Indian ink is a black pigment brought hither from China, which on being rubbed with water, dissolves; and forms a substance resembling ink; but of a consistence extremely well adapted to the working with a pencil-brush, on which account it is not only much used as a black colour in miniature painting; but is the black now generally made use of for all smaller drawings in chiaro obscuro (or where the effect is to be produced from light and shade only).

"The preparation of Indian ink, as well as of the other compositions used by the Chinese as paints, is not hitherto revealed on any good authority; but it appears clearly from experiments to be the coal of fish bones, or some other vegetable substance, mixed with isinglass size, or other size; and most probably, honey or sugar candy to prevent its cracking. A substance, therefore, much of the same nature, and applicable to the same purposes, may be formed in the following manner.

"Take of isinglass six ounces, reduce it to a size, by dissolving it over the fire in double its weight of water. Take then of Spanish liquorice one ounce; and dissolve it also in double its weight of water; and grind up with it an ounce of ivory black. Add this mixture to the size while hot; and stir the whole together till all the ingredients be thoroughly incorporated. Then evaporate away the water in baleno mariae, and cast the remaining composition into leaden molds greased; or make it up in any other form."

"The colour of this composition will be equally good with that of the Indian ink: the isinglass size, mixt with the colours, works with the pencil equally well with the Indian ink; and the Spanish liquorice will both render it easily dissolvable on the rubbing with water, to which the isinglass alone is somewhat reluctant; and also prevent its cracking and peeling off from the ground on which it is laid." * * * * * * *

There is found in small currents near the Baltick Sea, in the Dutchy of Prussia a certain coagulated bitumen, which, because it seems to be a juice of the earth is called succinum; and carabe, because it will attract straws; it is likewise called electrum, glessum, anthra citrina, vulgarly yellow amber.

"This bitumen being soft and viscous, several little animals, such as flies, and ants, do stick to it, and are buried in it.

"Amber is of different colours, such as white, yellow and black.

"The white is held in greatest esteem in physick, tho' it be opacous; when it is rubbed against anything, it is odoriferous, and it yields more volatile salt than the rest. The yellow, is transparent and pleasant to the eye, wherefore beads, necklaces, and other little conceits are made of it. It is also esteemed medicinal, and it yieldeth much oil.

"The black is of least use of all. (Sometimes used by the ancients in making ink.)

"Some do think that petroleum, or Oil of Peter, is a liquor drawn from amber, by the means of subterrenean fires, which make a distillation of it, and that jet, and coals are the remainders of this distillation.

"This opinion would have probability enough in it, if the places, from whence this sort of drogues does come, were not so far asunder the one from the other; f or petroleum is not commonly found but in Italy, in Sicily, and Provence. This oil distils through the clefts of rocks, and it is very likely to be the oil of some bitumen, which the subterranean fires have raised." * * * * * * *

There are various processes for obtaining gallic acid, one of which is to moisten the bruised galls and expose them for four or five weeks to a temperature of 80 degrees Fahr.; by which a mouldy paste is formed, which is pressed dry and then digested in boiling water, which after evaporation yields the acid, and mixed with the solution of green copperas, makes the, ink. A quicker process, however, is to put the bruised galls into a cylindrical copper of a depth equal to its diameter, and boil them in nine gallons of water—taking care to replace the water lost by evaporation. The decoction to be emptied into a tub, allowed to settle, and the clear liquid being drawn off, the lees are emptied into another tub to be drained. The green copperas must be separately dissolved in water, and then mixed with the decoction of the galls. A precipitate is then formed in the state of a fine black powder, the subsidence of which is prevented by the addition of the gum, which, separately dissolved in a small quantity of hot water, combines with the clear black liquid. Besides its effect in keeping the fine insoluble particles in suspension, the gum mucilage improves the body of the ink, prevents its spreading or sinking too much into the paper in writing, and also acts beneficially by forming a sort of compact varnish in it, which tends to preserve its colour, and shield it from the action of the air. If, however, too much mucilage is used, the ink flows badly from quill pens, and still more so from steel pens, which require a very limpid ink. The addition of sugar increases the fluidity of ink, and permits the quantity of gum to be increased over what it would bear without it; but, on the other hand, it causes it to dry more slowly, and besides it frequently passes into vinegar, when it acts injuriously on the pens. The dark- coloured galls, known as the blue Aleppo ones, are said by Ribaucourt, and others who have given much attention to the ingredients for ink-making to be the best for that purpose, and they are generally used by the best makers.

"From their high price, however, and that of galls generally, sumach, logwood, and even oak bark are too frequently substituted in the manufacture of inks, but it need scarcely be said always injuriously. Ink made according to the receipt given above is much more rich and powerful than many of those commonly made. To reduce it to their standard one half more water may be safely added; or even twenty gallons of tolerable ink may be made from the same weight of materials. Sumach and logwood admit of only about one-half or less of the green copperas that galls will take, to bring out the maximum amount of black colour. The colour of black ink gradually darkens in consequence of the peroxidation of the iron in it on exposure to the air, but it affords a more durable writing when used pale; its particles being then finer, penetrate the paper more intimately, and on its oxidation is mordanted into it. It is advisable so soon as the ink has acquired a moderately deep tint, to draw it off clear into bottles and cork them well.

"According to the most accurate experiments on the preparation of black writing inks, it appears that the proportion of the green copperas ought to be, and not to exceed, a third of the decoction of galls used; but the proportions used vary according to the practical experience of ink-makers, who have all receipts of their own, which they deem best, and, of course, keep secret. In the precipitate an excess of colouring matter, which is necessary for its durability, is preserved in it. The blue galls alone ought to be employed in making the best quality of black ink. Logwood is a useful. ingredient, because its colouring matter unites with the sulphate of iron and renders it not only of a very dark colour, but also less capable of change from the action of acids or of the atmosphere. Many attempts have been made by amateurs to make a good permanent black ink. A good story is told of Professor Traill. He had succeeded, after a long series of experiments, in producing an ink which he deemed to be in all respects A 1, and which resisted the action of all acids and alkalies alike. The pleased savant sent samples of it for trial to several banks and schools, where it gave general satisfaction; but, alas, an experimenting scribbler, thoughtlessly or otherwise, applied a simple test undreamt of by the Professor, and with a wet sponge completely washed off his 'indelible,' and thereby finished his career as an amateur ink-maker!" * * * * * * *

"Nicholson, in his Dictionary of Chemistry, an old but valuable work, says that Ribaucourt found vitriol of copper, in a certain proportion, to give depth and firmness to the colour of black ink; but, from whatever cause, this has not taken a place among the commonly-used ink-making ingredients— probably because it acts injuriously on steel pens." * * * * * * *

"A quart of rain Wate. 3 Ounces of Blue Knolly Gawalls. Bruise ym it must stand & be stirred 3 or 4 times in ym Day & then Strain out out all ye gawells all ten Days and 2 Ounces of Clear Gummary Beck & 1/2 an Ounce of Coperous 1/2 an Ounce of Rock Alum half an Ounce of Loafe sugar ye Bigness of a Hoarsel nut of Roman Vitterall Bray ym all small Before they be put in it must be stirred very well for ye space of two weeks.

"A receit forink.—1727

"William Satherwaite."

(The above receipt is a literal copy of the original, now in my possession. It purports to have been written with the mixture it specifies.) * * * * * * *

"M. de Champnor and M. F. Malepeyre, 1862, in their Mannel state that Ribaucourt's ink is one of the best then in use. The formula for its preparation is as follows:

Aleppo galls, in coarse powder, 8 ounces. Logwood chips, 4 " Sulphate of iron, 4 " Powdered gum-arabic, 3 " Sulphate of copper, 1 " Crystallized sugar, 1 "

Boil the galls of logwood together in twelve pounds of water for an hour, or till half the water has been evaporated; strain the decoction through a hair sieve, and add the other ingredients; stir till the whole, especially the gum, be dissolved; and then leave at rest for twenty-four hours, when the ink is to be poured off into glass bottles and carefully corked. * * * * * * *

"Mr. J. Horsley gives the following receipt: Triturate in a mortar thirty-six grains of gallic acid with three and one-half ounces of strong decoction of logwood, put it into an eight ounce bottle, together with one ounce of strong ammonia. Next dissolve one ounce of sulphate of iron in half an ounce of distilled water by the aid of heat; mix the solutions together by a few minutes' agitation, when a good ink will be formed, perfectly clear, which will keep good any length of time without depositing, thickening, or growing mouldy, which latter quality is a great desideratum, as ink undergoing that change becomes worthless. It will not do to mix with ordinary ink, nor must greasy paper be used for writing on with it."— Chemical News (1862). * * * * * * *

"New Indelible Marking Ink.—Dr. Elsner gives the following as a stamping ink for goods before undergoing bleaching, or treating with acids or alkalis. It consists merely of one ounce of fine Chinese vermilion and one drachm of protosulphate of iron, well triturated with boiled oil varnish." * * * * * * * *

"Put Aleppo galls, well bruised, 4 1/2 oz. and logwood chipped, 1 oz. with 3 pints soft water, into a stoneware mug: slowly boil, until one quart remains: add, well powdered, the pure green crystals of sulphate of iron, 2 1/2 oz. blue vitriol or verdigris, (I think the latter better) 1/2 oz. gum arabic 2 oz. and brown sugar, 2 oz. Shake it occasionally a week after making: then after standing a day, decant and cork. To prevent moulding add a little brandy or alcohol.

"The common copperas will not answer so well as it has already absorbed oxygen." * * * * * * *

"Pour a gallon of boiling soft water on a pound of powdered galls, previously put into a proper vessel. Stop the month of the vessel, and set it in the sun in summer, or in winter where it may be warmed by any fire, and let it stand two or three days. Then add half a pound of green vitriol powdered, and having stirred the mixture well together with a wooden spatula, let it stand again for two or three days, repeating the stirring, when add further to it 5 ounces of gum arabic dissolved in a quart of boiling water, and lastly, 2 ounces of alum, after which let the ink be strained through a coarse linen cloth for use.

"Another. A good and durable ink may be made by the following directions: To 2 pints of water add 3 ounces of the dark coloured rough- skinned Aleppo galls in gross powder, and of rasped logwood, green vitriol, and gum arabic, each, 1 oz.

"This mixture is to be put into a convenient vessel, and well shaken four or five time a day, for ten or twelve days, at the end of which time it will be fit for use, though it will improve by remaining longer on the ingredients. Vinegar instead of water makes a deeper coloured ink; but its action on pens soon spoils them." * * * * * * * *

"Beat up well together in an iron mortar the following ingredients in a dry state; viz. 8 oz. of best blue gall-nuts, 4 oz. of copperas, or sulphate of iron, 2 oz. of clear gum arabic, and 3 pints of clear rain water.

"When properly powdered, put to the above; let the whole be shaken in a stone bottle three or four times a day, for seven days, and at the end of that time, pour the liquid off gently into another stone bottle, which place in an airy situation to prevent it from becoming foul or mothery. When used put the liquid into the ink-stand as required."

Take 6 quarts (beer measure) of clear water, soft or hard, and boil in it for about an hour 4 oz. of the best Campeachy logwood, chipped very thin across the grain, adding, from time to time, boiling water to supply in part the loss by evaporation; strain the liquor while hot, and suffer it to cool. If the liquor is then short of 5 quarts, make it equal to this quantity by the addition of cold water. After which let 1 lb. of bruised blue galls, or 20 oz. of the best common galls, be added. Let a paste be prepared by triturating 4 oz. of sulphate of iron (green vitriol) calcined to whiteness, and let half an ounce of acetite of copper (verdigris) be well incorporated together with the above decoction into a mass, throwing in also 3 oz. of coarse brown sugar and 6 oz. of gum Senegal, or Arabic. Put the materials into a stone bottle of such a size as to half fill it; let the mouth be left open, and shake the bottle well, twice or thrice a day. In about a fortnight it may be filled, and kept in well- stopped bottles for use. It requires to be protected from the frost, which would considerably injure it."

Infuse a pound of pomegranate peels, broken to a gross powder, for 24 hours in a gallon and a half of water, and afterwards boil the mixture till 1-3d of the fluid be wasted. Then add to it 1 lb. of Roman vitriol, and 4 oz. of gum arabic powdered, and continue the boiling till the vitriol and gum be dissolved, after which the ink must be strained through a coarse linen cloth, when it will be fit for use.

"This ink is somewhat more expensive, and yet not so good in hue as that made by the general method, but the colour which it has is not liable to vanish or fade in any length of time." * * * * * * * *

"Infuse a pound of galls powdered and 3 ounces of pomegranate peels, in a gallon of soft water for a week, in a gentle heat, and then strain off the fluid through a coarse linen cloth. Then add to it 8 oz. of vitriol dissolved in a quart of water, and let them remain for a day or two, preparing in the meantime a decoction of logwood, by boiling a pound of the chips in a gallon of water, till 1-3d be wasted, and then straining the remaining fluid while it is hot. Mix the decoction and the solution of galls and vitriol together, and add 5 oz. of gum arabic, and then evaporate the mixture over a common fire to about 2 quarts, when the remainder must be put into a vessel proper for that purpose, and reduced to dryness, by hanging the vessel in boiling water. The mass left, after the fluid has wholly exhaled, must be well powdered, and when wanted for use, may be converted into ink by the addition of water." * * * * * * * *

"Ten parts of logwood are to be exhausted with eighty of boiling water. To the solution one thousandth of its weight of yellow chromate of potash is to be added gradually. The liquid turns brown and at last blue-black. No gum is needed, and the ink is not removed by soaking in water. —Chemical Gazette, London (1850)." * * * * * * * *

"Shellac, 2 oz.; borax, 1 oz.; distilled or rain water, 18 oz. Boil the whole in a closely covered tin vessel, stirring it occasionally with a glass rod until the mixture has become homogeneous; filter when cold, and mix the fluid solution with an ounce of mucilage or gum arabic prepared by dissolving 1 oz. of gum in 2 oz. of water, and add pulverized indigo and lampblack ad libitum. Boil the whole again in a covered vessel, and stir the fluid well to effect the complete solution and admixture of the gum arabic. Stir it occasionally while it is cooling; and after it has remained undisturbed for two or three hours, that the excess of indigo and lamp- black may subside, bottle it for use. The above ink for documentary purposes is invaluable, being under all ordinary circumstances, indestructible. It is also particularly well adapted for the use of the laboratory. Five drops of creosote added to a pint of ordinary ink will effectually prevent its becoming mouldy." * * * * * * * *

"In November, 1854, Mr. Grace Calvert read a paper before the London Society of Arts in which he said that he hoped before long some valuable dyeing substances other than carbo-azotic acid would be prepared from coal tar.

"In another paper read before the same society in 1858 he said: 'This expectation has now been fulfilled. Messrs. Perkins and Church have obtained several blue coloring substances from the alkaloids of coal tar, and one from naphthalene.' Also that himself and Mr. Charles Lowe had succeeded in obtaining coal tar products yielding colors of a beautiful pink, red, violet, purple, and chocolate. (These were not soluble in water)." * * * * * * * *

"Among vegetable substances useful in the arts is one that has long been known in New Grenada under the name of the ink-plant, as furnishing a juice which can be used in writing without previous preparation. Characters traced with this substance have a reddish color at first, which turns to a deep black in a few hours. This juice is said to be really less liable to thicken than ordinary ink, and not to corrode steel pens. It resists the action of water, and is practically indelible. The plant is known as coryaria thymifolia." * * * * * * * *

"Desormeaux recommends that the sulphate of iron be calcined to whiteness; coarse brown sugar instead of sugar candy; 1/4 oz. acetate of copper, instead of one ounce of the sulphate, and a drop or two of creosote or essential oil of cloves to prevent moulding." (See Ribaucourt receipt, p. 194.) * * * * * * * *

"Mr. John Spiller communicated to the London Chemical News (1861) a paper on the employment of carbon as a means of permanent record. The imperishable nature of carbon, in its various forms of lamp-black, ivory-black, wood-charcoal, and graphite or black lead, holds out much greater promise of being usefully employed in the manufacture of a permanent writing material; since, for this substance, in its elementary condition and at ordinary temperatures, there exists no solvent nor chemical reagent capable of affecting its alteration.

"The suggestion relative to the mode of applying carbon to these purposes, which it is intended more particularly now to enunciate, depends on the fact of the separation of carbon from organic compounds rich in that element, sugar, gum, etc., by the combined operation of heat and of chemical reagents, such as sulphuric and phosphoric acids, which exert a decomposing action in the same direction; and by such means to effect the deposition of the carbon within the pores of the paper by a process of development to be performed after the fluid writing ink has been to a certain extent absorbed into its substance—a system of formation by which a considerable amount of resistance, both to chemical and external influences, appears to be secured. An ink of the following composition has been made the subject of experiment: "Concentrated sulphuric acid, deeply colored with indigo .......... 1 fluid ounce. Water, .............................. 6 " " Loaf Sugar,.......................... 1 ounce, troy. Strong mucilage of gum-arabic 2 to 3 fluid ounces.

"Writing traced with a quill or gold pen dipped in this ink dries to a pale blue color; but if now a heated iron be passed over its surface, or the page of manuscript be held near a fire, the writing will quickly assume a jet black appearance, resulting from the carbonization of the sugar by a warm acid, and will have become so firmly engrafted into the substance of the paper as to oppose considerable difficulty to its removal or erasure by a knife. On account of the depth to which the written characters usually penetrate, the sheets of paper selected for use should be of the thickest make, and good white cartridge paper, or that known as 'cream laid,' preferred to such as are colored blue with ultramarine; for, in the latter case, a bleached halo is frequently perceptible around the outlines of the letters, indicating the partial destruction of the coloring matter by the lateral action of the acid.

"The writing produced in this manner seems indelible; it resists the action of "salts of lemon," and of oxalic, tartaric, and diluted hydrochloric acids, agents which render nearly illegible the traces of ordinary black writing ink; neither do alkaline solutions exert any appreciable action on the carbon ink. This material possesses, therefore, many advantageous qualities which would recommend its adoption in cases where the question of permanence is of paramount importance. But it must, on the other hand, be allowed that such an ink, in its present form, would but inefficiently fulfil many of the requirements necessary to bring it into common use. The peculiar method of development rendering the application of heat imperative, and that of a temperature somewhat above the boiling point of water, together with the circumstance that it will be found impossible with a thin sheet of paper to write on both sides, must certainly be counted among its more prominent disadvantages." * * * * * * * *

"Fire-proof ink for writing or printing on incombustible paper is made according to the following recipe: Graphite, finely ground, 22 drams; copal or other resinous gum, 12 grains; sulphate of iron, 2 drams; tincture of nutgalls, 2 drams; and sulphate of indigo, 8 drams. These substances are thoroughly mixed and boiled in water, and the ink thus obtained is said to be both fire- proof and insoluble in water. When any other color but black is desired, the graphite is replaced by an earthly mineral pigment of the desired color." * * * * * * * *

"Ineradicable Writing.—A French technical paper, specially devoted to the art and science of paper manufacture, states that any alterations or falsifications of writings in ordinary ink maybe rendered impossible by passing the paper upon which it is intended to write through a solution of one milligram (0.01543 English grain) of gallic acid in as much pure distilled water as will fill to a moderate depth an ordinary soup-plate. After the paper thus prepared has become thoroughly dry, it may be used as ordinary paper for writing, but any attempt made to alter, falsify, or change anything written thereon, will be left perfectly visible, and may thus be readily detected." * * * * * * * *

"Exchequer Ink.—To 40 pounds of galls, add 10 pounds of gum, 9 pounds of copperas, and 45 gallons of soft water. This ink will endure for centuries." * * * * * * * *

"Take of oil of lavender, 120 grains, of copal in powder, 17 grains, red sulphuret of mercury, 60 grains. The oil of lavender being dissipated with a gentle heat, a colour will be left on the paper surrounded with the copal; a substance insoluble in water, spirits, acids, or alkaline solutions.

"This composition possesses a permanent colour, and a MSS. written with it, may be exposed to the process commonly used for restoring the colour of printed books, without injury to the writing. In this manner interpolations with common ink may be removed." * * * * * * * *

Boil parchment slips or cuttings of glove leather, in water till it forms a size, which, when cool, becomes of the consistence of jelly, then, having blackened an earthern plate, by holding it over the flame of a candle, mix up with a camel hair pencil, the fine lamp-black thus obtained, with some of the above size, while the plate is still warm. This black requires no grinding, and produces an ink of the same colour, which works as fregy with the pencil, and is as perfectly transparent as the best Indian ink." * * * * * * * *

"Instead of water use brandy, with the same ingredients which enter into the composition of any ink, and it will never freeze." * * * * * * * *

"Bacteria in Ink—According to experiments which have recently been completed at Berlin and Leipzig by the leading bacteriologists of Germany the ordinary inks literally teem with bacilla of a dangerous character, the bacteria taken therefrom sufficing to kill mice and rabbits inoculated therewith in the space of from one to three days." * * * * * * * *

"The most easy and neat method of forming letters of gold on paper, and for ornaments of writing is, by the gold ammoniac, as it was formerly called: the method of managing which is as follows:

"Take gum ammoniacum, and powder it; and then dissolve it in water previously impregnated with a little gum arabic, and some juice of garlic. The gum ammoniacum will not dissolve in water, so as to form a transparent fluid, but produces a milky appearance; from whence the mixture is called in medicine the lac ammoniacum. With the lac ammoniacum thus prepared, draw with a pencil, or write with a pen on paper, or vellum, the intended figure or letters of the gilding. Suffer the paper to dry; and then, or any time afterwards, breath on it till it be moistened; and immediately lay leaves of gold, or parts of leaves cut in the most advantageous manner to save the gold, over the parts drawn or written upon with the lac ammoniacum; and press them gently to the paper with a ball of cotton or soft leather. When the paper becomes dry, which a short time or gentle heat will soon effect, brush off, with a soft pencil, or rub off by a fine linen rag, the redundant gold which covered the parts between the lines of the drawing or writing; and the finest hair strokes of the pencil or pen, as well as the broader, will appear perfectly gilt."

It is usual to see in old manuscripts, that are highly ornamented, letters of gold which rise considerably from the surface of the paper or parchment containing them in the manner of embossed work; and of these some are less shining, and others have a very high polish. The method of producing these letters is of two kinds; the one by friction on a proper body with a solid piece of gold: the other by leaf gold. The method of making these letters by means of solid gold is as follows:

"Take chrystal; and reduce it to powder. Temper it then with strong gum water, till it be of the consistence of paste; and with this form the letters; and, when they are dry, rub them with a piece of gold of good colour, as in the manner of polishing; and the letters will appear as if gilt with burnisht gold."

(Kunckel, in his fifty curious experiments, has given this receipt, but omitted to take the least notice of the manner these letters are to be formed, though the most difficult circumstance in the production of them.)



CHAPTER XXII.

INK INDUSTRY.

IMPORTANCE OF HONEST INK MANUFACTURE—ABSENCE OF INFORMATION AS TO NAMES OF MOST ANCIENT INK MAKERS,—WHERE TO LOOK FOR ANCIENT INK—THEIR PHENOMENAL IDENTITY—INK AND PAPER AS ASIATIC INVENTIONS ENTER EUROPE IN THE TWELFTH CENTURY— BOTH IN GENERAL USE IN THE FOURTEENTH CENTURY—MONKS AND SCRIBES AS THEIR OWN INK MANUFACTURERS—MODERN INDUSTRY OF INK BEGINS IN 1625—ITS GROWTH AND PRESENT SITUATION—THE GENERAL IGNORANCE OF THE SUBJECT—INK INDUSTRY IN THE EIGHTEENTH CENTURY—THE FIRST PIONEERS ABROAD AND THOSE AT HOME—OBSERVATIONS RESPECTING INK PHENOMENA OF THE PAST EIGHTY YEARS—WHAT SOME INK MAKERS SAY ABOUT IT—LITTLE DEMAND FOR PURE INKS—SOME SKETCHES OF THE LEADING INK MANUFACTURERS OF THE WORLD—ESTIMATION OF QUANTITY OF INK MADE IN THE UNITED STATES—THE "LIFE" OF A MARK MADE WITH ORDINARY WRITING FLUID—ESTIMATION OF MOST INKS BY PROFESSORS BAIRD AND MARKOE—FORMULA OF THE OFFICIAL INK OF THE STATE OF MASSACHUSETTS—VIEWS OF SOME PROMINENT INK MANUFACTURERS ABOUT SUCH INK—SOME COMMERCIAL NAMES BESTOWED ON DIFFERENT INKS—THE 200 OR MORE NAMES OF INK MANUFACTURERS OF THE NINETEENTH CENTURY.

THE consideration of the effect of the use of ink upon civilization from primitive times to the present, as we have seen, offers a most suggestive field and certifies to the importance of the manufacture of honest inks as necessary to the future enlightenment of society. That it has not been fully understood or even appreciated goes without saying; a proper generalization becomes possible only in the light of corroborative data and the experiences of the many.

History has not given us the names of ancient ink makers; but we can believe there must have been during a period of thousands of years a great many, and that the kinds and varieties of inks were without number. Those inks which remain to us are to be found only as written with on ancient MSS.; they are of but few kinds, and in composition and appearance preserve a phenomenal identity, though belonging to countries and epochs widely separated. This identity leads to the further conclusion that ink making must have been an industry at certain periods, overlooked by careful compounders who distributed their wares over a vast territory.

"Gall" ink and "linen" paper as already stated are Asiatic inventions. Both of them seem to have entered Europe by way of Arabia, "hand in hand" at the very end of the eleventh or beginning of the twelfth centuries and for the next two hundred years, notwithstanding the fact that chemistry was almost an unknown science and the secrets of the alchemists known only to the few, this combination gradually came into general vogue.

In the fourteenth century we find one or both of them more or less substituted for "Indian" ink, parchment, vellum and "cotton" paper. It was, however, the monks and scribes who manufactured for their own and assistants' use "gall" ink, just as they had been in the habit of preparing "Indian" ink when required, which so far as known was not always a commodity.

As an industry it can be said to have definitely begun when the French government recognized the necessity for one, A. D. 1625, by giving a contract for "a great quantity of 'gall ink' to Guyot," who for this reason seems to occupy the unique position of the father of the modern ink industry.

Ink manufacture as a growing industry heretofore and to a large extent at present, occupies a peculiarly anomalous situation. Other industries follow the law of evolution which may perhaps bear criticism; but the ink industry follows none, nor does it even pretend to possess any.

Thousands are engaged in its pursuit, few of whom understand either ink chemistry or ink phenomena. The consumer knows still less, and with blind confidence placidly accepts nondescript compounds labeled "Ink," whether purchased at depots or from "combined" itinerant manufacturing peddlers and with them write or sign documents which some day may disturb millions of property. And yet in a comparative sense it has outpaced all other industries.

With the commencement of the eighteenth century we find the industry settling in Dresden, Chemnitz, Amsterdam, Berlin, Elberfield and Cologne. Still later in London, Vienna, Paris, Edinburgh and Dublin, and in the first half of the nineteenth century in the United States, it had begun to make considerable progress.

Among the first pioneers of the later modern ink industry abroad, may be mentioned the names of Stephens, Arnold, Blackwood, Ribaucourt, Stark, Lewis, Runge, Leonhardi, Gafford, Bottger, Lipowitz, Geissler, Jahn, Van Moos, Ure, Schmidt, Haenle, Elsner, Bossin, Kindt, Trialle, Morrell, Cochrane, Antoine, Faber, Waterlous, Tarling, Hyde, Thacker, Mordan, Featherstone, Maurin, Triest and Draper.

In the period covered by the nineteenth century at home, the legitimate industry included over 300 ink makers. Those best known are Davids, Maynard and Noyes, Carter, Underwood, Stafford, Moore, Davis, Thomas, Sanford, Barnes, Morrell, Walkden, Lyons, Freeman, Murray, Todd, Bonney, Pomeroy, Worthington, Joy, Blair, Cross, Dunlap, Higgins, Paul, Anderson, Woodmansee, Delang, Allen, Stearns, Gobel, Wallach, Bartram, Ford and Harrison.

The ink phenomena included in the past eighty years has demonstrated a continuing retrogression in ink manufacture and a consequent deterioration of necessary ink qualities. When the attention of some ink makers are addressed to these sad facts, they attribute them, either to the demand of the public for an agreeable color and a free flowing ink, or to an inability to compete with inferior substitutes, which have flooded the market since the discovery of the coal tar colors; they have been compelled to depart from old and tried formulas, in the extravagant use (misuse) of the so-called "added" color.

An exceptional few of the older firms continue to catalogue unadulterated "gall" inks; but the demand for them except in localities where the law COMPELS their employment, is only little.

Interesting deductions can be made from the accompanying brief sketches of the leading ink manufacturers of the world.

The "Arnold" brand of inks possesses a worldwide reputation, although not always known by that name, beginning A. D. 1724 under the style of R. Ford, and continuing until 1772, when the firm name was changed to William Green & Co. In 1809 it became J. & J. Arnold, who were succeeded in 1814 by Pichard and John Arnold, the firm name by which it is known at the present day. This last named concern located at 59 Barbican, on the site of the old City Hall in London, and later moved to their present address, No. 155 Aldersgate street. The inks made by the "fathers" of the firm were "gall" inks WITHOUT "added" color. At the commencement of the nineteenth century we find them making tanno-gallate of iron inks to which were added extractive matter from logwood and other materials to form thick fluids for shipment to Brazil, India and the countries where brushes or reeds were used as writing instruments. For the more civilized portions of the world similar inks but of an increased fluidity were supplied, that the quill pens might be employed. The demands for still more fluid inks which would permit the use of steel pens, resulted in the modern blue-black chemical writing fluid, the "added" blue portion being indigo in some form. It was first put on the market in 1830. They manufacture over thirty varieties of ink, but only one real "gall" ink without "added" color.

In the early part of May, 1824, Thaddeus Davids started his ink factory at No. 222 William street, New York City. His first and best effort was a strictly pure tanno-gallate of iron ink, which he placed on the market in 1827 under the name of "Steel Pen Ink," guaranteed to write black and to possess "record" qualities. In 1833 he made innovations following the lines laid down by Arnold and also commenced the manufacture of a chemical writing fluid, with indigo for "added" color. Many more "added" colors were employed at different periods, like logwood and fustic, with the incorporation of sugar, glucose, etc. In the early fifties the cheap grades of logwood ink after the formula of Runge (1848) and which cost about four cents per gallon was marketed, principally for school purposes; it was never satisfactory, becoming thick and "color fading." Mr. Davids made many experiments with "alizarin" inks in the early sixties but did not consider them valuable enough to put on the market. In 1875 the firm introduced violet ink made from the aniline color of that name. Experimentations in 1878 with the insoluble aniline blacks and vanadium were unsuccessful; but the soluble aniline black (blue- black) known as nigrosine they used and still use in various combinations. During this long period their establishments have been in different locations. From No. 222 William street it was changed to Eighth street, with the office at No. 26 Cliff street. In 1854 the works were removed to New Rochelle, Westchester county, N. Y. In 1856 the firm name was Thaddeus Davids and Co., Mr. George Davids having been admitted as a partner and their warehouse and offices at this time were located at Nos. 127 and 129 William street, where a business of enormous proportions, which includes the manufacture of thirty-three inks and other products, is still carried on at the present day under the name and style of "Thaddeus Davids, Co." The old "Davids' Steel Pen Ink" continues to be manufactured from the original formula and is the only tanno-gallate of iron ink they make, WITHOUT "added" color.

The Paris house of "Antoine" as manufacturers of writing inks dates from 1840. They are best known as the makers of the French copying ink, of a violet- black color, made from logwood, which was first put on the market in 1853 under the name of Encres Japonaise. In 1860 an agency was established in New York City. They make a large variety of writing inks but do not offer for sale a tanno-gallate of iron ink without "added" color.

"Carter's" inks came into notoriety in 1861, by the introduction of a "combined writing and copying ink," of the gall and iron type and included "added " color. It was the first innovation of this character. At the end of the Civil War, John W. Carter of Boston, who had been an officer of the regular army, purchased an interest in the business, associating with himself Mr. J. P. Dinsmore of New York, the firm being known as Carter, Dinsmore & Co., Boston, Mass. In 1895 Mr. Carter died and Mr. Dinsmore retired from the business. The firm was then incorporated under the style of "The Carter's Ink Co." They do an immense business and make all kinds of ink. Of the logwoods, "Raven Black" is best known. When the state of Massachusetts in 1894 decided that recording officers must use a "gall" ink made after an official formula, they competed with other manufacturers for the privilege of supplying such an ink and won it. They do not offer for sale, however, "gall" ink WITHOUT added color. Their laboratories are magnificently equipped; the writer has had the pleasure of collaborating with several of their expert chemists.