314 BUNSEN ON THE CACODYL SERIES. 
I. II. III. Mean of I. and IIF. 
Carbon . 17°62 Lyle 17°86 su 17°74 
Hydrogen 4:29 4:24 4°32 Bis 4°31 
Arsenic . 55°15 ie i, bast 55°15 
Chlorine. 18°88 18°43 18°69 18°34 18°78 
Oxygen . 4°10 ay fs, ee 4:02 
100°00 100:00 
The atomic relation of the carbon, hydrogen, arsenic, and 
chlorine in the above composition, is exactly C, Hg As, Cle. 
We cannot determine from the analysis how much of the 4 per 
cent. oxygen really belongs to the substance itself, as it is im- 
possible to avoid a partial oxidation even with the greatest care ; 
and, moreover, the whole of the errors of experiment always fall 
upon this element. That the whole amount of oxygen does not 
much exceed 14 per cent., may be assumed on the supposition 
that all the other estimations being reconcilable with a possible 
theoretical composition, it must be an approximation. Assuming 
then an impurity of 2 per cent. of oxygen, we obtain the follow- 
ing results :— 
Found. Calculated. 
Sarpon 92°. 18°21 18°22 
Hydrogen. . Hg 4°43 4°46 
Arsenic ... As, 56°61 56°04 
Chlorine... Cls 19:28 19°79 
Oxygen i 7) Qi 1°47 17 
100°00 100°00 
We must therefore regard this substance as a compound of 1 at. 
oxide and 3 at. of the chloride, viz. 
(C,H, As, + O) + 3(C,H, As, + Cl) = KdO + 3Kd Cl. 
The formation of the substance is easily explained; the chlo- 
ride of cacodyl is decomposed along with water into muriatic 
acid and this basic chloride. 
ie Kd O + 3 Kd Cl 
ClH 
The ee are = details of the experiment to estimate the — 
specific gravity of its vapour :— 
Substance employed . . . . . 0'247 grm. 
Volume of the vapour. . . . . 69°78 C.C. 
Temperature .% 40. 2. «: » 164° centigy 
