HISTORY OF PRUSSIATES. %q3 



ft has been saen, that muriatic acid acts effectually on but not by mu- 

 this prussiate: it might be supposed, therefore, that muriate riate of amm °- 

 of ammonia, which oiFers the prussic acid a principle capa- 

 ble of uniting with it, should make a change of bases ; but 

 it does not. If a solution of prussiate of mercury be heated 

 with muriate of ammonia, nothing new is produced, and al- 

 cohol separates them completely. Potash and limewater 

 precipitate nothing from the mixture, not an atom of corro- 

 sive sublimate; and the green sulphate of iron, which would 

 not fail to form a prussiate of iron with that of ammonia, if 

 if met with any in the liquor, does not experience the least 

 change. 



Prussic gas. 



On heating 1440 grains of triple prussiate in a retort, p ru9S - lc gas# 

 with a sufficient quantity of dilute sulphuric acid, four ounces 

 [2304 grs.] of alcohol were impregnated with about 80 grs. 

 of gas. I kept the alcohol in a jar in a mercurial trough: 

 the gas dissolved in it rapidly, but it would have taken up 

 much more. The water of the intermediate receiver too was 

 loaded with it: its smell was suffocatingly pungent, and its 

 kernel flavour was extremely strong. This water did not 

 render that of barytes turbid. The gas has a constant ten- 

 dency to escape, and is perpetually raising up the cork. If 

 a small matrass filled with the solution be immersed in hot 

 uater, the gas separates rapidly, and burns at the orifice : 

 on bringing a candle near it, smoke is perceived; no doubt 

 because a part of the charcoal escapes, as in the combustion 

 gf volatile oils. 



Prussic acid dissolved in water, and kept in a bottle p russ i c ac id de- 

 closely stopped, is decomposed spontaneously. In four or composedspoa- 

 five months it becomes yellow. It gradually loses its smell, ^te° US y m 

 grows turbid, and deposits a coffee coloured sediment, 

 which, after being heated, exhibits all the characters of char- 

 coal. 



By distillation it affords a little water, prussic acid, and Decomposed 

 ammonia. The carbon is azotized; and it acquires one of b y beat, 

 the principles, which the acid relinquishes on being decom- 

 posed, for, on heating it with carbonate of potash, it afforded 

 me a lixivium capable of making prussian blue. 



But 



