MOLECULAR THEORY OF ORGANIC COMPOUNDS. 733 



Ferricyanic acid .... N 3 Pe a . N 3 



C 6 . C 6 H 3 



Ferricyanide of potassium . N 3 Fe 2 . N 3 



C 6 C 6 K 3 



Assigning to sulphocyanogeu, C 2 NS 2 , the molecular formula 



NS 2 ., , .... 



-f^~ , its compounds will be : 



U 2 



N S 



Hydrosulphocyanic acid . . __ 2 



C 2 H 



Sulphocyanide of potassium . ^ ^2 



C 2 K 



Hydrated cyanic acid and cyanate of potash will be represent- 

 ed byformulse which assimilate them to the preceding compounds : 



Hydrated cyanic acid . . _ 2 , 

 Cyan ate of potash . . 



C 2 K 



The two isomeric bodies cyanate of ammonia and urea (page 

 392) have different molecular formulae : 



Cyanate of ammonia . - 

 C 2 H . H 3 



Urea ...... N.O 2 .N 



C 2 .H 2 .H 2 



In the last formula urea is represented as containing 1 

 atom of cyanogen, 2 atoms of water and 1 atom of amidogen. 

 According to the more common opinion., it contains 2 atoms of 

 carbonic oxide and 2 atoms of amidogen, a view which may be 

 expressed by making a slight change in the upper line of the 

 preceding formula : 



Urea 



But the existence of cyanogen in urea being probable, the 

 first formula is preferable. Urea may then be compared with 

 allantoin^which contains 2 atoms of cyanogen and 3 atoms of 

 water : 



