300 BUNSEN ON THE CACODYL SERIES. 
And the specific gravity, calculated from the above, is therefore 
4°63. This theory requires 4°547, as will appear from the fol- 
lowing :— 
4 vols. Carbon vapour. . . . 3°371 
ig... Hydrogen > a ae 0°25 
Cities, WANRENTEL 10. LIV NOT I oo LOBEz 
Pile. Cyanogen’? “US. S638 
18191 :4 = 4547 
The specific gravity of the vapour of cacodyl itself may be 
deduced with some considerable probability from the relations 
in the condensation of the cyanide and oxide of cacodyl. There 
are one measure of oxygen and two measures of oxide of cacodyl, 
therefore the remaining one is that of the radical. If we argue 
from the relations in the condensations of inorganic compounds, 
this radical may be represented by one or two measures. In the 
first case, the elements would be combined without condensation, 
as in muriatic acid, &c.; in the other, three measures would be 
condensed into two, as in water. The specific gravity of the 
cyanide of cacodyl, and, in short, of the other haloid com- 
pounds, proves that the last supposition is the most correct. Four 
measures of the cyanogen compound contain two measures of 
cyanogen. On the supposition that the elements follow the 
same law of condensation in their organic as in their inorganic 
compounds, the radical must be combined without condensa- 
tion, and consequently be represented by two measures; we 
have, therefore, 
ASvols, Canker. cant. 6.0 Beii 
ROG. “Hydroren, 62800). 6... 2S 
Pts ATsehniee... 4 DAIL S67 
14°563.22 =|7:281 
The same conclusion may be deduced from the relations in 
the condensation of the sulphuret and chloride of cacody]l. 
5. Protochloride of Cacodyl. 
This substance cannot be procured pure by simply distilling 
oxide of cacody] with muriatic acid, for an oxy-chloride is formed 
at the same time, which cannot be entirely decomposed by di-— 
stillation with an acid. The best and most simple plan of pro- — 
curing it pure, is to distil a mixture of chloride of mercury and — 
