EXPERIMENTS WITH WET POISONS. 



225 



With our single pump we were able to cover only five rows of cotton 

 for each trip across the field and do it well. Including the time spent 

 in filling the barrel it took 45 minutes for each barrel of poison put out; 

 or, in ten hours, three hands and four mules would poison about 13 

 acres. 



On the 1st of September a light rain in the early afternoon became 

 heavier about 4 p. in. and lasted till some time in the night, a few driz- 

 zling showers having fallen the day before. 



When these poisons were applied there were scarcely any worms on 

 the cotton poisoned, but many eggs. On the 4th of September I noted 

 that these had hatched, but few larvae had yet eaten through the leaves 

 so as to reach such poison as the rains had left. Of the few worms on 

 the cotton before the rain I had noticed a small number of dead ones, 

 the most being found on section 17, the next on 15, the next on 16, but 

 neither 18 nor 19 did much good. Coming as they did, the rains re- 

 moved the greater part of the poison before the young worms could eat 

 it, so that little good was done by this poisoning. 



September 5, some cotton badly infested with newly-hatched cater- 

 pillars was poisoned, as follows : 



In all we poisoned a little less than 3 acres this time, using only about 

 half a barrel on section 22. One hand worked the pump, wetting six 

 rows at a time; another followed him with the bucket of poison. 

 Previously I had caused a barrel in the middle of the field to be filled 

 with water. In this I suspended the poison, having the men replenish 

 it as often as necessary. About four gallons each of the kerosene and 

 turpentine mixtures were used. 



The next day, when I examined the Paris-green sections, I found many 

 worms dead on each of them. When I rubbed the leaves with my hand, 

 or sprinkled water over them, I could not see but that one adhered as 

 well as another. Here and there a leaf was badly scorched, and some few 

 forms were injured ; but, taken as a whole the field suffered little. Here 

 I noticed what was also seen before and afterward, namely, that a leaf 

 may be completely covered with Paris-green sediment and yet show no 

 scorching ; but where the dead spots appear on the leaves there may be 

 15 c i 



