12 LOYAL SOCIETY OF CANADA 
sene oil, and is greatly interested in the still more important question of 
controlling the spread of malarial disease. The progress made in these 
experiments and the details in connection with them we shall hear from 
his own lips on Thursday. 
When one looks back a few years, it is wonderful to observe the pro- 
gress that has been made in the adoption of scientific methods of deal- 
ing with injurious insects. Since the discovery of Paris green as a 
remedy for the Colorado potato beetle, the use of arsenical insecticides 
has become almost universal, and their application by means of spraying 
pumps for the destruction of caterpillars and other mandibulate insects 
has wrought a revolution in horticulture and fruit-growing. Suctorial 
insects also, such as scale insects and aphis, can now be controlled by the 
spray pump, kerosene emulsion being employed instead of the virulent 
poison. The widespread use of these methods in Canada is very largely 
due to the persistence with which they have been urged upon our 
farmers and fruit-growers, in season and out of season, in the agricul- 
tural and horticultural press, in letters to newspapers, on the platform at 
meetings and in less formal addresses, by our Dominion Entomologist, 
Dr. James Fletcher. His zeal has been contagious and the good work 
bas been taken up by others, to such an extent that probably no intelli- 
gent person in the community is ignorant of the benefits to be derived 
from spraying even though he may not take the trouble to reap them 
himself. The good work never stops; new insecticides are being dis- 
covered by means of patient experiments and new machinery for their 
use is being developed year by year. 
The use of hydrocyanic acid gas has been already referred to in 
connection with the San José scale. It is now employed for fumigating 
nursery stock in houses specially built for the purpose, in accordance 
with the provisions of the Act of the Ontario Legislature ; in some parts 
of the United States it is also applied to growing fruit trees in the 
orchard, by inclosing them in a portable tent while the operation is 
going on. This will destroy every living being on the tree most effectu- 
ally, but it is a method that involves considerable expense and is not 
likely to be adopted by ordinary fruit-growers. The gas has also been 
made use of for the destruction of insects in green-houses, but it in- 
volves so much risk that one cannot recommend its general application. 
The material is one of the mostly deadly poisonous substances known and 
should not be employed except by those who have been specially trained 
and who may be trusted to exercise the greatest care and use all possible 
precautions. 
Another remedy that is used with great success is bisulphide of 
carbon. It is regularly employed by those in charge of the seed pea ware- 

