48 mainp: agricui^tural experiment station. 19 1 4. 



the most four milligrams oi arsenic in the form of arsenic 

 oxide. If any of these summer sprayed apples had been eaten 

 without wiping the parings in any way it would have taken 

 about half a bushel a day to get the maximum medicinal dose. 

 Hence any danger from the eating of sprayed apples from the 

 arsenical standpoint is a negligible quantitv^ Paring the apple 

 would exclude all of the arsenic which it carries, and ordinary 

 wiping of the apple would remoA^e practically all of it from the 

 skin. The poison does not penetrate below the skin and is 

 easily wiped off or washed off. 



Lead under some circumstances is a dangerous poison. It is 

 one of the so-called cumulative poisons. This simply means 

 that if one is constantly exposed to the poison, as a painter or 

 manufacturer of arsenate of lead might be, the lead might be 

 absorbed by the system faster than eliminated and this would 

 result in a case of so-called lead poisoning. Lead, however, is 

 not a cumulative poison in the sense that it is not eliminated 

 from the body, but it is more s'lowly eliminated than many other 

 poisonous materials. 



The amount of lead arsenate carried upon these apples tested 

 60 days or longer after spraying varied from an eighth to a 

 third of a milligram. This amount is insignificant and no harm 

 could come from the continued use of apples carrying this 

 amount of arsenate if no precautions were taken whatever in 

 removing it from the skin if the parings themselves were eaten. 

 Washing the apples or wiping the apples would remove prac- 

 tically all of the lead arsenate from them. Paring the apples 

 v/ould remove it entirely. 



SUMMARY. 



Mid-summer spraying with lead arsenate is an effective way 

 of combatting the brown-tail moth. The spraying should be 

 thorough and applied about the time the eggs are hatching. 



The amount of arsenic or of lead that will remain at harvest 

 upon the apples that are sprayed in mid-summer with arsenate 

 of lead is so slight as to have no practical bearing. 



