Intelligence and Miscellaneous Articles, 555 



is deposited from solutions containing free sulphuretted hydrogen ; 

 the more they contain of this the whiter is the sulphur. It is 

 never whiter than when it is deposited from water saturated with 

 sulphuretted hydrogen, in which the hydrogen of the sulphuretted 

 hydrogen has been gradually oxidized by the contact of the air. If 

 on the contrary finely divided sulphur be precipitated from solutions 

 which do not contain free sulphuretted hydrogen, it has a yellow 

 colour, even when the quantity is small. It is sufficient to decom- 

 I)ose a small quantity of a solution of an alkaline hyposulphite by 

 an acid, to be convinced of the truth of this assertion. 



White or gray precipitated sulphur, (milk of sulphur) contains a 

 very small quantity of sulphuretted hydrogen, in the state of per- 

 sulphuret of hydrogen. If it be fused and the small quantity of gas 

 disengaged from the surface of the fused sulphur be conducted by 

 the aid of a current of atmospheric air into a solution of lead, a no- 

 table quantity of sulphuret of lead is obtained. M. Rose treated in 

 this way a large quantity of the different modifications of this white 

 sulphur prepared in different modes, and he always obtained the 

 same result. 



In melting flowers of sulphur, or roll sulphur, it is true that there 

 is sometimes obtained a little sulphuretted hydrogen ; but the quan- 

 tity of it is so small that it cannot be compared with that disengaged 

 from the milk of sulphur. Water cannot remove from this last- 

 mentioned substance the small quantity of sulphuretted hj^drogen 

 which it contains ; for all the modifications examined were washed 

 with water till it produced no effect in a solution of lead. — Journal 

 de Pharmacie, Aout, 1839. 



URIC ACID. 

 M. Fritzsche has analysed hydrated crystallized uric acid. When 

 the process given by M. Bceteger of preparing uric acid is adopted, 

 and which consists in dissolving pigeons' dung in a solution of borax, 

 and precipitating the uric acid with hydrochloric acid, the acid is 

 procured in much larger crystals when the solution contains a great 

 quantity of organic matter than when it does not contain any. The 

 separation of the uric acid takes place readily, and but a small quan- 

 tity remains in the liquor. Even this separates on standing, in the 

 form of yellowish brown dendritic crystals, of a line in length, and 

 are hydrated uric acid. This hydrate, when dried at 212° Fahr., 

 loses about 2r52 per cent, of water. It is only these large crystals 

 which are hydrated ; whenever it is precipitated from hot dilute so- 

 lutions the acid is always of this kind ; the smaller the crystals are, 

 the more readily they part with a portion of their water at the usual 

 temperature, and it is on this account that they have been so long 

 unknown. — L'Institut, No. 304. 



CHLORIODIDE OF POTASSIUM. BY M. FILHOL. 



When a current of chlorine gas is passed through perfectly neu- 

 tral iodide of potassium dissolved in twice its weight of water, the first 

 bubbles of the gas communicate a brown colour to the liquor ; the 



Jfe 



