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mixture twice as strong as the last, or 1 pound to 30 gallons of water. 
This last application effectually destroyed the larvae, except some few 
in the top branches which w r ere not reached by the insecticide. The 
larvae, after eating a meal or two of the poisoned leaves, did not succumb 
immediately to the poison, but dragged out a sickly existence for sev- 
eral days without feeding, and more or less restlessly wandering about. 
Many of the nearly or quite full-grown larvae went to the base of the 
trees and died before pupating, while others, which even succeeded in 
pupating, later succumbed to the action of the arsenical. In the case 
of all the applications no injury whatever was done to the foliage. 
The result of these experiments on the elm leaf-beetle seem to be 
rather in favor of the use of Paris -green, but the merit of the arsenate 
of lead as an insecticide was plainly shown, and the perfect safety 
attending its use on foliage was distinctly brought out. Its action is 
undoubtedly slower than Paris green, and if used at the rate of the 
stronger mixtures noted above, will be much more expensive than Paris 
green, even if secured as cheaply as it is by the Gypsy Moth Com- 
mission, namely, at 7 cents per pound. 
The resin wash and resin-kerosene emulsion. — The standard Califor- 
nia insecticide, known as resin wash, has lately been called into service 
by Mr. Galloway's assistants in Florida as a fungicide, to remove the 
smoky fungus (Fumago salicina) following the attacks of the various 
plant lice. A slight modification in the making of this insecticide has 
been developed in connection with this use, which consists merely in the 
employment of granulated caustic soda in place of the crude caustic soda 
recommended in Mr. Coquillett's formula. It is claimed, and the limited 
tests made at Washington seem to sustain the claim, that by the use of 
this higher grade caustic soda the resin wash may be made in very 
much less time, since it is necessary to bring the ingredients to a boil 
only long enough to dissolve the soda and the resin. Mr. Galloway 
tells me that he has experimented with this resin wash or soap also in 
making kerosene emulsion, using it in lieu of soap. I have tested this 
emulsion, and in a rather limited experience am satisfied that a good 
emulsion can be made. Whether this will be a valuable addition to 
the common standard emulsions remains, however, to be shown, but it 
would seem on the surface to be useful, because it combines two impor- 
tant insecticides. The emulsion made with resin has the very decided 
disadvantage, however, that it soon separates into the resin mixture 
and oil when used in the same proportions as the whale-oil soap emul- 
sion. The proportion of resin to the oil to make a permanent mixture 
will have to be determined by later experiments. I found, however, 
that when the emulsion was immediately diluted after being made, the 
dilution remained uniform and without separation indefinitely, whereas 
in the undiluted emulsion, separation began within a very short time. 
Combinations of the Bordeaux mixture with kerosene emulsions. — The 
idea of the combination of insecticides and fungicides to form a mixture 
