Bulletin 36 June, 1896 



NEW HAMPSHIRE COLLEGE 



AGRICULTURAL EXPERIMENT STATION 



ANALYSES OF THREE COMMON INSECTICIDES 



BY FRED \V. MORSE 



Insecticides have become a necessity in farm economics, and 

 the quantity used is steadily increasing. Worthless substances 

 have from time to time been put on the market under various 

 names, and complaints have been heard that the standard poi- 

 sons have sometimes failed to kill the pests for whose destruc- 

 tion they were applied. In the summer of 1S95, Professor 

 Weed, entomologist of the Station, collected samples of five 

 different brands of Paris green, one of London purple, and one 

 of white hellebore, anl handed them to the chemist for analysis. 



Paris green, when carefully prepared, is a definite chemical 

 compound, described in text-books under the names of copper 

 aceto-arseniteand Schweinfurth's green, and contains fifty-eight 

 and six-tenths per cent, of arsenic trioxide (white arsenic), to 

 which its poisonous properties are mainly due. The ordinary 

 article, however, varies in composition between rather wide 

 limits. In Louisiana, a statute requires the substance to con- 

 tain not less than fifty per cent, of arsenic trioxide. 



In the bulletins of several of the agricultural experiment sta- 

 tions,* there have been reported fifty-four analyses of Paris 



♦Alabama, Bull. 58; Cornell, Bull. 18 ; Florida, Bull. 14; Louisiana, Bulls, i and 12; 

 2d series ; Massachusetts, State Sta., Rep. 1894; Hatch Sta , Bull. 38; South Caro- 

 lina, Rep. 18S8; Texas, Rep. 1S8S ; Vermont, Bull. 12. 



