CHBJOBTIY. 4S7 



CHEMISTRY. 



Soft Sulphur. — Baudrimont has fouud that fresh soft sulphur left for rive or 

 six days in contact with oil of turpentine in a closed tube, becomes opaque and 

 covered with 6mall transparent brilliant crystals, which are also deposited ou the 

 sides of the tube They are modifications of the symmetrical octohedron. This 

 arises probably from the greater solubility of soft sulphur in ••il of turpentine — 

 Compten Pendus, Ap. 2S. 



Carbonic Oxide. — Grimm and Ramdohr, have found that the Carbonic Oxide 

 gas, prepared by Fownes' process (heating 1 part ferrocyanide of potassium with 

 9 parts concentrated sulphuric acid.) is not quite pure, containing a small quantity 

 of carbonic as well as of sulphurous acid. It may be perfectly purified by 

 solution of potassa. — Ann. d. Ch. u. Ph , Ap., 1856 



Bone Earth. — Wohler has found that bone-dust if left some time in contact with 

 water gives up a certain proportion of the phosphates of lime and magnesia. The 

 same result is obtained if the water be perfectly freed from carbonic acid by long 

 boiling. The quantity dissolved seems to increase, as the organic matter putrifies 

 This fact is of considerable importance in reference to agriculture. — Ann. d. Ch 

 u. Ph. Ap. 1856. 



Pure Silver. — "Wicke dissolves the alloy of copper and silver in nitric acid, 

 precipitates with hot solution of carbonate of soda, boils the precipitate with a 

 solution of grape sugar by which the copper is obtained in the form of suboxide 

 and the silver as metal. The precipitate is treated with a hot solution of car- 

 bonate of ammonia, which dissolves the oxide of copper but none cf the silver. — 

 Ann. d. Ch. u. Ph. Ap . 1856. 



2'est for Iodine. — Liebig recommends the addition of a small quantity of an 

 alkalic iodate, followed by sulphuric or muriatic acid to a solution containing so 

 small a quantity of iodide that no coloration is produced by starch and nitric 

 acid; in this case a much deeper colour is produced. Neither iodic acid nor 

 iodide of potassium produces any colour with muriatic acid and starch paste, 

 The mother liquors of some mineral springs produce the colour without the ad- 

 dition of the iodate; they must contain some substance which acts in a -imilar 

 manner, possibly nitrates. — Ann. d. Ch. u. Ph Ap., 1 856. 



Determination of Chlorine. — Levol has described a method of determining 

 chlorine by means of a normal solution of nitrate of silver, in which he renders 

 the completion of the precipitation perceptible by an addition of phosphate of 

 soda, the presence of an excess of silver being indicate d How tint of the 



precipitate. This colour being very faint. Mohr recommends the use of chromate 

 of potash, the red colour of the chromate of silver becomes perceptible when a 

 very minute excess of the silver solution has been employed. The chromate and 

 not the bichromate should be used and the solution must not be acid. Mohr has 

 employed the process in the examination of urine, well water, mineral waters, 

 saltpetre, potaebes, soda, and chlorate of potash, and always with concordant 

 results. — Ann. d. Ch. u. Ph. A p.. 97. 



Silvering. — Liebig has given valuable directions for silvering glass mirrors in 

 the cold, the silvering is effected by a solution of ammoaiacal nitrate of silver, 

 excess of caustic potassa and milksugar. — Ann. d. Ch. u. PA., April, 135G, Ch. 

 Gaz. 327. 



Fur/urine — Svanbergand Sergstrand have examined the sulphate, phosphates 



