tent caterpillars. On the 4th, the leaves were very badly burned, 

 and on the afternoon of the 5th, the caterpillars were all dead. 



June 2. Sprayed a branch of an apple tree with arsenate of soda 

 in water in the proportion of 2 lb. to 150 gal., and sleeved in ten 

 caterpillars. On the 4th, the leaves were very badly burned, and the 

 caterpillars were all dead on the 5th. 



June 2. Sprayed a branch of an apple tree with arsenate of soda 

 in water in the proportion of 1 lb. to 150 gal., and sleeved in ten 

 caterpillars. On the 4th, the leaves were very badly burned, and all 

 the caterpillars were dead on the 7th. 



June 2. Sprayed a branch of an apple tree with arsenate of soda 

 in water in the proportion of ^ lb. to 150 gal., and sleeved in ten 

 caterpillars. On the 4th, the leaves were badly burned, and the 

 caterpillars were all dead on the 7th. 



June 2. Sprayed a branch of an apple tree with arsenate of soda 

 in water in the proportion of ^ lb. to 150 gal., and sleeved in ten 

 caterpillars. On the 4th, the leaves were very badly burned, and the 

 caterpillars were all dead on the 7th. 



June 6. Sprayed a branch of an apple tree with arsenate of soda 

 in water in the proportion of ^ lb. to'^ 150 gal., and sleeved in ten 

 caterpillars. On the 11th, the last of the caterpillars died. On the 

 17th, the leaves were slightly burned and a few days later they were 

 considerably burned. 



June 6. Sprayed a branch of an apple tree with arsenate of soda 

 in water in the proportion of ^ lb. to 150 gal., and sleeved in ten 

 caterpillars. On the 8th, one caterpillar died ; 10th, two died ; 11th, 

 one died ; 12th, one died ; 14th, four died; 18th, the last one died. 

 On the 17th, the leaves were slightly burned. 



CONCLUSIONS. 



All the proportions of arsenate of soda experimented with, from 

 3 pounds to 150 gallons down to ^ pound to 150 gallons of water, 

 injured the leaves more or less. The smallest proportion used, (|- 

 pound to 150 gallons) while injuring the leaves to some extent, 

 required twelve days to kill all of the caterpillars, even when confined 

 where they could obtain nothing to eat but the poisoned leaves. 



