Centrifugal action is not the only way in which particles of different specific gravity can he separated from each other by motion only. If a rapid "jigging" or up-and-down motion be given to a mixture of such particles, the tendency of the lighter to fly further under the action of the impulse causes them gradually to rise to the upper surface; this surface being free in the present case, and the result being therefore the reverse of what happens in the rotating chamber. If such a mixture be examined after this up-and down motion has gone on for a considerable period, it will be found that the particles are arranged pretty accurately in layers, the lightest being at the top and the heaviest at the bottom. This principle has long been taken advantage of in such cases as the separation of lead ores from the matrix in which they are embedded. The rock in these cases is crushed into small fragments, and placed on a frame having a rapid up-and-down-motion, when the heavy lead ore gradually collects at the bottom and the lighter stone on the top. To separate the two the machine must be stopped and cleared by hand. In the case of coal-washing, where the object is to separate fine coal from the particles of stone mixed with it, this process would be very costly, and indeed impossible, because a current of water is sweeping through the whole mass. In the case of the Coppee coal-washer, the desired end is achieved in a different and very simple manner. The well known mineral felspar has a specific gravity intermediate between that of the coal and the shale, or stone, with which it is found intermixed. If, then, a quantity of felspar in small fragments is thrown into the mixture, and the whole then submitted to the jigging process, the result will be that the stone will collect on the top, and the coal at the bottom, with a layer of felspar separating the two. A current of water sweeps through the whole, and is drawn off partly at the top, carrying with it the stone, and partly at the bottom, carrying with it the fine coal.

The above are instances where science has come to the aid of engineering. Here is one in which the obligation is reversed. The rapid stopping of railroad trains, when necessary, by means of brakes, is a problem which has long occupied the attention of many engineers; and the mechanical solutions offered have been correspondingly numerous. Some of these depend on the action of steam, some of a vacuum, some of compressed air, some of pressure-water; others again ingeniously utilize the momentum of the wheels themselves. But for a long time no effort was made by any of these inventors thoroughly to master the theoretical conditions of the problem before them. At last, one of the most ingenious and successful among them, Mr. George Westinghouse, resolved to make experiments on the subject, and was fortunate enough to associate with himself Capt. Douglas Galton. Their experiments, carried on with rare energy and perseverance, and at great expense, not only brought into the clearest light the physical conditions of the question (conditions which were shown to be in strict accordance with theory), but also disclosed the interesting scientific fact that the friction between solid bodies at high velocities is not constant, as the experiments of Morin had been supposed to imply, but diminishes rapidly as the speed increases—a fact which other observations serve to confirm.

The old scientific principle known as the hydrostatic paradox, according to which a pressure applied at any point of an inclosed mass of liquid is transmitted unaltered to every other point, has been singularly fruitful in practical applications. Mr. Bramah was perhaps the first to recognize its value and importance. He applied it to the well known Bramah press, and in various other directions, some of which were less successful. One of these was a hydraulic lift, which Mr. Bramah proposed to construct by means of several cylinders sliding within each other after the manner of the tubes of a telescope. His specification of this invention sufficiently expresses his opinion of its value, for it concludes as follows: "This patent does not only differ in its nature and in its boundless extent of claims to novelty, but also in its claims to merit and superior utility compared with any other patent ever brought before or sanctioned by the legislative authority of any nation." The telescope lift has not come into practical use; but lifts worked on the hydraulic principle are becoming more and more common every day. The same principle has been applied by the genius of Sir William Armstrong and others to the working of cranes and other machines for the lifting of weights, etc.; and under the form of the accumulator, with its distributing pipes and hydraulic engines, it provides a store of power always ready for application at any required point in a large system, yet costing practically nothing when not actually at work. This system of high pressure mains worked from a central accumulator has been for some years in existence at Hull, as a means of supplying power commercially for all the purposes needed in a large town, and it is at this moment being carried out on a wider scale in the East End of London.

Taking advantage of this system, and combining with it another scientific principle of wide applicability, Mr. J.H. Greathead has brought out an instrument called the "injector hydrant," which seems likely to play an important part in the extinguishing of fires. This second principle is that of the lateral induction of fluids, and may be thus expressed in the words of the late William Froude: "Any surface which in passing through a fluid experiences resistance must in so doing impress on the particles which resist it a force in the line of motion equal to the resistance." If then these particles are themselves part of a fluid, it will result that they will follow the direction of the moving fluid and be partly carried along with it. As applied in the injector hydrant, a small quantity of water derived from the high pressure mains is made to pass from one pipe into another, coming in contact at the same time with a reservoir of water at ordinary pressure. The result is that the water from the reservoir is drawn into the second pipe through a trumpet-shaped nozzle, and may be made to issue as a stream to a considerable height. Thus the small quantity of pressure-water, which, if used by itself, would perhaps rise to a height of 500 feet, is made to carry with it a much larger quantity to a much smaller height, say that of an ordinary house.

The above are only a few of the many instances which might be given to prove the general truth of the fact with which we started, namely, the close and reciprocal connection between physical science and mechanical engineering, taking both in their widest sense. It may possibly be worth while to return again to the subject, as other illustrations arise. Two such have appeared even at the moment of writing, and though their practical success is not yet assured, it may be worth while to cite them. The first is an application of the old principle of the siphon to the purifying of sewage. Into a tank containing the sewage dips a siphon pipe some thirty feet high, of which the shorter leg is many times larger than the longer. When this is started, the water rises slowly and steadily in the shorter column, and before it reaches the top has left behind it all or almost all of the solid particles which it previously held in suspension. These fall slowly back through the column and collect at the bottom of the tank, to be cleared out when needful. The effluent water is not of course chemically pure, but sufficiently so to be turned into any ordinary stream. The second invention rests on a curious fact in chemistry, namely, that caustic soda or potash will absorb steam, forming a compound which has a much higher temperature than the steam absorbed. If, therefore, exhaust-steam be discharged into the bottom of a vessel containing caustic alkali, not only will it become condensed, but this condensation will raise the temperature of the mass so high that it may be employed in the generation of fresh steam. It is needless to observe how important will be the bearing of this invention upon the working of steam engines for many purposes, if only it can be established as a practical success. And if it is so established there can be no doubt that the experience thus acquired will reveal new and valuable facts with regard to the conditions of chemical combination and absorption, in the elements thus brought together.

WALTER R. BROWNE.

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HYDRAULIC PLATE PRESS.

One of the most remarkable and interesting mechanical arrangements at the Imperial Navy Yard at Kiel, Germany, is the iron clad plate bending machine, by means of which the heavy iron clad plates are bent for the use of arming iron clad vessels.

Through the mechanism of this remarkable machine it is possible to bend the strongest and heaviest iron clad plates—in cold condition—so that they can be fitted close on to the ship's hull, as it was done with the man-of-war ships Saxonia, Bavaria, Wurtemberg, and Baden, each of which having an iron strength of about 250 meters.



One may make himself a proximate idea of the enormous power of pressure of such a machine, if he can imagine what a strength is needed to bend an iron plate of 250 meters thickness, in cold condition; being also 1.5 meters in width, and 5.00 meters in length, and weighing about 14,555 kilogrammes, or 14,555 tons.

The bending of the plates is done as follows: As it is shown in the illustration, connected herewith, there are standing, well secured into the foundation, four perpendicular pillars, made of heavy iron, all of which are holding a heavy iron block, which by means of female nut screws is lifted and lowered in a perpendicular direction. Beneath the iron block, between the pillars, is lying a large hollow cylinder in which the press piston moves up and down in a perpendicular direction. These movements are caused by a small machine, or, better, press pump—not noticeable in the illustration—which presses water from a reservoir through a narrow pipe into the large hollow cylinder, preventing at the same time the escape or return of the water so forced in. The hollow cylinder up to the press piston is now filled with water, so remains no other way for the piston as to move on to the top. The iron clad plate ready to undergo the bending process is lying between press piston and iron block; under the latter preparations are already made for the purpose of giving the iron clad plate such a form as it will receive through the bending process. After this the press piston will, with the greatest force, steadily but slowly move upward, until the iron clad plate has received its intended bending.

Lately the hydraulic presses are often used as winding machines, that is, they are used as an arrangement to lift heavy loads up on elevated points.

The essential contrivance of a hydraulic press is as follows:

One thinks of a powerful piston, which, through, human, steam, or water power, is set in a moving up-and-down motion. Through the ascent of the piston, is by means of a drawing pipe, ending into a sieve, the water absorbed out of a reservoir, and by the lowering of the piston water is driven out of a cylinder by means of a narrow pipe (communication pipe) into a second cylinder, which raises a larger piston, the so-called press piston. (See illustration.)

One on top opening drawing valve, on the top end of the drawing pipe prevents the return of the water by the going down of the piston; and a barring valve, which is lifted by the lowering of the piston, obstructs the return of the water by the ascent of the piston, while the drawing valve is lifted by means of water absorbed by the small drawing pipe.—Illustrirte Zeitung.

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FAST PRINTING PRESS FOR ENGRAVINGS.

Uber Land und Meer, which is one of the finest illustrated newspapers published in Germany, gives the following: We recently gave our readers an insight into the establishment of Uber Land und Meer, and to-day we show them the machine which each week starts our paper on its journey around the world—a machine which embodies the latest and greatest progress in the art of printing. The following illustration represents one of the three fast presses which the house of Hallberger employs in the printing of its illustrated journals.

With the invention of the cylinder press by Frederick Knig was verified the saying that the art of printing had lent wings to words. Everywhere the primitive hand-press had to make way for the steam printing machine; but even this machine, since its advent in London in 1810, has itself undergone so many changes that little else remains of Knig's invention than the principle of the cylinder. The demands of recent times for still more rapid machines have resulted in the production of presses printing from a continuous roll or "web" of paper, from cylinders revolving in one given direction. The first of this class of presses (the "Bullock" press) was built in America. Then England followed, and there the first newspaper to make use of one was the Times. The Augsburg Machine Works were the first to supply Germany with them, and it was this establishment which first undertook to apply the principle of the web perfecting press (first intended for newspaper work only, where speed rather than fine work is the object sought) to book printing, in which far greater accuracy and excellence is required, and the result has been the construction of a rotary press for the highest grade of illustrated periodical publications, which meets all the requirements with the most complete success.



The building of rotary presses for printing illustrated papers was attempted as early as 1874 or 1875 in London, by the Times, but apparently without success, as no public mention has ever been made of any favorable result. The proprietor of the London Illustrated News obtained better results. In 1877 an illustrated penny paper, an outgrowth of his great journal, was printed upon a rotary press which was, according to his statement, constructed by a machinist named Middleton. The first one, however, did not at all meet the higher demands of illustrated periodical printing, and, while another machine constructed on the same principle was shown in the Paris Exposition of 1878, its work was neither in quality nor quantity adequate to the needs of a largely circulated illustrated paper. A second machine, also on exhibition at the same time, designed and built by the celebrated French machinist, P. Alauzet, could not be said to have attained the object. Its construction was undertaken long after the opening of the Exposition, and too late to solve the weighty question. But the half-successful attempt gave promise that the time was at hand when a press could be built which could print our illustrated periodicals more rapidly, and a conference with the proprietors of the Augsburg Machine Works resulted in the production by them of the three presses from which Uber Land und Meer and Die Illustrirte Welt are to-day issued. As a whole and in detail, as well as in its productions, the press is the marvel of mechanic and layman.

As seen in the illustration, the web of paper leaves the roll at its right, rising to a point at the top where it passes between two hollow cylinders covered with felt and filled with steam, which serve to dampen the paper as may be necessary, the small hand-wheel seen above these cylinders regulating the supply of steam. After leaving these cylinders the paper descends sloping toward the right, and passes through two highly polished cylinders for the purpose of recalendering. After this it passes under the lowest of the three large cylinders of the press, winds itself in the shape of an S toward the outside and over the middle cylinder, and leaves the press in an almost horizontal line, after having been printed on both sides, and is then cut into sheets. The printing is done while the paper is passing around the two white cylinders. The cylinder carrying the first form is placed inside and toward the center of the press, only a part of its cog-wheel and its journal being shown in the engraving. The second form is placed upon the uppermost cylinder, and is the outside or cut form. Each one of the form cylinders requires a separate inking apparatus. That of the upper one is placed to the right at the top, and the bottom one is also at the right, but inside. Each one has a fountain the whole breadth of the press, in which the ink is kept, and connected with which, by appropriate mechanism, is a system of rollers for the thorough distribution of the ink and depositing it upon the forms.

The rapidity with which the impressions follow each other does not allow any time for the printing on the first side to dry, and as a consequence the freshly printed sheet coming in contact with the "packing" of the second cylinder would so soil it as to render clean printing absolutely impossible. To avoid this, a second roll of paper is introduced into the machine, and is drawn around the middle cylinder beneath the paper which has already been printed upon one side, and receives upon its surface all "offset," thus protecting and keeping perfectly clean both the printed paper and the impression cylinder. This "offset" web, as it leaves the press, is wound upon a second roller, which when full is exchanged for the new empty roller—a very simple operation.

The machines print from 3,500 to 4,000 sheets per hour upon both sides, a rate of production from twenty-eight to thirty-two times as great as was possible upon the old-fashioned hand-press, which was capable of printing not more than 250 copies upon one side in the same time.

The device above described for preventing "offset" is, we believe, the invention of Mr. H.J. Hewitt, a well known New York printer, 27 Rose Street.

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FRENCH CANNON.

Five new cannons, the largest yet manufactured in France, have been successfully cast in the foundry of Ruelle near Angouleme. They are made of steel, and are breech loading. The weight of each is 97 tons, without the carriage. The projectile weighs 1,716 pounds, and the charge or powder is 616 pounds. To remove them a special wagon with sixteen wheels has had to be constructed, and the bridges upon the road from Ruelle to Angouleme not being solid enough to bear the weight of so heavy a load, a special roadway will be constructed for the transport of these weapons, which are destined for coast defences and ironclads.

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WOODLANDS, STOKE POGIS, BUCKS.

The illustration represents a house recently reconstructed. The dining-room wing was alone left in the demolition of the old premises, and this part has been decorated with tile facings, and otherwise altered to be in accordance with the new portion. The house is pleasantly situated about a mile from Stoke Church of historic fame, in about 15 acres of garden, shrubbery, and meadow land. The hall and staircase have been treated in wainscot oak, and the whole of the work has been satisfactorily carried out by Mr. G. Almond, builder, of Burnham, under the superintendence of Messrs. Thurlow & Cross, architects.—The Architect.



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CHINA GRASS.

The following article appeared in a recent number of the London Times:

The subject of the cultivation and commercial utilization of the China grass plant, or rhea, has for many years occupied attention, the question being one of national importance, particularly as affecting India. Rhea which is also known under the name of ramie, is a textile plant which was indigenous to China and India. It is perennial, easy of cultivation, and produces a remarkably strong fiber. The problem of its cultivation has long being solved, for within certain limits rhea can be grown in any climate. India and the British colonies offer unusual facilities, and present vast and appropriate fields for that enterprise, while it can be, and is, grown in most European countries. All this has long been demonstrated; not so, however, the commercial utilization of the fiber, which up to the present time would appear to be a problem only partially solved, although many earnest workers have been engaged in the attempted solution.

There have been difficulties in the way of decorticating the stems of this plant, and the Indian Government, in 1869, offered a reward of 5,000 for the best machine for separating the fiber from the stems and bark of rhea in its green or freshly cut state. The Indian Government was led to this step by the strong conviction, based upon ample evidence, that the only obstacle to the development of an extensive trade in this product was the want of suitable means for decorticating the plant. This was the third time within the present century that rhea had become the subject of official action on the part of the Government, the first effort for utilizing the plant dating from 1803, when Dr. Roxburg started the question, and the second from 1840, when attention was again directed to it by Colonel Jenkins.

The offer of 5,000, in 1869, led to only one machine being submitted for trial, although several competitors had entered their names. This machine was that of Mr. Greig, of Edinburgh, but after careful trial by General (then Lieutenant Colonel) Hyde it was found that it did not fulfill the conditions laid down by the Government, and therefore the full prize of 5,000 was not awarded. In consideration, however, of the inventor having made a bona fide and meritorious attempt to solve the question, he was awarded a donation of 1,500. Other unsuccessful attempts were subsequently made, and eventually the offer of 5,000 was withdrawn by the Government.

But although the prize was withdrawn, invention did not cease, and the Government, in 1881, reoffered the prize of 5,500. Another competition took place, at which several machines were tried, but the trials, as before, proved barren of any practical results, and up to the present time no machine has been found capable of dealing successfully with this plant in the green state. The question of the preparation of the fiber, however, continued to be pursued in many directions. Nor is this to be wondered at when it is remembered that the strength of some rhea fiber from Assam experimented with in 1852 by Dr. Forbes Royle, as compared with St. Petersburg hemp, was in the ratio of 280 to 160, while the wild rhea from Assam was as high as 343. But, above and beyond this, rhea has the widest range of possible applications of any fiber, as shown by an exhaustive report on the preparation and use of rhea fiber by Dr. Forbes Watson, published in 1875, at which date Dr. Watson was the reporter on the products of India to the Secretary of State, at the India Office. Last year, however, witnessed the solution of the question of decortication in the green state in a satisfactory manner by M.A. Favier's process, as reported by us at the time.

This process consists in subjecting the plant to the action of steam for a period varying from 10 to 25 minutes, according to the length of time the plant had been cut. After steaming, the fiber and its adjuncts were easily stripped from the wood. The importance and value of this invention will be realized, when it is remembered that the plant is cultivated at long distances from the localities where the fiber is prepared for the market. The consequence is, that for every hundredweight of fiber about a ton of woody material has to be transported. Nor is this the only evil, for the gummy matter in which the fiber is embedded becomes dried up during transport, and the separation of the fiber is thus rendered difficult, and even impossible, inasmuch as some of the fiber is left adhering to the wood.

M. Favier's process greatly simplifies the commercial production of the fiber up to a certain point, for, at a very small cost, it gives the manufacturer the whole of the fiber in the plant treated. But it still stops short of what is required, in that it delivers the fiber in ribbons, with its cementitious matter and outer skin attached. To remove this, various methods have been tried, but, as far as we are aware, without general success—that is to say, the fiber cannot always be obtained of such a uniformly good quality as to constitute a commercially reliable article. Such was the position of the question when, about a year ago, the whole case was submitted to the distinguished French chemist, Professor Fremy, member of the Institute of France, who is well-known for his researches into the nature of fibrous plants, and the question of their preparation for the market. Professor Fremy thoroughly investigated the matter from a chemical point of view, and at length brought it to a successful and, apparently, a practical issue.

One great bar to previous success would appear to have been the absence of exact knowledge as to the nature of the constituents of that portion of the plant which contains the fiber, or, in other words, the casing or bark surrounding the woody stem of the rhea. As determined by Professor Fremy, this consists of the cutose, or outer skin, within which is the vasculose containing the fiber and other conjoined matter, known as cellulose, between which and the woody stem is the pectose, or gum, which causes the skin or bark, as a whole, fiber included, to adhere to the wood. The Professor, therefore, proceeded to carefully investigate the nature of these various substances, and in the result he found that the vasculose and pectose were soluble in an alkali under certain conditions, and that the cellulose was insoluble. He therefore dissolves out the cutose, vasculose, and pectose by a very simple process, obtaining the fiber clean, and free from all extraneous adherent matter, ready for the spinner.

In order, however, to insure as a result a perfectly uniform and marketable article, the Professor uses various chemicals at the several stages of the process. These, however, are not administered haphazard, or by rule of thumb, as has been the case in some processes bearing in the same direction, and which have consequently failed, in the sense that they have not yet taken their places as commercial successes. The Professor, therefore, carefully examines the article which he has to treat, and, according to its nature and the character of its components, he determines the proportions of the various chemicals which he introduces at the several stages. All chance of failure thus appears to be eliminated, and the production of a fiber of uniform and reliable quality removed from the region of doubt into that of certainty. The two processes of M. Favier and M. Fremy have, therefore, been combined, and machinery has been put up in France on a scale sufficiently large to fairly approximate to practical working, and to demonstrate the practicability of the combined inventions.

The experimental works are situated in the Route d'Orleans, Grand Montrouge, just outside Paris, and a few days ago a series of demonstrations were given there by Messrs. G.W.H. Brogden and Co., of Gresham-house, London. The trials were carried out by M. Albert Alroy, under the supervision of M. Urbain, who is Professor Fremy's chief assistant and copatentee, and were attended by Dr. Forbes Watson, Mr. M. Collyer, Mr. C.J. Taylor, late member of the General Assembly, New Zealand, M. Barbe, M. Favier, Mr. G. Brogden, Mr. Caspar, and a number of other gentlemen representing those interested in the question at issue. The process, as carried out, consists in first treating the rhea according to M. Favier's invention. The apparatus employed for this purpose is very simple and inexpensive, consisting merely of a stout deal trough or box, about 8 ft. long, 2 ft. wide, and 1 ft. 8 in. deep. The box has a hinged lid and a false open bottom, under which steam is admitted by a perforated pipe, there being an outlet for the condensed water at one end of the box. Into this box the bundles of rhea were placed, the lid closed, steam turned on, and in about twenty minutes it was invariably found that the bark had been sufficiently softened to allow of its being readily and rapidly stripped off by hand, together with the whole of the fiber, in what may be called ribbons. Thus the process of decortication is effectively accomplished in a few minutes, instead of requiring, as it sometimes does in the retting process, days, and even weeks, and being at the best attended with uncertainty as to results, as is also the case when decortication is effected by machinery.

Moreover, the retting process, which is simply steeping the cut plants in water, is a delicate operation, requiring constant watching, to say nothing of its serious inconvenience from a sanitary point of view, on account of the pestilential emanations from the retteries. Decortication by steam having been effected, the work of M. Favier ceases, and the process is carried forward by M. Fremy. The ribbons having been produced, the fiber in them has to be freed from the mucilaginous secretions. To this end, after examination in the laboratory, they are laid on metal trays, which are placed one above the other in a vertical perforated metal cylinder. When charged, this cylinder is placed within a strong iron cylinder, containing a known quantity of water, to which an alkali is added in certain proportions. Within the cylinder is a steam coil for heating the water, and, steam having been turned on, the temperature is raised to a certain point, when the cylinder is closed and made steam-tight. The process of boiling is continued under pressure until the temperature—and consequently the steam pressure—within the cylinder has attained a high degree.

On the completion of this part of the process, which occupies about four hours, and upon which the success of the whole mainly depends, the cementitious matter surrounding the fiber is found to have been transformed into a substance easily dissolved. The fibrous mass is then removed to a centrifugal machine, in which it is quickly deprived of its surplus alkaline moisture, and it is then placed in a weak solution of hydrochloric acid for a short time. It is then transferred to a bath of pure cold water, in which it remains for about an hour, and it is subsequently placed for a short time in a weak acid bath, after which it is again washed in cold water, and dried for the market. Such are the processes by which China grass may become a source of profit alike to the cultivator and the spinner. A factory situate at Louviers has been acquired, where there is machinery already erected for preparing the fiber according to the processes we have described, at the rate of one ton per day. There is also machinery for spinning the fiber into yarns. These works were also visited by those gentlemen who were at the experimental works at Montrouge, and who also visited the Government laboratory in Paris, of which Professor Fremy is chief and M. Urbain sous-chef, and where those gentlemen explained the details of their process and made their visitors familiar with the progressive steps of their investigations.

With regard to the rhea treated at Montrouge, we may observe that it was grown at La Reolle, near Bordeaux. Some special experiments were also carried out by Dr. Forbes Watson with some rhea grown by the Duke of Wellington at Stratfield-saye, his Grace having taken an active interest in the question for some years past. In all cases the rhea was used green and comparatively freshly cut. One of the objects of Dr. Watson's experiments was, by treating rhea cut at certain stages of growth, to ascertain at which stage the plant yields the best fiber, and consequently how many crops can be raised in the year with the best advantage.

This question has often presented itself as one of the points to be determined, and advantage has been taken of the present opportunity with a view to the solution of the question. Mr. C.J. Taylor also took with him a sample of New Zealand flax, which was successfully treated by the process. On the whole, the conclusion is that the results of the combined processes, so far as they have gone, are eminently satisfactory, and justify the expectation that a large enterprise in the cultivation and utilization of China grass is on the eve of being opened up, not only in India and our colonies, but possibly also much nearer home.

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APPARATUS FOR HEATING BY GAS.

This new heating apparatus consists of a cast iron box, E, provided with an inclined cover, F, into which are fixed 100 copper tubes that are arranged in several lines, and form a semi-cylindrical heating surface. The box, E, is divided into two compartments (Fig. 5), so that the air and gas may enter simultaneously either one or both of the compartments, according to the quantity of heat it is desired to have. Regulation is effected by means of the keys, G and G', which open the gas conduits of the solid and movable disk, H, which serves as a regulator for distributing air through the two compartments. This disk revolves by hand and may be closed or opened by means of a screw to which it is fixed.

Beneath the tubes that serve to burn the mixture of air and gas, there is placed a metallic gauze, I, the object of which is to prevent the flames from entering the fire place box. These tubes traverse a sheet iron piece, J, which forms the surface of the fire place, and are covered with a layer of asbestos filaments that serve to increase the calorific power of the apparatus.



The cast iron box, E, is inclosed within a base of refractory clay, L, which is surmounted by a reflector, M, of the same material, that is designed to concentrate the heat and increase its radiation. This reflector terminates above in a dome, in whose center is placed a refractory clay box. This latter, which is round, is provided in the center with a cylinder that is closed above. The box contains a large number of apertures, which give passage to the products of combustion carried along by the hot air. The carbonic acid which such products contain is absorbed by a layer of quick-lime that has previously been introduced into the box, N.

This heating apparatus, which is inclosed within a cast iron casing similar to that of an ordinary gas stove, is employed without a chimney, thus permitting of its being placed against the wall or at any other point whatever in the room to be heated.—Annales Industrielles.

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IMPROVED GAS BURNER FOR SINGEING MACHINES.

Since the introduction of the process of gas-singeing in finishing textiles, many improvements have been made in the construction of the machines for this purpose as well as in that of the burners, for the object of the latter must be to effect the singeing not only evenly and thoroughly, but at the same time with a complete combustion of the gas and avoidance of sooty deposits upon the cloth. The latter object is attained by what are called atmospheric or Bunsen burners, and in which the coal gas before burning is mixed with the necessary amount of atmospheric air. The arrangement under consideration, patented abroad, has this object specially in view. The main gas pipe of the machine is shown at A, being a copper pipe closed at one end and having a tap at the other. On this pipe the vertical pipes, C, are screwed at stated intervals, each being in its turn provided with a tap near its base. On the top of each vertical table the burner, IJ, is placed, whose upper end spreads in the shape of a fan, and allows the gas to escape through a slit or a number of minute holes. Over the tube, C, a mantle, E, is slipped, which contains two holes, HG, on opposite sides, and made nearly at the height of the outlet of the gas. When the gas passes out of this and upward into the burner, it induces a current of air up through the holes, HG, and carries it along with it. By covering these holes with a loose adjustable collar, the amount of admissible air can be regulated so that the flame is perfectly non-luminous, and therefore containing no free particles of carbon or soot. The distance of the vertical tubes, C; and of the fan-shaped burners is calculated so that the latter touch each other, and thus a continuous flame is formed, which is found to be the most effective for singeing cloth. Should it be deemed advisable to singe only part of the cloth, or a narrow piece, the arrangement admits of the taps, D, being turned off as desired.—Textile Manufacturer.



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SILAS' CHRONOPHORE.

In many industries there are operations that have to be repeated at regular intervals, and, for this reason, the construction of an apparatus for giving a signal, not only at the hour fixed, but also at equal intervals, is a matter of interest. The question of doing this has been solved in a very elegant way by Mr. Silas in the invention of the apparatus which we represent in Fig. 1. It consists of a clock whose dial is provided with a series of small pins. The hands are insulated from the case and communicate with one of the poles of a pile contained in the box. The case is connected with the other pole. A small vibrating bell is interposed in the circuit. If it be desired to obtain a signal at a certain hour, the corresponding pin is inserted, and the hand upon touching this closes the circuit, and the bell rings. The bell is likewise inclosed within the box. There are two rows of pins—one of them for hours, and the other for minutes. They are spaced according to requirements. In the model exhibited by the house Breguet, at the Vienna Exhibition, there were 24 pins for minutes and 12 for hours. Fig. 2 gives a section of the dial. It will be seen that the hands are provided at the extremity with a small spring, r, which is itself provided with a small platinum contact, p. The pins also carry a small platinum or silver point, a. In front of the box there will be observed a small commutator, M, (Fig. 1). The use of this is indicated in the diagram (Fig. 3). It will be seen that, according as the plug, B, is introduced into the aperture to the left or right, the bell. S, will operate as an ordinary vibrator, or give but a single stroke.



P is the pile; C is the dial; and A is the commutator.

It is evident that this apparatus will likewise be able to render services in scientific researches and laboratory operations, by sparing the operator the trouble of continually consulting his watch.—La Lumiere Electrique.



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[THE GARDEN.]



THE ZELKOWAS.

Two of the three species which form the subject of this article are not only highly ornamental, but also valuable timber trees. Until recently they were considered to belong to the genus Planera, which, however, consists of but a single New World species; now, they properly constitute a distinct genus, viz., Zelkova, which differs materially from the true Planer tree in the structure of the fruit, etc. Z. crenata, from the Caucasus, and Z. acuminata, from Japan, are quick growing, handsome trees, with smooth bark not unlike that of beech or hornbeam; it is only when the trees are old that the bark is cast off in rather large sized plates, as is the case with the planes. The habit of both is somewhat peculiar; in Z. crenata especially there is a decided tendency for all the main branches to be given off from one point; these, too, do not spread, as for instance do those of the elm or beech, but each forms an acute angle with the center of the tree. The trunks are more columnar than those of almost all other hardy trees. Their distinct and graceful habit renders them wonderfully well adapted for planting for effect, either singly or in groups. The flowers, like those of the elm, are produced before the leaves are developed; in color they are greenish brown, and smell like those of the elder. It does not appear that fruits have yet been ripened in England. All the Zelkowas are easily propagated by layers or by grafting on the common elm.



Zelkcova crenata—The Caucasian Zelkowa is a native of the country lying between the Black and the Caspian Sea between latitudes 35 and 47 of the north of Persia and Georgia. According to Loudon, it was introduced to this country in 1760, and it appears to have been planted both at Kew and Syon at about that date. A very full account of the history, etc., of the Zelkowa, from which Loudon largely quotes, was presented to the French Academy of Science by Michaux the younger, who speaks highly of the value of the tree. In this he is fully corroborated by Mirbel and Desfontaine, on whom devolved the duty of reporting on this memoir. They say that it attains a size equal to that of the largest trees of French forests, and recommend its being largely planted. They particularly mention its suitability for roadside avenues, and affirm that its leaves are never devoured by caterpillars, and that the stems are not subject, to the canker which frequently ruins the elm. The name Orme de Siberie, which is or was commonly applied to Zelkova crenata in French books and gardens, is doubly wrong, for the tree is neither an elm nor is it native of Siberia. In 1782 Michaux, the father of the author of the paper above mentioned, undertook, under the auspices, of a Monsieur (afterward Louis XVIII.), a journey into Persia, in order to make botanical researches.



"Having left Ispahan, in order to explore the province of Ghilan, he found this tree in the forests which he traversed before arriving at Recht, a town situated on the Caspian Sea. In this town he had opportunities of remarking the use made of the wood, and of judging how highly it was appreciated by the inhabitants." The first tree introduced into Europe appears to have been planted by M. Lemonnier, Professor of Botany in the Jardin des Plautes, etc., in his garden near Versailles. This garden was destroyed in 1820, and the dimensions of the tree when it was cut down were as follows: Height 70 feet, trunk 7 feet in circumference at 5 feet from the ground. The bole of the trunk was 20 feet in length and of nearly uniform thickness; and the proportion of heart-wood to sap-wood was about three quarters of its diameter. This tree was about fifty years old, but was still in a growing state and in vigorous health. The oldest tree existing in France at the time of the publication of Loudon's great work, was one in the Jardin des Plantes, which in 1831 was about 60 feet high. It was planted in 1786 (when a sucker of four years old), about the same time as the limes which form the grand avenue called the Allee de Buffon. "There is, however, a much larger Zelkowa on an estate of M. le Comte de Dijon, an enthusiastic planter of exotic trees, at Podenas, near Nerac, in the department of the Lot et Garonne. This fine tree was planted in 1789, and on the 20th of January, 1831. it measured nearly 80 feet high, and the trunk was nearly 3 feet in diameter at 3 feet from the ground." A drawing of this tree, made by the count in the autumn of that year, was lent to Loudon by Michaux, and the engraving prepared from that sketch (on a scale of 1 inch to 12 feet) is herewith reproduced. At Kew the largest tree is one near the herbarium (a larger one had to be cut down when the herbarium was enlarged some years ago, and a section of the trunk is exhibited in Museum No. 3). Its present dimensions are: height, 62 feet; circumference of stem at 1 foot from the ground, 9 feet 8 inches; ditto at ground level, 10 feet; Height of stem from ground to branches, 7 feet; diameter of head, 46 feet. The general habit of the tree is quite that as represented in the engraving of the specimen at Podenas. The measurements of the large tree at Syon House were, in 1834, according to Loudon: Height, 54 feet; circumference of of stem, 6 feet 9 inches; and diameter of head, 34 feet; the present dimensions, for which I am indebted to Mr. Woodbridge, are: Height, 76 feet; girth of trunk at 2 feet from ground, 10 feet; spread of branches, 36 feet.



IDENTIFICATION.—Zelkova crenata, Spach in Ann. des Sc. nat. 2d ser. 15, p. 358. D. C. Prodromus, xvii., 165 Rhamnus ulmoides, Gldenst. It., p. 313. R carpinifolius, Pall. Fl Rossica, 2 p. 24, tab. 10. Ulmus polygama, L C. Richard in Mem. Acad. des Sciences de Paris, ann. 1781. Planera Richardi, Michx. Fl. bor. Amer. 2, p. 248; C.A. Meyer, Enumer. Causas. Casp., n. 354; Dunal in Bulletin Soc. cent d'Agricult. de l'Herault. ann. 1841, 299, 303, et ann. 1843, 225, 236. Loudon, Arbor, et Frut. Brit., vol. 3, p. 1409. Planera crenata, Desf. Cat. Hort. Paris et hortul, fere omnium. Michaux fil. Mem. sur le Zelkowa, 1831. Planera carpinifolia, Watson, Dend. Brit., t. 106. Koch Dendrologie, zweit theil, sweit. Abtheil. p. 425.



Var pendula (the weeping Zelkowa).—This is a form of which I do not know the origin or history. It is simply a weeping variety of the common Zelkowa. I first saw it in the Isleworth Nurseries of Messrs. C. Lee & Son, and a specimen presented by them to Kew for the aboretum is now growing freely. I suspect that the Zelkova crenata var. repens of M. Lavallee's "Aboretum Segrezianum" and the Planera repens of foreign catalogues generally are identical with the variety now mentioned under the name it bears in the establishment of Messrs. Lee & Son.



Z. acuminata is one of the most useful and valuable of Japanese timber trees. It was found near Yeddo by the late Mr. John Gould Veitch, and was sent out by the firm of Messrs. J. Veitch & Sons. Maximowicz also found the tree in Japan, and introduced it to the Imperial Botanic Gardens of St. Petersburg, from whence both seeds and plants were liberally distributed. In the Gardeners' Chronicle for 1862 Dr. Lindley writes as follows: "A noble deciduous tree, discovered near Yeddo by Mr. J. G. Veitch, 90 feet to 100 feet in height, with a remarkably straight stem. In aspect it resembles an elm. We understand that a plank in the Exotic Nursery, where it has been raised, measures 3 feet 3 inches across. Mr. Veitch informs us that it is one of the most useful timber trees in Japan. Its long, taper-pointed leaves, with coarse, very sharp serratures, appear to distinguish it satisfactorily from the P. Richardi of the northwest of Asia." There seems to be no doubt as to the perfect hardiness of the Japanese Zelkowa in Britain, and it is decidedly well worth growing as an ornamental tree apart from its probable value as a timber producer. A correspondent in the periodical just mentioned writes, in 1873, p. 1142, under the signature of "C.P.": "At Stewkley Grange it does fairly well; better than most other trees. In a very exposed situation it grew 3 feet 5 inches last year, and was 14 feet 5 inches high when I measured it in November; girth at ground, 8 inches; at 3 feet, 5 inches." The leaves vary in size a good deal on the short twiggy branches, being from 3 inches to 3 inches in length and 1 inches to 1 inches in width, while those on vigorous shoots attain a length of 5 inches, with a width of about half the length. They are slightly hairy on both surfaces. The long acuminate points, the sharper serratures, the more numerous nerves (nine to fourteen in number), and the more papery texture distinguish Z. acuminata easily from its Caucasian relative, Z. crenata. The foliage, too, seems to be retained on the trees in autumn longer than that of the species just named; in color it is a dull green above and a brighter glossy green beneath. The timber is very valuable, being exceedingly hard and capable of a very fine polish. In Japan it is used in the construction of houses, ships, and in high class cabinet work. In case 99, Museum No. 1 at Kew, there is a selection of small useful and ornamental articles made in Japan of Keyaki wood. Those manufactured from ornamental Keyaki (which is simply gnarled stems or roots, or pieces cut tangentially), and coated with the transparent lacquer for which the Japanese an so famous, are particularly handsome. In the museum library is also a book, the Japanese title of which is given below—"Handbook of Useful Woods," by E. Kinch. Professor at the Imperial College of Agriculture, at Tokio, Japan. This work contains transverse and longitudinal sections of one hundred Japanese woods, and numbers 45 and 46 represent Z. acuminata. It would be worth the while of those who are interested in the introduction and cultivation of timber trees in temperate climates to procure Kinch's handbook.

IDENTIFICATION.—Zelkova acuminata, D.C. Prodr., xvii., 166; Z. Keaki, Maxim. Mel. biol. vol. ix, p. 21. Planera acuminata, Lindl. in Gard. Chron. 1862, 428; Regel, "Gartenflora" 1863, p. 56. P Japonica, Miq. ann. Mus. Ludg Bat iii., 66; Kinch. Yuyo Mokuzai Shoran, 45, 46. P. Keaki, Koch Dendrol. zweit. theil zweit Abtheil, 427. P. dentata japonica, Hort. P. Kaki, Hort.



Z. cretica is a pretty, small foliaged tree, from 15 to 20 feet in height. The ovate crenate leaves, which measure from an inch or even less, to one inch and a half in length by about half the length in breadth, are leathery, dark green above, grayish above. They are hairy on both surfaces, the underside being most densely clothed, and the twigs, too, are thickly covered with short grayish hairs. This species, which is a native of Crete, is not at present in the Kew collection; its name, however, if given in M. Lavallee's catalogue, "Enumeration des Arbres et Arbris Cultives Segrez" (Seine-et-Oise).



IDENTIFICATION.—Zelkova cretica. Spach in Suit Buff, ii, p. 121. Ulmus Abelicea, Sibth & Sm. Prod. Fl., Graeca, i., p. 172. Planera Abelicea Roem. & Schltz. Syst., vi. p. 304; Planch, in Ann. des Sc. Nat. 1848, p. 282. Abelicea cretica, Smith in Trans. Linn. Sov., ix., 126.

I have seen no specimens of the Zelkova stipulacea of Franchet and Savatier's "Enumeratio Plantarum Japonicarum," vol. ii., p. 489, and as that seems to have been described from somewhat insufficient material, and, moreover, does not appear to be in cultivation, I passed it over as a doubtful plant.

GEORGE NICHOLSON.

Royal Gardens, Kew.

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A NEW ENEMY OF THE BEE.

Prof. A.J. Cook, the eminent apiarist, calls attention to a new pest which has made its appearance in many apiaries. After referring to the fact that poultry and all other domestic animals of ten suffer serious injury from the attacks of parasitic mites, and that even such household stores as sugar, flour, and cheese are not from their ravages, he tells of the discovery of a parasitic pest among bees. He says:

"During the last spring a lady bee-keeper of Connecticut discovered these mites in her hives while investigating to learn the cause of their rapid depletion. She had noticed that the colonies were greatly reduced in number of bees, and upon close observation found that the diseased or failing colonies were covered with the mites. So small are these pests that a score of them can take possession of a single bee and not be crowded for room either. The lady states that the bees roll and scratch in their vain attempts to rid themselves of these annoying stick-tights, and finally, worried out, fall to the bottom of the hive, or go forth to die on the outside. Mites are not true insects, but are the most degraded of spiders. The sub-class Arachnida are at once recognized by their eight legs. The order of mites (Accorina), which includes the wood-tick, cattle-tick, etc., and mites, are quickly told from the higher orders—true spiders and scorpions—by their rounded bodies, which appear like mere sacks, with little appearance of segmentation, and their small, obscure heads. The mites alone, of all the Arachinida, pass through a marked metamorphosis. Thus the young mite has only six legs, while the mature form has eight. The bee mite is very small, not more than one-fiftieth of an inch long. The female is slightly longer than the male, and somewhat transparent. The color is black, though the legs and more transparent areas of the female appear yellowish. All the legs are fine jointed, slightly hairy, and each tipped with two hooks or claws."

As to remedies, the Professor says that as what would kill the mites would doubtless kill the bees, makes the question a difficult one. He suggests, however, the frequent changing of the bees from one hive to another, after which the emptied hives should be thoroughly scalded. He thinks this course of treatment, persisted in, would effectually clean them out.

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CRYSTALLIZATION OF HONEY.

To the Editor of the Scientific American:

Seeing in your issue of October 13, 1883, an article on "Crystallization in Extracted Honey," I beg leave to differ a little with the gentleman. I have handled honey as an apiarist and dealer for ten years, and find by actual experience that it has no tendency to crystallize in warm weather; but on the contrary it will crystallize in cold weather, and the colder the weather the harder the honey will get. I have had colonies of bees starve when there was plenty of honey in the hives; it was in extreme cold weather, there was not enough animal heat in the bees to keep the honey from solidifying, hence the starvation of the colonies.

To-day I removed with a thin paddle sixty pounds of honey from a large stone jar where it had remained over one year. Last winter it was so solid from crystallization, it could not be cut with a knife; in fact, I broke a large, heavy knife in attempting to remove a small quantity.

As to honey becoming worthless from candying is a new idea to me, as I have, whenever I wanted our crystallized honey in liquid form, treated it to water bath, thereby bringing it to its natural state, in which condition it would remain for an indefinite time, especially if hermetically sealed. I never had any recrystallize after once having been treated to the water bath; and the flavor of the honey was in no way injured. I think the adding of glycerine to be entirely superfluous.

W.R. MILLER.

Polo, October 15.

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AN EXTENSIVE SHEEP RANGE.

The little schooner Santa Rosa arrived in port from Santa Barbara a few days ago. She comes up to this city twice a year to secure provisions, clothing, lumber, etc., for use on Santa Rosa Island, being owned by the great sheep raiser A.P. Moore, who owns the island and the 80,000 sheep that exist upon it. The island is about 30 miles south of Santa Barbara, and is 24 miles in length and 16 in breadth, and contains about 74,000 acres of land, which are admirably adapted to sheep raising. Last June, Moore clipped 1,014 sacks of wool from these sheep, each sack containing an average of 410 pounds of wool, making a total of 415,740 pounds, which he sold at 27 cents a pound, bringing him in $112,349.80, or a clear profit of over $80,000. This is said to be a low yield, so it is evident that sheep raising there, when taking into consideration that shearing takes place twice a year, and that a profit is made off the sale of mutton, etc., is very profitable. The island is divided into four quarters by fences running clear across at right angles, and the sheep do not have to be herded like those ranging about the foothills.

Four men are employed regularly the year round to keep the ranch in order, and to look after the sheep, and during the shearing time fifty or more shearers are employed. These men secure forty or fifty days' work, and the average number of sheep sheared in a day is about ninety, for which five cents a clip is paid, thus $4.50 a day being made by each man, or something over $200 for the season, or over $400 for ninety days out of the year. Although the shearing of ninety sheep in a day is the average, a great many will go as high as 110, and one man has been known to shear 125.

Of course, every man tries to shear as many as he can, and, owing to haste, frequently the animals are severely cut by the sharp shears. If the wound is serious, the sheep immediately has its throat cut and is turned into mutton and disposed of to the butchers, and the shearer, if in the habit of frequently inflicting such wounds, is discharged. In the shearing of these 80,000 sheep, a hundred or more are injured to such an extent as to necessitate their being killed, but the wool and meat are of course turned into profit.

Although no herding is necessary, about 200 or more trained goats are kept on the island continually, which to all intents and purposes take the place of the shepherd dogs so necessary in mountainous districts where sheep are raised. Whenever the animals are removed from one quarter to another, the man in charge takes out with him several of the goats, exclaims in Spanish, "Cheva" (meaning sheep). The goat, through its training, understands what is wanted, and immediately runs to the band, and the sheep accept it as their leader, following wherever it goes. The goat, in turn, follows the man to whatever point he wishes to take the band.

To prevent the sheep from contracting disease, it is necessary to give them a washing twice a year. Moore, having so many on hand, found it necessary to invent some way to accomplish this whereby not so much expense would be incurred and time wasted. After experimenting for some time, he had a ditch dug 8 feet in depth, a little over 1 foot in width, and 100 feet long. In this he put 600 gallons of water, 200 pounds of sulphur, 100 pounds of lime, and 6 pounds of soda, all of which is heated to 138. The goats lead the sheep into a corral or trap at one end, and the animals are compelled to swim through to the further end, thus securing a bath and taking their medicine at one and the same time.

The owner of the island and sheep, A.P. Moore, a few years ago purchased the property from the widow of his deceased brother Henry, for $600,000. Owing to ill health, he has rented it to his brother Lawrence for $140,000 a year, and soon starts for Boston, where he will settle down for the rest of his life. He still retains an interest in the Santa Cruz Island ranch, which is about 25 miles southeast of Santa Barbara. This island contains about 64,000 acres, and on it are 25,000 sheep. On Catalina Island, 60 miles east of Santa Barbara, are 15,000 sheep, and on Clementa Island, 80 miles east of that city, are 10,000 sheep. Forty miles west of the same city is San Miguel, on which are 2,000 sheep. Each one of these ranches has a sailing vessel to carry freight, etc., to and fro between the islands and the mainland, and they are kept busy the greater part of the time.—San Francisco Call.

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THE DISINFECTION OF THE ATMOSPHERE.

At the Parkes Museum of Hygiene, London, Dr. Robert J. Lee recently delivered a lecture on the above subject, illustrated by experiments.

The author remarked that he could not better open up his theme than by explaining what was meant by disinfection. He would do so by an illustration from Greek literature. When Achilles had slain Hector, the body still lay on the plain of Troy for twelve days after; the god Hermes found it there and went and told of it—"This, the twelfth evening since he rested, untouched by worms, untainted by the air." The Greek word for taint in this sense was sepsis, which meant putrefaction, and from this we had the term "antiseptic," or that which was opposed to or prevented putrefaction. The lecturer continued:

I have here in a test tube some water in which a small piece of meat was placed a few days ago. The test tube has been in rather a warm room, and the meat has begun to decompose. What has here taken place is the first step in this inquiry. This has been the question at which scientific men have been working, and from the study of which has come a valuable addition to surgical knowledge associated with the name of Professor Lister, and known as antiseptic. What happens to this meat, and what is going on in the water which surrounds it? How long will it be before all the smell of putrefaction has gone and the water is clear again? For it does in time become clear, and instead of the meat we find a fine powdery substance at the bottom of the test tube. It may take weeks before this process is completed, depending on the rate at which it goes on. Now, if we take a drop of this water and examine it with the microscope, we find that it contains vast numbers of very small living creatures or "organisms." They belong to the lowest forms of life, and are of very simple shape, either very delicate narrow threads or rods or globular bodies. The former are called bacteria, or staff-like bodies; the latter, micrococci. They live upon the meat, and only disappear when the meat is consumed. Then, as they die and fall to the bottom of the test tube, the water clears again.

Supposing now, when the meat is first put into water, the water is made to boil, and while boiling a piece of cotton wool is put into the mouth of the tube. The tube may be kept in the same room, at the same temperature as the unboiled one, but no signs of decomposition will be found, however long we keep it. The cotton wool prevents it; for we may boil the water with the meat in it, but it would not be long before bacteria and micrococci are present if the wool is not put in the mouth of the test tube. The conclusion you would naturally draw from this simple but very important experiment is that the wool must have some effect upon the air, for we know well that if we keep the air out we can preserve meat from decomposing. That is the principle upon which preserved meats and fruits are prepared. We should at once conclude that the bacteria and micrococci must exist in the air, perhaps not in the state in which we find them in the water, but that their germs or eggs are floating in the atmosphere. How full the air may be of these germs was first shown by Professor Tyndall, when he sent a ray of electric light through a dark chamber, and as if by a magician's wand revealed the multitudinous atomic beings which people the air. It is a beautiful thing to contemplate how one branch of scientific knowledge may assist another; and we would hardly have imagined that the beam of the electric light could thus have been brought in to illumine the path of the surgeon, for it is on the exclusion of these bacteria that it is found the success of some great operation may depend. It is thus easy to understand how great an importance is to be attached to the purity of air in which we live. This is the practical use of the researches to which the art of surgery is so much indebted; and not surgery alone, but all mankind in greater or less degree. Professor Tyndall has gone further than this, and has shown us that on the tops of lofty mountains the air is so pure, so free from organisms, that decomposition is impossible.

Now, supposing we make another experiment with the test tube, and instead of boiling we add to its contents a few drops of carbolic acid; we find that decomposition is prevented almost as effectually as by the use of the cotton wool. There are many other substances which act like carbolic acid, and they are known by the common name of antiseptics or antiseptic agents. They all act in the same way; and in such cases as the dressing of wounds it is more easy to use this method of excluding bacteria than by the exclusion of the air or by the use of cotton wool. We have here another object for inquiry—viz., the particular property of these different antiseptics, the property which they possess of preventing decomposition. This knowledge is very ancient indeed. We have the best evidence in the skill of the Egyptians in embalming the dead. These substances are obtained from wood or coal, which once was wood. Those woods which do not contain some antiseptic substance, such as a gum or a resin, will rot and decay. I am not sure that we can give a satisfactory reason for this, but it is certain that all these substances act as antiseptics by destroying the living organisms which are the cause of putrefaction. Some are fragrant oils, as, for example, clove, santal, and thyme; others are fragrant gums, such as gum bezoin and myrrh. A large class are the various kinds of turpentine obtained from pine trees. We obtain carbolic acid from the coal tar largely produced in the manufacture of gas. Both wood tar, well known under the name of creosote, and coal tar are powerful antiseptics. It is easy to understand by what means meat and fish are preserved from decomposition when they have been kept in the smoke of a wood fire. The smoke contains creosote in the form of vapor, and the same effect is produced on the meat or fish by the smoke as if they had been dipped in a solution of tar—with this difference, that they are dried by the smoke, whereas moisture favors decomposition very greatly.

I can show why a fire from which there is much smoke is better than one which burns with a clear flame, by a simple experiment. Here is a piece of gum benzoin, the substance from which Friar's balsam is made. This will burn, if we light it, just as tar burns, and without much smoke or smell. If, instead of burning it, we put some on a spoon and heat it gently, much more smoke is produced, and a fragrant scent is given off. In the same way we can burn spirit of lavender or eau de Cologne, but we get no scent from them in this way, for the burning destroys the scent. This is a very important fact in the disinfection of the air. The less the flame and the larger the quantity of smoke, the greater the effect produced, so far as disinfection is concerned. As air is a vapor, we must use our disinfectants in the form of vapor, so that the one may mix with the other, just as when we are dealing with fluids we must use a fluid disinfectant.

The question that presents itself is this: Can we so diffuse the vapor of an antiseptic like carbolic acid through the air as to destroy the germs which are floating in it, and thus purify it, making it like air which has been filtered through wool, or like that on the top of a lofty mountain? If the smoke of a wood fire seems to act as an antiseptic, and putrefaction is prevented, it seems reasonable to conclude that air could be purified and made antiseptic by some proper and convenient arrangement. Let us endeavor to test this by a few experiments.

Here is a large tube 6 inches across and 2 feet long, fixed just above a small tin vessel in which we can boil water and keep it boiling as long as we please. If we fill the vessel with carbolic acid and water and boil it very gently, the steam which rises will ascend and fill the tube with a vapor which is strong or weak in carbolic acid, according as we put more or less acid in the water. That is to say, we have practically a chimney containing an antiseptic vapor, very much the same thing as the smoke of a wood fire. We must be able to keep the water boiling, for the experiment may have to be continued during several days, and during this time must be neither stronger nor weaker in carbolic acid, neither warmer nor colder than a certain temperature. This chimney must be always at the same heat, and the fire must therefore be kept constantly burning. This is easily accomplished by means of a jet of gas, and by refilling the vessel every 24 hours with the same proportions of carbolic acid and water.

The question arises, how strong must this vapor be in carbolic acid to act as an antiseptic? It is found that 1 part acid to 50 of water is quite sufficient to prevent putrefaction. If we keep this just below boiling point there will be a gentle and constant rising of steam into the cylinder, and we can examine this vapor to see if it is antiseptic. We will take two test tubes half filled with water and put a small piece of beef into each of them and boil each for half a minute. One test tube we will hang up inside the cylinder, so that it is surrounded by carbolic acid vapor. The other we stand up in the air. If the latter is hung in a warm room, decomposition will soon take place in it; will the same thing happen to the other cylinder? For convenience sake we had best put six tubes inside the cylinder, so that we can take one out every day for a week and examine the contents on the field of a microscope. It will be necessary to be very particular as to the temperature to which the tubes are exposed, and the rates of evaporation beneath the cylinder. I may mention that on some of the hottest days of last summer I made some experiments, when the temperature both of the laboratory and inside the cylinder was 75F. I used test tubes containing boiled potatoes instead of meat, and found that the tube in the air, after 48 hours, abounded not simply with bacteria and other small bodies present in decomposition, but with the large and varied forms of protozoa, while the tube inside the cylinder contained no signs of decomposition whatever. When the room was cold the experiments were not so satisfactory, because in the former case there was very little if any current of air in the cylinder. This leads us to the question, why should we not make the solution of carbolic acid and water, and heat it, letting the steam escape by a small hole, so as to produce a jet? It is a singular fact that for all practical purposes such a steam jet will contain the same proportion of acid to water as did the original solution. The solution can of course be made stronger or weaker till we ascertain the exact proportion which will prevent decomposition.

From this arises naturally the question, what quantity of vapor must be produced in a room in order to kill the bacteria in its atmosphere? If we know the size of the room, shall we be able tell? These questions have not yet been answered, but the experiments which will settle them will be soon made, I have no doubt, and I have indicated the lines upon which they will be made. I have here a boiler of copper into which we can put a mixture, and can get from it a small jet of steam for some hours. A simple experiment will show that no bacteria will exist in that vapor. If I take a test tube containing meat, and boil it while holding the mouth of it in this vapor, after it has cooled we close the mouth with cotton wool, and set it aside in a warm place; after some days we shall find no trace of decomposition, but if the experiment is repeated with water, decomposition will soon show itself. Of course, any strength of carbolic acid can be used at will, and will afford a series of tests.

There are other methods of disinfecting the atmosphere which we cannot consider this evening, such as the very potent one of burning sulphur.

In conclusion, the lecturer remarked that his lecture had been cast into a suggestive form, so as to set his audience thinking over the causes which make the air impure, and how these impurities are to be prevented from becoming deleterious to health.

* * * * *



A NEW METHOD OF STAINING BACILLUS TUBERCULOSIS.

By T.J. BURRILL, M.D., Champaign, Ill.

Having had considerable experience in the use of the alcoholic solutions of aniline dyes for staining bacteria, and having for some months used solutions in glycerine instead, I have come to much prefer the latter. Evaporation of the solvent is avoided, and in consequence a freedom from vexatious precipitations is secured, and more uniform and reliable results are obtained. There is, moreover, with the alcoholic mixtures a tendency to "creep," or "run," by which one is liable to have stained more than he wishes—fingers, instruments, table, etc.

From these things the glycerine mixtures are practically free, and there are no compensating drawbacks. For staining Bacillus tuberculosis the following is confidently commended as preferable to the materials and methods heretofore in use. Take glycerine, 20 parts; fuchsin, 3 parts; aniline oil, 2 parts; carbolic acid, 2 parts.

The solution is readily and speedily effected, with no danger of precipitation, and can be kept in stock without risk of deterioration. When wanted for use, put about two drops into a watch glass (a small pomatum pot is better) full of water and gently shake or stir. Just here there is some danger of precipitating the coloring matter, but the difficulty is easily avoided by gentle instead of vigorous stirring. After the stain is once dissolved in the water no further trouble occurs; if any evaporation takes place by being left too long, it is the water that goes, not the main solvent. The color should now be a light, translucent red, much too diffuse for writing ink. Put in the smeared cover glass, after passing it a few times through a flame, and leave it, at the ordinary temperature of a comfortable room, half an hour. If, however, quicker results are desired, boil a little water in a test tube and put in about double the above indicated amount of the glycerine mixture, letting it run down the side of the tube, gently shake until absorbed, and pour out the hot liquid into a convenient dish, and at once put in the cover with sputum. Without further attention to the temperature the stain will be effected within two minutes; but the result is not quite so good, especially for permanent mounts, as by the slower process.

After staining put the cover into nitric (or hydrochloric) acid and water, one part to four, until decolorized, say one minute; wash in water and examine, or dry and mount in balsam.

If it is desired to color the ground material, which is not necessary, put on the decolorized and washed glass a drop of aniline blue in glycerine; after one minute wash again in water and proceed as before.

Almost any objective, from one-fourth inch up will show the bacilli if sufficient attention is paid to the illumination.—Med. Record.

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CURE FOR HEMORRHOIDS.

"The carbolic acid treatment of hemorrhoids is now receiving considerable attention. Hence the reprint from the Pittsburgh Medical Journal, November, 1883, of an article on the subject by Dr. George B. Fundenberg is both timely and interesting. After relating six cases, the author says: "It would serve no useful purpose to increase this list of cases. The large number I have on record all prove that this treatment is safe and effectual. I believe that the great majority of cases can be cured in this manner. Whoever doubts this should give the method a fair trial, for it is only those who have done so, that are entitled to speak upon the question."

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A catalogue, containing brief notices of many important scientific papers heretofore published in the SUPPLEMENT, may be had gratis at this office.

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