But even the Chinese carrier may not strike us so curiously as another associate, given in our next picture, Fig. 21, and yet he is a European employe from the Landes department of highly cultivated France. The inhabitants of this country buckle stilts on to their feet, so as to make their way faster through brambles and underbrush which surrounds them. The mail carrier copied them in his equipment, and thus he goes around on stilts, provided with a large cane to help him keep his balance, and furnishes a correct example of a post office official suiting the demands of every district.

While the mail in Europe has but little to do with the transportation of passengers, it is important in its activity in this respect in the large Russian empire.



The tarantass (Fig. 22), drawn by three nimble horses, flies through the endless deserts with wind-like rapidity.

The next illustration (Fig. 23) leads us to a much more remote and deserted country, "Post office on the Booby Island," occupied only by birds, and a hut containing a box in which are pens, paper, ink, and wafers. The mariners put their letters in the box, and look in to see if there is anything there addressed to them, then they continue their journey.

Postage stamps are not demanded in this ideal post office, but provision is made for the shipwrecked, by a notice informing them where they can find means of nourishment.

Once again we make a leap. The Bosnian mail carrier's equipment (Fig. 24) is, or rather was, quite singular, for our picture was taken before the occupation.

This mounted mail carrier with his weapons gives one the impression of a robber.

The task of conducting the mail through the Alps of Switzerland (Fig. 25) must be uncomfortable in winter, when the sledges glide by fearful precipices and over snow-covered passes.

Since the tariff union mail developed from the Prussian mail, and the world's mail from the tariff union, it seems suitable to close our series of pictures by representing the old Prussian postal service (Fig. 26) carried on by soldier postmen in the eighteenth century during the reign of Frederick the Great.



The complaint is made that poetry is wanting in our era, and it has certainly disappeared from the postal service. One remembers that the postilion was for quite a while the favorite hero of our poets, the best of whom have sung to his praises, and given space to his melancholy thoughts of modern times in which he is pushed aside. It is too true that the post horn, formerly blown by a postilion, is now silenced, that the horse has not been able to keep up in the race with the world in its use of the steam horse, and yet how much poetry there is in that little post office all alone by itself on the Booby Island, that we have described—the sublimest poetry, that of love for mankind!

The poet of the modern postal system has not yet appeared; but he will find plenty of material. He will be able to depict the dangers a postman passes through in discharging his duty on the field, he will sing the praises of those who are injured in a railroad disaster, and yet continue their good work.



He can also praise the noble thought of uniting the nations, which assumed its first tangible form in the world's mail. It will not be a sentimental song, but one full of power and indicative of our own time, in spite of those who scorn it.—Translated for the Scientific American Supplement by Jenny H. Beach, from Neue Illustrirte Zeitung.

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ON NICKEL PLATING.

By THOMAS T.P. BRUCE WARREN.

The compound used principally for the electro-deposition of nickel is a double sulphate of nickel and ammonia. The silvery appearance of the deposit depends mainly on the purity of the salt as well as the anodes. The condition of the bath, as to age, temperature, and degree of saturation, position of anodes, strength of current, and other details of manipulation, which require care, cleanliness, and experience, such as may be met with in any intelligent workman fairly acquainted with his business, are easily acquired.

In the present paper I shall deal principally with the chemical department of this subject, and shall briefly introduce, where necessary, allusion to the mechanical and electrical details connected with the process. At a future time I shall be glad to enlarge upon this part of the subject, with a view of making the article complete.

A short time ago nickel plating was nearly as expensive as silver plating. This is explained by the fact that only a few people, at least in this country, were expert in the mechanical portions of the process, and only a very few chemists gave attention to the matter. To this must be added that our text-books were fearfully deficient in information bearing on this subject.

The salt used, and also the anodes, were originally introduced into this country from America, and latterly from Germany. I am not aware of any English manufacturer who makes a specialty in the way of anodes. This is a matter on which we can hardly congratulate ourselves, as a well known London firm some time ago supplied me with my first experimental anodes, which were in every way very superior to the German or American productions. Although the price paid per pound was greater, the plates themselves were cheaper on account of their lesser thickness.

The texture of the inner portions of these foreign anodes would lead one to infer that the metallurgy of nickel was very primitive. A good homogeneous plate can be produced, still the spongy, rotten plates of foreign manufacture were allowed the free run of our markets. The German plates are, in my opinion, more compact than the American. A serious fault with plates of earlier manufacture was their crumpled condition after a little use. This involved a difficulty in cleaning them when necessary. The English plates were not open to this objection; in fact, when the outer surfaces were planed away, they remained perfectly smooth and compact.

Large plates have been known to disintegrate and fall to pieces after being used for some time. A large anode surface, compared with that of the article to be plated, is of paramount importance. The tank should be sufficiently wide to take the largest article for plating, and to admit of the anodes being moved nearer to or further from the article. In this way the necessary electrical resistance can very conveniently be inserted between the anode and cathode surfaces. The elimination of hydrogen from the cathode must be avoided, or at any rate must not accumulate. Moving the article being plated, while in the bath, taking care not to break the electrical contacts, is a good security against a streaky or foggy appearance in the deposit.

At one time a mechanical arrangement was made, by which the cathodes were kept in motion. The addition of a little borax to the bath is a great advantage in mitigating the appearance of gas. Its behavior is electrical rather than chemical. If the anode surface is too great, a few plates should be transferred to the cathode bars.

When an article has been nickel plated, it generally presents a dull appearance, resembling frosted silver. To get over this I tried, some time ago, the use of bisulphide of carbon in the same way as used for obtaining a bright silver deposit. Curiously the deposit was very dark, almost black, which could not be buffed or polished bright. But by using a very small quantity of the bisulphide mixture, the plated surfaces were so bright that the use of polishing mops or buffs could be almost dispensed with. When we consider the amount of labor required in polishing a nickel plated article, and the impossibility of finishing off bright an undercut surface, this becomes an important addendum to the nickel plater's list of odds and ends.

This mixture is made precisely in the same way as for bright silvering, but a great deal less is to be added to the bath, about one pint per 100 gallons. It should be well stirred in, after the day's work is done, when the bath will be in proper condition for working next day. The mixture is made by shaking together, in a glass bottle, one ounce bisulphide and one gallon of the plating liquid, allow to stand until excess of bisulphide has settled, and decant the clear liquid for use as required. It is better to add this by degrees than to run the risk of overdoing. If too much is added, the bath is not of necessity spoiled, but it takes a great deal of working to bring it in order again.

About eight ounces of the double sulphate to each gallon of distilled or rain water is a good proportion to use when making up a bath. There is a slight excess with this. It is a mistake to add the salt afterward, when the bath is in good condition. The chloride and cyanide are said to give good results. I can only say that the use of either of these salts has not led to promising results in my hands.

In preparing the double sulphate, English grain nickel is decidedly the best form of metal to use. In practice, old anodes are generally used.

The metal is dissolved in a mixture of nitric and dilute sulphuric acid, with the application of a gentle heat. When sufficient metal has been dissolved, and the unused nitric acid expelled, the salt may be precipitated by a strong solution sulphate of ammonia, or, if much free acid is present, carbonate of ammonia is better to use.

Tin, lead, and portion of the iron, if present, are removed by this method. The silica, carbon, and portions of copper are left behind with the undissolved fragments of metals.

The precipitated salt, after slight washing, is dissolved in water and strong solution ammonia added. A clean iron plate is immersed in the solution to remove any trace of copper. This plate must be cleaned occasionally so as to remove any reduced copper, which will impede its action. As soon as the liquid is free from copper, it is left alkaline and well stirred so as to facilitate peroxidation and removal of iron, which forms a film on the bath. When this ceases, the liquid is rendered neutral by addition of sulphuric acid, and filtered or decanted. The solution, when properly diluted, has sp. gr. about 1.06 at 60 deg. F. It is best to work the bath with a weak current for a short time until the liquid yields a fine white deposit. Too strong a current must be avoided.

If the copper has not been removed, it will deposit on the anodes when the bath is at rest. It should then be removed by scouring.

Copper produces a reddish tinge, which is by no means unpleasant compared with the dazzling whiteness of the nickel deposit. If this is desired, it is far better to use a separate bath, using anodes of suitable composition.

The want of adhesion between the deposited coating and the article need not be feared if cleanliness be attended to and the article, while in the bath, be not touched by the hands.

The bath should be neutral, or nearly so, slightly acid rather than alkaline. It is obvious that, as such a liquid has no detergent action on a soiled surface, scrupulous care must be taken in scouring and rinsing. Boiling alkaline solutions and a free use of powdered pumice and the scrubbing brush must on no account be neglected.

A few words on the construction of the tanks. A stout wood box, which need not be water-tight, is lined with sheet lead, the joints being blown, not soldered. An inner casing of wood which projects a few inches above the lead lining is necessary in order to avoid any chance of "short circuiting" or damage to the lead from the accidental falling of anodes or any article which might cut the lead. It is by no means a necessity that the lining should be such as to prevent the liquid getting to the lead.

On a future occasion I hope to supplement this paper with the analysis of the double sulphates used, and an account of the behavior of electrolytically prepared crucibles and dishes as compared with those now in the market.—Chem. News.

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CHILLED CAST IRON.

At a recent meeting of the engineering section of the Bristol Naturalists' Society a paper on "Chilled Iron" was read by Mr. Morgans, of which we give an abstract. Among the descriptions of chilled castings in common use the author instanced the following: Sheet, corn milling, and sugar rolls; tilt hammer anvils and bits, plowshares, "brasses" and bushes, cart-wheel boxes, serrated cones and cups for grinding mills, railway and tramway wheels and crossings, artillery shot and bolts, stone-breaker jaws, circular cutters, etc. Mr. Morgans then spoke of the high reputation of sheet mill rolls and wheel axle boxes made in Bristol. Of the latter in combination with wrought iron wheels and steeled axles, the local wagon works company are exporting large numbers. With respect to the strength and fatigue resistance of chilled castings, details were given of some impact tests made in July, 1864, at Pontypool, in the presence of Captain Palliser, upon some of his chilled bolts, 123/4 in. long by 4 in. diameter, made from Pontypool cold-blast pig iron. Those made from No. 1 pig iron—the most graphitic and costly—broke more easily than those from No. 2, and so on until those made from No. 4 were tested, when the maximum strength was reached. No. 4 pig iron was in fracture a pale gray, bordering on mottled. Several points regarding foundry operations in the production of chilled castings were raised for discussion. They embraced the depth of chill to be imparted to chilled rolls and railway wheels, and in the case of traction wheels, the width of chill in the tread; preparation of the chills—by coating with various carbonaceous matters, lime, beer grounds, or, occasionally, some mysterious compost—and moulds, selection and mixture of pig irons, methods and plant for melting, suitable heat for pouring, prevention of honeycombing, ferrostatic pressure of head, etc. Melting for rolls being mostly conducted in reverberatories, the variations in the condition of the furnace atmosphere, altering from reducing to oxidizing, and vice versa, in cases of bad stoking and different fuels, were referred to as occasionally affecting results. Siemens' method of melting by radiant heat was mentioned for discussion. For promoting the success of a chilled roll in its work, lathing or turning it to perfect circularity in the necks first, and then turning the body while the necks bear in steady brasses, are matters of the utmost importance.

The author next referred to the great excellence for chilling purposes possessed by some American pig irons, and to the fact that iron of a given carbon content derived from some ores and fluxes differed much in chilling properties from iron holding a similar proportion of carbon—free and combined—derived from other ores and materials. Those irons are best which develop the hardest possible chill most uniformly to the desired depth without producing a too abrupt line of division between the hard white skin and the softer gray body. A medium shading off both ways is wanted here, as in all things. The impossibility of securing a uniform quality and chemical composition in any number grade of any brand of pig iron over a lengthened period was adverted to. Consequent from this a too resolute faith in any particular make of pig iron is likely to be at times ill-requited. Occasional physical tests, accompanied with chemical analysis of irons used for chilling, were advocated; and the author was of opinion it would be well whenever a chilled casting had enjoyed a good reputation for standing up to its work, that when it was retired from work some portions of it should be chemically analyzed so as to obtain clews to compositions of excellence. Some of the physical characteristics of chilled iron, as well as the surprising locomotive properties of carbon present in heated iron, were noticed.

Attention was called to some German data, published by Dr. Percy in 1864, concerning an iron which before melting weighed—approximately—4481/4 lb. per cubic foot, and contained—approximately—4 per cent. of carbon—31/4 being graphitic and 3/4 combined. The chilled portion of a casting from this had a specific gravity equivalent to 471 lb. per cubic foot, and contained 5 per cent. of carbon, all combined. The soft portion of the same casting weighed 4473/4 lb. per cubic foot, and contained 34.5 per cent. of carbon—31.5 being graphitic and 3.5 combined. Mr. Morgans doubted whether so great an increase in density often arises from chilling. Tool steel, when hardened by being chilled in cold water, does not become condensed, but slightly expanded from its bulk when annealed and soft. Here an increase of hardness is accompanied by a decrease of density. The gradual development of a network of cracks over the face of a chilled anvil orbit while being used in tilt hammers was mentioned. Such minute cleavages became more marked as the chill is worn down by work and from grinding. Traces of the same occurrence are observable over the surface of much worn chilled rolls used in sheet mills. In such cases the sheets get a faint diaper pattern impressed upon them. The opening of crack spaces points to lateral shrinkage of the portions of chilled material they surround, and to some release from a state of involuntary tension. If this action is accompanied by some actual densification of the fissured chill, then we have a result that possibly conflicts with the example of condensation from chilling cited by Dr. Percy.

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SNOW HALL.

The recent dedication of Snow Hall, at Lawrence, Kansas, is an event in the history of the State, both historic and prophetic. Since the incorporation of the University of Kansas, and before that event, there has been a steady growth of science in the State, which has culminated in Snow Hall, a building set apart for the increase and diffusion of the knowledge of natural science, as long as its massive walls shall stand. It is named in honor of the man who has been the inspiration and guiding spirit of the whole enterprise, and some incidents in his life may be of interest to the public.

Twenty years ago Professor Frank H. Snow, a recent graduate of Williams College, came to Kansas, to become a member of the faculty of the State University. His election to the chair of natural science was unexpected, as he first taught mathematics in the university, and expected in due time to become professor of Greek. As professor of the mellifluous and most plastic of all the ancient tongues, he would undoubtedly have been proficient, as his college classics still remain fresh in his warm and retentive memory, and his literary taste is so severe and chaste as to make some of his scientific papers read like a psalm. But nature designed him for another, and some think a better, field, and endowed him with powers as a naturalist that have won for him recognition among the highest living authorities of his profession.

Upon being elected to the chair of natural history, Prof. Snow entered upon his life work with an enthusiasm that charmed his associates and inspired his pupils. The true naturalist must possess large and accurate powers of observation and a love for his chosen profession that carries him over all obstacles and renders him oblivious to everything else except the specimen upon which he has set his heart. Years ago the writer was walking in the hall of the new university building in company with General Fraser and Professor Snow, when the latter suddenly darted forward up the stairs and captured an insect in its flight, that had evidently just dug its way out of the pine of the new building. In a few moments he returned with such a glow on his countenance and such a satisfied air at having captured a rare but familiar specimen, whose name was on his lips, that we both felt "Surely here is a genuine naturalist."

Some years ago an incident occurred in connection with his scientific excursions in Colorado that is quite characteristic, showing his obliviousness to self and everything else save the object of his scientific pursuit, and a fertility in overcoming danger when it meets him face to face. He was descending alone from one of the highest peaks of the Rockies, when he thought he could leave the path and reach the foot of the mountain by passing directly down its side over an immense glacier of snow and ice, and thus save time and a journey of several miles. After a while his way down the glacier grew steeper and more difficult, until he reached a point where he could not advance any further, and found, to his consternation, that he could not return by the way he had come. There he clung to the side of the immense glacier, ready, should he miss his hold, to be plunged hundreds of feet into a deep chasm. The situation flashed over him, and he knew now it was, indeed, a struggle for dear life. With a precarious foothold, he clung to the glacier with one hand, while with his pocket knife he cut a safer foothold with the other. Resting a little, he cut another foothold lower down in the hard snow, and so worked his way after a severe struggle of several hours amid constant danger to the foot of the mountain in safety. "But," continued the professor, speaking of this incident to some of his friends, "I was richly repaid for all my trouble and peril, for when I reached the foot of the mountain I captured a new and very rare species of butterfly." Multitudes of practical men cannot appreciate such devotion to pure science, but it is this absorbing passion and pure grit that enable the devotees of science to enlarge its boundaries year by year.

Once, while on a scientific excursion on the great plains, with the lamented Prof. Mudge, he nearly lost his life. He had captured a rattlesnake, and, in trying to introduce it into a jar filled with alcohol, the snake managed to bite him on the hand. The arm was immediately bound tightly with a handkerchief, and the wound enlarged with a pocket knife, and both professors took turns in sucking it as clean as possible, and ejecting the poison from their mouths. This and a heavy dose of spirits brought the professor through in safety, although the poison remaining in the wound caused considerable swelling and pain in the hand and arm. When this incident was mentioned in the Kansas Academy of Science that year, some one said, "Now we know the effect of the bite of the prairie rattlesnake on the human system. Let some one, in the interests of pure science, try the effect of the timber rattlesnake on the human system." But like the mice in the fable, no one was found who cared to put the bell on the cat.

Professors Mudge and Snow, because scientists were so few in the State at that early day, divided the field of natural science between themselves, the former taking geology and the latter living forms. Professor Mudge built up at the agricultural college a royal cabinet, easily worth $10,000, and Professor Snow has made a collection at the State University whose value cannot be readily estimated until it is catalogued and placed in cases in Snow Hall.

As a scientist, Professor Snow is an indefatigable worker, conscientious and painstaking to the last degree, never neglecting anything that can be discovered by the microscope, and when he describes and names a new species, he gives the absolute facts, without regard to theories or philosophies. For accuracy his descriptions of animal and vegetable life resemble photographs, and are received by scientists with unquestioned authority. He possesses another quality, which may be called honesty. Some scientists, whose reputation has reached other continents, cannot be trusted alone in the cabinet with the keys, for they are liable to borrow valuable specimens, and forget afterward to return them.

It is possible only to glance at the immense amount of work performed by Professor Snow during the last twenty years. Neglecting the small fry that can only be taken in nets with very fine meshes, he ascertained that there are twenty-seven species of fish in the Kansas River at Lawrence. Work on this paper occupied the leisure time of two summers, as much time in such investigations only produces negative results. For several years he worked on a catalogue of the birds of Kansas, inspiring several persons in different parts of the State to assist him. Later this work was turned over to Colonel N.S. Gross, of Topeka, an enthusiast in ornithology. Colonel Goss has a very fine collection of mounted birds in the capitol building at Topeka, and he has recently published a catalogue of the "Birds of Kansas," which contains 335 species. Professor Snow has worked faithfully on the plants of Kansas, but as other botanists came into the State, he turned the work over to their hands. For several years he has given a large share of his time and strength to entomology. Nearly every year he has led scientific excursions to different points in Colorado, New Mexico, Arizona, etc., where he might reap the best results.

Once, during a meeting of the Kansas Academy of Science, at Lawrence, Professor Snow was advertised to read a paper on some rare species of butterflies. As the hour approached, the hall in the university building was thronged, principally by ladies from the city, when Professor Snow brought out piles of his trays of butterflies, and without a note gave such an exhibit and description of his specimens as charmed the whole audience.

In meteorology, Professor Snow is an acknowledged authority, wherever this science is studied, and he has, probably, all things considered, the best meteorological record in the State.

Personally, Professor Snow possesses qualities that are worth more, perhaps, to his pupils, in forming character, than the knowledge derived from him as an instructor. His life is pure and ennobling, his presence inspiring, and many young men have gone from his lecture room to hold good positions in the scientific world. When one sees him in his own home, surrounded by his family, with books and specimens and instruments all around, he feels that the ideal home has not lost everything in the fall.

Snow Hall is the natural resultant of twenty years of earnest and faithful labor on the part of this eminent scientist. The regents displayed the rare good sense of committing everything regarding the plans of the building, and the form and arrangement of the cases, to Professor Snow, which has resulted in giving to Kansas the model building of its kind in the West, if not in this country. Very large collections have accumulated at the State University, under the labors of Professor Snow and his assistants, which need to be classified, arranged, and labeled; and when the legislature appropriates the money to furnish cases to display this collection in almost every department of natural science, Kansas will possess a hall of natural science whose influence will be felt throughout the State, and be an attraction to scientists everywhere.—Chaplain J.D. Parker, in Kansas City Journal.

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ELIMINATION OF POISONS.

A study of the means by which nature rids the economy of what is harmful has been made by Sanquirico, of Siena, and his experiments and conclusions are as follows:

He finds that the vessels of the body, without undergoing extensive structural alteration, can by exosmosis rid themselves of fluid to an amount of eight per cent. of the body weight of the subject of the experiment.

Through the injection of neutral fluids a great increase in the vascular tension is effected, which is relieved by elimination through the kidneys.

With reference to this fact, the author, in 1885, made experiments with alcohol and strychnine, and continued his researches in the use of chloral and aconitine with results favorable to the method employed, which is as follows:

The minimal fatal dose of a given poison was selected, and found to be in a certain relation to the body weight.

Immediately upon the injection of the poison a solution of sodium chloride, 0.75 per cent. in strength, was injected into the subcutaneous tissues of the neck, in quantities being eight per cent. of the body weight of the animal.

In the case of those poisons whose effect is not instantaneous, the injection of saline solution was made on the first appearance of toxic symptoms. In other poisons the injection was made at once.

The result of the use of salines was a diuresis varying in the promptness of its appearance and in its amount.

Those animals in which diuresis was limited at first and then increased generally recovered, while those in which diuresis was not established perished. The poison used was found in the urine of those which died and also those which recovered.

The author succeeded in rescuing animals poisoned by alcohol, strychnine, chloral, and aconitine. With morphine, curare, and hypnone, the method of elimination failed, although ten per cent. in quantity of the body weight of the animal was used in the saline injection. With aconitine, diuresis was not always established, and when it failed the animal died in convulsions.—Centralblatt fur die Medicinischen Wissenschaften, December 18, 1886.

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