U. S. DEPARTMENT OF AGRICULTURE. 

 BUREAU OF CHEMISTRY BULLETIN No. 89. 



H. W. WILEY, Chief of Bureau. 



INJURY TO V 



IN BY SI 



BY 



J. K HAYWOOD, 



Chief, Insecticide and Agricultural Water Laboratory. 



WASHINGTON: 



GOVERNMENT PRINTING OFFICE. 



1 9 5 . 



