CHEMICAL NEwa,

May 2, 1863.

NOTICES OF PATENTS.

2. Manufacture of Leather Cloth. N. C. SZERELMEY, Brixton.

Dated January 1, 1862.

For the purpose of rendering linen, woollen, and other fabrics waterproof, and for the manufacture of a kind of imitation leather, or leather cloth, the patentee claims the employment of a material known under the name of "zopissa."

The substance used by Mr. Szerelmey in his experiments upon the decayed stone of the Houses of Parliament is likewise called "zopissa," but its nature never having been disclosed by the inventor, it becomes question. able whether the declaration contained in the foregoing announcement is sufficiently explicit to permit of a valid claim being based thereon.

The imitation leather shown by Mr. Szerelmey at the International Exhibition was, however, a very beautiful article, and appeared to be generally admired.

25. Artificial Fuel. G. STRACEY, Rackheath Hall, near Norwich. Dated January 3, 1862. (Not proceeded with.)

THE inventor mixes together small coal, sawdust, and cut straw, and makes these into blocks of fuel by the help of clay and chalk under powerful pressure.

It seems hardly politic to increase the proportion of mineral matter in a fuel whilst abundant supplies of low quality coal can be obtained at a trifling cost from natural

sources.

37. Purifying Coal Gas. A. WARNER, Threadneedle Street, London. Dated January 4, 1862. (Not proceeded with.)

THE inventor proposes to employ in the purification of gas a material prepared from the cinders, hammer-slag, and other waste oxides of iron produced in iron works. These substances are reduced to powder and levigated in water in order to fit them for successful employment in the dry gas purifiers.

The litigation respecting the earlier and rival claims of Hills v. Evans, for the application of oxides of iron in the removal of sulphuretted hydrogen from coal gas, disposes at once of this suggestion.

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oxides of iron which have been employed in the purification of coal gas may be submitted. These bear reference to the collection of the sulphur by distillation in retorts. sulphurous acid and sulphites by combustion in a current or by simple fusion and pressure; to the production of of air, at the same time saving the ammonia; to the extraction of sulphate or sulphide of iron from the metallic residues; and by secondary reactions to make alum, sulphate of soda, ferruginous pigments, &c. In some of these processes the material becomes again available for use as a gas purifying agent.

THE ALKALI WORKS REGULATION BILL. THE bill introduced by Lord Derby has been read a third time in the House of Lords; any opposition, if necessary, must therefore be made in the House of Commons. The title and provisions of the bill may be shortly stated as follows: -It is to be cited as the "Alkali Act, 1863." It is to come into operation on January 1, 1864. The term "alkali work is to mean every work in which muriatic acid is evolved. Every alkali work is to be carried on so as to ensure, to the satisfaction of the inspector, the condensation of not less than ninety-five per cent. of the muriatic acid evolved. Any less condensation than this will make the owner liable to a penalty of fifty pounds for a first offence, and for every subsequent offence to a penalty not exceeding twenty pounds, nor less than two pounds, for every day the offence continues. All alkali works must be registered, and every change of ownership must be registered. The Board of Trade is to appoint inspectors to assigned districts. The next clause is important, as showing the wish of Lord Derby to ensure fairness in carrying out the Act. No land agent, nor any one engaged in any manufacture, or interested in any patent in or according to which the decomposition of salt or the condensation of muriatic acid may be effected, shall act as inspector under this Act. The inspectors may enter works at all reasonable times, day and night, without giving notice, but so as not to interrupt the process of the manufacture, to see that the provisions of the Act are carried out. The owners of

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the works, upon demand, are to supply the inspector with plans of those parts of the works (to be kept secret by the inspector) in which the salt is decomposed and the muriatic acid condensed. The inspector may make any experiments to ascertain the efficiency of the condensing apparatus, and the owner of the works is to give him all necessary facilities for the testing. All persons obstructing an inspector or refusing to give him the facilities incurs a penalty of 10l. for every offence. The inspectors are to report to Parliament every year. Owners of works may, with the sanction of the Board of Trade, make special rules for the workmen attending to the condensing apparatus, and may annex penalties to the violation of such rules. The remainder of the Act refers to the recovery of penalties.

The Oil Springs of America and Canada.— Mr. A. S. Macrae, petroleum oil broker, Liverpool, writes: "The demand for all descriptions of petroleum has been very large this week, and prices to the close are well maintained. Owing to the bracing nature of the weather, the temperature in the various stores is as it ought to be, and, so far as leakage and evaporation are concerned, there is nothing at all to intimidate; while it seems probable that the expenses of holding will be considerably less than has generally been anticipated. Last year it was stowed miscellaneously in sheds, and even amongst cotton; whereas now it is in vaults and level ground, where everything contiguous is cool and drafty, and where leakage would be immediately apparent. Crude.-1000 casks of American at 11. 158. to 127. for 81° and under. Much that is coming over now is 830° and upwards, and the condition of it very bad. Water and sand are being repeatedly found in the casks, and a searching scrutiny has to be made on the quay here, all of which adds seriously to the expense. Such, of course, only fetches a proportionate value, while it creates great distrust and much disappointment amongst buyers. In Canadian no sales. Refined.-8000 casks have changed hands this week at Is. 8d. up to 1s. 10d. for present delivery, 2s. for September-October, and 28. 1d. for November-December delivery. Benzine is in more demand. 400 casks sold at 1s. 6d., and 250 cases at 1s. 9d."

The Effects of Sulphuret of Carbon on Health. The symptoms caused by sulphuret of carbon are peculiarly severe, and the situation of the workers really most miserable. Few of the workers marry, as it is well known that those who habitually work among these fumes rarely or never have children, and the malady is one which will only succumb to good air and rest, and total exclusion from the work-sheds. The head is much affected, and partial insanity is far from uncommon. The sight is troubled frequently. The taste is vitiated, so that most things appear to taste of sulphur. The hearing is likewise affected, and the digestive functions are sometimes strangely excited, though this latter symptom is less frequent than the others. Appetite is increased to the verge of gluttony, and nausea is almost invariable. The breathing and the circulation are injured, and most, if not all, of the secretive functions are disordered in a very alarming manner. In fact, the wretched people-we can give them no other name-who work with this agent are miserable to themselves and the world; they live in pain and trouble of both body and mind, with no hope or expectation of cure so long as they continue at their particular occupa tion. As to the remedies to be taken for alleviation of these misfortunes, baths, good air, a few simple medicines, and a country life-of course necessitating total abstinence from the poisonous work-have been found most efficacious. The power and density of the fumes may be better appreciated, when we state that in many cases the sheds are merely roofs supported by poles, and open to every breeze or gale that blows. M. Delpech does not appear to propose any method for ameliorating the condition of

{CHEMICAL NEWS,

May 2, 1863.

the workpeople. He mentions that the injury is due entirely to sulphuret of carbon; not to the chloride of sulphur; and says that phosphorus has had a beneficial effect in many cases of depression." In fact, it would, we suppose, be almost impossible to do anything except abolish the process, and as this cannot be effected, it only remains for scientific men to discover some agent which will produce the same results in the arts, without any of the great and certain dangers of sulphuret of carbon. There are many minds at work on this project, but as yet no practical result has been secured.-Social Science Review.

SOCIETY OF ARTS-John Street, Adelphi. 8 p.m. Dr. A Wynter, "On Bread-making, particularly with Reference to the Condition of those Employed in its Manufacture." GEOLOGICAL-Burlington House. 8 p.m. ROYAL SOCIETY OF LITERATURE-4, St. Martin's Place. 8.30 p.m. 7. Thursday. ROYAL-Burlington House. 8.30 p.m. CHEMICAL-Burlington House. 8 p.m. Dr. Lyon Playfair, C.B., F.R.S., "On the Constitution of Salts." LINNEAN-Burlington House. 8 p.m. ANTIQUARIES--Somerset House. 8.30 p.m. ROYAL SOCIETY CLUB-St. James's Hall. 6 p.m. ARTISTS AND AMATEURS-Willis's Rooms, St. James's. 8p.m. ROYAL INSTITUTION-Albemarle Street. 3 p.m. Prof. Ansted, "On Geology."

8. Friday. ASTRONOMICAL-Somerset House. 8 p.m. ROYAL INSTITUTION-Albemarle Street. Voelcker, "On the Soils of England." 9. Saturday.

8 p.m. Prof.

ROYAL BOTANIC-Inner Circle, Regent's Park. 3.45 p.m.
ROYAL INSTITUTION-Albemarle Street.
3 p.m. Prof.
Max Müller, "On the Science of Language.'

ANSWERS TO CORRESPONDENTS.

adopt the views of the writers. In publishing letters from our Correspondents we do not thereby question will frequently oblige us to publish opinions with which we Our intention to give both sides of a do not agree.

H. G.-The idea is very good, and, as far as we know, original. Send a description for publication, and we shall have much pleasure in inserting it in the CHEMICAL NEWS.

J. T. T.-No curriculum is prescribed. The title F.C.S. is not a Society; and it is open to any qualified person to become so, Write degree, it simply expresses that the person is a Fellow of the Chemical to the secretary, Burlington House.

PATENTS FOR INVENTIONS IN CHEMICAL

ARTS.

THE defects, anomalies, and vices of the present patent laws are now becoming very generally recognised, not only in this country, but also on the Continent, and proposals for their amendment, or even total abolition, are not unfrequent topics of discussion at scientific and technical societies.

Among the evils of the present system in this country, the indiscriminate granting of patents is perhaps the worst. The host of patents that are annually granted for alleged inventions-which are in reality nothing more than repetitions of prior patented methods, or applications of facts that are well known, and have in some cases been already used, or for sweeping and comprehensive claims devised for the purpose of including manufacturing operations that are likely to be carried out, and making them subject to claims for royalty, or for the most absurd projects-constitute in themselves a growing incubus on invention, and a source of impediment to enterprise, which is the very opposite of the object that the grant of a limited monopoly in the form of a patent is intended to conduce to.

Those who are in favour of the continuance of the patent system, either as it exists or in some amended form, have one argument which is entitled to consideration-viz., that the advantages conferred by a patent constitute a legitimate reward for the publication of valuable inventions, and that by this means the industrial progress of the nation is encouraged. But this argument raises the prior question, whether the grant of a patent is a reward for real invention? There is much reason for the opinion that it is not so. It is true that the reduction of the charges for a patent has made them more easily obtainable by the real inventor; but this is a facility that is equally afforded to the spurious inventor, who is thus enabled to enter the field with the true man, and either deprive him of his legitimate right, or oblige him to defend it by a costly legal process. The same necessity of costly defence against infringement is involved by the holding of a patent for any really valuable manufacturing operation.

The inventor pays for his patent, and gives his invention to the public. He receives nothing in return but a qualification to maintain a suppositious privilege, with the understanding that the State affords him no further protection than he can obtain by his own means, and it does not even guarantee the validity of the qualification The payment of fees for a patent is only to be defended under the admission that patents are granted indiscriminately to those who have a claim to them and to those who have no claim. The possible propriety of the system in the latter case is no excuse for the injustice in the former case. If an invention is worthy the grant of a limited monopoly as a reward to the inventor, he renders his equivalent for that reward by giving to the

public the advantages of his invention after the expiration of a certain time. This should be sufficient without the imposition of preliminary and periodical fees, however small. It is reasonable enough, in its way, that the man who takes out a patent with no idea of ever working it, but merely for the sake of turning a penny. honestly or otherwise, by means of it, should pay for the privilege he thus obtains. But it is unreasonable to treat these men in the same manner.

The only reason why these two classes of men are, as regards patents, placed on the same footing, is the difficulty, or, it may be said, the impossibility of discriminating as to the value, the novelty, or the utility of an alleged invention. The system of preliminary inquiry into these points has broken down every where. Its adoption is surrounded with all sorts of objectionable features, and one of the most serious is the fact that it is precisely with regard to great inventions that there is the greatest chance of its being impossible to appreciate their utility.

Would it not, therefore, be a lesser disadvantage to the real inventor to abolish the patent system, and to leave him to exercise his energies in carrying his invention into practice, or in submitting it to trial, instead of conferring upon him a semblance of protection which involves the exercise of those energies in supporting the title it seems to confer? This is now an almost invariable result of the establishment of any new industry under the aegis of the patent laws. Whether the invention be a steam-plough, an iron ship, a new dye, or a new manufacture of any kind, its value may be estimated most correctly by its more or less early appearance as a bone of contention in our courts of law. There the real advantages of patents are reaped, not, unfortunately, by the inventors, if by any of the contending parties.

But, it may be asked, do real inventors look to the patent laws as affording them a reward for the communication of their inventions, and protection in the enjoyment of such reward? A fact that was mentioned the other evening at the Society of Arts would seem to indicate that this is not the case. It was there stated that notwithstanding the existence of a vast number of British patents relating to sewing-machines, few, if any, of those patents are worked; and while the patents that are worked are chiefly American, the manufacture of those machines is almost altogether carried on in America.

The reason assigned for these conditions was the influence of the patent laws, which, instead of fostering invention and promoting manufacturing industry, encouraged piracy of ideas.

The same view of the case is indicated by the fact that manufacturers, who professedly work under patents, nevertheless maintain a profound secresy as to their operations, and trust to the honesty of their workmen rather than the protection of their patents.

If any feasible means should be devised for amending

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the patent law, and removing the serious evils it now presents, some provision should be made for limiting the barrier that old, and sometimes utterly forgotten, patents present to the patenting of what may be, to all intents and purposes, a new invention at the present time, but which cannot be made the subject of a patent by reason of a prior patent existing for an invention which has either never been brought into use, or which was at the time impracticable. It would seem that in such cases as this the absence of novelty, as regards patents, in a really valuable invention should not bar the validity of a second patent for that invention at a later period.

SCIENTIFIC AND ANALYTICAL CHEMISTRY.

Analytical Notes on Thallium-Separation of Thallium from Copper, by WILLIAM CROOKES.

IN the CHEMICAL NEWS for March 21 for this year (vol. vii., p. 133), a process was given for separating these two metals. Continuing my researches upon this point, I have found another method more delicate than the former one in its results, and requiring different reagents; it may therefore be found more serviceable in certain cases than the former process, and for this reason I consider that no apology is necessary for recording it. Moreover, in the present state of our knowledge respecting this new metal, any contributions to its history are of value, even though they be nothing more than different ways of effecting the same result. The plan formerly recommended consists in adding cyanide of potassium to the mixed ammoniacal solutions, and then sulphide of ammonium, the thallium being precipitated and the copper remaining in solution. This, as I have already said, is an exceedingly delicate process, but it is, I think, inferior to the following:-To the acid solution of thallium and copper add sulphurous acid in excess, and iodide of potassium. A dirty white precipitate will fall, consisting of subiodide of copper and iodide of thallium; if the precipitate is dark-coloured, and smells of free iodine, more sulphurous acid or sulphite of soda must be added, until the liquid, after agitation, smells of sulphurous acid. Now filter and wash well. Next, place the precipitate in a small flask with a wide neck, and pour pure ammonia over it; the iodide of copper will rapidly dissolve, with absorption of atmospheric oxygen, to a deep blue liquid, whilst the iodide of thallium will be left behind as an insoluble yellow powder, resembling iodide of lead, but not quite so dark; this may be filtered off and washed from copper.

Having constantly had occasion to decompose large quantities of iodide and chloride of thallium, it may be of some service to give the plan I found easiest to reduce these compounds to the metallic state. I formerly advised their conversion into sulphate, by heating with excess of oil of vitriol, and this is the plan now generally adopted. It is a troublesome process, as it requires the heat to be continued until the greater portion of the free sulphuric acid is volatilised, or a residue of chloride or iodide will be left behind on dissolving the mass in water. Another objection is, that the great heat required to effect complete decomposition volatilises some of the thallium. I now invariably adopt the following plan:-Boil the chloride or iodide of thallium in sulphide of ammonium for some minutes; decomposition takes place readily. Filter and wash with hot sulphuretted water (see note, page 133) until no chlorine or iodine is

CHEMICAL NEWS, May 9, 1863.

detected in the filtrate, and then dissolve in hot dilute sulphuric acid. If the operation has been conducted properly, complete solution will take place almost instantly. The metal can now be precipitated from this liquid by two or three Groves's batteries, or the sulphate can be obtained in the crystalline form by evaporation. It forms brilliant colourless prisms, permanent in the air, anhydrous, and fusible without decomposition below a red heat. The crystals are soluble in about five times their weight of boiling water, and twenty times their weight of cold water.

On the Reciprocal Action of Subsalts of Copper and Salts of Silver, by MM. E. MILLON and A. COMMAILLE. ON pouring a solution of ammoniacal subchloride of copper into a solution of nitrate of silver, also containing a little ammonia, perfectly pure metallic silver is immediately precipitated. At the same time, the following particulars may be observed :—

The silver precipitate is amorphous, and in so minute a state of division, that the diameter of each grain does not exceed o'0025 of a millimetre. We know that silver obtained by an electric current, or by the action of metals is often brilliant, and always crystalline. The amorphous silver obtained by us is of a dull grey colour, but sometimes nearly white; but in each case it assumes when burnished the highest metallic lustre, and, by reason of its divided condition, it can be easily applied to a variety of substances, such as wood, stone, leather, and different tissues. Thus, by one process, silver, both pure and divided, is at once obtained. These conditions are doubtless favourable to its application to many purposes.

In order to arrive at a due appreciation of the usefulness of this reaction, whether to extract, purify, or estimate silver, or to analyse exactly the compounds of copper, it ought to be understood that the reaction takes place among the principal reagents in the proportion of their chemical equivalents.

Thus, by the weight of silver precipitated, the quantity of suboxide of copper engaged in the reaction is exactly determined, it matters little whether the subsalt is pure or mixed with protosalt. This is a new and exact method of analysing a mixture of subsalt and protosalt of copper, and suitable for the study of cupreous compounds, and is free from all the uncertainty which formerly attended this study.

If the cupreous compound is used in sufficient quantity in relation to the salt of silver, all the metal of the silver salt will be precipitated. This, in fact, is what takes place, which we have verified by operations with a known quantity of silver dissolved in nitric acid, which we recovered with no appreciable difference of weight by the action of ammoniacal subchloride of copper.

Thus, 1115 grm. of fine silver dissolved in nitric acid, and the liquid rendered strongly ammoniacal, we added to it some equally ammoniacal subchloride of copper. The precipitated silver, well washed and dried, weighed 1114 grm. or 99'99 per cent.

o 588 grm. of silver treated in the same way was reduced to 0.5855 grm., or 99'57 per cent.

o'9827 grm. of same metal dissolved in the same way, then precipitated by ammoniacal cupreous chloride, weighed o983; 100'03, instead of 100 of recovered silver. This process, which is exact, gives the silver in a condition so easy to be collected and estimated, that the analysis of silver compounds by this method is very simple, and, above all, is speedily effected by it.

CHEMICAL NEWS, May 9 1863.

}

Passing over the preceding facts relating to the purification and extraction of silver, we were desirous of determining the solubility of chloride of silver in different liquids. For this purpose we used as solvent for the precipitated or melted chloride of silver, sometimes pure ammonia at different degrees of concentration, occasionally ammonia containing a solution of potassic or ammonic chloride, &c.; we have besides investigated the solubility of chloride of silver in chlorides, without free ammonia.

We used very ammoniacal subchloride of copper for the precipitation of metallic silver with the result shown in the following table, which indicates the proportion of metallic silver to one litre of each liquid :

These numbers were obtained with precipitated chloride of silver, but the solubility of melted chloride seems much the same; thus, the solubility of precipitated chloride being represented by 49.6 of metal, 48.4 would represent the melted chloride. It is, however, necessary to prolong the contact by occasional shaking the melted chloride reduced to small fragments.

The above table proves that it is easy to dissolve in a litre of commercial ammonia (the strength most easily obtainable) as much as 58 grammes of metallic silver in the state of chloride. This degree of solubility seems to us sufficient to render it possible that silver ores converted into chloride may have an industrial application, and it may supplant for this purpose mercury, so dangerous and expensive in the operation of extracting, which may be effected with peculiar simplicity.*

A litre of ammonia, saturated with chloride of silver, is precipitated by 230 cubic centimetres of an ammoniacal solution of subchloride of copper at its maximum of concentration; the precipitant must always be in excess, and the same quantity of copper serves any number of times; the protochloride of copper when formed being reduced by zinc, which is most energetically affected in the ammoniacal liquid. By this means the metallic copper required for the formation of subchloride is constantly reproduced; and, on the other hand, the ammonia disengaged by lime, and brought to the desired degree of concentration may be constantly re-employed. There is no need to show how much by this means the process of purifying silver is simplified.-ComptesRendus, February, 1863.

Analytical Notices on Arsenic, by M. H. Rose. ARSENIC may be estimated by difference in many of its combinations with metallic oxides, by calcination of the substance with sulphur; the arsenic volatilises as sulphide, the base remaining under the form of fixed

The silver residuums in laboratories are so quickly recovered by

this process, that probably it will soon be exclusively used.

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sulphide. The operation is easily effected in a hydrogen current, but is especially successful with arseniates of manganese, iron, zinc, lead, and copper.

Calcination with sulphur in a porcelain crucible completely eliminates the arsenic of arseniates of nickel and cobalt; but the weight of nickel and cobalt cannot be calculated from the residual sulphide.

Arseniate of silver, heated in a hydrogen current, or with sulphur, leaves silver which obstinately retains a certain quantity of arsenic.

The alumina resulting from the calcination of arseniate of alumina in a hydrogen current, whether singly or with sulphur, also invariably retains arsenic. It is the same with the magnesia resulting from ammoniacomagnesian arseniate.

The above process applies, of course, to many metallic arsenides, particularly to arsenical iron, to mispickel (arsenio-sulphide of iron), to arsenical nickel, and to grey cobalt (arsenio-sulphide of cobalt), though with greater difficulty. Grey cobalt must be previously oxidised by nitric acid, and the mixture of oxides then treated by sulphur; and this must be repeated several times.

In many instances the best way to expel arsenic acid from arseniates is to calcine them with hydrochlorate of ammonia. Alkaline arseniates are perfectly transformed into chlorides by a single calcination; arseniates of alkaline earths offer more resistance, and the magnesia of the arseniate always retains a certain proportion of arsenic.

Many oxides of true metals are reduced to a metallic state by calcination with sal ammoniac; but the metal will contain arsenic.

Bisulphate of ammonia, as shown by M. H. Finkener, can often advantageously replace the hydrochlorate. However, the fused bisulphate attacks the porcelain crucible, which must be used on account of the arsenic, and the sulphates obtained are mingled with those produced by this attack. The arsenic is generally entirely expelled. The author has ascertained this to be the case with ammonio-magnesian arseniate, with arseniates of soda, lime, and lead. Arsenides of nickel and cobalt are more easily freed from arsenic by this method than by fusion with sulphur.

Some few metallic arseniates may be decomposed by boiling with a solution of a hydrated or carbonated alkali. The author in this way has been successful with arseniates of peroxide of iron and copper; arseniates of zinc and protoxide of manganese yield oxides retaining notable quantities of arsenic.-Poggendorff's Annalen der Physik und Chemie, vol. cxvi., p. 453.

On the Electro-Chemical Decomposition of Insoluble Substances, by M. BECQUEREL. WHILST seeking to oxidise silicium at the positive pole, in distilled water, with a pile of eighty elements of sulphate of copper, I found that this metalloid is not, as has hitherto been supposed, a non-conductor, but that it possesses, when traversed by an electric current, sufficient conductility to produce remarkable caloric effects, by reason of its great resisting powers. By putting small cylindroid crystals of silicium, prepared by M. Deville's process, into a porcelain, or better still a platinum capsule, in communication with one of the poles of the pile, and closing the circuit with a platinum-wire, at least one millimetre in diameter, then by simply touching with this wire one only of the crystals, the adjacent crystals become incandescent. All the crystals follow