312 BUNSEN ON THE CACUODYL SERIES. 
part of this memoir, when I propose discussing the higher com- 
pounds of cacodyl. 
The chloride of mercury with oxide of cacodyl forms a fine 
white crystalline powder when obtained in the form of a preci- 
pitate. It is deposited in the form of groups of large and very 
soft crystals when its aqueous solution is slowly cooled. They 
assume the form of small rhombic plates with angles of about 
60° and 120°, but the crystals are too small to be accurately 
measured. 
100 parts of boiling water dissolve 3°47 parts, and water at 
18° C. only takes up 0°21 parts. 
Alcohol also dissolves it, and in larger quantity when warm 
than cold. It is quite inodorous; but if the smallest quantity 
reaches the nose, a continuous, insupportable smell is felt. The 
taste is disagreeably metallic, and produces nausea. It is very 
poisonous in larger quantities. It is easily decomposed by heat, 
and diffuses itself in the air without any residue. When heated 
in close vessels it emits an odious vapour, a sublimate contain- 
ing chloride of mercury, calomel, and erytrarsin, and leaves a 
light porous charcoal behind, which burns with an arsenious 
odour without any residue. 
11. Compound of Bromide of Mercury with Oxide of Cacodyl. 
This substance agrees so completely with the corresponding 
chlorine compound, that I have not thought it necessary to make 
any analysis. It also is formed by adding bromide of mercury 
to oxide of cacodyl, or to the mixed oxidized product noticed 
before, and may be rendered quite pure by crystallization. It 
forms a white crystalline powder, which has a slight shade of 
yellow, and does not appear so capable of being crystallized from 
its aqueous solution as the chlorine compound. 
It has nearly the same degree of solubility as the chlorine 
compound, is also inodorous, has the same disagreeable metallic 
taste, and is easily decomposed by boiling the aqueous solution. 
When it is heated in close vessels, it melts before it is decom- 
posed. It undergoes decomposition when strongly heated; pro- 
and perbromide of mercury sublime, a disagreeable liquid con- 
taining bromine distils, and charcoal is left behind. It burns in 
contact with the air without leaving any residue. Its other 
relations and decompositions are precisely the same as those 
described in the preceding section. 
