control over in its manufacture.

Two points of interest occurred to me during the time I was occupied with
the research, which I had not time to complete; one was whether the
aceto-arsenite can be formed, adopting the old method for its formation,
if there is more than a certain quantity of water; from some experiments I
made in this direction I was inclined to the opinion it could not. I have
already stated that emerald-green is soluble to a certain extent in acids,
and that it is formed in a more or less acid solution; consequently a
varying amount of the pigment is always lost by being dissolved in the
supernatant liquid. To prevent to a certain extent this loss I
precipitated the copper from it as arsenite; but I was not successful in
the few experiments I had time to make on this part of the subject of
reconverting the copper arsenite thus obtained into the aceto-arsenite by
the addition of acetic acid.--_Jour. of Science._

* * * * *




ANALYSIS OF ZINC ASH AND CALCINED PYRITES BY MEANS OF AMMONIUM CARBONATE.


In a recent issue of the _Chemiker Zeitung_ Dr. Kosmann has reported an
analytical method for the examination of zinciferous products; according
to this report, the ash and flue dust produced by the extraction of zinc
from its ore comprise:

1. Zinc dust, from the distillation of zinc,