398 Intelligence and Miscellaneous Articles. 



are dissolved in the water ; the liquor then contains selenious acid 

 and hydrochloric acid resulting from the decomposition of the proto- 

 and deuto -chloride of selenium in water. 



On the addition of hydrochloric acid, and tten sulphite of ammo- 

 nia, this salt is decomposed by the hydrochloric acid, and the sul- 

 phurous acid which is set free precipitates the selenium in the state 

 of a grayish powder, which afterwards becomes yellowish-white. 



M. Trez thinks that the seleniate of potash may either have been 

 fraudulently added, or that it was extracted with the iodine. — Journ. 

 de Ch. Med., Avril 1848. 



ON TRANSPARENT AND OPAKE ARSENIOUS ACIU. BY M. BUSSY. 



It is well known that arsenious acid exists in the different states 

 above-mentioned, and also that the transijarent variety becomes 

 opake ; it has been stated that the former is less soluble in water 

 than the latter. By performing experiments to determine this point, 

 M. Bussy has arrived at the following conclusions : — 



1st. 'I'hat the transparent acid, far from being less soluble than 

 the opake, as stated by several chemists, is, on the contrary, much 

 more so ; the difference is nearly as 3 to 1, at the temperature of about 

 55° F. ; thus a litre of water which dissolves 40 grammes of the 

 transparent acid dissolves only 12 to 13 grammes of the opake. 



2nd. That the transparent acid dissolves much more rapidly than 

 the opake. 



3rd. That neither of these acids possesses a perfectly constant 

 degree of solubility. 



4th. That the opake acid is converted into the transparent by 

 long-continued boiling in water, that is to say, it acquires the same 

 degree of solubility as the transparent acid, which is such that 100 

 grammes of acid dissolve in a litre of water at 212°. 



5th. That under the influence of water and a low temperature the 

 transparent is converted into the opake acid. 



6th. That the mixture of the two varieties of acid in the same 

 solution explains the anomalies observed in thesolubility of arsenious 

 acid. 



7th. That division which facilitates the solution of the opake 

 arsenious acid without increasing its solubilitj% considerably dimi- 

 nishes that of the transparent acid, and to such an extent, that the 

 latter, reduced to fine powder and levigated, is not sensibly more 

 soluble in the cold than the o])ake acid ; this effect undoubtedly re- 

 sults from a transformation which it undergoes, either at the moment 

 of pulverizing, or of its contact with water. 



8th. That the acid which has become opake by the slow trans- 

 formation of the transparent, by the action of ammonia, and the acid 

 crystallized in water, are similarly acted upon Ijy water, and appear to 

 belong to the same variety. 



9th. Tliat under the influence of dilute hydrochloric acid, the 

 opake acid dissolves more slowly than the transparent ; this circum- 

 stance, which modifies the nature of the products formed during 



