UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 1027 
Contribution from the Bureau of Chemistry 
W. G. CAMPBELL, Acting Chief 
Washington, D. C. 
April 17, 1922 
POISONOUS METALS ON SPRAYED FRUITS AND 
VEGETABLES. 
By W. D. Lynch, Assistant Chemist, C. C. McDonnell, Chief, Insecticide and 
Fungicide Laboratory, and J. K. Haywood, Chief, Miscellaneous Division, Bureau 
of Chemistry; A. L. Quaintance, Entomologist in Charge, Fruit Investigations, 
Bureau of Entomology; and M. B. Waite, Pathologist in Charge, Fruit-Disease 
Investigations, Bureau of Plant Industry. 1 s 
CONTENTS. 
Purpose of investigation 1 
Results of previous investigations 1 
Experimental work 16 
Page. 
Results of experimental work IS 
Summary 58 
Literature cited 5S 
PURPOSE OF INVESTIGATION. 
In the spring of 1915 a cooperative study was undertaken in the 
United States Department of Agriculture to ascertain the amounts 
of arsenic, lead, and copper remaining on fruits and vegetables 
treated with poisonous sprays. The spraying was done under the 
direction of the Bureau of Entomology and the Bureau of Plant 
Industry, and the chemical work by the Bureau of Chemistry. The 
plan was to spray various fruit trees and vegetables according to 
accepted schedules, and also with excessive amounts of material to 
determine how much of the metals may be present under adverse 
conditions. In case the investigation showed that poisonous metals 
remained on the fruit in amounts which might prove injurious to 
the consumer, the results would constitute a basis for so changing 
or regulating the spraying schedules as to eliminate this danger. 
RESULTS OF PREVIOUS INVESTIGATIONS. 
Arsenical compounds first appeared as insecticides in the United 
States (63) 2 about 1860, when Paris green was used to check the 
1 Credit is due to John G. Fairchild and Wilbur A. Gersdorff for assistance in the analytical work re- 
ported in this paper. 
• Figures in parentheses refer to Literature Cited, pp. 58 to 66. 
72638—22— Bull. 1027 1 
