108 THE ENTOMOLOGIST. 



more or less injury to the leaves. In cases where Paris-green 

 is not obtainable this might be used as a substitute, in the 

 proportion of one ounce to a pound of a flour, which should 

 always be coloured with some black powder, such as char- 

 coal or black antimony, so as to lessen the risk of accident 

 from its use. 



"Powdered Cobalt or Fly-poison. — Another arsenical com- 

 pound was also tested, known in commerce as powdered 

 cobalt, or fly-poison. This was used in the same proportions 

 as the last mentioned, and with similar results, but, owing to 

 its higher price, we do not recommend it for general use. 



" Sulphate of Copper {Blue-stone). — A strong solution of 

 this salt was tried in the proportion of two ounces to one 

 gallon of water, and showered on the vines with a watering- 

 pot, without damage to either the insect or the plant. 



"Bichromate of Potash. — This is a poisonous substance 

 largely used in dyeing, and one which has attracted some 

 attention in France of late, as a remedy for insects. We used 

 it dissolved in water, in the proportion of two ounces to three 

 gallons of water. This killed the insects effectually, but, at 

 the same time, destroyed the plants. Whether, in a more 

 diluted form, this remedy could be eff'ectively used without 

 injury to the foliage, we are unable at present to say, but 

 shall experiment further with it. 



" Powdered Hellebore. — This powerful irritant, which is so 

 effectual as a remedy for the currant-worm, we tried without 

 perceptible effect, both in powder and also mixed with 

 water. Several other poisonous substances were also used 

 with like results. 



"Carbonate of Lime. — There are several preparations sold 

 under this name, which we found to vary much in composi- 

 tion and character, and equally so in effect. We tried an 

 article known as Dougall's, without auy good result, but 

 succeeded better with one prepared by Lynam Brothers, of 

 Toronto, — a black powder, manufactured, we understand, from 

 coal-tar. This destroyed a large proportion of the larvae, but 

 we doubt whether it would kill the perfect insect ; it is, 

 moreover, used in an undiluted form, which would render its 

 cost greater than that of the Paris-green mixture. Some see 

 no advantage in using it, although the fact of its being less 

 poisonous may induce some to try it who are prejudiced 

 against Paris-green. 



