52 The Spraying of Plants. 



so valuable in the destruction of fungi, it was probably sup- 

 posed that some material could be found which would bear 

 the same relation to insects that the copper compounds do to 

 the mildew. The idea was certainly a good one, but since no 

 such substance at that time in general use by the French has 

 remained as a leading remedy, their new introductions appear 

 to have been at least only partially successful. The use of the 

 following formula was advised : 



Salicylic acid 2 grams. 



Red oxide of mercury 2 " 



Pyrolignic acid 1000 " 



The above was diluted with 30 parts of water when applied. 



The cochylis (Cochylis roserana) is an insect which often does 

 much damage in French vineyards, as it feeds upon the leaves 

 and the inner portions of the berries. One preparation which 

 was recommended 1 for its destruction is made as follows: 



Carbonate of soda 100 grams. 



Rain water 1 hectoliter. 



When dissolved add to the solution a mixture of 



Carbon bisulphide 1 part. 



Oil (Colsa, etc.) 1 " 



The last two ingredients form an oleo-sulphide of carbon, 10 

 liters of which are poured into each hectoliter of the carbonate 

 of soda solution, thus forming an emulsion of carbon bisul- 

 phide. Quantin, director of the agricultural laboratory of Loiret, 

 said he had freed his vines of the cochylis by means of the 

 above remedy. 



A. Lesne 2 tried experiments with eighty preparations for the 

 destruction of the cochylis. His work showed that a prepara- 

 tion of pyre thrum and soap gave the best results. He had it 

 tested by thirty-seven vineyardists and most of them reported 

 favorably regarding it. The ingredients used were 



Black soap 3 kilos. 



Warm water 10 liters. 



Pyrethrum powder 1-1^ kilos. 



1 Jour. d'Ag. Prat. 1891, Aug. 6, 209. 2 Ibid. 1892, May 5, 639. 



