THE CANADIAN ENTOMOLOGIST. 185 



lions generally adopted many accidents which now occur would be pre- 

 vented. It has been urged by some that so many evils have attended the 

 use of Paris Green that it does more harm than good, and that its use 

 should be discontinued ; but in this I am not prepared to concur, as I am 

 satisfied that without it, unless some suitable substitute were found, the 

 potato crop in many localities could not be preserved from destruction. 

 If reasonable care is exercised and the powder be used mixed with water, 

 there is no danger attending it, and its use in this manner in the propor- 

 tion already mentioned of a teaspoonful to a pail of water and applied 

 with a whisk, is not only safe but most economical. 



For some years past experiments have been made with various other 

 substances with the view of finding a substitute for Paris Green which 

 would be less dangerous in the hands of the careless, and among them I 

 believe none have been used with greater success than common blue 

 vitriol or sulphate of copper, in solution in the proportion of about an 

 ounce to a pail of water, and applied in the same manner as the Paris 

 Green mixture. This article is woithy of, and will doubtless receive, a 

 more extended trial, as its use under any circumstances would be attended 

 with but little danger. For the destruction of household pests Insect 

 Powder has lately attracted much attention, and is probably the most 

 valuable agent we have for this purpose, and it is quite harmless to man 

 and the higher animals. There are two sorts of this powder, known in 

 commerce under the respective names of Persian and Dalmatian Insect 

 Powder ; the former is the powdered flowers of Pyrethrum roseum, the 

 latter of Pyrethrum cinnerariaz-folium. The Dalmatian Powder is most 

 highly esteemed. The powder is diffused through the atmosphere by 

 means' of a small bellows, or insect gun, and in a very short time it brings 

 house-flies, cockroaches, etc., on their backs, and dusted among bed- 

 clothing is equally effectual on noxious pests there. It does not at first 

 kill the insects outright, but paralyzes them so that they are unable to use 

 either legs or wings, and after remaining in this condition many hours and 

 sometimes days, a solitary individual here" and there will either wholly or 

 partially recover, but the great bulk of them die, 



A very active blue-bottle fly placed under the influence of the powder 

 was brought on its back in one and a half minutes. After six minutes it 

 performed some remarkable evolutions, throwing itself about in the most 

 desperate manner by the aid of its wings, for by this time it had lost the 

 use of its legs ; in a few moments more it was quiet, but still able to move 



