INSECTICIDES, FUNGICIDES, AND SPRAYING 205 



third, if any substance has been mixed and packed with it 

 so as to reduce or lower or injuriously affect its quality 

 or strength. 



' ' In the case of lead arsenate : First, if it contains more 

 than fifty per centum of water; second, if it contains total 

 arsenic equivalent to less than twelve and one-half per cen- 

 tum of arsenic oxid (AS2O5) ; third, if it contains arsenic in 

 water-soluble forms equivalent to more than seventy-five 

 one-hundredths per centum of arsenic oxid (AszOs) ; fourth, 

 if any substances have been mixed and packed with it so to 

 reduce, lower, or injuriously affect its quality or strength : 

 Provided, however, That extra water may be added to lead 

 arsenate (as described in this paragraph) if the resulting 

 mixture is labeled lead arsenate and water, the percentage of 

 extra water being plainly and correctly stated on the label. 



"In the case of insecticides or fungicides other than 

 Paris green and lead arsenate : First, if its strength or purity 

 fall below the professed standard or quality under which it 

 is sold ; second, if any substance has been substituted wholly 

 or in part for the article; third, if any valuable constituent of 

 the article has been wholly or in part abstracted; fourth, if 

 it is intended for use on vegetation and shall contain any 

 substance or substances which, although preventing, de- 

 stroying, repelling, or mitigating insects, shall be injurious 

 to such vegetation when used." 



Contact Poisons. — Whale-oil soap, which is a common 

 name for all fish-oil soaps now on the market, is the simplest 

 contact insecticide, especially if only a few trees are to be 

 sprayed. Used at the rate of one pound in from four to six 

 gallons of water in the summer-time it will kill plant lice 

 and other sucking insects. At the rate of one pound in two 

 gallons of water it can be used on dormant trees for winter 



