The potash, free ammonia, and uric acid of urine, will interfere slightly with the accuracy of this result, but even this cause of error can be avoided, by first adding to another weighed portion of the urine, some chloride of platinum with three volumes of alcohol and one of ether; which will give the double chloride of the potash and free ammonia contained in the urine, that can be subtracted from what was given by the reaction of sulphuric acid. The error arising from the uric acid is seldom more than Tʊʊʊ; and this acid may be separated from the urine prior to adding the sulphuric acid, by treating the three drachms of urine with thirty drops of muriatic acid, allowing it to stand for twenty-four hours and filtering. J. LAWRENCE SMITH.

3. Determination of the amount of Ammonia contained in the Atmosphere; by A. GRAEGER, (Archiv. der Pharm., xliv, p. 35, and Chem. Gazet., Jan. 1846, p. 34.)-The method employed by the author, was to pass the atmosphere through muriatic acid contained in a convenient vessel. After thirty-six cubic feet of air had been made to pass through slowly, the acid liquid was evaporated to dryness in a small platinum crucible placed in a water bath, chloride of platinum being previously added. The residue was treated with alcohol and ether, and the insoluble portion collected and weighed. In the above experiment 0·006 grm. of ammonio-chloride of platinum were obtained, and this was found on calculation to correspond to millionth of carbonate of ammonia in the atmosphere. The experiment has been performed in both dry and wet weather with very nearly the same result. J. L. S.

4. Test for Ruthenium; by M. CLAUS, (Chemist, Jan. 1, 1846-7.) -The best means of ascertaining the presence of Ruthenium in the ore of platinum is the following:-Melt it with an excess of nitre in a small platinum spoon, exposing it to a strong heat until the mass no longer swells, but becomes perfectly liquid; then allow it to cool and dissolve it in a small quantity of distilled water. A few drops of nitric acid produce in the orange colored solution, a black precipitate, consisting of ruthenium and potash. If we add hydrochloric acid to the liquid in which the precipitate is found, and heat it in a porcelain capsule, the oxide is dissolved, and by concentration assumes a beautiful orange color. Finally, if we cause sulphuretted hydrogen to pass through the solution until it has become almost black, and then filter it; a liquid of a beautiful sky-blue color will pass through. J. L. S.

5. Iodine used to distinguish between the Arsenical Antimonial taches formed by Marsh's Apparatus; by M. LASSAIGNE, (Comptes Rendus, Dec. 1845, p. 1324.)-The taches formed by Marsh's apparatus are exposed to vapor of iodine, when, if they be arsenical, they become of a pale yellowish brown color, which changes to a lemon yellow, and subsequently disappears by exposure to air or to a gentle heat.

The antimonial taches under the same circumstances, become of a carmelite yellow, which, by exposure to the air, passes to an orange and then they remain unchanged.

The alcoholic solution of iodine dissolves instantaneously the arsenical tache. The antimonial tache is not acted upon immediately by the same solution, although as the solution evaporates, the metallic antimonial tache is replaced by one of an orange red, (the ioduret of antimony.) J. L. S.

6. On the Decomposition and Analysis of the Compounds of Ammonia and Cyanogen; by R. SMITH, (Phil. Mag., March, 1846, p. 222.) -The ammonia compounds are analyzed by liberating all their nitrogen by means of some of the chlorine compounds, and estimating the amount of ammonia by the gaseous nitrogen. The chloride of lime was the salt usually employed for this purpose. This method is regarded by the author as being peculiarly applicable to the analysis of organic substances. He also proposes the employment of chloride of lime as a ready and accurate method of estimating the quantity of nitrogen contained in urine, from the amount of gas disengaged by its action in the nitrogenous compounds.

Hydrocyanic acid and the cyanides are also very rapidly decomposed by the chloride of lime or soda, yielding nitrogen gas and carbonate of lime or soda. The author has also discovered that the hypochlorites decompose uric acid in a very satisfactory manner, and he is inclined to believe that they may be advantageously used as solvents for uric acid calculi in the bladder. J. L. S.

7. Preparation of the Hypophosphite of Baryta; by M. WARTZ, (Ann. de Chim. et de Phys., Feb. 1846.)-This salt is prepared by boiling a solution of sulphuret of barium with phosphorus, until gas ceases 'to be evolved. If the ebullition be continued long enough, the whole of the sulphuret will be decomposed; should this not be the case, it is readily got rid of by the addition of a little carbonate of lead, or by the careful addition of sulphuric acid as long as sulphuretted gas is evolved. If an excess of acid be added, it is easily got rid of by a little carbonate of baryta.

All the other hypophosphites are formed from this by double decomposition with the soluble sulphates. J. L. S.

8. New Acid in Tobacco; by M. BARRAL, (Comptes Rendus, Dec. 1845.)-It has been found that the acidity of water in which tobacco leaves have been steeped, is due to a new acid, called by the discoverer nicotic acid, composed of C3HO3+HO. J. L. S.

9. Valerianic Acid and a New Substance from Caseine; by Prof. LIEBIG, (Annal. der Chem. und Pharm., Jan. 1846.)-Caseine when fused with its own weight of caustic potash, until hydrogen gas is evolv.

ed along with the ammonia, allowed to cool, dissolved in warm water, and super-saturated with acetic acid, furnishes a crystalline substance that is but slightly soluble in cold water and insoluble in alcohol and ether. Its composition is C16NH905. It is soluble in the alkalies, and com bines with acids. If the fused caseine and potash be treated with tartaric instead of acetic acid, and the liquid submitted to distillation, it furnishes valerianic acid. This acid appears to be preceded in its formation by leucine, which substance is itself converted in to valerianic acid by the action of potash. J. L. S.

10. Bromo-boracic Acid, (Bromide of Boron;) by M. POGGIALE, (Comptes Rendus, Jan. 1846.)-It is prepared by passing the vapor of bromine through a mixture of charcoal and boracic acid, heated to redness in a porcelain tube. It is well to heat the mixture of charcoal and boracic acid for about half an hour previous to passing the vapor of bromine through it, in order to get rid of any moisture. The acid, which is a gas, can be collected over mercury, this metal absorbing any excess of bromine. It is a colorless gas with a pungent odor and acid taste; it extinguishes combustion and affords white vapors in contact with the air. Chlorine decomposes it with the liberation of bromine. Its density is 8-6443, and its composition is BBr3. J. L. S.

11. Quantitative estimation of Bromine in Mineral Waters; by M. HEINE, (Journ. für Prakt. Chem., xxxvi, 181, and Chem. Gazet., March, 1846, p. 103.)-A series of liquids containing a known amount of bromine is prepared, by dissolving in every ounce of distilled water from five to fifty milligrammes of bromide of potassium, making a series of ten liquids. Equal quantities of ether, measured in the same glass, are added to these different solutions and the tubes immediately closed. An equal quantity of chlorine water is next added to the solutions and the mixture well shaken. Upon allowing it to rest, the ether collects on the surface, holding in solution the bromine, and we thus obtain a regular scale of colors, from yellow to brown, and these solutions now serve as standards of comparison. Beyond fifty the comparision becomes more uncertain, because the tints of every additional five milligrammes of bromide of potassium can no longer be well distinguished, on account of the dark color. Five milligrammes of bromide of potassium is equal to 3.3 milligrammes of bromide.

As soon as the scale of colors has been prepared, an ounce of the liquid to be examined, is introduced into a vessel similar to the ones containing the test solutions, and to it is added the same amount of chlorine and ether as in the other cases, it is shaken, and the ether allowed to collect upon the surface, the color of which, by comparison with the scale colors, will indicate the amount of bromine present. J. L. S. SECOND SERIES, Vol. II, No. 4.-July, 1846.

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12. Solubility of Sulphate of Lime; by M. ANTHON, (Chem. Gaz., May 1, p. 173, from Buch. Report, xli, 363.)-M. Anthon digested pure artificially prepared gypsum, at the ordinary temperature, in a close vessel with distilled water, and in another with a saturated solution of common salt. On examination he obtained from 1000 grains of the first liquid with chloride of barium, 31 grains, and from the second, 111 grains, sulphate of baryta. In accordance with this, gyp sum dissolves in 438 parts pure water, and in 122 parts solution of chloride of sodium.

13. Analyses of Glass; by M. PELIGOT, (L'Institut, No. 638, March 28, 1846.)-Bohemian fine glass-silica 76, potash 15, lime 8, alumina 1.

Bohemian agate glass-silica 80-9, potash 17-6, alumina 8, traces of oxyd of iron 0.8, lime 0.7.

Artificial aventurine from the works at Murano and Venice-silica 67-7, lime 8-9, sesquoxide of iron 35, oxyd of tin 2-3, metallic copper 3.9, oxyd of lead 1.1, potash, soda 12·6, with traces of alumina, magnesia, and phosphoric or boracic acid. From this analysis it appears that this aventurine differs widely from the glass made in imitation of it by MM. Frémy and Clémandot.*

14. On the Solubility of Fluoride of Calcium in water, and its Relation to the occurrence of Fluorine in Minerals, and in Recent and Fossil Plants and Animals; by GEORGE WILSON, M. D., F.R.S.E., (Chem. Gaz. May 1. 1846, p. 183-read before Roy. Soc. Edinb.)— After a preliminary reference to the existence of fluorine in recent and fossil bones, Dr. Wilson stated that he had made a series of experiments with a view to discover what solvent carried fluoride of calcium into the tissues of plants and animals.

His first trials were made with carbonic acid, which was passed in a current through water containing pure fluor-spar in fine powder suspended in it. The fluor-spar was, by this treatment, dissolved, yielding a solution which precipitated oxalate of ammonia, and when evaporated left a residue, which on being treated with sulphuric acid gave off hydrofluoric acid. The author was inclined, in consequence, to suppose that carbonic acid conferred upon water the power of dissolving fluoride of calcium; but on observing that, long after the whole of that gas had been expelled by warming the liquid, the latter remained untroubled, he became satisfied that water alone can dissolve fluoride of calcium, contrary to the universal statement of writers on chemistry.

On prosecuting the inquiry, he found that water at 212° dissolved more of the fluor-spar than water at 60°; but he has not yet ascertained the proportion taken up by that liquid at either temperature.

See this Journal, Second Series, i. 430.

The aqueous solution of fluoride of calcium was found to give with salts of baryta a precipitate, which required a large addition of hydrochloric and nitric acid to dissolve it.

The author pointed out the difficulty which must in consequence occur in distinguishing between fluorides and sulphates, and suggested that fluorides may have been mistaken for sulphates in the analysis of min eral waters. He referred also to the objection which must now lie against the present method of determining the quantity of fluorine pres. ent in bodies, consisting as it does in converting that element into fluoride of calcium, which, in the course of the necessary analytical operations, is washed freely, and must be seriously diminished in quantity; a fact which has of necessity been hitherto overlooked.

Dr. Wilson stated, that he was not yet able to suggest an unexcep. tionable quantitative process; but that, at all events, the fluoride of barium, being much less soluble than the fluoride of calcium, might in the meanwhile be substituted for it in the examination of fluoride.

The author then proceeded to state, that, in consequence of the ob servation he had made as to the solubility of fluoride of calcium in water, he had been led to look for that body in natural waters, and had found it in one of the wells of Edinburgh, viz. in that supplying the brewery of Mr. Campbell, in the Cowgate, behind Minto House. At the same time he stated, that preceding observers had already found it in other waters. He believed however, that he was the first to detect it in sea water, where, by using the bittern or mother-liquor of the saltpans in which water from the Frith of Forth is evaporated, he had found it present in most notable quantity. The author referred to the presence of fluorine in sea water, as adding another link to the chain of observed analogy between that body and chlorine, iodine and bromine.

Dr. Wilson further stated, that he had confirmed the observations of Will as to the presence of fluorine in plants: and Berzelius's discovery, that fluorine exists in the secretion from the kidneys; and had, in addition, detected fluorine in milk and blood, in neither of which has it hitherto been suspected to occur. The paper concluded by some observations on the presence of fluorine in fossils, and its relation to animal life.

15. Remarkable Discoveries in Isomorphism; by M. SCHEERER, (in a letter to B. Silliman, Jr., from Berzelius, dated March 10, 1846.)Mr. Scheerer has just found that in compounds containing magne. sia, protoxide of iron, oxide of nickel and other oxides isomorphous with magnesia, a part of the base may be wanting without a change of crystalline form, provided that this part be replaced by a quantity of water which contains three times as much oxygen as this part of the base. For example, the compounds Mg3Si, Mg2Si+3, and