104 
ORCHARD MOTH CATERPILLARS. 
down in the same way by addition of the rest of the water until the 
barrel is full. The amount of flour used to a given quantity of water 
or Paris-green appears not to be very important. 
The preceding observations give the main points of our work, that 
is, the work of the Evesham Fruit Conference Experimental Committee 
during 1890, carried on with such co-operation as I was myself able 
to give by information from Government and Official Reports for 
many years hack, of successful methods of operation both in Canada 
and the United States of America, and aided also by special advice 
with which we were kindly favoured in our difficulties by Mr. J. 
Fletcher, the Dominion Entomologist of Canada. 
Requirements of space only allow of insertion of a portion of the 
observations, but a large mass of details are in my hands, from which 
I shall be happy to give any information, and also may remark that 
in addition to the great amount of information which has long been, 
and still continues to be, laid before the public in the Reports of the 
Dept, of Agriculture of the U.S.A., on the subject of arsenical insecti¬ 
cides, that the increasing attention given to the method of lessening 
amount of insect ravage is furnishing a large mass both of evidence of 
their utility and details of methods of application, which may be very 
serviceably consulted in the reports of the Experiment Stations of the 
Agricultural Colleges of various of the United States, as of Ohio, 
Massachusetts, Iowa, &c. 
London-purple .—In the past season, some amount of trial was also 
made of another arsenical insecticide which has long been used in 
America, known as London-purple. This is an arsenite of lime. A 
notice of the method of preparation and also analysis of this chemical, 
by Prof. Collier (then Chemist of the Dept, of Agriculture, U.S.A.), 
will be found at p. 149 of the 4tli Report of the United States 
Entomological Commission, followed by report of the results of trial of 
the “ purple,” of which a number of barrels had been placed at the 
disposal of the U.S.A. Government by the liberality of the manu¬ 
facturers, Messrs. Hemingway & Co., in 1879. 
The analysis given is as follows :— 
Rose aniline . 
Per cent. 
12.46 
Arsenic acid . 
. 43.65 
Lime .... 
21.82 
Insoluble residue . 
14.57 
Iron oxide 
1.16 
Water .... 
2.27 
Loss .... 
4.07 
Total 
. 100.00 
The “ purple ” may be used either as a powder dressing, or it may 
be mixed with water, or water and flour, and sprayed on the trees just 
