VOLATILE CHLORIDES WITH AMMONIA. 47 
chloride of carbon (phosgene gas) with ammonia. The carbonate 
of the chloride of carbon, C CP + C. is regarded, according to 
the theory of substitutions, as a carbonic acid in which half of 
the oxygen is replaced by an equivalent of chlorine, C Cl. But 
one atom of C Cl takes up two double atoms, or C Cl? + C takes 
up four double atoms of ammonia. But anhydrous carbonic acid 
can only combine with a double atom of ammonia, to form car- 
bonat-ammon, C + NH3, even when the carbonic acid gas is 
mixed with the greatest excess of ammoniacal gas. But since the 
combination contains just as much again of ammonia as ac- 
cording to the theory of substitutions it should, it follows like- 
wise from its composition, that in the carbonate of the chloride 
of carbon the chlorine cannot be regarded as replacing oxygen. 
The carbonate of the chloride of carbon fixes quite an analo- 
gous quantity of ammonia as the sulphate of the chloride of sul- 
phur. Ifthe combination was treated with water, its constitu- 
tion might then be conceived, as consisting of chloride of ammo- 
nium and carbonat-ammon. Regnault looks upon it as a mix- 
ture of chloride of ammonia with a carbamide, CN H?, without, 
however, having effected the separation of the constituents *. 
* Annales de Chimie et de Physique, t. Ixxix. p- 180. 
