380 Eliot and Storer on Arsenic as 
ArT. XLITI.— Arsenic as an Impurity of Metallic Zine; by 
Cuas. W. Eviot and Frank H. Srorer. 
[ Remark :—W e now cite in full from their memoir on ‘The im- 
purities of Commercial Zinc’ (Mem. Am. Acad., vol. viii, 1860), 
American readers. Its value in a medico-legal point of view 
cannot be too highly estimated.—Eps. | 
metal, not recognized till 1817, has since been shown to be a very ame 
mon admixture in the zinc of commerce. The invention of Marsh’s ap- 
. t 0 
tains no arsenic that can be detected by the most delicate tests — 
in commerce do very often ,contain arsenic, and are always so al 
contain it as to be utterly unfit for use in Marsh’s process without spect 
purification for that purpose. The steps by whi nel 
pedgrey and the evidence on which they are founded, we proc 
escribe, : 
’e have used exclusively Marsh’s process for the detection of mice 
applied with the apparatus and with all the precautions recommen 
* Edinburgh New Phil. Jour., xxxv, 235. Pe " 
{ Extract a thesis presented by M. Schauefele. Jour. de Chimie Médieale, 
[3], vi, 178; also in Dingler’s Polyt. Jour. 1850, exvi, 248. 
