26 



Owing to the lateness of the hour, discussion was deferred until the 

 afternoon session, when it was proposed to present all communications 

 relating to insecticides, following with a general discussion. 



AFTERNOON SESSION, A UG UST S7, 1895. 



The following paper by Mr. H. E. Weed was read, in his absence, by 

 Mr. Davis : 



SOME EXPERIMENTS WITH THE KNAPSACK KEROSENE 

 ATTACHMENT. 



By Howard Evarts Weed, Agricultural College, Miss. 



At the meeting of this association last year Mr. Marlatt reported 

 unfavorably upon a kerosene attachment to the knapsack pump. As 

 my own exi^eriments of last season agreed in the main with those of 

 Mr. Marlatt, steps were taken for the improvement of the attachment 

 so as to obviate (1) any mixture of the two liquids, except in the act of 

 pumping, and (2) guesswork as to the iH'oportions being pumped. As 

 all are doubtless familiar with the improved attachment as now placed 

 upon the market by the Deming Company, and especially as most of 

 the members of this association have personally tried the attachment 

 this season, any description of the apparatus is unnecessary in this 

 connection. I trust that a full discussion of the merits or demerits of 

 the attachment will take place at this meeting, and only regret that I 

 am unable to be present to give the results of my own experiments 

 more informally than can be presented in a paper. 



There are two main i^oints to be considered with a new insecticide or 

 an old insecticide ap])lied m a new way: (1) The ehect of the insecticide 

 upon insect life, and (2) the etiect on tlie foliage upon which the insects 

 may feed. The mechanical mixture of kerosene with water is designed 

 to do all the work of a kerosene emulsion, and if it accomplishes this 

 matters are greatly simi)lified and kerosene will be more largely used 

 as an insecticide. 



In this paper 1 had expected to go into detail with each species of 

 insect against which the kerosene attachment has been used, and also 

 present in tabular form a statement giving the results of different 

 strengths of kerosene which different foliages will bear without injury. 

 I find, however, that in the case of the insects against whicli the kero- 

 sene attachment has been used the subject can best be presented in 

 the form of general statements and noting particular species for con- 

 firmation, while in the case of the strength of kerosene which foliage 

 will bear without injury the results have been so uniform as to make 

 the contemplated table unnecessary. 



In general I find that in the use of the mechanical mixture it takes 

 slightly more kerosene to accomplish the same result as an emulsion. 



