238 Report oF THE CHEMIST OF THE 
have been frequent complaints on the part of farmers that Paris 
green has proved inefficient in so many instances as to lead to 
serious suspicions in regard to its purity. As a result of such 
complaints, the State legislature, in March, 1898, passed a law 
intended to prevent fraud in the sale of Paris green; but no ap- 
propriation was made for the enforcement of the provisions of 
the law and no work was done until 1899. 
During 1899 samples of Paris green were collected and the 
results of analysis of these samples are presented in this bulle- 
tin. Some materials were collected which were found in the 
market as insecticides, but which contained little or no Paris 
green. A general statement of the composition of these will also 
be given, as information of this kind is often desired. 
CHEMICAL COMPOSITION OF PARIS GREEN. 
There is more or less confusion as to the exact chemical com- 
pound that goes under the name of Paris green. Many chemical 
writers include two different arsenic compounds under this name, 
but the compound most frequently met in commerce contains 
copper, arsenic and acetic acid, and is chemically known as copper 
aceto-arsentte ; in the trade this compound, in a form not chemi- 
cally pure, is known as Paris green, Schweinfurt green, Imperial 
green, French green, Emerald green, ete. 
Paris green, or copper aceto-arsenite, when chemically pure, 
contains the following amounts of the different elements indi- 
cated : 
ATSONIC . AS RID, BURA Re et 44.44 per ct. 
Copperttadr. gireiauark ad Ta mayig, oe 94,990 Tt 
Oxyrons Gt CONE. tA, Bina. 25°. 25a 
Carbon s1nath 200). AOPRT RIA ae ATSMUL S 
Hivdrovene ce. eee Petree OFD9 207 vg 
Paris green may be regarded as approximately consisting of — 
Copperarseniteis: As. wnmaleite wtf ab gie 82 per ct. 
Copper ‘acetate: cece ee eee LS i tas 
