vention, chloride of copper is volatilised; and it is by this invention obtained in a dry state from the gases issuing from the apparatus by passing them through a suitable column or tower made of stone or other suitable material, and partly filled with pieces of burnt clay or other similar material, the whole arrangement acting as a "scrubber" of the gases, and being kept at any temperature between that at which aqueous hydrochloric acid gas condenses, and that at which chloride of copper sublimes, say about between 300 and 600° F. The chloride of copper condenses in this apparatus in a state much like wool, and may be removed from time to time, and utilised; and this method of separating chloride of copper from gases containing it may be employed whenever these gases containing it are obtained in the manufacture of chlorine by any other process than the process described herein.

Improvements in apparatus for ventilating mines. W. Knott, Wigan, and T. Rudd, Blackrod, near Wigan, Lancaster. March 12, 1875.No. 916. Our invention consists in placing the wings of ventilating fans at an angle to the axis instead of parallel thereto as now usual; also in making the casing of such fans of cast- or wrought-iron instead of brickwork; also in varying the discharge orifice by means of a pair of plates hinged together, and moved to and fro in the flue; also in the use of one or more stationary plates that are put into the flue at various distances from the sides to reduce the discharge orifice; also in driving the said fans by means of steam-engines set diagonally on the frame supporting the fan-shaft.

Improvements in apparatus for the evaporation or concentration of fluids at high or low temperatures with or without the application of a current of air or steam. W. Morgan-Brown, Southampton Buildings, London. (A communication from G. A. Hagemann, Copenhagen.) March 16, 1875.-No. 965. This invention consists in evaporating fluids by letting them trickle down vertical or conical tubes, the outer part of such tubes being heated by steam or fire, and in some cases currents of air, cold or warm, are passed up the interior of the tubes in the contrary direction to falling fluid to assist the evaporation by removing the vapour or adding to the heat of the liquid being evaporated. Improvements in the treatment of sugar-cane for the manufacture of sugar and of paper-pulp, and in the machinery or apparatus employed therein. J. H. Johnson, Lincoln's Inn Fields, Middlesex. (A communication from J. B. J. Mignon and S. H. Rouart, both of Paris.) March 16, 1875.-No. 973. This invention has for its object treating sugar-cane in such a manner as to render the extraction of the juice more complete, in order to obtain an increased yield of sugar, which result has also the effect of bringing the cane-trash into a better condition for the manufacture of paper, for which purpose it may be utilised. According to this invention it is proposed to split the cane in the direction of its length before it is subjected to the actual or final crushing operation.

Improvements in the manufacture of sulphate of soda or potash and bleaching powder, and in apparatus employed therein. G.D. Mease, Lake Chemical Works, South Shields. March 16, 1875.-No. 977. This Provisional Specification relates to the manufacture of sulphates by the direct action of sulphurous acid, air, and steam upon chlorides of sodium and potassium. Also the processes for producing chlorine and for preparing lime for the manufacture of bleaching-powder.

Improvements in the manufacture of soap. S. S. Lewis, Southampton Buildings, London, and A. Copie, Bolsover Street, Middlesex. March 17, 1875.-No. 988. The said invention relates to the mode of and means for improving the qualities and decreasing the cost of hard, soft, and toilet soaps. We dissolve ordinary soap, and mix with the solution china clay or other ingredient. We use this compound as a vehicle or body to hold the chemicals: we also add to the compound a portion of poudre de savon de palm. We add perfume when the compound is cooling for the toilet soap in the usual manner. The detergent or cleansing property of this soap is the silicate of soda. Improvements in forming the hearth of puddling-furnaces. W. Inns, Stockton-on-Tees, Durham. March 18, 1875.-No. 1005. According to my invention I take "best tap" in the liquid state direct from the cinder bottom furnace, and before it becomes cocl cover with a layer of the same of suitable thickness the cast-iron plates of the hearth of the puddling furnace.

Improvements in the manufacture of colouring-matter suitable for dyeing and printing. T. Holliday, Huddersfield, York. March 20 1875-No. 1031. Chlorinated or brominated anthrachinon, obtained as described in the Specification of Letters Patent granted to Charles Liebermann and Charles Graebe, dated December 18, 1868, No. 3850, or otherwise, is heated with strong sulphuric acid until the compound obtained is soluble in water. This product is then diluted with water, and the excess of acid it contains neutralised with an alkali or an alkaline carbonate. The clear liquid obtained is then concentrated and heated with caustic alkali, as is now well understood, until the colour is developed.

{CHEMICAL NEWS,

July 1876.

tion of water and other liquids. H. Rawlings, Stamford Street, Lambeth. March 23, 1875.-No. 1053. The nature of this invention is to provide a means of controling the currents of liquids passing through any filtering medium and substance by mechanical arrangements and dispositions in the filtering vessels to attain this result, and to construct portable and table filters on an improved plan, that storage of filtered waters may be unnecessary. Also to provide a ready means of regulating the flow of water through filters in the total quantity of liquid delivered, and for entirely stopping the flow if required.

Improvements in the treatment of slag or scoria, and of iron. J. J. Bodmer, The Grove, Hammersmith, and L. R. Bodmer, Lansdowne Road, Notting Hill, Middlesex. March 23, 1875.-1054. Our invention consists, first, in disintegrating or granillating the scoria or slag from blast-furnaces and other furnaces by means of jets of water directed or projected against the flow or s ream of slag on its issuing from the furnace or runner. Secondly: in disintegrating or granulating iron in its liquid condition as its flow from the furnace or runner by jets of water, and also in disintegrating, granulating, and partly fining the iron by using jets of steam either alone or together with jets of water, the disintegrated iron falling into water.

Improvements in the manufacture of glucose-sugar, and in ob'aining infusions and extracts for brewing and other purposes J. N. Lessware, Bow, Middlesex. March 24, 1875.-No. 1083. The invention consists, first, in causing the materials to circulate continuously through the converter, whereby the process of converting them into glucose or grape-sugar is accelerated, the same process being also applicable for obtaining infusions and extracts for brewing ane other purposes. Secondly; in decolourising the liquor by means of sulphurous acid gas in its passage from the converter to the neutraliser. An improved method of and apparatus for carbonising coal, slack, peat, wood, bones, and other like materials, subjected to a coking process, or to destructive distillation, whereby commercial products are obtained, and the vapours or gases utilised. J. Nicholas, Hope, near Mold, Flint. March 27, 1875.-No. 1116. The features of novelty which constitute this invention consist in constructing an apparatus, being a chamber, oven, or vessel of fire-brick or iron with a range of fire-bars at the bottom, so arranged that they can be dropped to allow the contents of the chamber to fall out. On the top of the chamber there are apertures, and to one of these there is connected a pipe which leads to a condenser. The condenser is connected to a purifier which is connected to an exhausting force-pump. This pump propels the incondensible gases to where they are to be stored or utilised. Attached to the condenser is a pump to free it from the condensed products.

Improvements in purifying raw or partly refined sugar. R. F. Smith, Greenock, Renfrew, North Britain. March 29, 1875.-No. 1136. The feature of novelty which constitutes this invention is the use of steam, conjoined with a vacuum, for the purification or partial purification of raw or partly refined sugar in the manner described, or any mere modification thereof.

Improvements in machinery or apparatus for the manufacture of pulp for paper. De'Angelis Rocco, Rome, Italy. March 31, 1875.No. 1155. The wood from which the pulp is to be made is first cut into very small pieces by means of a revolving cylinder provided with a very large number of steel knives, under which is drawn a carriage on which the wood is fixed. The wood thus prepared (or straw or rags may be employed) is then placed in a cylindrical wooden vessel containing water, and provided with a mixing wheel. Sulphurous acid gas is introduced into this vessel, and the substances under operation are converted into a colourless pulp, which is then conveyed to a hopper, from which it passes on to an endless cloth, and thence between a revolving granite cylinder and concave granite bed. A tube then conveys it to a drum provided with three receivers, and the pulp which has become reduced to the requisite degree of fineness passes through a metallic wire gauze into a box beneath. The pulp not sufficiently reduced passes out of the drum, and is carried back by a chain-pump to the hopper, to be again passed under the granite cylinder.

NOTES AND QUERIES.

Decomposing Furnace.-In reading over the discussion on Jones and Walsh's decomposing furnace (CHEMICAL NEWS, vol. xxxiv., p. 28) I see the percentage of sulphate put down from a calculation made during the discussion at 114. Should it not from the data given be rather more, viz., 11785.-A PRIVATE STUDENT.

Improvements in the manufacture of colouring matters. F. Versmann, THE LATE SIR CHARLES WHEATSTONE,

Ph.D., Brecknock Crescent, Camden Town, Middlesex. March 20, 1875. No. 1038. This Provisional Specification describes the separation of the yellow dye, known as chrysotoluydin or phosphine, from rosanilin, or from any by-product, residue, or refuse resulting from the manufacture of rosanilin, by means of bisulphide of carbon or petroleum.

Improvements in converting glassy slag resulting from metallurgical operations for the utilisation thereof. F. W. Dahne, Swansea, Glamorgan. March 22, 1875.-No. 1052. This invention mainly consists in converting the glassy slag resulting from iron blast-furnaces and other metallurgical operations into a stony or basaltic mass, and also casting said slag into any shape required. The slag is cast into hot moulds, which are heated and kept at a high temperature, and then allowed to cool for about twenty-four hours. Arrangements for carrying out this invention are described in the Specification.

Certain improvements in the construction of filters for the purifica

F.R.S.

The Physical Society of London, with the con

currence and co-operation of the Representatives of the late Sir Charles Wheatstone, are preparing to issue a collected edition of his published and unpublished scientific papers. Separate copies of several of the former being wanted for the use of the printers, the undersigned will be glad to receive offers of them on loan or for sale. DR. E. ATKINSON, York Town, Surrey.

Ryall's Chemical Black Lead (Registered)

creates no waste or dust by its magnetic adherence to the stove, and the cleanliness of application makes this one of the marvels of household economy.-Sold by all respectable grocers and oilmen in blocks id., 2d., 4d., and is. boxes. Works, 94, Little Compton Street Soho, London.

CHEMICAL NEWS,
August 4, 1876.

THE

METHODS
AS

Chemical Decomposition as Illustrated by Water.

CHEMICAL

VOL. XXXIV. No. 871.

OF CHEMICAL

43

phenomena. He held that "dephlogisticated air" is an NEWS. elementary substance-oxygen-united with imponderable caloric, and that "inflammable" air, or hydrogen, is capable of taking the oxygen from the caloric, thus producing water and heat. "Water is not a simple substance, but is composed, weight for weight, of inflammable and vital air." Thus water was at length deposed from its rank as an element.

DECOMPOSITION
ILLUSTRATED BY WATER.*

By Prof. J. H. GLADSTONE, Ph.D., F.R.S.

AMONG the most venerable of the Chinese classics is the "Shoo King," a collection of ancient historical records; and one of these records, the fourth book of Chow, contains a still more ancient document "The Geat Plan with its Nine Divisions," which purports to date from the early part of the Han dynasty-according to Dr. Legge, about 2000 B.C. This remarkable treatise bears on physical as well as ethical philosophy, and commences with an account of the five elements, viz., water, fire, wood, metal,

and earth. The first element, water, is said to "soak and descend," and also to "become salt."

This seems to be the earliest known record of that doctrine of elements which spread widely over the ancient world. In the "Institutes of Manu," we read of the elements also as five, but they are earth, fire, water, air, and ether; and according to the cosmogony of the Hindoo legislator, light or fire produced water, and water produced earth. There was, however, at least as late as two centuries ago, a sect in India who held it as a religious tenet that water was the prime and original element. Similar opinions found their way to Europe. Thus Thales, of Miletus, who flourished in the sixth century B.C., taught that water was the origin of all things. The Greek philosophers generally adopted the theory of several elements, but reduced the number to four-fire, air, earth,

and water.

It is hard to say what was the precise meaning attached by the ancients to the term "element." It no doubt did not always convey the same idea. Water also, at least in the Aristotelian philosophy, was a generic expression for many bodies in a fluid condition, and signified not so much a special material substance as an inherent quality of things. Thus it was said to be cold and moist, and the opposite of fire which was hot and dry. In the philosophy of the middle ages we find the same views prevailing, and the early chemists still looked upon water in the same light. Thus Becker enumerated five elements-air, water, and inflammable, mercurial, and infusible earth; while Stahl adopted four-water, acid, earth, and phlogiston. The ancient theory maintained its hold till the experimental philosophers at the latter part of the eighteenth century gave a definite meaning to the term element, and showed that water, air, and earth are compound bodies. Yet the idea of the elementary character of water was not easily abandoned.

In 1781 Cavendish found that when a mixture of what were then called "inflammable air" and "dephlogisticated air" is exploded by a spark in such proportions that the burnt air is almost entirely phlogisticated, pure water condenses on the sides of the vessel, and is equal in weight to the weight of the two airs. His theory was that water consists of "dephlogisticated air united to phlogiston," and that "inflammable air is water united to phlogiston." At the time of explosion, according to him, the excess of phlogiston was transferred from the inflam mable to the phlogisticated air, and thus both airs "turned into water." Cavendish also explained Priestley's production of inflammable air on heating iron filings strongly, by contending that the phlogiston of iron united with the moisture from which they had not been freed. Lavoisier gave a different explanation of these

A lecture delivered at the Royal Institution of Great Britain, Friday, May 5, 1876.

In the first year of this century, when the news of Volta's great discovery of the pile was made known in England, Messrs. Nicholson and Carlisle made various experiments with a series of halfcrowns, zinc plates, and electricity, they inserted brass wires through corks at the pasteboard soaked in salt. Knowing that water conducted two ends of a tube filled with water, which they are careful to tell us came from the New River. They were surprised to see a stream of minute bubbles rising from one pole while the other was corroded, and that this decomposition took place at each pole, though they were nearly 2 inches apart. They enlarged the distance, and found that 36 inches of water was too much for their force to traverse. Substituting flattened platinum for their brass wires, they found that the water was decom. posed with the production of hydrogen at one end and oxygen at the other.

turned into stone had been previously dispelled by The old notion that water, by continuous boiling, was Lavoisier, but Davy found that some salts and earths remained' behind when water was electrolysed, and that when the experiment was conducted in two cells communicating with one another, the liquid in the one cell became acid and the other alkaline. He traced the origin of this in a masterly research, which formed the Bakerian lecture for 1806. He found that the earthly substances were original impurities in the water, or came from the vessels employed; and using gold cones filled with distilled water and united together by asbestos, he convinced himself that nitric acid was produced at the positive pole and ammonia at the negative. Suspecting that these were produced from the small quantities of nitrogen dissolved in the water combining with the liberated oxygen and hydrogen respectively, he took extraordinary precautions. Making use of water which he had carefully distilled in a silver still at 140° F., and performing the experiment in vacuo, or rather in a space which he had twice filled with hydrogen and exhausted as thoroughly as the means at his disposal would permit, he then found that the water was decomposed without the least production of either acid or alkali. "It seems evident then," wrote Davy," that water, chemically pure, is decomposed by electricity into gaseous matter alone, into oxygene and hydrogene.

In the following year Davy discovered the metals of the alkaline earths, potassium and sodium, and found that when these bodies are thrown upon water they decompose This is due to the superior chemical power or "affinity" it, appropriating its oxygen and setting free its hydrogen.

of the alkaline metals.

when steam was subjected to something like a white heat, In 1846 Mr., now Sir William, Grove observed that small quantities of mixed oxygen and hydrogen gas were always produced.+. It has since been shown that the gases are actually dissociated in one part of the flame of the oxy-hydrogen blowpipe, after their first combination. which water may be decomposed :-By an electric curIt thus appears that there are three distinct ways in rent; by some substance which has a superior attraction for one of its elements; or by heat alone.

It will readily be understood that the power of any one of these agents will be augmented by the co-operation of

44

ures.

Chemical Decomposition as Illustrated by Water.

either of the others. Thus, the action of chemical affinity is usually augmented by heat; for instance, if a pellet of sodium be thrown upon cold water it melts, on account of the chemical action at once set up, but if upon boiling water it not only melts but bursts into flame through the greater violence of the action. This is the reason why, in Priestley's experiment, iron at a red heat decomposed team, though it will not do so at ordinary temperaSimilarly the electrolysis of water is much facilitated if there is some chemical affinity between the oxygen and the metallic conductors. It is generally said that it requires two cells to decompose water electrolytically. Now, it is true that if piatinum poles are employed there is no visible disengagement of gas when one cell only is used; but with zinc poles a single cell of Bunsen or Grove is amply sufficient. Zinc alone without the voltaic current is incapable of displacing the hydrogen in water; but it must be borne in mind that the tendency to combine with oxygen is a constant property of this metal, and is easily brought into activity by the co-operation of the feeble voltaic current. The increased effect upon electrolysis which is due to the nature of the poles is in proportion to the electromotive force of the different metals. For pure water the order is-zinc, lead, iron, copper, silver, platinum, as tested by a galvanometer. This difference of result according to the nature of the metals employed in the electrolytic cell appears generally to have been overlooked, and it is the feeblest metal-platinum-which is usually employed for experimental purposes, doubtless because it is incapable of oxidation-the very reason of its feebleness.

When the other metals of the above list are used, not only does the positive pole oxidise, but the oxide, or rather hydrate, dissolves more or less in the pure water, and becomes itself an electrolyte. The consequence of this is that the positive electrode gradually wears away, while the metal is transferred to the negative electrode, and is deposited upon it in crystalline fringes or filaments. With silver these are particularly beautiful, as they assume arborescent forms, especially when able to spread over the surface of the containing vessel.

CHEMICAL NEWS,
August 4, 1876.

positing the copper upon the zinc in a spongy condition; then the zinc will be oxidised, and bubbles of hydrogen will appear among the branches of the copper, even at the ordinary temperature, but the effect is greatly increased by the application of heat.

The arrangement just described is the " copper zinc couple," which has been employed by Mr. Tribe and the speaker, and more recently by others, to effect a variety of chemical decompositions. Zinc foil is immersed in a solution of sulphate of copper until a black velvety deposit of the metal is produced: the soluble salts are then washed away, and the couple after being dried is ready to be placed in any liquid it is desired to decompose. Water was the first body experimented upon, and it was found that the action would go on as long as there was any metallic zinc left in union with the copper, the amount of hydrogen evolved gradually diminishing, though varying somewhat with the temperature of the day. The great influence exerted by heat is, however, better shown in the subjoined table, which gives the results of an experiment reduced to the unit of an hour's work.

At 2.2° C.

22.2

34'4

55'0 74'4 93'0

I'I c.c. of hydrogen produced. 5'5

13'9

62'0

174.6 528'0

of the action at the higher temperatures.
These figures strikingly exhibit the rapid acceleration

A greater effect may be produced by substituting for the copper a still more negative metal. Thus a zinc platinum Gold couple acts with much greater energy upon water. zinc couples, and many others also, have been tried, but gold has the practical disadvantage that the precipitated metal does not adhere well to the zinc. Aluminium alone does not decompose water, not even, according to Deville, at a red heat; but an aluminium copper couple decomposes it slowly, and an aluminium platinum couple more rapidly, even in the cold. One of the most recent discoveries is that aluminium when amalgamated with mercury The temperature also of the liquid subjected to elec- is converted into hydrate, even by the moisture of the air. The most powerful combination, however, might be trolysis has a great influence upon the result. Thus in an experiment where zinc poles and pure water were emexpected to be that of the most positive and the most negative metal which can be conveniently brought toployed, the deflection of a galvanometer was found to increase about fourfold between 5° C. and 80° C., and the gether. These are magnesium and platinum; and in fact, action augmented nearly pari passu with the tempera-platinum by immersing them in platinic chloride, and the if strips of magnesium foil be coated with finely-divided

ture.

A similar result occurs, as might be expected, when two dissimilar metals, such as zinc and copper, are placed in cold water in connection with one another, and the water is heated. The deflection was found to double between about 30° and 80° C., but the difference for every 5° at the higher temperatures was several times greater than at the

lower ones.

Another very important point in the electrolysis of water is to reduce to a minimum the very great resistance offered by the water itself. This is effected by bringing the electrodes as near to one another as possible; and for the same reason, if the force be generated by the action of two dissimilar metals upon water, they should be brought into the closest proximity.

A still more powerful means of decomposing water would evidently be a combination, not of two, but of all three agents, chemical affinity, heat, and voltaic force acting at an insensible distance. Thus zinc has a strong affinity for oxygen, but is unable of itself to displace the hydrogen of water; when united, however, with a more negative metal, such as copper, its power is enhanced to such a degree that a separation of the constituents does take place; but in the ordinary arrangement of a voltaic cell the action is so slight that no evolution of gas is perceptible. To produce a visible effect, the metals must not only be close together, but ought to touch one another at a myriad of points. This may be brought about by de

resulting salts be washed away, a couple may be obtained which produces a most vigorous evolution of hydrogen when it is placed even in cold water."

The decomposition of water by the copper zinc couple was of course a matter of little practical importance; it does, however, yield hydrogen in a state of purity, even though the zinc be largely contaminated with such a substance as arsenic-a fact which may prove of great consequence in medico-legal inquires. These observations on water led to a long series of experiments on other bodies, especially organic compounds. The action of the two metals in conjunction frequently effects not only the splitting up of a compound, but a re-distribution of its elements; and this has resulted not only in the discovery of a simple means of producing various substances previously known, but the formation of several others hitherto unknown. Thus the first trials were made on iodide of ethyl in the hope that Prof. Frankland's beautiful process for making zinc ethyl might be simplified; and not only was a better result obtained in a shorter time, but when the experiment was performed in the presence of alcohol it was found that pure hydride of ethyl was given off, and

frequently been observed by several experimenters, and some of them

* Phenomena resulting from different metals in combination have are described by Mr. W. N. Hartley in the CHEMICAL NEWS (vol. xiv., p. 73); but it does not appear that the metals have ever been freed from concomitant salts, or their action understood or appreciated.

The substances that have been discovered by this agency WHILST air is continually introduced so much lime is are the following:

Atomicity as a Principle of Classification.