potash. It has a very pungent odour, acts powerfully upon the tongue, and is very volatile. By exposure to light, it becomes yellow; its aqueous solution reddens litmus, but its alcoholic solution does not, until the paper has been exposed afterwards to a moist atmosphere. Alkalies combine with it, neutralizing its striking properties. The moistened crystals put into the voltaic circuit between silver poles, are decomposed. Sulphur passes to the positive pole, and an odour of almonds is perceived at the negative pole. Potassium decomposes it, producing cyanide and sulphuret of potassium.

The substance has several of the properties of an acid. As before said, it combines with, and neutralizes alkalies and its solution, or the solution of its salts produces the same red colour with persalts of iron, as Porret's ferrochyazic acid. In certain states, indeed, it almost appears to be identical with Porret's acid, but in other points it differs; as, for instance, in its solid state, and in the action of oxide of silver upon it, which causes decomposition, abstracting the sulphur.

To ascertain the ratio of the cyanogen and sulphur in this compound, a certain weight was combined with potash, and the compound produced being mixed with six times its weight of nitre, was calcined in a silver crucible. The mass dissolved in water was neutralized by nitric acid, and the sulphuric acid formed precipitated by muriate of baryta. 100 parts of the substance gave, in one experiment, 180 of sulphate of baryta, in another 176. Calculating from this the quantity of sulphur, and, from the deficiency, the quantity of cyanogen, the compound would appear to consist of 75.8 cyanogen and 24.2 sulphur; and, therefore, the substance probably contains, according to M. Lassaigne's numbers, 4 proportionals of cyanogen, and I of sulphur, or 2 proportions of cyanogen 52, and 1 of sulphur 16.-Ann. de Chimie, xxxix. p. 197.

10. Supposed Discovery of a method of making Diamonds.Much expectation has been excited by the announcement of a method of making diamonds discovered in France, and actually communicated to the Academy of Sciences, at Paris, by M. Gannal, on the 3d of November last; but, as yet, the expectation has not been satisfied, and no philosopher, who can be considered as competent to judge of the process and the products, has as yet sanctioned the announcement by the authority of his opinion. The point to be gained is the crystallization of carbon, and this, it is said, is done by, the simplest possible case of chemical affinity. The well-known liquid compound of sulphur and carbon is put into a vessel, covered with a layer of water, and then a stick of phosphorus introduced; the phosphorus dissolves in the sulphuret of carbon, soon takes the sulphur to form a sulphuret of phosphorus, and the carbon is set free as a crystalline diamond powder.

It is distinctly said that crystals are obtained, white or colourless,

very brilliant, hard, extremely refractive, and admitted by workers to be real diamonds.

Since M. Gannal's announcements, other diamond makers have come forward. On the 10th of November, M. Arago communicated a note to the Academy of Sciences, from M. Cagniard de la Tour, in which the latter said that he also had succeeded in crystallizing carbon and obtaining diamonds by methods different from those of M. Gannal, and that a sealed packet, left with the Secretary in 1824, contained an account of his first processes. From M. Cagniard de la Tour's character as a philosopher, we must feel satisfied he would not say so much without some good foundation; and on this ground, therefore, we have hopes that, upon inquiry, the crystallization of carbon may prove to have been effected by art.

M. Arago also announced that he knew another person who had arrived at similar results. As to M. Gannal's experiments, M. Gay Lussac said that, eight years ago, M. Gannal spoke to him about his attempts.

Academy of Sciences of Paris, Nov. 24th.-M. Thenard gave an account of the experiments made by himself, MM. Dumas and Cagniard de la Tour, to verify the trials, by which the latter thought he had obtained the power of crystallizing carbon, and forming diamond. An accurate analysis of these crystals, which had no colour, proved, however, that they were only silicates, and not artificial diamond.—Ann. de Chimie, xxxix. 327.

11. Manufacture of Flint Glass.-The Annales de l'Industrie Française announce the discovery of a regular process for manufacturing flint glass for optical purposes, and states that the success is certain. The process has been the result of the patient and expensive investigations made by MM. Thibeaudeau and Bontemps. The specimens of glass, both flint and crown, have been laid before the Academy of Sciences, but, as yet, no report upon their quality has been given, nor any account of the process itself published, so that opinions must remain a little longer in suspense.—Vol. ii. p. 251.

12. Action between Metallic Chlorides and Olefiant Gas.-M. Wöhler has remarked that, when olefiant gas is sent into liquid chloride of antimony, a very large quantity is absorbed; heat is evolved, and the fluid becomes brown. On cooling, crystals of chloride of antimony are deposited, but there is now little power of producing fumes in the air, and a strong odour of chloric ether is perceived. When distilled, a liquid product is obtained, which gradually separates into two layers, the lower being pure chloric ether, and the upper a solution of chloride of antimony in the same fluid. :

The red and fluid chloride of chrome acts in a similar manner. Chloride of copper heated in olefiant gas is decomposed, and char

coal is deposited, whilst a portion of sub-chloride is formed.Annalen der Physik, Bull. Univ. A. x. 258.

13. On the Presence of Iron in Tin.-From M. Fischer's experiments, it would appear that even the very best tin contains small quantities of iron occasionally, which, entering into the compounds afterwards formed by the metal, cannot be easily separated. The best method to decide upon its presence, is to decompose a salt formed from the tin by ammonia, and separate the protoxide which is thrown down. This precipitate is then to be digested in cold muriatic acid; nearly all the oxide dissolves; but if the portion which last remains be removed, it will be found to contain but little oxide of tin, mixed with a large proportion of oxide of iron. This portion, acted upon by warm and strong muriatic acid, will dissolve; and then the iron may be recognized in the usual manner.—Kastner, Bull. Univ., A. x. 313.

14. Supposed Presence of Mercury in Sea-water.-Dr. Torrey, incited by the notices that at various times have appeared in journals, of the presence of mercury in sea-water, made an expe, riment, in which a small plate of polished gold, of known purity, was attached to the bottom of a vessel, in a situation where any great friction from the motion of the vessel was avoided. The ship sailed from New York to Liverpool, and returned to New York, when the plate of gold being examined, was found to exhibit no appearance of the presence of mercury, and to retain its original brightness.-Silliman's Journal, xv. 357.

Supposing that there is any other reason to suspect the presence of mercury in sea-water, we hardly think the above experiment a conclusive one. A soluble compound of mercury in sea-water would have no tendency to be decomposed by gold thus situated.-Ed.

15. Method of detecting Arsenic in Sulphur.-MM. Geiger and Reimann say, that the presence of arsenic in sulphur, to the amount only of 0.000061, may be discovered in the following manner :-A certain quantity of precipitated sulphur, flowers of sulphur, or ordinary sulphur finely pulverised, is to be digested with ammonia for a considerable time, then filtered, and afterwards the clear liquid acted upon by excess of muriatic acid. If a yellow precipitate occurs, it is an indication of the presence of arsenic; if not, the liquid is to be evaporated until only a few drops remain. A little ammonia is then to be added; afterwards, a small quantity of muriatic acid; and, finally, a little solution of sulphuretted hydrogen. If there be the smallest quantity of arsenic, it will be rendered evident by a yellow precipitate.-Bull. Univ., A. x. 266, -~

f

16. Spontaneous Inflammation of Arsenical Cobalt-In conse

quence of a fire which occurred in a drug warehouse, an examination was made into the circumstances, and it was found that it arose from moist powdered arsenical cobalt, closely packed together. When this substance is pulverised, as the powder is poisonous, it is usually moistened, to prevent it from flying about. This circumstance, with the presence of the pyrites, and the closely-packed state of the whole, had produced spontaneous inflammation, the cause of which being now discovered, all druggists are warned not to keep quantities of such cobalt together in a moist state.-Recueil Industriel, viii. 168.

17. Sulphate of Potash and Chrome.-The best method of preparing this salt is to add one part of concentrated sulphuric acid to three parts of a saturated solution of chromate of potash. The precipitate at first formed will be re-dissolved, and then two parts of alcohol are to be added. The mixture soon acquires a green colour, and crystals often form immediately; if not, sufficient water may be added to dissolve all the salt separated, and the solution is to be evaporated spontaneously. To purify the crystals, they should be washed in small quantities of water, until the latter is of a pure violet colour, without any green appearance. 100 parts of this salt contain 32 sulphuric acid, 8.4 of potash, 15.6 protoxide of chrome, and 44.08 of water.

The crystals are octoedra. Solution and evaporation, at common temperatures, do not change them; but by heat, the solutions are decomposed, become green, and leave a fine green mass, or else form crystals of sulphate of potash, whilst sulphate of chrome remains in solution. A heat, from 122° to 167° F., is sufficient to effect this change perfectly, even in dilute solutions.-Bull. Univ., A. x. 316.

We

18. Preparation of Spongy Platina for effecting Ignition.M. Pleischel recommends that a piece of paper be imbibed three times in succession with a solution of muriate of platina, and then burnt. The residue is the platina, he says, in its best state. have always found that, when prepared by heating a little pure ammonio-muriate of platina upon platina-foil in a spirit-lamp, at a temperature as low as possible, so that it be sufficient to dissipate every thing volatile, that then the platina would inflame a mixture of oxygen and hydrogen, at the lowest possible temperature.-Ed.

19. Muriates of Ammonia and Platina.-M. Fischer says, there are three of these triple salts:-that which is well known, or the neutral ammonio-muriate; another, which is white, containing excess of ammonia; and a third, which is yellow, containing excess of oxide of platina.

The white ammonio-muriate is obtained by dissolving the ordinary triple salt in ammonia, and applying slight heat. A clear, faintly

yellow liquid is obtained. Alkaline carbonates, sulphates, oxalates, or phosphates, cause a white precipitate, which is the salt in question. It is obtained also by the addition of concentrated sulphuric, phosphoric, nitric, or muriatic acid. Alcohol and protosulphate of iron also produce it; but then the precipitate has to be cleared from oxide of iron by a little muriatic acid.

The yellow salt is to be prepared in a similar way. The sulphate and phosphate of soda are the best precipitants, but some hours are required for the action. A quantity of the salt to be prepared always remains in solution. Alcohol and the phosphate of soda are the best agents in this respect for the white salts; the sulphate of iron, used as mentioned, the best for preparing the yellow salt.

The following are some of the distinguishing characteristics of these three salts:-the ordinary salt crystallizes in octoedra; is soluble in 150 parts of water at common temperatures, and in 80 of boiling water; is perfectly soluble in ammonia, giving a permanent solution without colour; is insoluble in muriatic acid at common temperatures, and but little soluble by heat; is slightly soluble in dilute sulphuric acid: its solution is not affected by ferroprussiate of soda: when heated, it does not fuse; and it evolves muriate of aminonia and chlorine.

The white salt forms an adhesive or filamentous powder; is scarcely soluble even in boiling water; is insoluble in boiling ammonia; dissolves by heat in muriatic acid, and, upon cooling, is deposited, changed into the yellow salt; is insoluble in dilute sulphuric acid; its ammoniacal solution is precipitated pale brown by ferro-prussiate of soda. When heated, it fuses, and then evolves muriate of ammonia and free ammonia.

The yellow salt forms an adhesive or filamentous powder; is less soluble than the ordinary salt at common temperatures, but very soluble at high temperatures, forming a pale turbid solution: it dissolves in ammonia by ebullition, and is converted into the white salt; it dissolves in muriatic acid without change; it dissolves in dilute sulphuric acid; its aqueous solution is precipitated yellow or brown by ferro-prussiate of soda. When heated, it first fuses, and then is decomposed, evolving muriate of ammonia, but neither free chlorine nor ammonia.-Kastner's Archives, xiv. 145.

20. On Glucium and Yttrium, by F. Wöhler.-Both of the earths glucina and yttria have been decomposed by M. Wöhler, by a process the same as that which he applied successfully to alumina*. The metallic bases are as little oxidable as aluminum, and have many analogies with it.

Glucinum. The glucina was prepared from beryl, and being mixed with charcoal, and heated in a tube, chlorine, was passed over it †, and a chloride formed; this was obtained both in white

* Quarterly Journal of Science, N. S. vol. iv. p. 209; vol, ii. p. 474.

† Ibid. vol. iv.

p. 211.