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twenty to twenty-five 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 eab- 
bage, dusted as 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). 
The simple remedies for this class of insects, such as soap and lye 
washes, tobacco decoction, ete., are frequently of the greatest service, 
but need no special explanation. The whale oil is the most valuable of 
the soaps, and at the rate of 1 pound to 4 gallons of water, dissolved by 
heating, kills most soft-bodied insects, and at 1 to 2 pounds to the gal- 
lon is an effective winter wash for scale insects, even the very resistant 
San José seale succumbing to the latter strength. The insect powders 
(Pyrethrum or Buhach) are effective, but too expensive for any but 
limited or indoor use. The following are standard reniedies for this 
group of insects: Kerosene emulsions, resin washes, hydrocyanie acid 
gas, and vapor of bisulphide of carbon. 
THE KEROSENE WASHES, 
The kerosene and soap emulsion formula. 
UR @ROR EINE EL & ls ES oS I ee Se oe se ee gallons.. 2 
Wihale-oil-soap (or 1 quartisoftsoap) -22- 2. 2. 22-a52.L2. 2222 22.- pound.. 4 
NEL UG Ie eer estat: eeyeem ann ne at Ne cor Se eee peo eels ci tlat gallon.. 1 
The soap, first finely divided, is dissolved in the water by boiling 
and immediately added boiling hot, away from the fire, to the kerosene. 
The whole mixture is then agitated violently while hot by being pumped 
back upon itself with a force pump and direct-discharge nozzle throw- 
ing a strong stream, preferably one-eighth inch in diameter. After from 
three to five minutes’ pumping the emulsion should be perfect, and the 
mixture will have increased from one-third to one-half in bulk and 
assumed the consistency of cream. Well made, the emulsion will keep 
indefinitely, and should be diluted only as wanted for use. 
The use of whale oil seap, especially if the emulsion is to be kept for 
any length of time, is strongly recommended, not only because the soap 
possesses considerable insecticide value itself, but because the emul- 
sion made with it is more permanent, and does not lose its creamy con- 
sistency, and is always easily diluted, whereas with most of the other 
common soaps the mixture becomes cheesy after a few days and needs 
reheating to mix with water. Soft soap answers very well, and 1 quart 
of it may be taken in lieu of the hard soaps. 
