10 
CARE IN USK OF ARSENICALS. 
It must be remembered that these arsenicals are very poisonous, and 
should be so labeled. If ordinary precautions are taken there is no 
danger to man or team attending their application, and the wetting 
of either, which can not always be avoided, is not at all dangerous on 
account of the great dilution of the mixture, and no ill results what- 
ever have resulted from this source. 
The poison disappears from the plants almost completely within 20 
to 25 days, and even if the plants were consumed shortly after the 
application, an impossible quantity would have to be eaten to get a 
poisonous dose. To illustrate, in the case of the apple, if the entire 
fruit were eaten, core and all, it would take several barrels at a single 
sitting to make a poisonous dose (Riley), and with the cabbage dusted 
us recommended above, 28 heads would have to be eaten at one meal 
to reach this result (Gillette). It is preferable, however, to use other 
insecticides in the case of vegetables soon to be eaten, and thus avoid 
all appearance of danger. 
INSECTICIDES FOR EXTERNAL SUCKING INSECTS (CONTACT POISONS). 
Two classes of insecticides have proven themselves far superior to 
all others for this group of insects, viz, (1) the kerosene emulsions and 
resin washes, and (2) the gas treatment. The simpler remedies, such 
as soap and lye washes, tobacco decoction, etc., need no special expla- 
nation. The Pyrethrum powders, Persian insect powder, and Buhach 
are effective, but too expensive for any but limited applications or 
indoor use. 
THE KEROSENKE WASHES. 
Pure kerosene is very destructive to plant life, but diluted it may be 
safely applied, and the emulsions made by combining it with either 
soap or milk are so far the most satisfactory means of diluting it dis- 
covered. 
The kerosene and soap emulsion.—This is made after the following 
formula: 
Kerosene 3.232902. see fice. 2b hs ee ae ee ee gallons.- 2 
SOR DM obs emscce/s tees Cet ee che Meme bares sere ne eer pound... 3 
Wratemec sonnti lth coe bacon. ot Meee ote eae Peo bas ee eee gallon.. 1 
The soap, first finely divided, is dissolved in the water by boiling, 
and then added boiling hot, away from the fire, to the kerosene. The 
whole mixture is then agitated violently by being pumped back upon 
itself with a foree pump and direct-discharge nozzle throwing a strong 
stream, preferably one-eighth inch in diameter. After about five min- 
utes’ pumping, the emulsion should be perfect, and the mixture will 
have increased from one third to one-half in bulk, and assumed the con- 
sistency of cream. It should adhere to glass without oiliness. Well 
made, the emulsion will keep indefinitely, or may be diluted for imme- 
diate application. 

