Not only are the duties of the military engineer similar in many respects to those of the civil engineer, but there are many instances in which the duties of one branch of the profession have been performed by members of the other branch, quite as efficiently as though they had been performed by engineers specially educated for the purpose. During the late civil war there were many illustrations of this, all showing that an ingenious engineer can readily adapt himself to circumstances entirely different from those to which he has been accustomed. A very good example of this occurred in the Red River expedition of General Banks and Admiral Porter. In that memorable but disastrous campaign an army accompanied by a fleet of transports and light draught gunboats, sometimes called "tin clads" because some parts of them were covered with boiler plate to stop the bullets of the enemy, ascended the Red River in Louisiana; but the advance having been checked and a retreat commenced, it was found that the river had fallen to such a low state that the fleet was caught above the rapids near Alexandria, and it would in all probability have been a complete loss had it not been for the timely application of engineering skill by Lieut. Col. Joseph Bailey, a civil engineer from Wisconsin, who built a temporary dam across the river below the rapids and floated out the entire fleet. This dam was over 750 feet long and in connection with some auxiliary dams raised the water level some 61/2 feet. It was built under many difficulties, but by the skill and ability of the engineer and the co-operation of the troops it was completed in ten days. Another case was at the siege of Petersburg, Va., where Lieut. Col. Pleasants, a Pennsylvania coal miner, ran a gallery from our lines, under the rebel battery, some 500 feet distant, and blew it entirely out of existence. The mine contained four tons of powder and produced a crater 200 feet by 50 feet and 25 feet deep, and was completed in one month. The sequel to this was to be an attack on the enemy's line through the gap made by the explosion, and such an attack properly followed up would doubtless have had a marked effect in shortening the duration of the war, but this attack was so badly managed that it utterly failed and caused a severe loss to our own army. The mine itself, however, was a great success and produced a decided moral effect on both sides which lasted until the end of the war.

It may be out of place to digress a moment to illustrate the moral effect of such a convulsion. Several weeks after this great mine explosion, the 18th Army Corps, to which I then belonged, was holding a line of works recently captured from the rebels, about six miles from Richmond, when one night the colonel commanding Fort Harrison, a large field work forming a part of this line, came down to headquarters and reported that some old Pennsylvania coal miners in his command had heard mining going on under the fort. As the nearest part of the enemy's line was some 400 yards from the fort, I was quite certain that they could not have run a gallery that distance in the time that had elapsed since we occupied the work, but there was of course the possibility that the mine had been partly built beforehand so as to be ready in just such a case as had arisen, viz., the capture of the fort by our troops. I therefore went with the colonel up to the fort to listen for the mining operations, and got the men who claimed to have heard the subterranean noises, down in the bottom of the ditch of the fort, which was ten feet deep, and at the angles formed a fairly good listening gallery, but nothing unusual could be heard. I therefore made arrangements to sink a line of pits in the bottom of the ditch, something like ordinary wells; the bottoms of these pits to be finally connected by a horizontal gallery which would envelop the fort and enable us to hear the enemy and blow him up, before he could get under the fort. Although the commanding officer of that fort was as brave an officer as the war developed, he would not keep his men in the fort after dark, but withdrew them quietly to the flanks of the work, where they not only would be safe from an explosion, but would be ready to fall upon the enemy in case he should blow up the fort and rush in to capture the line, as our troops had attempted to do at Petersburg. No explosion took place, however, and after our countermining work was completed, the garrison became reassured and remained in the fort at night as well as in day time. A few months later, when the enemy was driven from his lines, I went through his works to see whether any mining had been attempted, and found that a gallery leading toward Fort Harrison had been carried quite a distance, but was still incomplete, and it is barely possible that the old miners were right, after all, in thinking that they could hear the sound of the pick, although the distance was almost too great to make this theory very probable.

Still another illustration of the way in which civil engineers can make themselves extremely useful in military operations was the wonderful system of military railways, or railways operated for military purposes, that formed complete lines of transportation for the armies and their enormous quantities of supplies and munitions, more especially those in the West and Southwest. Construction trains were organized in the most complete style, and when a piece of track or a number of bridges were destroyed by the enemy, they would be rebuilt so rapidly that our trains would hardly seem to be delayed by it. The trains carried spare rails, ties, and bridges of various lengths ready to put up, and they also carried the necessary rolling stock and tools for destroying the roads and bridges of the enemy. So expert had this construction corps become that the enemy was ready to believe almost any statement in regard to it. General Sherman tells of an instance where it was proposed to blow up a tunnel, to check his "March to the Sea," when one of the men objected, saying it was of no use, for Sherman had a duplicate tunnel in his train.

Although this is not a sermon, it may not be out of place to point out a few qualifications common to all engineers, for they all deal more or less with the same materials and forces and employ similar methods of investigation and construction. Wood, iron, steel, copper and stone and their compounds are the materials of the civil, mining, mechanical and electrical, as well as of the military engineers. They all deal with the forces of gravitation, cohesion, inertia and chemical affinity. They all require skill, intelligence, industry, confidence, accuracy, thoroughness, ingenuity and, beyond all, sound judgment. Wanting in any one of these qualifications, an engineer is more or less disqualified for important work. It is said that a distinguished engineer was always afraid to cross his own bridges, although built in the most thorough and approved manner. He was deficient in confidence. Another engineer distinguished for his mathematical attainments built a bridge which promptly collapsed at the first opportunity. On overhauling his computations he ejaculated somewhat forcibly, "That confounded minus sign! It should have been plus." He was deficient in sound judgment, or what is sometimes called "horse sense."

Another and more common defect in young engineers is a want of thoroughness. It is generally best to go to the bottom of a question at first and keep at it until it is thoroughly and fully completed. Confucius says, "If thou hast aught to do, first consider, second act, third let the soul resume her tranquillity." Those who begin a great many things and never fully complete them lose a great deal of valuable time, but do very little valuable work. The way to avoid this difficulty is to be cautious about beginning things, but when once started don't leave it until you are satisfied to leave it for good. There is an Arabian saying, "Never undertake all you can do, for he who undertakes all he can do will frequently undertake more than he can do."

Another common error is extravagance. On the plea that "the best is always the cheapest," and to be sure of a large factor of safety, or as the late Mr. Holley called it a "factor of ignorance," without much trouble to themselves, some engineers use more or better materials than the work requires, and thus greatly increase the cost without any corresponding advantage. Almost any engineer can do almost anything in the way of engineering if not limited by the cost, but the man who knows just what materials to use and how to use them so that they will answer the purpose as to strength and durability can save his own salary to his employer many times over by simply omitting unnecessary expense.

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HOW MECHANICAL RUBBER GOODS ARE MADE.

While the manufacture of rubber goods is in no sense a secret industry, the majority of buyers and users of such goods have never stepped inside of a rubber mill, and many have very crude ideas as to how the goods are made up. In ordinary garden hose, for instance, the process is as follows: The inner tubing is made of a strip of rubber fifty feet in length, which is laid on a long zinc-covered table and its edges drawn together over a hose pole. The cover, which is of what is called "friction," that is cloth with rubber forced through its meshes, comes to the hose maker in strips, cut on the bias, which are wound around the outside of the tube and adhere tightly to it. The hose pole is then put in something like a fifty foot lathe, and while the pole revolves slowly, it is tightly wrapped with strips of cloth, in order that it may not get out of shape while undergoing the process of vulcanizing. When a number of these hose poles have been covered in this way they are laid in a pan set on trucks and are then run into a long boiler, shut in, and live steam is turned on. When the goods are cured steam is blown off, the vulcanizer opened and the cloths are removed. The hose is then slipped off the pole by forcing air from a compressor between the rubber and the hose pole. This, of course, is what is known as hose that has a seam in it.

For seamless hose the tube is made in a tubing machine and slipped upon the hose pole by reversing the process that is used in removing hose by air compression. In other words, a knot is tied in one end of the fifty foot tube and the other end is placed against the hose pole and being carefully inflated with air it is slipped on without the least trouble. For various kinds of hose the processes vary, and there are machines for winding with wire and intricate processes for the heavy grades of suction hose, etc. For steam hose, brewers', and acid hose, special resisting compounds are used, that as a rule are the secrets of the various manufacturers. Cotton hose is woven through machines expressly designed for that purpose, and afterward has a half-cured rubber tube drawn through it. One end is then securely stopped up and the other end forced on a cone through which steam is introduced to the inside of the hose, forcing the rubber against the cotton cover, finishing the cure and fixing it firmly in its place.

CORRUGATED MATTING.

After the mixing of the compound and the calendering, that is the spreading it in sheets, the great roll of rubber and cloth that is to be made into corrugated matting is sent to the pressman. Here it is hung in a rack and fifteen or twenty feet of it drawn between the plates of the huge hydraulic steam press. The bottom plate of this press is grooved its whole length, so that when the upper platen is let down the plain sheet of rubber is forced into the grooves and the corrugations are formed. While in that position steam is let into the upper and lower platens and the matting is cured. After it has been in there the proper time, cold water is let into the press, it is cooled off, and the upper platen being raised, it is ready to come out. A simple device for loosening the matting from the grooves into which it has been forced is a long steel rod, with a handle on one hand like an auger handle, which, being introduced under the edge and twisted, allows the air to enter with it and releases it from the mould.

PACKING.

Sheet packing is often times made in a press, like corrugated matting. The varieties, however, known as gum core have to go through a different process. Usually a core is squirted through a tube machine and the outside covering of jute or cotton, or whatever the fabric may be, is put on by a braider or is wrapped about it somewhat after the manner of the old fashioned cloth-wrapped tubing. The fabric is either treated with some heat-resisting mixture or something that is a lubricant, plumbago and oil being the compound. Other packings are made from the ends of belts cut out in a circular form and treated with a lubricant. There are scores of styles that make special claims for excellences that are made in a variety of ways, but as a rule the general system as outlined above is followed.

JAR RINGS.

The old fashioned way of making jar rings was first to take a large mandrel and wrap it around with a sheet of compounded rubber until the thickness of the ring was secured. It was then held in place by a further wrapping of cloth, vulcanized, put in a lathe and cut up into rings by hand. That manner of procedure, however, was too slow, and it is to-day done almost wholly by machinery. For example, the rubber is squirted out of a mammoth tubing machine in the shape of a huge tube, then slipped on a mandrel and vulcanized. It is then put in an automatic lathe and revolving swiftly is brought against a sharp knife blade which cuts ring after ring until the whole is consumed, without any handling or watching.—India Rubber World.

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HOW ENAMELED LETTERS ARE MADE.

The following is a description of a brief visit by a representative of the Journal of Decorative Art to the new factory of the Patent Letter and Enamel Company, Ltd., situate in the East End of London.

The company have recently secured a large freehold plot in the center of the East End of London, and have built for themselves a most commodious and spacious factory, some hundreds of feet in length, all on one floor, and commanded from one end by the manager's office, from whence can be seen at a glance the entire premises.

The works are divided into two large compartments, and are lighted from the roof, ample provision being made for ventilation, and attention being given to those sanitary conditions which are, or should be, imperative on all well managed establishments.

We first explore the stockroom. Here are stored the numerous dies, of all sizes and shapes, which the company possess, varying in size from half an inch to twelve or sixteen inches. Here, too, is kept the large store of thin sheet copper out of which the letters are stamped. Our readers are familiar with the form or principle upon which these letters are made. It is simply a convex surface, the reverse side being concave, and being fixed on to the glass or other material with a white lead preparation. When these letters were first made, the practice was to cut or stamp them out in flat copper, and then to round or mould them by a second operation. Recent improvements in the machinery, however, have dispensed with this dual process, and the stamping and moulding is done in the one swift, sharp operation.

The process of making an enameled letter has four stages—stamping, enameling, firing, and filing. There are other and subsequent processes for elaborating, but those named are of the essence of the transaction.

STAMPING.

The stamping is done by means of presses, and is a very rapid and complete operation.

The operator takes a piece of the sheet copper, places it on the press, the lever descends, there is a sharp crunching, bursting sound, and in a time shorter than it has taken to describe, the letter is made, sharp and perfect in every way.

ENAMELING.

The letters are now taken charge of by a girl, who lays them out on a wire tray, the hollow side up, and paints them over with a thin mordant. While they are in this position, and before the mordant dries, they are taken on the gridiron-like tray to a kind of large box, which is full of the powdered enamel, and, holding the tray in her left hand, the girl takes a fine sieve full of the powder and dusts it over the letter, all superfluous powder falling through the open wirework and into the bin again, so that there is absolutely no waste.



FIRING.

The letters are now taken and placed carefully on thin iron disks or plates on the bench, where they remain until they are fired. It will be remembered that we said at the outset that the factory was divided into two large compartments, and it is into the second of these that we now go.

Here are ranged the series of furnaces which convert the copper and superincumbent enamel into one common body—fuse the one into the other. An unwary step soon warns us that we are too near the furnace, unless we want to run the risk of a premature cremation, and in the interests of the readers of this journal we step back to a respectful and proper distance, and watch the operations from afar.

There seems to be something innately picturesque about all furnaces and those who work about them. Whether it is the Rembrandt effects produced by the strong light and shade, or whether it is that the necessary use of the long iron instruments, such as all furnace workers employ, compels a certain dignity and grace of poise and action, we know not; but certain it is that the grace is there in a marked degree, and as we watched the men take their long-handled iron tongs and place in or lift out the plates of hot metal, we could not fail to be impressed with the charm of the physical action they displayed.

The disk containing the enameled letters is taken at the end of a long iron handle and carefully placed in a dome-shaped muffle. These muffles are all heated from the outside; that is, the fire is all round the chamber, but not in it, the fumes of the sulphur being destructive of the enamel if they are allowed to come into contact with it. So intense is the heat, however, that a muffle lasts only about nine days, and at the end of that time has to be renewed.



After the enamel is fused on to the copper, the disk is taken out and placed on a side slab, where it is allowed to cool.

This process is repeated on the front side of the letter, when all that remains to complete it is

THE FILING.



This is done by girls, who, with very fine files, rub off the edges and any protuberances which may be there. Every letter is subject to this operation, and all are turned out smooth and well finished.

Sometimes the letters are colored or further defined by the addition of a line, but the essentials are as we have already described.



BRUSHING OUT.

There are, however, one or two other operations of interest which we may notice. The company do not confine their exertions to the making of letters, various collateral developments having taken place which fill an important part in this scheme of work.

Of these, small tablets, containing advertisements or notices, such as we see in railway carriages, "Push after raising window," or "Close this door after you," or some legend pertaining to Brown's Soap or Robinson's Washing Powder. These are done by different processes, the transfer process, as used in the potteries, being employed, but the one most largely used is that of "brushing out," which is done by plates.

Let us suppose that the tablet shows white letters on a dark ground, the modus operandi is as follows:

The tablet has been enameled, as already described, and is white. The operator now takes a dark enamel and spreads it evenly over the entire surface of the tablet. He, or she, now takes a stencil plate, of tinfoil, out of which the ground is cut, leaving the letter in the center.

This is carefully placed over the tablet and held tight with the left hand, while with the right hand he holds a fine brush, which he uses with a quick, sharp movement over the surface. This action readily removes the unfired color from the hard, glassy surface underneath, and leaves a white letter. This is fired, and is then complete.

Sometimes two and, it may be, three plates are necessary to complete the brushing out, as ties must be left, as in the case of ordinary stencils, and these have to be brushed out with additional plates. Two or three colors may be introduced by this process, but each separate color means separate firing. If the letters are dark on a light ground, the process is exactly the same, the stencil only being modified. In addition to the letters and tablets thus described, the company also undertake the production of large enameled signs, and to cope with the rapid expansion of this department of their work they are erecting special furnaces, to enable them to deal with any demand likely to be made upon them. The call for things permanent and washable in the way of advertising is on the increase, and the enameled plates made by the company is one of the most successful ways of meeting the demand.



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BURNING BRICK WITH CRUDE OIL FUEL.

At the present time there is not the least reason why either wood, coal, or any other solid fuel should be used for the burning of brick. This style of burning brick belongs to a past age. The art of brickmaking has made tremendous progress during the past quarter of a century. It is no longer the art of the ignorant; brains, capital, experience, science, wide and general knowledge, must in these days be the property of the successful brick manufacturer. There are some such progressive brick manufacturers in Chicago, who use neither coal nor wood in the drying or burning of their clay products. Crude oil is the fuel which they employ, and with this fuel they obtain cheaper and better brick than do manufacturers who employ solid fuel. Some of these manufacturers have expressed themselves as preferring to quit the brick business rather than return to the use of wood or coal as fuel in brick burning.

This shows plainly that progress in our art, when it does come, comes to remain. It is true that crude oil for brick-burning purposes is not everywhere obtainable. But there is a fuel which is even better than crude oil, namely, fuel gas, and which can be produced and employed on any brick yard at a saving of seventy-five per cent. over coal or other solid fuel.

The Rose process for making fuel gas gives a water gas enriched by petroleum. Roughly, about half the cost of this gas as made at Bellefonte, Pa., was for oil. The gas cost 6.68c. per 1,000 cu. ft., with oil at 21/4c. a gallon. At double this price the gas would cost but 10c., and show that in practice, foot for foot, it equals natural gas.

Fuel gas means a larger investment of capital than does any of the other modes of brick burning, and is, therefore, not within the reach of the entire trade. The cost of appliances for burning brick with crude oil is not very large, and as all grate bars, iron frames, and doors can be dispensed with in the use of crude oil fuel, the cost of an oil-burning equipment is but little in excess of an equipment of grates, etc., for coal-burning kilns.

At works using small amounts of fuel, especially if cost of fuel bears but a small proportion to total cost of the manufactured product, oil will be in the future very largely used. It is clean, as compared with coal, can be easily handled, and when carefully used in small quantities, is safe. There are several methods of burning oil that are well adapted to the use of brick manufacturers and other fuel consumers.

The Pennsylvania Railroad made some very thorough experiments on the use of petroleum in their locomotives, and while the results obtained are reported to have been satisfactory, it was the opinion of those having the experiments in charge that the demand for the Pennsylvania Railroad alone, were it to change its locomotives from coal to oil, would consume all the surplus and send up the price of oil to a figure that would compel a return to coal.

It is true that production has enormously increased in the last three years, and the promise for the near future is that a high rate will be maintained. It is further true that the production of Russia has increased enormously, and will probably be larger this year than ever before. This Russian oil must go to markets and supply demands that have been met by American oil, and this will still further increase the amount of oil available for fuel purposes.

There is no doubt, therefore, that petroleum has a future for fuel uses. Many brick manufacturers are ready to use it, notwithstanding the possibility of an advance in its cost.

While there are some objections to the use of petroleum as a fuel, growing chiefly out of the risk attending its storage and conveyance to the point of consumption, it is undoubtedly true that the chief objection is the fear that with the increased demand that would follow any extended use for this purpose would come an increase in price that would make its continued use too expensive.

Just four years ago, when the fuel oil industry was first projected, it was cried down because, as its enemies claimed, there was not enough oil fuel to be obtained in America to supply the New York City factories alone, to say nothing of other territory, and because of the high prices for oil that were sure to follow its substitution for coal fuel. Since then the industry has experienced a magnificent success, the sales exceeding 20,000,000 barrels a year, while the price is lower than ever.

A curious impression seems to have gained ground to the effect that the Standard Oil Company does not want to sell oil for fuel. It may be stated authoritatively that the company is not only able but willing to sell and deliver oil for fuel purposes in any quantity that may be desired. It is now delivering oil for fuel purposes in fourteen States of the Union. For its sales in Chicago and the West and Northwest, the delivery is by tank cars from the terminus of the pipe line at South Chicago, to which point it is pumped from Lima, O. The Chicago price is 1-2/3c. per gallon, or 70c. per barrel of 42 gallons, f.o.b. cars at Chicago.

A great many of the brick manufacturers here and throughout the Northwest are beginning to use crude petroleum as a substitute for soft coal. It is smokeless, for the fine spray of oil which comes from the injector consists of such minute drops of the liquid and is so thoroughly mixed with oxygen that when it burns the combustion is complete, and only steam and carbonic acid gas go out of the top of the kiln. Not a speck of soot comes from the kiln or the smokestack or soils the whitewashed purity of the boiler room. Oil fuel is absolutely clean. It is labor saving, too. No fireman has to keep shoveling coal, there are no ashes to be dragged out from under the furnace grates, and there are no clinkers to clog up the bars. One man, by turning a valve, may regulate the heat of a kiln containing one million brick.

Not only is it cleaner than coal and calls for less labor, but it is actually cheaper as a fuel. A barrel and a half of crude oil is equal for furnace fuel to a ton of the best Illinois bituminous coal, and at 70c. a barrel any one can easily calculate the advantages petroleum has over its smoky rival. Theoretically, two barrels of oil equal in heating power one ton of best Pittsburg coal.

An examination into the relative cost of the Pittsburg and Chicago coal to the oil consumed shows that the price of oil at Pittsburg is 59c. per barrel of 42 gallons, and slack coal can be purchased at from 70c. to 80c. per ton, and the best quality of lump coal at from $1.10 to $1.25 per ton, while the same quality of fuel can be bought in Chicago at about 70c. a barrel, as against coal at from $2 to $3.50 per ton. It would, therefore, look as though there could be no question whatever as to the economy and advantages to be derived from the use of oil as a fuel in this vicinity.

The weight of oil required is less than half that of average coal to produce the same amount of steam.

A great advantage in using oil as fuel in brick burning is that the fires are always under the absolute and direct control of the man in charge of the burning, who can regulate the volume of flame to the nicest degree and throw the heat to any part of the arches that he may desire.

From present indications, oil will be the fuel adopted generally for generating power and for brick burning in Chicago, as it saves the boilers, avoids grate bars, saves dirt and cinders, and reduces running expenses, etc.

Much skepticism was at first exhibited in Chicago only a few years ago when one of the leading brick manufacturers attempted to burn a kiln of brick with coal for fuel. Nearly all the brickmakers then in business put on wise looks and predicted the failure of the experiment with coal. But coal proved to be a better and cheaper fuel than wood, and in five or six years wood was used only for the kindling of the coal fires.

Then came the attempt to burn brick with crude oil, and the experiment having proved a success, coal has been banished from the leading brick yards in Chicago and vicinity.

The Purington-Kimball Brick Co., Adams J. Weckler, Weber & La Bond, the May-Purington Brick Co., the Union Brick Co., and the Pullman Brick Co., all having headquarters in Chicago, as well as the Peerless Brick Co. and the Pioneer Fireproof Construction Co., both of Ottawa, Ill., are using crude oil fuel for brick burning.

Lima crude oil is used, and it is atomized by means of steam in small furnaces extending about two feet from the face of the brick kilns, and in which furnaces combustion occurs, and the conversion of the oil and steam into a gaseous fuel is secured. There is little doubt that the fuel employed in the future by the successful brick manufacturer must be in the gaseous form. Owing to the enormous cost of handling coal, wood, and other crude fuel, and of removing the ash resulting from such fuel, it has been demonstrated in practice by the use of crude oil that the expense connected with the burning of brick can be reduced fully 60 per cent. This large saving is made by converting crude petroleum into gas and utilizing this fuel, either directly in the arches of the kiln or by converting the crude oil into gas in a gas producer, and drawing this fuel gas from the producer and burning the same as required in kilns of suitable construction.

Crude oil fuel must in the future play an important part in all branches of manufacture requiring high, constant heats, and in which the cost of wood, coal, and other solid fuels, together with the labor cost of handling them, forms a considerable part of the cost of production. Where coal is required to be hauled in carts from the wharves, or from a line of railway to the brick yard, located a mile, more or less, from the places where the coal is received, the cost of handling, haulage, and waste is an important item. Added to these costs, the deterioration of soft coal under atmospheric influences and the waste from imperfect combustion and from the particles which fall from the grate bars into the ash pits, all eat a large hole in the brickmakers' profit.

Mr. D.V. Purington, of Chicago, Ill., in speaking on this subject, says:

"I will say that my fuel bill for oil is cheaper than it would cost me for coal. There is a very wide difference in the cost of unloading, hauling away ashes and cinders, and getting my coal around to the kiln, or boilers, or drier, or wherever I use it, and I get very much better results by being able to put the heat from oil fuel just where I want it."

In order to secure the best results with any fuel it is not only necessary that a cheap fuel should be used, but that it should be always obtainable, and that all of it should be burned and turned to commercial account in the operations of brick manufacture.

Owing to the losses which we have previously mentioned, and resulting from the use of coal, this fuel is destined to be superseded by some form of fuel which will avoid such losses, and which will dispense with all of the inconveniences now encountered in the handling of coal and of the ashes resulting from combustion. Wood is rapidly becoming too scarce and high near the great centers of man's habitation to be regarded in the present discussion.

Fully two hundred million of brick a year are being burned in the city of Chicago with crude oil fuel, and a clamp kiln containing one million brick can be burned with crude oil in Chicago at a labor cost of less than $100, and at a total cost for labor and oil of about 40c. per thousand brick.

There are not, however, many places in the world where brick can be burned with oil at such a low cost as in the city of Chicago; the reason being that oil is not everywhere obtainable so cheaply as in this city, and because few clays in the world are so easily burned into brick as are the clays of Chicago. In Milwaukee, Wis., and in other places within a distance of 100 miles from Chicago, the time required to burn building brick with crude oil fuel averages from sixteen to twenty-one days, whereas the time of burning the Chicago clays averages only about five days, and splendid "burns" have been secured there with crude oil in three and one-half days. It is evident, therefore, that the advantages of using crude oil fuel for the burning of brick will vary in different parts of the United States.

Where circumstances and the nature of the clay permit of its use, crude oil is, next to fuel gas, the brickmakers' ideal fuel.—The Brickmaker.

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INVESTIGATION OF A MOUND NEAR JEFFERSON CITY, MO.

By A.S. LOGAN.

Recently, a party consisting of engineers and employes of the Missouri River Improvement Commission began an exploration of one of the mounds, a work of a prehistoric race, situated on the bluff, which overlooks the Missouri River from an elevation of one hundred and fifty feet, located about six miles below Jefferson City.

This mound is one of about twenty embraced in a circle one quarter of a mile in diameter.

The above party selected the mound in question apparently at haphazard; all the mounds presenting nearly a uniform outline, differing only in size and mostly circular in form, and from twenty to twenty-four feet at the base, rising to a height of eight feet and under. A trench was cut on a level with the natural soil, penetrating the mound about eight feet. A stone wall was encountered which was built very substantially, making access in that direction difficult, in consequence of which the earth was removed from the top for the purpose of entering from that direction. The earth was removed for a depth of four feet, when the top of the wall was exposed. Further excavation brought to light human bones, some of them fairly well preserved, especially the bones of the legs. On the removal of these and a layer of clay, another layer of bones was exposed, but presenting a different appearance than the first, having evidently been burned or charred, a considerable quantity of charcoal being mixed with the bones. In this tier were found portions of several skulls, lying close together, as if they had been interred without regard to order. They were, in all probability, detached from the body when buried.

The portions of the skulls found were those of the back of the head, no frontal bones being discovered. Some jaw bones with the teeth attached were among the remains, but only that portion of the jaw containing the molar teeth.

A few pieces of flint weapons were found in the upper layers, and nothing else of any significance.

At this juncture the diggers abandoned the search, and some days later the writer, desirous of seeing all that was to be seen, resumed the work and removed the earth and remains until the bottom of the vault was reached; several layers being thus removed. All of these had evidently been burned, as charcoal and ashes were mixed with the bones of each succeeding layer. The layers were about an inch in thickness, with from two to four inches of earth between, and small flat stones, about the size of a man's hand, spread on each different layer, as if to mark its division from the next above.

Between the bottom layers, mixed with charcoal, ashes and small portions of burned bones were found what gives value to the search, numbering about fifty tools and a smoking pipe.

The material of the tools is the same as the rock forming the vault, locally known as "cotton rock." I would consider it a species of sandstone.

Overlying the edge of "cotton rock" in the bluff is flint in great quantities, and in every conceivable shape, that these people could have resorted to had they been so disposed, and why they used the softer material I will leave to some archaeologist to determine. The tools themselves are made after no pattern, but selected for their cutting qualities, as they all have a more or less keen edge which could be used for cutting purposes, and were no doubt highly prized, as they were found all in a pile in one corner of the vault and on top of which was found a stone pipe. The pipe is made bowl and stem together, and it is curious that people of such crude ideas of tools and weapons should manufacture such a perfect specimen of a pipe. It is composed of a very heavy stone, the nature of which would be difficult to determine, as it is considerably burned.

A description of the vault will be found interesting to many. The wall of the vault rests upon the natural surface of the ground, about three feet high and eight and a half feet square, the inside corners being slightly rounded; it is built in layers about four inches in thickness and varying in length upward to three feet, neither cement nor mortar being used in the joints; the corners formed a sort of recess as they were drawn inward to the top, in which many of the stones were found. The stone for constructing the vault was brought from a distance of about a quarter of a mile, as there is none in sight nearer.

I assume from all these circumstances that these people lived in this neighborhood anterior to the age of flint tools, as the more recent interments indicate that they were then entering upon the flint industry, and it may be that the "cotton rock" had become obsolete.

These people buried their dead on the highest ground, covering and protecting them with these great mounds, when it would seem much easier to bury as at the present day; but instead, they, with great labor, carried the rock from a great distance, and it is reasonable to suppose, also, that the earth was brought from a distance with which they are surrounded, and piled high above, as there is no trace of an immediate or local excavation.

In my view from the mounds and their surroundings I would unhesitatingly say the water, the foot hills of the glacier and the swamps left in its wake were but a short distance to the north of them, and during the summer months the melting ice would send a volume of water down this valley that the Missouri River of to-day is but a miniature of, and therefore the highest hills were the only land that could be used by that ancient race.

In this connection I would make the following suggestions that may lead to more important disclosures: My object is the hope of a more thorough investigation at some future time. Nearer to the top of the mound was found, certainly, the remains of a people of more recent date than those found in the vault, as their bones were larger, which would indicate a more stalwart tribe, and also their mode of burial was different, as there was no indication of fire being used, as was the case with the lower burials. I would pronounce the upper interments those of Indians of the present day; the tools found with these were weapons of the chase. On the other hand, those found in the vault were of a peaceful character, and their surroundings would readily comport, in my opinion, to the glacial period. The entire absence of flint in the bottom of the mound would show one of two things, either they were unacquainted with the use of flint or at that time there was no flint to be had. It is there now in great abundance, in such forms for cutting purposes that would render the "cotton rock" almost useless. The flint is found in a hill close to the river bank, about half a mile from the mound, and the upper portion of the ledge has the appearance, to me, of glacial action and probably forms a moraine, as it has, evidently, been pushed over the underlying ledge, and been ground and splintered in a manner that could not have been without great crushing force. It would be reasonable enough to suppose that the action of the river may have uncovered this flint by washing away the softer material since the occupation of the older race.

In relation to the Indian interment in the examined mound, I could not say distinctly whether the Indian burials had been such as to make them aware of former burials or not, but I think from the thickness of the clay between the two that they were ignorant of former burials. The mounds of the modern Indian, so far as my investigations are concerned, would indicate a more rudely formed structure which would appear to be an imitation of the older mounds, as they are not finished with like care nor have they the ulterior structures.—The Scientist.

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ACTION OF CAUSTIC SODA ON WOOD.

By M.H. TAUSS.

The researches of the author upon the action which water exerts upon wood at a high temperature have shown how much of the incrusting material can be removed without the aid of any reagent.

In connection with the manufacture of cellulose, it is also interesting to prosecute at the same time experiments with solutions of the caustic alkalies, in order to study the mode of action upon both wood and pure cellulose. The manufacture of cellulose has for many years been an industry, and yet little or nothing from a chemical point of view is known of the action of caustic soda upon vegetable fibers.

Braconnot, in 1820, obtained alumina by treating wood with an alkali, but the first application of wood to the manufacture of paper was due to Chauchard. By boiling vegetable fibers with caustic lyes, Collier and Piette obtained cellulose. Again, in 1862, Barne and Blondel proposed to make cellulose in a similar way, but employed nitric acid in the place of soda.

The first cellulose made exclusively from wood and caustic soda was produced at the Manayunk Wood Pulp Works, in 1854, in the neighborhood of Philadelphia, by Burgess & Watt. The operation consisted in treating the wood for six hours at a pressure of from six to eight atmospheres, with a solution of caustic soda of 12 deg. B.

Ungerer noticed that it was sufficient to limit the pressure from three to six atmospheres, according to the quality of the wood, and advised the use of solutions containing four to five per cent. of caustic soda. He employed a series of cylinders, arranged vertically, in which the wood was subjected to a methodical system of lixiviation. The same lye passed through many cylinders, so that when it made its exit at the end it was thoroughly exhausted, and the wood thus kept coming in contact with fresh alkaline solutions.

According to the account of Kiclaner, the disintegration of wood may be effected in the following four ways:

1. By heating direct in boilers at a pressure of 10 atmospheres. (See Dresel and Rosehain.)

2. In vertical boilers heated direct or by steam, and kept at a pressure of from 10 to 14 atmospheres. (Sinclair, Nicol, and Behrend.)

3. In revolving boilers, maintained at a pressure of 12 atmospheres by direct steam.

4. By means of a series of small vessels communicating with each other, and through which a lye circulates at a pressure of six atmospheres. (Ungerer.)

This latter process is preferable to the others.

Researches have also been made by the author in order to ascertain the loss which wood and cellulose suffer at different temperatures or in contact with varying quantities of alkali (NaHO).

The following is a resume of the experiments, giving the loss in per cent. resulting from a "cooking" of three hours duration:

I. Ordinary pressure: 10 grms. cellulose, with 580 c.c. of caustic soda solution, sp. gr. 1.09 21.99 10 grms. of soft wood, treated as above 49.19 10 " hard " " " 53.68

II. Pressure of five atmospheres: 10 grms. cellulose, with 500 c.c. caustic soda solution of sp. gr. 1.099 58.02 10 grms. of soft wood, treated as above 75.85 10 " hard " " " 69.80

III. Pressure of ten atmospheres: 10 grms. of cellulose 58.99 10 " soft wood 81.80 10 " hard " 70.39

IV. Ordinary pressure: 10 grms. of cellulose, with 500 c.c. caustic soda solution of sp. gr. 1.162 21.88 10 grms. of soft wood 35.45 10 " hard " 46.43

V. Pressure of five atmospheres: 10 grms. of cellulose, with 500 c.c. caustic soda solution of sp. gr. 1.162 77.33 10 grms. of soft wood 97.13 10 " hard " 91.48

VI. Ordinary pressure: 10 grms. of cellulose, with 500 c.c. caustic soda solution of sp. gr. 1.043 12.07 10 grms. of soft wood 28.37 10 " hard " 30.25

VII. Pressure of five atmospheres: 10 grms. of cellulose, with 500 c.c. of caustic soda solution of sp. gr. 1.043 15.36 10 grms. of soft wood 50.96 10 " hard " 55.66

VIII. Pressure of ten atmospheres: 10 grms. of cellulose, with 200 c.c. caustic soda solution of sp. gr. 1.043 20.28 10 grms. of soft wood 70.31 10 " hard " 65.59

From this it is evident that by increasing the temperature and pressure the solvent action of the alkali is increased, but the strength of the lye exercises an influence which is even more marked. Thus, at a pressure of five atmospheres, the loss of cellulose was 0.75 with a caustic lye containing 14 per cent. of NaHO, while it was only 0.05 with a lye of 8 per cent. NaHO.

To further elucidate the action of the alkali under the conditions given above, the author has estimated the amount of precipitate which alcohol gives with the soda solutions, after boiling with the wood:

1. 2. 3. Specific gravity of NaHO solutions 1.043 1.09 1.162 Soft wood, ordinary pressure 1.043 traces 4.8 " pressure of five atmospheres 1.043 2.0 26.8 " " ten " 1.043 1.7 — Hard wood, ordinary pressure 11.10 27.40 30.80 " pressure of five atmospheres 1.10 25.70 15.8 " " ten " traces 5.20 15.8

The estimation of the precipitate, produced in the soda solutions employed in the experiments cited above, gives:

Soft wood, ordinary pressure 1.31 traces 2.0 " pressure of five atmospheres 15.94 16.0 24.80 " " ten " 17.00 25.4 — Hard wood, ordinary pressure 5.40 6 5.60 " pressure of five atmospheres 9.40 15.40 33.60 " " ten " 14.00 18.40 33.60

As a general rule manufacturers employ a greater pressure than that which was found necessary by the author. As a result, it appears from these experiments that the wood not only loses incrusting matter, but that part of the cellulose enters into solution. As a matter of fact, the yield obtained in practical working from 100 parts of wood does not exceed 30 to 35 per cent.—Le Bull. Fab. Pap.; Chemical Trade Journal.

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NEW BORON COMPOUNDS.

An important paper is contributed by M. Moissan to the current number of the Comptes Rendus, describing two interesting new compounds containing boron, phosphorus, and iodine. A few months ago M. Moissan succeeded in preparing the iodide of boron, a beautiful substance of the composition BI{3}, crystallizing from solution in carbon bisulphide in pearly tables, which melt at 43 deg. to a liquid which boils undecomposed at 210 deg.. When this substance is brought in contact with fused phosphorus an intense action occurs, the whole mass inflames with evolution of violet vapor of iodine. Red phosphorus also reacts with incandescence when heated in the vapor of boron iodide. The reaction may, however, be moderated by employing solutions of phosphorus and boron iodide in dry carbon bisulphide. The two solutions are mixed in a tube closed at one end, a little phosphorus being in excess, and the tube is then sealed. No external application of heat is necessary. At first the liquid is quite clear, but in a few minutes a brown solid substance commences to separate, and in three hours the reaction is complete. The substance is freed from carbon bisulphide in a current of carbon dioxide, the last traces being removed by means of the Sprengel pump. The compound thus obtained is a deep red amorphous powder, readily capable of volatilization. It melts between 190 deg. and 200 deg.. When heated in vacuo it commences to volatilize about 170 deg., and the vapor condenses in the cooler portion of the tube in beautiful red crystals. Analyses of these crystals agree perfectly with the formula BPI{2}. Boron phospho-di-iodide is a very hygroscopic substance, moisture rapidly decomposing it. In contact with a large excess of water, yellow phosphorus is deposited, and hydriodic, boric, and phosphorus acids formed in the solution. A small quantity of phosphureted hydrogen also escapes. If a small quantity of water is used, a larger deposit of yellow phosphorus is formed, together with a considerable quantity of phosphonium iodide. Strong nitric acid oxidizes boron phospho-di-iodide with incandescence. Dilute nitric acid oxidizes it to phosphoric and boric acids. It burns spontaneously in chlorine, forming boron chloride, chloride of iodine, and pentachloride of phosphorus. When slightly warmed in oxygen it inflames, the combustion being rendered very beautiful by the fumes of boric and phosphoric anhydrides and the violet vapors of iodine. Heated in contact with sulphureted hydrogen, it forms sulphides of boron and phosphorus and hydriodic acid, without liberation of iodine. Metallic magnesium when slightly warmed reacts with it with incandescence. When thrown into vapor of mercury, boron phospho-di-iodide instantly takes fire.

The second phospho-iodide of boron obtained by M. Moissan is represented by the formula BPI. It is formed when sodium or magnesium in a fine state of division is allowed to act upon a solution of the di-iodide just described in carbon bisulphide; or when boron phospho-di-iodide is heated to 160 deg. in a current of hydrogen. It is obtained in the form of a bright red powder, somewhat hygroscopic. It volatilizes in vacuo without fusion at a temperature about 210 deg., and the vapor condenses in the cooler portion of the tube in beautiful orange colored crystals. When heated to low redness it decomposes into free iodine and phosphide of boron, BP. Nitric acid reacts energetically with it, but without incandescence, and a certain amount of iodine is liberated. Sulphuric acid decomposes it upon warming, without formation of sulphurous and boric acids and free iodine. By the continued action of dry hydrogen upon the heated compound the iodine and a portion of the phosphorus are removed, and a new phosphide of boron, of the composition B{5}P{3}, is obtained.—Nature.

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BORON SALTS.

A paper upon the sulphides of boron is communicated by M. Paul Sabatier to the September number of the Bulletin de la Societe Chimique. Nature gives the following: Hitherto only one compound of boron with sulphur has been known to us, the trisulphide, B{2}S{3}, and concerning even that our information has been of the most incomplete description. Berzelius obtained this substance in an impure form by heating boron in sulphur vapor, but the first practical mode of its preparation in a state of tolerable purity was that employed by Wohler and Deville. These chemists prepared it by allowing dry sulphureted hydrogen gas to stream over amorphous boron heated to redness. Subsequently a method of obtaining boron sulphide was proposed by Fremy, according to which a mixture of boron trioxide, soot, and oil is heated in a stream of the vapor of carbon bisulphide. M. Sabatier finds that the best results are obtained by employing the method of Wohler and Deville. The reaction between boron and sulphureted hydrogen only commences at red heat, near the temperature of the softening of glass. When, however, the tube containing the boron becomes raised to the temperature, boron sulphide condenses in the portion of the tube adjacent to the heated portion; at first it is deposited in a state of fusion, and the globules on cooling present an opaline aspect. Further along the tube it is slowly deposited in a porcelain like form, while further still the sublimate of sulphide takes the form of brilliant acicular crystals. The crystals consist of pure B{2}S{3}; the vitreous modification, however, is usually contaminated with a little free sulphur. Very fine crystals of the trisulphide may be obtained by heating a quantity of the porcelain-like form to 300 deg. at the bottom of a closed tube whose upper portion is cooled by water. The crystals are violently decomposed by water, yielding a clear solution of boric acid, sulphureted hydrogen being evolved. On examining the porcelain boat in which the boron had been placed, a non-volatile black substance is found, which appears to consist of a lower sulphide of the composition B{4}S. The same substance is obtained when the trisulphide is heated in a current of hydrogen; a portion volatilizes, and is deposited again further along the tube, while the residue fuses, and becomes reduced to the unalterable subsulphide B{4}S, sulphureted hydrogen passing away in the stream of gas.

Two selenides of boron, B_{2}Se_{3} and B_{4}Se, corresponding to the above described sulphides, have also been prepared by M. Sabatier, by heating amorphous boron in a stream of hydrogen selenide, H_{2}Se. The triselenide is less volatile than the trisulphide, and is pale green in color. It is energetically decomposed by water, with formation of boric acid and liberation of hydrogen selenide. The liquid rapidly deposits free selenium, owing to the oxidation of the hydrogen selenide retained in solution. Light appears to decompose the triselenide into free selenium and the subselenide B_{4}Se.

Silicon selenide, SiSe_{3}, has likewise been obtained by M. Sabatier by heating crystalline silicon to redness in a current of hydrogen selenide. It presents the appearance of a fused hard metallic mass incapable of volatilization. Water reacts most vigorously with it, producing silicic acid, and liberating hydrogen selenide. Potash decomposes it with formation of a clear solution, the silica being liberated in a form in which it is readily dissolved by alkalies. Silicon selenide emits a very irritating odor, due to the hydrogen selenide which is formed by its reaction with the moisture of the atmosphere. When heated to redness in the air it becomes converted into silicon dioxide and free selenium.

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NATURAL SULPHIDE OF GOLD.

By T.W.T. ATHERTON.

The existence of gold in the form of a natural sulphide in conjunction with pyrites has often been advanced theoretically as a possible occurrence, but up to the present time this occurrence has, I believe, never been established as an actual fact.

During my investigations on the ore of the Deep Creek Mines, I have found in them what I believe to be gold existing as a natural sulphide. The description of this ore will, no doubt, be of interest to your readers.

The lode is a large irregular one of pure arsenical pyrites, existing in a felsite dike near the sea coast. Surrounding it on all sides are micaceous schists, and in the neighborhood is a large hill of granite about 800 ft. high. In the lode and the rock immediately adjoining it are large quantities of pyrophylite, and in some places of the mine are deposits of this pure white, translucent mineral, but in the ore itself it is a yellow and pale olive green color, and is never absent from the pyrites.

From the first I was much struck with the exceedingly fine state of division in which the gold existed in the ore. After roasting and very carefully grinding down in an agate mortar, I have never been able to get any pieces of gold exceeding the one-thousandth of an inch in diameter, and the greater quantity is very much finer than this. Careful dissolving of the pyrites and gangue, so as to leave the gold intact, failed to find it in any larger diameter. As this was a very unusual experience in investigations on many other kinds of pyrites, I was led further into the matter. Ultimately, after a number of experiments, there was nothing left but to test for gold as a sulphide.

Taking 200 grammes of pyrites from a sample assaying 17 ounces fine gold per ton, grinding it finely, and; heating for some hours with a solution of sodium sulphide (Na{2}S{2}), on decomposing the filtrate and treating it for gold I got a result at the rate of 12 ounces gold per ton. This was repeated several times with the same result.

This sample came from the lode at the 140 ft. level, while samples from the higher levels where the ore is more oxidized, although carrying the gold in the same degree of fineness, do not give as high a percentage of auric sulphide.

It would appear that all the gold in the pyrites (and I have never found any apart from it) has originally taken its place there as a sulphide.

The sulphide is an analysis of a general sample of the ore:

Silica 13.940 p.c. Alumina 6.592 " Lime 0.9025 " Sulphur 16.584 " Arsenic 33.267 " Iron 27.720 " Cobalt 0.964 "

Per Ton. Nickel Traces. Gold 5 ozs. 3 dwts. 8 grs. Silver 0 " 16 " 0 " ———- 99.969

Nambucca Head's Gold Mining Company, Deep Creek, N.S. Wales, Oct. 9, 1891.—Chemical News.

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SOME MEANS OF PURIFYING WATER.

There are several methods extant for the purpose of purifying and softening water, and in the following brief account some of the chief features of these methods are summarized. The Slack and Brownlow apparatus we will deal with first. This purifier is one which is intended to remove the matter in suspension in the water to be treated by subsidence and not by filtration. The apparatus consists of a vertical iron tank or cylinder, inside which are a series of plates arranged in a spiral direction around a fixed center, and sloping at an angle of 45 deg. on both sides outward. The water to be dealt with flows through a large inlet tube fixed to the bottom of the cylinder, rises to the top by passing spirally round the whole circumference, and depositing on the plates or shelves all solids and impurities at the outer edges of the plates. Mud cocks are placed to remove the solids deposited during the flow of the water upward to the outlet pipe, placed close to the top of the cylinder. One of these tanks, a square one, is at work purifying the Medlock water at Manchester, and on drawing samples of water from nearly every plate, that from the lower mud cock showed considerable deposit, which decreased in bulk until the top mud cock was reached, when the water was quite free from deposit. It is stated that one man would be sufficient to attend to 20 of these purifiers.

To filter or purify 2,000,000 gallons per 24 hours would require 40 tanks, 10 ft. by 7 ft. diameter, each doing 2,000 gallons per hour, and would cost, with their fittings, L6,400, including all patent rights, but exclusive of lime mixing tanks, agitators, lime water and softening tanks, engine and boiler, and suitable buildings, the cost of which would not be far short of L5,000, or a total of L11,400 to soften 2,000,000 gallons per 24 hours. The labor and other working expenses in connection with this plant would not be less than that necessary to work the Porter-Clark process, which is given as O.55d. per 1,000 gallons.

The Brock and Minton filter press system is another method. This patent press is made of steel, perforated with 1/2 inch holes. On the inside of the shell there is first laid a layer of fine wire netting, then a layer of cloth, and lastly another layer of wire netting of a larger mesh than the other. The matter treated is pumped into the body of the cylinder, the liquid passing through the filtering material to the outside, the solids being retained inside, and are got rid of by partially revolving the upper half to relieve it from the knuckle joint, and, after being raised, the lower half is turned over by machinery, and the solid matter is simply allowed to fall out into wagons or trucks run underneath for that purpose. Such, in brief, is the manner of using this filter press for chemical works' purposes. The cost of each filter press, including royalties, is from L250 to L300, the size being 8 ft. by 4 ft. diameter. Having a filtering area of 100 square feet, it would require 32 of these applied to softening water to effectually deal with 2,000,000 gallons per 24 hours; this, at the lowest estimate for filters alone, would be L8,000, and, using the same figures, L5,000 for lime mixing tanks, etc., as referred to in the "Slack and Brownlow" purifier, would bring the total cost up to L13,000, and the working expense would not be less than that required to work the Porter-Clark process, and would probably be very much greater. This filter press is not in use anywhere for dealing with large quantities of water in connection with a town water supply.

A process which has been working for a long time at Southampton is the Atkins system, which also includes the use of filter presses. The pumping station and softening works are situated at Otterbourne, eight miles from Southampton, and were built together as one scheme. The mixing room has two slaking lime tanks, with agitators driven by steam power. The mixture is then run as cream of lime into a tank 20 ft. square and is then pumped into the lower ends of two lime water producing cylinders. The agitation is here obtained by pressure from a small cistern placed above them with a 12 ft. head, the pipe from which is attached to the lower ends of the cylinders. This has been found by experiment to be the most satisfactory means of obtaining the proper degree of agitation necessary; the clear lime water is then drawn off at the top of the cylinders, and flows by gravity into a mixer, where it comes in contact with the hard water. Both flow together into a distributing trough, from which it overflows into a small softening reservoir, having a capacity of one hour's supply, a weir being placed along the lower end, over which the water flows to 13 filter presses. The clear water from the filters is then conveyed to a small well, from which the permanent engines raise it to the first of a series of high level covered service reservoirs.

In the filter press there are 20 hollow disks representing a filtering area of 250 square feet, or a total of 3,250 square feet. The water to be filtered passes into the body of the filter and then through a filtering medium of cloth laid on a thin perforated zinc plate, into the inner side of the disks, from whence it is conveyed through the hollow shaft, to which the disks are attached, to the high level pumps.

The filter cloths are cleaned three times every 24 hours, without removal, by jets of softened water from the main, having a pressure of 60 pounds to the square inch. During cleaning operations the disks are made to revolve slowly; this only occupies a space of five minutes for each cleaning. The cloths last from six to eight months without being renewed. They also occasionally use for further cleaning the cloths a jet of steam injected upon the center of the disks in order to remove by partial boiling the insoluble particles engrained in the cloths. This has been found to make the cloths last longer. This cloth is obtained from Porritt Bros. and Austen, Stubbing Vale, Ramsbottom, and costs 131/2d. per lineal yard of a width to suit the disks.

The quantity softened is 21/4 million gallons per 24 hours, but the present plant can deal with 21/2 million gallons, and the buildings are erected for 31/2 million gallons, additional filters and lime producing tanks being only required to deal with the increased quantity. The costs of the softening works was L10,394, of which L7,844 was for the softening machinery and plant and L2,550 for the reservoir, buildings, etc.

The working expenses, including lime, labor, cloths, general repairs, and steam, is stated to be 0.225d. per 1,000 gallons, the labor required being only two men, one on the day and the other on the night shift, with an occasional man to assist.

The hardness of the Southampton water on Clark's scale is 18 deg. of total hardness, and this is reduced down to 6 deg. or 8 deg. by this process.—Chem. Tr. Jour.

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A NEW LABORATORY PROCESS FOR PREPARING HYDROBROMIC ACID.

By G.S. NEWTH.

This method is a synthetical one, and consists in passing a stream of hydrogen and bromine vapor over a spiral of platinum wire heated to bright redness by means of an electric current. A glass tube, about 7 inches long and 5/8 of an inch bore, is fitted at each end with a cork carrying a short straight piece of small tube; through each cork is also fixed a stout wire, and these two wires are joined by means of a short spiral of platinum wire, the spiral being about 1 inch long. One end of this apparatus is connected to a small wash bottle containing bromine, through which a stream of hydrogen can be bubbled. The other end is attached to a tube dipping into a vessel of water for the absorption of the gas, or, if a large quantity of the solution is required, to a series of Woulf's bottles containing water. Hydrogen is first slowly passed through the tube until the air is displaced, when the platinum spiral is heated to bright redness by the passage of a suitable electric current. Complete combination takes place in contact with the hot wire, and the color imparted to the ingoing gases by the bromine vapor is entirely removed, and the contents of the tube beyond the platinum are perfectly colorless. The vessel containing the bromine may be heated to a temperature of about 60 deg. C. in a water bath, at which temperature the hydrogen will be mixed with nearly the requisite amount of bromine to combine with the whole of it. So long as even a slight excess of hydrogen is passing, which is readily seen by the escape of bubbles through the water in the absorbing vessels, the issuing hydrobromic acid will remain perfectly colorless, and therefore free from bromine; so that it is not necessary to adopt any of the usual methods for scrubbing the gas through vessels containing phosphorus. When the operation is proceeding very rapidly a lambent flame occasionally appears in the tube just before the platinum wire, but this flame is never propagated back through the narrow tube into the bromine bottle. The precaution may be taken, however, of plugging this narrow tube with a little glass wool, which renders any inconvenience from this cause quite impossible. By this method a large quantity of bromine may be rapidly converted into hydrobromic acid without any loss of bromine, and the operation when once started can be allowed to proceed without any further attention.—Chemical News.

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SAPOTIN: A NEW GLUCOSIDE.

By GUSTAVE MICHAUD.

Achras Sapota, L., is a large tree scattered through the forests of Central America and the West Indies; its fruit is often seen upon the Creole dinner table. This fruit is a berry, the size of an orange, the taste of which suggests the flavor of melon, as well as that of hydrocyanic acid. The fruit contains one or two seeds like large chestnuts, which, if broken, let fall a white almond. This last contains the glucoside which I call sapotin.

I obtained sapotin for the first time by heating dry raspings of the almond with 90 per cent. alcohol. While cooling, the filtered liquid deposited a good deal of the compound. Since that time I have advantageously modified the process and increased the amount of product. I prepare sapotin in the following way: The almonds are rasped, dried at 100 deg. C. and washed with benzene, which takes away an enormous quantity of fatty matter. The benzene which remains in the almond is driven put first by compression, afterward by heating. Then the raspings are exhausted with boiling 90 per cent. alcohol. The solution is filtered as rapidly as possible, in order to avoid its cooling and depositing the sapotin in the filter. As soon as the temperature of the filtered liquid begins to fall, a voluminous precipitate is seen to form, which is the sapotin.

In order to purify it, the precipitate is collected in a filter and expressed between sheets of filter paper. When dry it is washed with ether, which takes away the last particles of fatty and resinous matter. The purification is completed by two crystallizations from 90 per cent. alcohol. At last the substance is dried at 100 deg..

The sapotin separates from its alcohol solution in the form of microscopic crystals. When dry, it is a white, inodorous powder. Its taste is extremely acrid and burning. If the powder penetrate into the nostrils or the eyes, it produces a persistent burning sensation which brings about sneezing and flow of tears. It melts at 240 deg. C., growing brown at the same time.

It has a laevo-rotatory power of [a]_{j} = -32.11, which was determined with an alcoholic solution, the aqueous solution not being sufficiently transparent.

It is very soluble in water, easily soluble in boiling alcohol, much less in cold alcohol, and insoluble in ether, chloroform and benzene. Its alcoholic solution is precipitated by ether.

Tannin has no action on it, but basic acetate of lead produces a gelatinous precipitate in its aqueous solution. Strange enough, this precipitate is entirely soluble in a small excess of basic acetate of lead. If thrown into concentrated sulphuric acid, sapotin colors it with a garnet red tint. It does not reduce Fehling's solution. Its analysis gave the following results:

Calculated for Found. C_{29}H_{52}O_{20}. I. II.

C 48.33 48.69 48.31 H 7.23 7.33 7.45

When heated with water and a little sulphuric acid, sapotin is decomposed and yields glucose and an insoluble matter which I call sapotiretin. One hundred parts of sapotin produce 51.58 parts of glucose and 49.67 of sapotiretin. The equation which represents this reaction is:

C{29}H{52}O{20} + 2H{2}O = 2C{6}H{12}O{6} + C{17}H{32}O{10}

and requires 50 per cent. of glucose and 55 per cent. of sapotiretin.

Sapotiretin is an amorphous compound, insoluble in water, very soluble in alcohol, less soluble in chloroform, insoluble in ether. Below is the result of its analysis:

Calculated for Found. C_{17}H_{32}O_{10}. I. II.

C 51.52 51.51 51.20 H 8.08 8.19 8.34

—Amer. Chem. Jour.

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DETECTION OF PEANUT OIL IN OLIVE OIL.

Holde, after a careful trial of the various processes for detecting the above adulteration, gives the preference to Renard's, which he describes as follows:

Ten grms. of the suspected oil, after being saponified, and the fatty acids separated by hydrochloric acid, are dissolved in 90 per cent. alcohol, and precipitated by sugar of lead. The oleate of lead is separated by ether, and the residuum, consisting of palmitic and arachic acids, is decomposed by hydrochloric acid. The fatty acids are dissolved, with the aid of heat, in 50 c.c. of 90 per cent. alcohol. The arachic acid which separates after cooling is filtered out and washed, first with 90 per cent. and afterward with 70 per cent. alcohol. It is then dissolved in hot alcohol, and the solution evaporated in a weighed saucer. The weight of the residuum, after taking into account the acid dissolved in the alcohol, equals the whole amount of arachic acid contained in the oil; the melting point of this residuum should be 70 deg. to 71 deg. C. With this process the author has always been successful; but when the olive oil contains not more than 5 to 10 per cent. of peanut oil, it is necessary to make the test with 40 grms. of the former, otherwise the melting point of the arachic acid cannot be estimated. Furthermore, the acids which are separated from the lead salt by hydrochloric acid must be recrystallized repeatedly with 90 per cent. alcohol, until the melting point ceases to rise, in case the latter is not found to exceed 70 deg. C. at the first estimation. When peanut oil is present, the melting point will always be above 70 deg..—Chem. Zeit.

* * * * *



HYDROXYLAMINE.

Free hydroxylamine, NH{2}OH, has been isolated by M. Lobry de Bruyn, and a preliminary account of its mode of preparation and properties is published by him in the current number of the Recueil des travaux chimiques des Pays-Bas (1891, 10, 101). The manner in which the free base was obtained was briefly as follows. About a hundred grammes of hydroxylamine hydrochloride, NH{2}OH.HCl, were dissolved in six hundred cubic centimeters of warm methyl alcohol. To this solution a quantity of sodium dissolved in methyl alcohol was added, in such proportion that the hydrochloride of hydroxylamine was present in slight excess over and above that required to convert it to sodium chloride. After deposition of the separated sodium chloride the solution was decanted and filtered.

The greater portion of the methyl alcohol was next removed by distillation under the reduced pressure of 160-200 mm. The remainder was then treated with anhydrous ether, in order to completely precipitate the last traces of dissolved sodium chloride. The liquid eventually separated into two layers, an upper ethereal layer containing about 5 per cent. of hydroxylamine, and a lower layer containing over 50 per cent. of hydroxylamine, the remainder of the methyl alcohol, and a little dissolved salt. By subjecting this lower layer to fractional distillation under 60 mm. pressure, it was separated into three fractions, of which the first contained 27 per cent. of hydroxylamine, the second 60 per cent., and the third crystallized in the ice-cooled receiver in long needles. This third fraction consisted of free solid NH_{2}OH. Hydroxylamine as thus isolated in the free state is a very hygroscopic substance, which rapidly liquefies when exposed to air, owing to the absorption of water.

The crystals melt at 33 deg., and the fused substance appears to possess the capability of readily dissolving metallic salts. Sodium chloride is very largely soluble in the liquid; powdered niter melts at once in contact with it, and the two liquids then mix. Free hydroxylamine is without odor. It is heavier than water. When rapidly heated upon platinum foil it suddenly decomposes in a most violent manner, with production of a large sheet of bright yellow flame. It is only very slightly soluble in liquid carbon compounds, such as chloroform, benzene, ether, acetic ether, and carbon bisulphide. The vapor attacks corks, so that the solid requires to be preserved in glass-stoppered bottles. The free base appears also to act upon cellulose, for, upon placing a few drops of the melted substance upon filter paper, a considerable amount of heat is evolved. The pure crystals are very stable, the base in the free state appearing to possess much greater stability than when dissolved in water. The instability of the solution appears, however, to be influenced to a considerable extent by the alkalinity of the glass of the containing vessel, for concentrated solutions free from dissolved alkali are found to be perfectly stable. Bromine and iodine react in a remarkable manner with free hydroxylamine.

Crystals of iodine dissolve instantly in contact with it, with evolution of a gas and considerable rise of temperature. Bromine reacts with violence, a gas again being explosively evolved and hydrobromic acid formed. The nature of the gas evolved is now undergoing investigation. A letter from M. Lobry de Bruyn appears in the number of the Chemiker Zeitung for October 31, warning those who may attempt to prepare free hydroxylamine by the above method that it is a dangerously explosive substance when warmed to a temperature of 80 deg.-100 deg.. Upon warming a flask containing the free solid base upon a water bath a most violent explosion occurs. A spontaneous decomposition appears to set in about 80 deg., and even in open vessels the explosion is very violent. Care must also be taken during the fractional distillation of the concentrated solution in methyl alcohol to cool the apparatus before changing the receiver, as if air is admitted while the retort is heated the experiment ends with an explosion.—Nature.

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