REPORT OF ANALYSES OF PARIS GREEN AND 
OTHER INSECTICIDES IN 1900.*+ 
L. L. VANSLYKE AND W. H. ANDREWS, 
SUMMARY. 
In accordance with the provisions of a law designed to protect 
purchasers of Paris green, samples were secured during 1900 and 
the results are published in this bulletin. 
Paris green contains as its chief constituent a compound called 
copper aceto-arsenite, which, when chemically pure contains: 
Arsenious oxide 58.64 per ct. 
Copper oxide, DEO 
VAceucC acid, 10.06 “ 
In the 22 samples of Paris green examined, the arsenious oxide 
varied from 55.83 to 60.80 per ct. and averaged 57.05 per ct. The 
water-soluble arsenious oxide varied from (0.61 to 15.69 per ct. 
and averaged 1.68 per ct. 
The copper oxide varied from 27.22 to 31.20 per ct. and 
averaged 30.02 per ct. The amount of arsenious oxide for each 
- pound of copper oxide varied from 1.81 to 2.24 and averaged 1.89 
pounds. The impurity most commonly found was white arsenic | 
and this did not appear to be excessive. The general result of 
the examination is to show a good quality of Paris green in the 
market at the time the samples were taken. 

*Printed by the authority and under the direction of the Commissioner 
of Agriculture. 
{Reprint of Bulletin No. 190. 
29 
