February, '19] BRITTON AND ZAPPE: KEROSENE V. NICOTINE 77 



Mr. W. E. Britton: I understand that the nicotine solution 

 with soap and lead arsenate has been used in Massachusetts and has 

 been recommended there; that while there may be occasional injuries, 

 it isn't necessary to take it into consideration as compared with the 

 injury done by the aphis. 



I wish to say one word in regard to the question of the supply of 

 nicotine solution. I am told by a man representing the Kentucky 

 Tobacco Products Company, that they have arranged to have a 

 supply in each state, so that the situation that I mentioned as occur- 

 ring in Connecticut will probably not occur again. 



Mr. Safro made one statement; he said the use of soap is for the 

 purpose of obtaining the alkali. It is necessary to have some grease 

 with it. That is, you would not recommend household lye in connec- 

 tion with nicotine alone, would you? 



Mr. V. I. Safro: I wouldn't recommend it, but it will do if it is 

 used accurately. An entomologist can use household lye. In the 

 northwest, where some of the growers are as careful and as painstaking 

 as we are, they can use lye safely, but you certainly wouldn't recom- 

 mend it to a grower, under the penalty of being forever discredited. 



Mr. T. H. Parks: I am particularly interested in Dr. Britton's 

 talk because what I am after is to get the farmers to put on this spray 

 and not get scared at the expense, and that is what they did in Ohio 

 last year. If we can safely use kerosene emulsion as a substitute for 

 tobacco sprays we shall have more people spraying to solve the potato 

 aphis problem. 



Last year I noticed that many would apply one spray and then if they 

 did not get results they would quit. I had read Professor William 

 Moore's article in the June number of the Journal. He combined oleic 

 acid (red oil) with a 40 per cent nicotine solution which made the tobacco 

 spray cheaper. I tested this in the field according to Professor Moore's 

 formula, though we were able to purchase only a few ounces of oleic 

 acid. When this spray (nicotine oleate) was applied as strong as 1 

 part to 500 of water, it did the work as well as Black-Leaf 40 (1-500) 

 plus soap (2 pounds). Weaker strengths of nicotine oleate were not 

 satisfactory. I figured out the difference in the cost and it was favor- 

 able for the new spray. I then got in touch with one of our commer- 

 cial insecticide companies and obtained the wholesale price of oleic 

 acid f. o. b. New York. 



Later in spraying for turnip aphis we experimented with Black-Leaf 

 40 and soap at various strengths in comparison with this Black-Leaf 

 40 and oleic acid combination at different strengths. Here it was 

 found that Black-Leaf 40 (1-800) and soap (2 pounds) when used 

 thoroughly did the work and did it well. The weakest nicotine oleate 



