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mixture twice as strong as the last, or 1 pound to 30 gallons of water. 

 This last application eifectually destroyed the larvae, except some few 

 in the top brandies which were 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 larvse 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 n-ash and resin-l-erosene 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 salieina) 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. Co(iuillett'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 icith lerosene emulsions. — The 

 idea of the combination of insecticides and fungicides to form a mixture 



