BUNSEN ON THE CACODYL SERIES. 293 
arsenic, sulphuret of arsenic, and charcoal. It inflames in com- 
mon air, and burns with a pale arsenious flame, which is coloured 
bright blue on the exterior. The sulphur is oxidized when it is 
treated with moderately concentrated nitric acid, but the cacodyl 
does not undergo any change. It is almost insoluble in water, 
but the water acquires its disagreeable penetrating odour. It is 
miscible with ether and alcohol in any proportion, and is again 
precipitated from the latter by adding water. Sulphur combines 
with it when in the anhydrous form, or dissolved in alcohol, and 
forms a sulphur combination of a higher order, which can be ob- 
tained from ether in a crystalline form. This body possesses very 
remarkable properties, and I shall recur to it in another place. A 
similar compound is formed with selenium, which crystallizes in 
large colourless plates. It dissolves phosphorus, which is de- 
posited again unchanged on cooling. It forms a most peculiar 
crystalline substance with iodine. It is converted into large 
transparent crystals in contact with oxygen, which consist of 
alcargen and another substance not yet examined. 
Muriatic acid decomposes the sulphuret of cacodyl into chlo- 
ride of cacodyl and sulphuretted hydrogen. Sulphuric and 
phosphoric acids also expel sulphuretted hydrogen, and form 
corresponding salts of the oxide of cacodyl. The weaker acids, 
as acetic, &c., do not effect this decomposition. Carbonate of 
lead also is not decomposed by sulphuret of cacody]l. 
The analysis of this substance is attended with no difficulty : 
the sulphur is determined by oxidation with nitric acid. 1°309 
grm. heated with nitric acid, with the usual precautions, afforded 
1061 grm. sulphate of barytes, and 0-013 grm. sulphur. 
Burnt with chromate of lead, 
I. 09713 grm. yielded 0°720 grm. carbonic acid, and 0°4385 
grm. water. 
II. 0°902 grm. yielded 0°664 grm. carbonic acid, and 0:407 
grm. water. 
If we estimate the arsenic by the loss, we obtain the following 
calculated and experimental results :— 
I. II. Calculated. 
Carbon ... C, 20°49 20°35 20°1 
Hydrogen .. H,, 5°02 5°01 4:9 
mmeenic; .... As, 63°32 ae 61°8 
Sulphur ...S 12°17 Pr 13°2 
100°00 100°0 
