260 Translations and abstracts from the French, 



It is evident from the preceding statement, that chlorine 

 combined with cyanogen, exerts an action upon water anal- 

 ogous to that of other chlorides, iodides and bromides; that 

 this combination is transformed, by the decomposition of 

 water into hydro-chloric and cyanic acid ; that the latter 

 being more fi.vcd and very stable, may be separated, by 

 evaporation, from the other, which is very volatile. 



The discovery of the perchloride of cyanogen, indepen- 

 dently of the interest which it presents in itself, becomes 

 more important by the discovery of cyanic acid, which re- 

 sults from it, since the latter creates a class of salts before 

 unknown to chemisti;\ 



M. Serulas has combined the acid with several oxides, but 

 as the cyanates may be numerous, he reserves them for the 

 subject of another memoir. — Annales de Chimie ct de Phys- 

 ique^ Aout, 1828. 



Preservation of Hydro-cyanic Acid, by M. Schutz. — A 

 quantity of hydro-cyanic acid, prepared agreeably to the 

 process of Ittner, having begun to turn yellow in the course 

 of a month, M. Schiitz rectified a part of it from calcined 

 sulphate of zinc, and obtained a colorless acid, which pre- 

 served its qualities three years and a half: ten drops were 

 sufficient to kill a large dog. — Aim. de Chim. et de Phys. 



2. Specific gravity considered as a inineralogical charac- 

 ter. — The statement given in treatises of mineralogy, of the 

 specific gravity of different varieties of the same substance, 

 shews so much discordance among these varieties, as to pre- 

 vent specific gravity from being worthy of any reliance as a 

 character. F. S. Beudant, suspecting that this difference 

 has arisen in part, from the presence of foreign substances in 

 the specimens examined, and partly from the want of per- 

 fect accuracy in the different persons who have described 

 them, has taken pains to ascertain what actual agreement 

 there is, in the specific gravity of the same substance in a 

 pure state in its difierent forms. 



The specific gravity of carbonate of lime, varies accord- 

 ing to the books^ from 2.324 to 3.672. M. Beudant, in limit- 

 ing himself strictly to those varieties which were identical in 

 chemical composition, so as to avoid the influence of mix- 

 tures, finds indeed in different varieties some difference of 

 specific gravity, but far more Hmited in its extent than ap- 



