58 
The only insecticide which has hitherto been found effective under 
these circumstances, as far as I know, is hot water, which has oc- 
casionally been used on a small scale; but it is of course difficult 
and quite expensive to heat, keep hot, and apply a sufficient quan- 
tity of water to protect a field of corn. Believing it advisable to 
exhaust every possible expedient for controlling the ravages of this’ 
most destructive enemy of our crops, I early began experiments with 
emulsions of kerosene, which have the advantage of cheapness and 
abundance of the materials composing them, and have been found 
deadly in small quantities to’ many other insects. The principal 
drawback to the use of these emulsions is the labor of preparing 
them, but this objection was obviated by the discovery that a simple 
mechanical mixture of kerosene and water is equally effective and 
equally harmless to the corn with a carefully prepared emulsion. 
As the kerosene emulsions have many other uses than the one here 
given, taking effect upon by far the greater part of the soft-bodied 
insects of all kinds, it will be worth while to give here an account 
of the method of preparing them. ‘The following is from an article 
by Prof. Riley, published in the Scientific American for May 27, 1882: 
“There is a safe and ready method of diluting kerosene and similar 
oils, and of rendering them miscible with water. The difficulty of 
diluting them, from the fact that they do not mix well with water, 
. has been solved by first combining them with either fresh or spelled 
milk, to form an emulsion, which is easily effected; while this, i 
turn, like milk alone, may be diluted to any extent, so that panniee 
of oil will be held homogeneously in suspension. ‘Thus, the ques- 
tion of applying oils in any desired dilution, is settled, and some- 
thing practicable from them may be looked for. Mr. Hubbard has 
had no difficulty whatever in making a perfectly stable emulsion, 
and the secret of so doing consists in the proper amount of churn- 
ing,—for the whole process may be comparable to butter-churning, 
with the exception that the oil and milk, in any desired proportion, 
must be much more violently churned for a period varying with the 
temperature from fifteen to forty-five minutes. On continued churn- 
ing, the liquid finally curdles, and suddenly thickens to form a white 
and glistening butter, perfectly homogeneous in texture, and stable. 
The whole amount of both ingredients solidifies together, and there 
is no whey or other residue. If, however, the quantity of the mix- 
ture is greater than can be kept in constant agitation, a portion of 
the oil is apt to separate at the moment of emulsification, and will 
require the addition of a few ounces of milk, and further churning 
for its reduction. This kerosene butter mixes readily with water, 
eare being taken to thin it first with a small quantity of that liquid. 
The time required to ‘bring the butter’ varies, with the tempera- 
ture: at 60° F., half to three-quarters of an hour; at 75°, fifteen 
minutes,—and the process may be still further facilitated by heat- 
ing the milk up to, but not past the boiling point. Either fresh or 
sour milk may be used, and the latter is even preferakle. The pres- 
ence of kerosene does not prevent or hinder the fermentation of the 
milk; on standing a day or two the milk curdles, and although 
there is no separation of the oil, the emulsion thickens and hardens, 
and requires to be stirred, but not churned, until it regains its former 
smoothness. Exposure to the air not only permits the evaporation 
