74 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



different compositions, we must standardize the ingredients, and that 

 it will be perfectly easy for some of the big oil companies to put out a 

 standardized kerosene, meeting best the requirements that are needed 

 for this particular work. 



Mr. C. R. Crosby: I would like to ask Dr. Britton what results 

 he got from using blackleaf with the Bordeaux. 



Mr, W. E. Britton: We couldn't see that it sprayed much better 

 than the blackleaf and water alone. Of course that can be modified 

 somewhat by using greater pressure in the pump. We had a hand 

 outfit. I suppose the pressure was between 75 and 100 pounds. 



Mr. W. H. Goodwin: May I ask what make of pump you used? 



Mr. W. E. Britton: I think the pump was one of the Hardie 

 pumps, using two lines of hose. We used the "Friend" disk nozzle 

 with rather small hole. 



Mr. W. H. Goodwin: The reason I ask this question is that 

 different makes of nozzles and pumps give vastly different results. 

 Spray solution may be effective or ineffective due largely to the force 

 with which it is applied, its fineness, and the liberality in the quantities 

 of spray used. An apparent excess per acre usually more than pays 

 in the results obtained. Nozzles throwing a hollow cone spray require 

 considerable care in handling them in order to get every bit of foliage 

 sprayed covered evenly and forcefully with spray. 



Mr. W. E. Britton: The same outfit was used in spraying with 

 the nicotine solution, the arsenate of lead and the Bordeaux, and also 

 in the nicotine solution with soap. 



Mr. W. H. Goodwin: In some of my experiments I have found 

 I can apply a much weaker spray solution by applying more spray per 

 acre, and produce satisfactory results, provided I apply enough force 

 behind the spray to get a thorough cover. 



Mr. T. J. Headlee: The Kentucky Tobacco Products Company, 

 the makers of "Black-Leaf 40," recommend for aphis a mixture com- 

 posed of 1 part of the "Black-Leaf 40" to 1,000 parts of water with the 

 addition of two or more pounds of soap to each 50 gallons. Even when 

 applied with an engine-driven potato sprayer this formula has been 

 with us an absolute failure. In spite of these facts, however, the com- 

 pany has until recently persisted in the recommendation. I am making 

 these statements in the hope that Mr. Safro will explain the action of 

 the company. 



Mr. Safro: Before discussing this matter I would like to go back 

 to Professor Houser's question, which did not seem to be answered as I 

 thought it would be. His question was in regard to the use of washing 

 powder as a spreader. Before going further, I want to make this state- 



