228 



REPORT UPON COTTON INSECTS. 



At the time these poisons were applied this cotton was beginning to 

 be honeycombed by the caterpillars; but none large enough to eat 

 through the leaves were to be found on the adjoining sections 5, 6, 7, 

 and 8. Between 8 and 9 a small section was left unpoisoned, and this 

 was defoliated within the next five days, while all of these sections re- 

 tained their foliage up to the time when I left the field, September 15. 



September 4, I noted that the cotton on section 10 was badly scorched, 

 though the worms were killed on it. The poison was as thickly applied 

 on 9 as on 10, yet, despite the double quantity of poison used, it was in- 

 jured very little. The caterpillars were killed. Very little poison re- 

 mained on sections 1, 2, and 3, of August 22, yet in a very few places 

 there was enough to kill the worms that were then appearing in large 

 numbers on it. None remained on section 4, the foliage of which was, 

 for the most part, eaten up. 



September 7, the poison was found adhering finely to sections 5 and 

 6, and the cotton was not at all badly scorched. There were very few 

 worms on it. No traces of the poison on section 7 could be found, but 

 there were no worms on it, and it was not materially injured by scorch- 

 ing. Not very much remained on section 8, but there were few cater- 

 pillars to be found. The cotton was uninjured. The poison adhered in 

 quantity to 9 and 10, where the worms were all dead. Section 9 was 

 slightly scorched, section 10 badly. The unpoisoned section before 

 mentioned was covered with caterpillars, its foliage being entirely gone. 



September 9, about midday, when the sun was shining brightly, I ap- 

 plied poisons to three sections to test the resistance of different sub- 

 stances to the action of the weather. The quantity and quality of the 

 poison being unimportant, I shall give only the proportions of the sub- 

 stances used to dilute it. 



September 14, 1 noted that my sections up to No. 11 were about as 

 before the rain. Of 11', 12, and 13, all were more or less removed, and 

 strangely enough the last, containing the smallest quantity of flour, 

 had resisted the rain better than either of the others. None of these 

 stood it as well as most of the earlier sections which had already been 

 exposed to numerous rains. Owing to my departure from the field at 

 this time these later experiments are exceedingly unsatisfactory, and I 

 hesitate to base a very pronounced opinion on them, but think that they 

 go to demonstrate that plaster, unless accompanied by a large quantity 



