MACHINES FOR DISTRIBUTING POISONS. 229 



of flour, will not -do to apply poisons with unless it is absolutely certain 

 that no rain will fall till they shall have time to kill the caterpillars they 

 are intended to destroy. 



In applying poisons it is desirable, if possible, to employ machines by 

 which they may be more rapidly distributed. For, as the time when 

 poisoning must be done, all of the regular plantation-hands ought to be 

 engaged in saving fodder or picking cotton, day-hands are doing this 

 work for themselves, and, aside from the mere question of cost, it is 

 often impossible to get over a plantation in time to meet the worms on 

 their emergence from the egg without exposing some of the poison to 

 the danger of being removed by rain. This is especially true of dry 

 poisons, for if applied by hand they require far more time per acre than 

 liquids do. Moreover, on their emergence from the egg the larvae do 

 not eat entirely through the leaf, but spend from two to four days on 

 the lower surface ; therefore, as suggested to me by Professor Comstock, 

 it is desirable to apply the poisons to the lower surface of the leaf, so 

 that they may be killed without so long au exposure of the poison to 

 chances of being removed by rain. Since the moths feed on the nectar 

 secreted by the glands on the lower surface of the leaf, it may also be 

 possible to apply some soluble poison to this surface, some of which 

 being absorbed by the nectar will poison the moths. 



Aside from these reasons, I do not see why any machines should apply 

 liquid poisons better or more expeditiously than can be doue by the 

 fountain pumps. A machine which fills these requirements is that in- 

 vented by William T. Daughtrey, of Selma, which throws a finely divided 

 spray up through the leaves ; this in its descent wetting the upper sur- 

 face. In its present form this machine is intended to be drawn by two 

 mules, poisoning four rows of cotton; but it is entirely impracticable to 

 use it as now made. Mr. Daughtrey, however, soon expects to have a 

 lighter and more manageable machine, drawn by one mule and poison- 

 ing as many rows as the machine he now has. Having seen his jet I 

 see nothing further to be desired in that line, and when combined with 

 a properly constructed body it seems likely to meet every want. I have, 

 though, grave doubts as to any machines proving superior to the foun- 

 tain pump, when everything is taken into consideration. 



The slowness and expense of applying dry poisons, on the other hand, 

 make it desirable to employ some machine if possible. Such machines 

 have been devised and patented ; but, as I saw none of them in opera- 

 tion, it is unecessary for me to speak of them. 



With some machine doing away with the greater part of the labor 

 otherwise required, I think that, in spite of its greater original cost, 

 the dry form of poison is far preferable to the wet, on account of its 

 greater adhesiveness. 



Starting on a certain part of every plantation, as they do, the cater- 

 pillars may be watched as they increase in numbers. My advice would 

 be that as soon as they appear in any numbers in such places probably 



