45 



noticed forty-eight hours after application feeding as usual though 

 themselves and the leaves were coated with powder. I n breeding cages 

 better results were obtained. Light applications did but little good as 

 outside, but heavy applications, where plants were completely covered 

 with powder, were quite effective, both species being destroyed to the 

 extent of 80 per cent, to 90 per cent. (No substance was more carefully 

 or thoroughly used than this in the above experiments.) In solutions 

 the effect was about the same. It was used up to 8 ounces to 1 pint of 

 water, making almost a thick mixture. In this manner about 25 per 

 cent, of rapce were killed in the field; not tried in cages. 



All of my work points to the conclusion that brassicce is more diffi- 

 cult to deal with than rapcv; especially is this true where the poison is 

 a powder to be eaten. They are easily disturbed and will move away 

 to the under side of the leaves until disturbing cause has disappeared. 



This powder cannot be successfully applied with a bellows, because 

 of its characteristic "of accumulating in little bails or masses which can- 

 not pass the bellows, and, also, it must be applied heavily to accomplish 

 any results whatever. Heavy applications by hand will probably prove 

 the only means of doing any good with it. 



TOBACCO SOAPS. 



Of these several were used, Wolf's Vermin Soap and different brands 

 from the Eose Manufacturing Company, of New York, known as sulfo- 

 tobacco soaps. Also two brands made by the above company were 

 sent me by the Division, viz, a soda and a potash tobacco soap. These 

 two packages seem not to be the same grade of goods the company at 

 present manufacture, as evidenced by the difference in strength shown 

 by my tests. The samples sent by the Eose Company were a plain 

 and scented soda soap and a scented potash soap. The sample of Wolfs 

 soap was received from the Milwaukee Soap Company, Milwaukee, Wis. 

 It is a stiff soda soap strongly scented with tobacco and very offensive 

 to handle. The potash soaps above mentioned were much softer than 

 the soda soaps. They all dissolved readily at 100° Fall., and the Rose 

 soaps remained in solution, but the Wolf's soap solidifies the whole so- 

 lution even when very weak, forming a jelly-like mass. This is a very 

 objectionable point if this soap is desired to be used as spray, as it 

 necessitates heating every time before using. 



On Cabbage ]Yorms. 



The two samples received from the Division were thoroughly tested 

 on both species previously mentioned in this report. The solutions 

 were made of different strengths up to 4 ounces to 1 pint of water, at 

 which strength the soda soap destroyed slowly but thoroughly all larvae 



of both species, and the potash soap was sure death to all larvae which 

 came in contact with it. These solutions improved with age as did all 

 the soap solutions. 



