324 Proceedings of the British Association. 
On the radical of the Kakodyle Series, by Prof. Bunsen.— 
The easiest method of procuring pure kakodyle is the following. 
Chloride of kakodyle, carefully freed from the oxide by treatment 
with strong hydrochloric acid, is allowed to stand some time over 
chloride of calcium and quick lime, to remove the water and all 
excess of acid. It is then introduced into a distillatory apparatus 
carefully filled with carbonic acid, and containing some slips of 
clean sheet zinc. Any of the metals which decompose water 
will answer, but zinc is the best. It is probable that hydrogen 
or carbon would produce a similar decomposition with suitable 
modifications of the apparatus. The vessel is then hermetically 
sealed, and the mixture of zinc with the chloride, is exposed for 
some hours in a water bath to a temperature of 212° F. When 
the decomposition is complete, a white saline mass is formed, 
which melts into an oily liquid between 240° and 248° F’.; while 
the tube is still hot, the point of the tube leading into the con- 
denser is dipped below the surface of boiled distilled water: as 
the apparatus cools, the water rises into it. The tube is hermet- 
ically sealed: the water dissolves chloride of lime, leaving the 
excess of zine and the kakodyle, which falls as an oily liquid to 
the bottom. This is rectified twice or three times, filled with 
carbonic acid as before; the water being afterwards removed by 
chloride of calcium in the usual way. ‘Thus obtained, it isa 
colorless liquid, transparent and of a high refractive power, in 
appearance and odor much resembling the oxide of kakodyle, 
and ignites instantly on being brought in contact with air, giving 
off water, and carbonic and arsenious acids. 
Abstract of a letter from Prof. Liebig to Dr. Playfair —This 
letter announces the discovery of a white crystalline substance, 
in large quantities, obtained by M. Schunk: from the lichens 
which are employed in preparing archil, (Lecanora tartarea, é&¢.) 
by extraction with ether. It differs from erythrine, and the com- 
pounds described by Dr. Kane, in its insolubility in water. It 
dissolves readily in alkaline solutions, and is capable of being 
again precipitated by acids, if the solution be recently made ; on 
if kept standing for some hours, acids produce no precipitates: ! 
has been decomposed, and is converted into carbonic acid, an 
orceine. If the substance be dissolved in baryta water, and the 
clear solution boiled, a large precipitate of puahensie of baryta 
occurs, and the filtered tion, large quan- 
St ves, on Vay 
