256 Mr. E. A. Parnell on Sulpftocyanogen. 



83'3— 28*3 = 55*0; therefore 83*3 of mixture contain 28*3 

 of nitrogen, and 55*0 of carbonic acid: and as 28*3 : 550 

 : : 1 : 1 *94- ; or as 1 of nitrogen to 2 of carbon nearly. 



We have then for the per-centage, 





uuumui 



Carbon . 



. < 



17*59 





Nitrogen , 



• . i 



20*37 





Hydrogen 



, . 



1-76 





Oxygen (loss) . , 



5-12 





100-00 



ich numbers closely correspond to 









Calculated. 



12 



Sulphur s . . 



. 2414* 



55*64 



10 



Carbon . . . 



. 764-3 



17-61 



5 



Nitrogen. . . 



. 885-S 



20-42 



6 



Hydrogen . . 



. 74*8 



1-72 



2 



Oxygen . . . 



. 200-C 



4-61 



1 equivalent 4338*3 100-00 



Since it appears to be a hydrated hydracid of a snlphuret of 

 cyanogen, the name hydrothiocyanic acid will perhaps not 

 be inapplicable. Its salts will then be thiocyanides, and its 

 symbol may be They H 4 . 



Thiocyanides. — The alkaline reaction of potash, soda, am- 

 monia, and barytes cannot be completely destroyed by any 

 excess of this acid, although the pure salts are neutral. The 

 alkaline carbonates are not decomposed by it at common 

 temperatures, but if boiled, carbonic acid is evolved, and a salt 

 of the alkali formed. Its solutions in potash and soda give yel- 

 low uncrystallized residues on evaporation. The acid was 

 digested some time with ammonia, filtered and evaporated 

 over sulphuric acid in vacuo : this gave a yellow uncrystallized 

 salt, soluble in water, giving a solution neutral to test paper, 

 and intensely bitter; but free acid had been deposited du- 

 ring evaporation, notwithstanding it was at first highly al- 

 kaline. 



Barytes. — The acid was digested with barytes, water, and 

 carbonic acid gas passed through the solution to separate 

 excess of barytes: a yellow solution remained, which on eva- 

 poration gave a yellow salt, but mixed with crystals of hy- 

 drate of barytes. 



A solution of the acid produces no precipitate in solutions 

 of salts of magnesia, both oxides of iron, manganese, zinc, or 

 nickel. 



Copper, — A solution of the acid produces an ochre-brown 



