mixed solution, which consists of the potassiocyanide of brass and the potassio-cyanide of zink. The solution is very readily decomposable; it is therefore necessary to prepare it a short time previously to its use.' Many specimens were exhibited of copper and other metals coated with brass. The author makes some remarks on the theory of the action; and concludes by stating that it will be quite possible to determine, within certain limits, the character of the alloy that shall present itself, and that we may be enabled to throw down gold and silver according to standard.

Experiments on the Spheroidal State of Bodies, and its Application to Steam-boilers, and on the Freezing of Water in red-hot Vessels.

A paper under this title, by Professor Boutigny, was read and illustrated by experiments. The Professor commenced by showing that when cold water is poured on a hot metallic surface, the heat is not communicated to it; and that the water assumes a spheroidal form, and continues to roll about, upheld at a minute distance from the heated surface, without boiling. The water poured into a heated platinum cup kept in rapid motion, and resembled a small globe of glass dancing about. There was no hissing noise nor appearance of steam, though the globule of water must, nevertheless, have evaporated rapidly; for, after gradually diminishing in size, in the course of about two minutes it disappeared. The same result takes place when any substance capable of assuming a globular form is placed on a heated surface. In proof of this, the Professor placed in the heated cup of platinum, iodine, ammonia, and some inflammable substances; each of which became globular, and danced about like the globule of water, but without emitting vapour or smell, or being inflamed, until the platinum cup was cooled. Another experiment was yet more curious. Professor Boutigny heated a silver weight, of the same shape as the weight of a clock, until it was red-hot; and then lowered it by a wire into a glass of cold water, without there being the slightest indication of action in the water, more than if the weight had been quite cold. Professor Boutigny advanced no theory to account for these peculiar actions, further than that a film of vapour intervenes between the heated body and the substance, which prevents the communication of heat. The facts, however, he thought were of importance in a practical point of view, both as regards the tempering of metals, and in the explanation of the causes of steam-boiler explosions. It would seem from these experiments, in tempering metals,

that if the metal be too much heated, the effect of plunging it into water will be diminished. In steam-boilers also, if the water be introduced into a heated surface, the heat may not be communicated to the water, and the boiler may become red hot, and without any great emission of steam; until at length, when the boiler cools, a vast quantity of steam would become suddenly generated, and the boiler burst. The last and most curious experiment performed by Professor Boutigny was the freezing of water in a redhot vessel.* Having heated a platinum cup red-hot, he poured into it a small quantity of water, which was kept in a globular form, as in the other experiments. He then poured into the cup some liquid sulphurous acid; when a sudden evaporation ensued, and, on quickly inverting the cup, there came out a small mass of ice. This experiment called forth loud and continued applause. The principle on which this experiment depends is this-sulphurous aeid has the property of boiling when it is at a temperature below the freezing point; and when poured into the heated vessel, the suddenness of the evaporation occasions a degree of cold sufficient to freeze water.

DR. W. G. TURNER'S PATENT METHOD OF PURIFYING THE VAPOURS OF CHEMICAL WORKS.

Dr. Turner's patent (dated August 22, 1844, specified February 8, 1845,) is for an improved method of directing the passage of, and otherwise dealing with, noxious vapours, and other matters arising from chemical works in certain cases.'

The nature of this invention consists in the application of certain mechanical contrivances to produce a draught in the manufacture of sulphuric acid, muriatic acid, and sulphate of soda, and to the roasting and smelting of metallic ores, in aid of, or as a substitute for, the ordinary draft of a chimney; by which contrivances, together with certain improved processes, that portion of the acid gases and metallic fumes are condensed, which, in the methods now employed, escape into the atmosphere. Moreover, the products obtained from a certain quantity of materials are stated by this invention to be considerably increased, while the causes of injury to vegetation, &c. are completely removed.

The apparatus by which the object of this patent is effected, consists of a horizontal

For the first account published in England of this remarkable experiment, see Mechanics' Magazine, vol. xli. p. 23.

13

vessel, which may be of sheet iron, firebrick, or stone, according to the corrosive or non-corrosive nature of the substances employed therein. In this vessel is placed a continuous screw, made of suitable materials, and revolving on an axis, which is connected with a steam-engine, water-wheel, or other moving power, in such a manner as to cause the screw to revolve with great rapidity, and thereby to produce the requisite draft, the threads or vanes of the screw being made of considerable width for that purpose. Upon the shaft of the screw, and at certain intervals along its length, are placed long arms, projecting perpendicularly from the shaft to distances nearly equal to the thread of the screw. The vessel in which the screw revolves is then connected with the furnace from which the fumes are emitted by means of a flue, and a quantity of water is allowed to enter the vessel by means of a feed-cock, so as to cover the lower edge of the screw to the depth of three or four inches, the lower part of the vessel forming a trough for the water, from which, by means of a suitable tap, it may be abstracted at pleasure. The arrangement being thus effected, the screw is put in motion up to a speed competent to produce the requisite draft in a direction from the furnace; at the same time the water in the vessel is worked by the action of the screw, and violently dashed and broken, by the arms projecting from the shaft, into a mass of foam and spray, which wets the fumes by beating them about with the water in their passage through the ves sel, until they become too heavy to pass on with the draft, when they descend to the bottom of the trough. When this apparatus is applied to the condensation of lead, or other metallic fumes, the water must be drawn off from time to time, into proper tanks or receivers, in which, by standing, the metals are deposited.

When this invention is applied to the manufacture of sulphuric acid, the patentee avails himself of the aid of such condensing agents as the acid gases have an affinity for; and in order to this, he employs a series of air-tight vessels, called condensers, which should be made of wood, and lined with lead, and strong enough to bear a considerable pressure. In one of the conden sers with which the draft pipe is connected, a quantity of what is usually called chamber acid is admitted, so as to cover the opening of the draft pipe from the sulphuric acid chamber to the depth of two or three feet. The upper part of this condenser is then connected with air-pumps of sufficient power and capacity to draw through 162,000 cubic feet of air for every hundred pounds of sulphur burnt, and to cause a partial

vacuum to be made and maintained in the upper part of this condenser. By this arrangement, the gases from the sulphuric acid chamber force their way in a continuous stream through the acid in the condenser, and thus cause a draught from the sulphuric acid chamber.

For the better understanding of this invention, it must particularly be remarked, that there are three causes which operate to produce the loss of nitre in the common method of manufacturing sulphuric acid; which causes of loss are stated to be entirely prevented, or at least greatly diminished, by this improved draft, and mode of dealing with the noxious vapours. The apparatus and processes by which these objects are effected are fully described in the specification; but being too long to admit of a brief and perspicuous analysis without reference to the drawings, we think proper to conclude by merely stating the objects of the claim, which are ranged under five different heads, as follows:

Se

Firstly, the application of a screw and arms working in water, the one for the purpose of creating and increasing the draft, and the other for wetting and condensing the noxious vapours proceeding from furnaces in which the roasting and smelting of metallic ores are being carried on. condly, the application of the screw, or of airpumps and condensers, in the manufacture of sulphuric acid, muriatic acid, and sulphate of soda. Thirdly, the substitution of nitric acid to the sulphuric acid, in the acid chamber, for nitre in the furnace. Fourthly, the substitution of a shallow sulphuric acid chamber, instead of the deeper one hitherto in use, to prevent the formation of the crystalline compound of sulphuric and hyponitrous acids therein. And fifthly, the working the vapours in, and escaping from the acid chamber, through the condensers, with the condensing media or agents.

FRENCH PATENT LAW CASE.* Tribunal Correctionel de la Seine, June 6, 1845.

M. Perrot, President.

MM. Christofle and Co. v. M. Bertrand.

The plaintiffs have a license to use MM, Elkington and Ruolz's patents for electrogilding and plating; and have already maintained several actions. The present action occupied the tribunal during four sittings; and is interesting both in respect to the

For the translation of this Report we are indebted to the last Number of Mr. C. V. Walker's valuable Periodical, The Electrical Magazine.

questions which it raises, and to the developments which it has given of the respective pretensions of individuals.

The following are the facts :

Several seizures were made, at the request of M. Christofle, in the workshops of one Bertrand, a gilder; and a jury of three, MM. Chevalier, Barrel, and Henry, appointed by the magistrate who has this affair in hand, have drawn out a detailed report of the objects seized, and placed it on the rolls of the court. Their opinion is favourable to the patentées.

M. Emanuel Arago opened the case for the plaintiffs, by detailing the affair, and commenting on the report of the jury.

M. Marie, on the part of the defendant, put forth three propositions, and gave evidence in support of them :

1st. There was no invention of galvanic gilding, either on the part of Mr. Elkington or of M. de Ruolz; and consequently their patents cannot be regarded as valuable. In support of which, he cited the chemical labours of Brugnatelli,* and De la Rive,† and a publication by M. Louyet, of Brussels.‡ Brugnatelli and De la Rive had discovered the principle of the new gilding; and this principle, in his opinion, contains the germ of all the ulterior labours of MM. Elkington and De Ruolz, which ought to be considered as simple applications, of a more or less happy kind, but not patentable.

2nd. Supposing that there was an invention, and that the patents were valid, M. Bertrand cannot be condemned for infringement; for before the patents were taken out, he gilt by the same processes that are now in use; he ought to enjoy the benefit of the anterior possession. In support of this, M. Marie presented to the Tribunal numerous attestations in proof that, before the patents were taken out, M. Bertrand had gilt objects that could not be gilt by the old process, such as filigrees and solderings of tin; he also put forth invoices proving that, before the patents, M. Bertrand had purchased certain chemical products, and especially the cyanides, the useful application of which to galvanic gilding had afterwards been pointed out by MM. Elkington and De Ruolz. And, according to the learned counsel, M. Bertrand is not the only one who had employed these substances anterior to the patent. M. Perrot, of Rouen, has just published a pamphlet, in which he maintains having gilt

with the cyanides before the patents were out.*

3rd. In the next place, the report of the jury cannot serve as the ground for an immediate solution; and this for several reasons, first, because it says nothing in a precise manner on the question of novelty, and then, because it is ex parte; if it is ex parte-if M. Bertrand would not assist the operations of the jury; it is because, in his opinion, the questions were not well put by the magistrate. A second report is therefore necessary; and a fresh jury ought to be named. He here gave a critical examination of the report, which appeared to him incomplete, and by no means conclusive.

M. Emanuel Arago, in reply, said that he could not comprehend how the discovery of MM. Elkington and De Ruolz could be denied, to whom the Academy of Sciences had awarded two grand Monthyon prizes, upon the report of M. Dumas, as one of a commission, consisting of MM. Thenard, Darcet, Chevreul, Pelouze, and Pelletier. In order that the defence be admissible, we must admit that all these philosophers were ignorant of the labours of De la Rive. Now, this same commission that decreed a prize of 8000 fr. to Mr. Elkington, and another of 8000 fr. to M. De Ruolz, had given M. De la Rive a prize of 4000 fr., in recompense for the discovery of

* We give the following extracts from M. Per, rot's pamphlet, entitled, "Machine LithographiqueMachine à Imprimer les Etoffes et Dorure Galvanique," published by Lange, Levy and Co., Paris,. 1844.

"1805. BRUGNATELLI.-The first idea of gilding by the galvanic pile is traced to Brugnatelli. He states his having gilt silver medals with a pile of several elements.t

"1840.-M. DE LA RIVE.-This learned philosopher gilds silver, copper, and brass with chloride of gold, by means of a galvanic apparatus of a single element. The piece to be guilt forms the negative pole of the single element.

"1840, August, M. PERROT.-I obtain on gold, silver, copper, and on every oxidizable metals, such as iron and steel, very fine gildings, without the interposition of any metal. Not any of these gildings could hitherto be obtained, except by the employment of the battery and the alkaline cyanides.

"1840, September. MR. ELKINGTON.-He demands a further patent (brevet d'addition, Fr.,) in which he appropriates M. De la Rive's process. But, instead of dissolving the gold in chlorine, he uses prussiate of potash (alkaline cyanides); and he replaces the bladder used by M. De la Rive by porous earth, as has been long the practice in electrotype.

"1840, December 15. M. DE RUOLZ.-He proposes to cover silver objects with a film of copper, so as to render them fit to be gilt by M. De la Rive's process."

"To one part of the saturated solution of gold in nitro-muriatic acid, add six parts of solution of ammonia, by which the solution is decomposed, and oxide of gold is precipitated, and a portion is set free, forming ammoniuret of gold."-Brugnatelli's gilding solution, extracted by Editor Elec. Mag., from Zantedeschi's Elecricity, vol. ii. p. 468.

a scientific principle-a scientific principle inapplicable, as they explain in their report, to the actual art of gilding; whilst, in the processes of MM. Elkington and Ruolz, they find all the conditions of a good applicable gilding—a marketable gilding by electricity-a gilding that was impossible before their processes.

M. E. Arago, in support of his assertion, cited several passages from the report of the Academy of Sciences, proving that the liquids described by MM. Elkington and De Ruolz, cover objects to be gilt with a continuous and perfectly adhering layer of gold, without in any way attacking and corroding the objects; whilst M. De la Rive's liquor reacts on the objects, attacks them, and cannot cover them with that adhesive and continuous layer of gold which is alone acceptable in commerce. He further added, that if De la Rive and Brugnatelli did produce good gildings, let M. Bertrand adopt their processes, and the patentees would not in any way interfere with his operations. With respect to the anterior possessions, the learned counsel canvassed the specimens produced by M. Marie, which did not appear to him in any way decisive. With regard to M. Perrot, he appears in exactly the same position as M. Bertrand, but, even supposing he were right, this would have no bearing on M. Bertrand; for if M. Perrot had shown his gildings before the patents, he had never told, had never published how he had obtained them. M. Arago concluded by repelling the demand for a fresh jury.

After a fresh reply from M. Marie, the King's Counsel, Camusat Busseroles, gave his opinion in favour of M. Christofle :

"The Tribunal, &c., as concerns Cloménil,-inasmuch as there is no proof that he acted otherwise than as workman to Bertrand, executing the orders of his patron, dismiss him without expenses. As concerns Bertrand,-and first, with respect to the demand for a new jury to report also on the process claimed by Bertrand; inasmuch as Bertrand's process, so far as it constitutes a personal and distinct discovery, is not in question; inasmuch, on the other hand, as there does not appear any legitimate motive for recommencing the investigation that was made, as it is regular, and contains sufficient elements, when joined to the other specimens and documents of the process, to throw light upon the decision that is to be given; and mainly, inasmuch as it follows from the debates, the specimens and the documents produced, that the preparations seized at Bertrand's are conformable to those, for which the prosecutors or their authorities have obtained some of their patents; that Bertrand maintains that these patented preparations have not the character of true inventions; that he also opposes the exception of forfeiture, and in all cases anterior possession.

"But in respect to the question of invention,-inasmuch as, in the matter of discoveries, not only are the principles susceptible of being patented; that their consequences, their divers applications and combinations, may also constitute new ideas and found privative rights; that, if it is true that the cy,

anides of gold were for a long time in science, as well as was the galvanic pile, the efficacious application of these cyanides to gilding and plating metals, in a manner, moreover, such as to endow society with a new and so valuable a branch of industry, assuredly merits the title of invention. In respect to the exception of nullity or forfeiture,-inasmuch as the rule is, that a patent is worth nothing, if the discovery, invention, or application is not new; that is to say, if, anteriorly to the date of the deposit of the demand, it has received in France or abroad a sufficient publicity to be executed; but, in fact, inasmuch as it is true that the chemists Brugnatelli and De la Rive had opened the career, their labours, which were curious and interesting in a scientific point of view, were as yet, to speak truly, but simple trials; that it follows from all the documents of the process, that before Ruolz and Elkington, gilding and plating, by aid of the galvanic pile, had remained in such a state of imperfection that the arts and commerce could not gain any thing from them, and that it was the cyanides of these latter, their preparations and combinations, which raised the discovery from its sterility, in order to extend it by a new discovery into the industrial arts; whence it follows that there is in very truth a novelty in their particular invention. As concerning anterior possession,-inasmuch as, rightfully, this means is purely personal; that we cannot invoke the possession of another; inasmuch as, therefore, Bertrand cannot create a title to the possession of MM. Perrot of Rouen, and Louyet of Brussels, if such exists; and moreover, as nothing proves that these two philosophers were in possession of the means of MM. Ruolz and Elkington before their demand for the delivery of patents; further, that nothing establishes their having spread them abroad, either by printed writings or otherwise, so as to attain the degree of publicity necessary to their being henceforth considered as new; finally, inasmuch as, with respect to Bertrand, he by no means justifies his personal possession; that the productions which he makes with this intent are utterly insufficient. That it follows from all which precedes, that there is truly a patentable invention in the processes of Ruolz and Elkington; a new invention without anterior possession on the part of a third individual, to wit, Bertrand; that thus he has rendered himself guilty of the crime of infringement, provided against and punished by the articles 40 and 49 of the Law of July 5, 1844:

"For these reasons, without delaying or having regard to the demand for a new investigation, nor to the exception of the defence, which are rejected as being badly founded;

"Condemns Bertrand to a fine of 300 fr., pronounces confiscation of the preparations and objects seized; orders that they be handed over to Christofle and Co.;

And, inasmuch as it has been established, that the latter have suffered prejudice from the deed of the aforesaid Bertrand, that reparation is due to them, and that the Tribunal is prepared to appreciate the value;

"Condemns the aforesaid Bertrand to pay to Christofle and Co. the sum of 3,000 fr. as costs and damages; and

"Condems him to the expenses;

"Fixes to one year the duration of the writ of arrest." From Le Droit, June 7, 1845.