Materials for a History of the Prussiates. ^ 45 



ide of mercury would not succeed perhaps in decomposing 

 a combination so strong as that of the triple prussiate. 



Diluted sulphuric acid has no action upon the prussiate 

 of mercury even with heat, and not the slightest smell of 

 prussic gas is perceived. 



Potass saturates the sulphuric acid as the excipient of the 

 prussiate, but precipitates nothing. 



Concentrated sulphuric acid destroys the prussic acid, 

 gives sulphureous acid, and thereby puts an end to every 

 mean of comparison. 



The nitric acid is not more successful, even after ebul- 

 lition. We perceive very early a little nitrous gas, but it is 

 certainly the black oxide containing the prismatic prussiate 

 which occasions it : to conclude, the prussiate crystallizes 

 in the mass of the acid. The alkalis saturate this last, and 

 also precipitate nothing from it. 



It does not elude the muriatic acid in the same way, how- 

 ever. There is a separation of prussic gas, a complete de- 

 composition, and the prussiate is totally changed into corro- 

 sive sublimate. Alcohol also dissolves entirely the saline 

 residue of this operation : finally, examined by the reagents, 

 we find no longer any sublimate. Alcohol, as we know 

 already, does not dissolve the prussiate of mercury. 



Potash dissolves in abundance the prussiate of mercury by 

 means of heat. This salt crystallizes in it upon cooling. 

 Alcohol separates it from it, and we recover it entirely. 



The muriate of tin at the minimum, and hydro-sulphu- 

 retted water instantly decompose this prussiate, and the 

 prussic acid becomes free. 



We have seen that the muriatic acid acted efficaciously 

 upon this prussiate. From this it should seem that the sal 

 ammoniac which presents to the prussic acid a principle ca- 

 pable of uniting with it, should be able to exchange the 

 oiher with the mercury : this does not happen, however. If 

 we heat a solution of mercurial prussiate, and of muriate of 

 ammonia, there is nothing new. Alcohol separates them 

 entirelv. Potash and limewater precipitate nothing from 

 them ; not an atom of corrosive sublimate; and the green 

 Sulphate, which could uot fail to form prussiate of iron 



with 



