Insecticides. 51 



The most important additions to the list of insecticides made 

 in France were American remedies. During 1884, Professor 

 C. V. Riley of the Agricultural Department at Washington, 

 visited France, and in an address delivered before the Societe 

 Centrale d'Agriculture de 1'Herault, June 30, 1884, he spoke of 

 the emulsions of kerosene with milk or soap, of the arsenites 

 as used in America, and of pyrethrum. 1 The formula for mak- 

 ing the first preparation was as follows : 



Petroleum 8 liters. 



Common soap 175 grams. 



Water 4 liters. 



Dilute with water as experience may suggest. The directions 

 were slightly modified in later years, but on the whole this 

 remedy was soon widely used in France. 



Although the attention of experimenters was more particu- 

 larly directed towards the fungous diseases of plants, various 

 other insecticides were tested. 



For large caterpillars, Leizour advised the use of 



Water 25 liters. 



Sulphide of potassium 100 grams. 



Black soap , 250 " 



The soap and the sulphide of potassium are separately dis- 

 solved in a few liters of water. The tw T o are mixed, and the 

 remaining amount of water is added immediately before the 

 applications are made. 



A remedy supposed to be particularly valuable for the de- 

 struction for the woolly aphis was made by taking, 



"Water 100 grams. 



Benzine '. 50 " 



Strong glue 10 " 



This was to be applied in March and April. A decoction of 

 datura plants, when used with the sulphate of iron, was also 

 recommended, as well as amylic alcohol and soap water. 2 



Another preparation of a more complicated character was 

 recommended for the same insects. Chemicals having proved 



1 Messager Agricole, 1884, July 10, 255. 

 * Jour. &Ag. Prat. 1890, June 19, 901. 



