( 5 ) 
On these points Mr. Fletcher, the Dominion Entomologist 
of Canada, wrote to me as follows, and also enforcing care 
as to over-application :— 
“ Paris-green. —You are quite safe in recommending this; 
but insist upon these two things, viz., 1st, to keep the mixture 
(which is a mixture, not a solution) well stirred all the time, 
and have the barrel well washed out after it has been filled ten 
or twelve times. The Paris-green is very heavy, and will keep 
sinking to the bottom unless constantly agitated; and as the 
barrel is frequently re-filled the residue will keep accumulating, 
until it will be too strong as the mixture reaches the bottom. 
“ 2ndly. The other point is to insist upon the mixture not 
being made too strong ; 1 lb. to 200 gallons I find very useful, 
and I never use stronger than 1 lb. to 120 gallons.”—(J. F.) 
With regard to method of application of the spray. — This 
should be thrown so finely as to reach all parts of the tree and 
both sides of the leaves, and coat the leaves as with a fine 
dew, but it should not be allowed to run down and drip. As 
soon as dripping begins spraying should cease. 
It should on no account whatever be thrown so as to “ swill ” 
or “souse” the trees, and run off the leaves in drops or 
streams ; this is bad practice in every way. It uses a great 
deal more of the chemical than is needed ; the leaves get little 
but pure water at their highest part, and much too strong 
application where the fluid has settled at the tips; and also a 
drip is caused on to the ground beneath, which may render 
the grass temporarily poisonous. 
Also, spraying should not be done ivhilst the trees are in 
blossom, and warning is also given in the American works 
that sprayings should not be given in rapid succession. 
Several days, it is advised, should elapse between, unless 
of course, as may easily happen in difficulties of first experi¬ 
ments, the spray was manifestly so weak that the previous 
application counted for nothing. The effect of the Paris-green 
on the caterpillars does not always show directly, and it 
is undesirable to waste labour and material where the work is 
already done, and only requires a day or two to show it. 
Non-feeding of animals under sprayed trees. —As it is totally 
impossible to guard against what may be done by careless 
workers, or those who will not take the trouble to understand 
what they are about, in all ive (that is to say, the Experi¬ 
mental Committee as a body and myself personally) are 
desired to advise on, we most scrupulously direct that cattle 
and stock and other animals should never be allowed to pasture 
or feed under trees that are being, or have recently been, sprayed , 
for fear of injury from feeding on Grass on which there may 
