214 NEBRASKA STATE HORTICULTURAL SOCIETY. 



used to defend against the potato beetle and all leaf or bud-eating in- 

 sects that defoliate our fruit trees early in the season, and on our 

 SHADE and forest trees for such insects at any time." * * * 



KEROSENE EMULSION. 



So far as I know, next to London purple and Paris green no other 

 preparation equals kerosene as an insecticide. In fact, personally, I 

 prefer the use of the kerosene to the arsenites; for, like the darkies 

 in the cotton fields of the south, I am afraid of "pisen" under all 

 circumstances. The pure kerosene is, however, just as injurious to 

 vegetation as it is to insect life. To dilute it with water is not possi- 

 ble without the addition of soap or fresh milk. Either of these latter, 

 if thoroughly mixed with a certain proportion of the oil, will render 

 it possible to be diluted with water to such a degree that it will no 

 longer destroy the foliage to which it is applied. 



The term "kerosene emulsion" probably had its origin in the De- 

 partment of Agriculture at Washington, although Professor A. J. 

 Cook possibly was the first to use the mixture as an insecticide. He 

 (Cook) writes about this insecticide as follows in the bulletin already 

 quoted : 



"The great value of this substance rests in the fact that it kills by 

 contact, and insects that suck, like lice and true bugs, are killed by its 

 use. * * * The way I prepare this kerosene and soap emulsion 

 is as follows : I mix one quart of soft soap, or one-fourth pound of 

 hard soap, with one or two quarts of boiling water ; as soon as the 

 soap is all dissolved, I stir in, while all is yet hot, one pint of kero- 

 sene oil. This is now violently stirred till it is permanently mixed ; 

 that is, till, upon standing, the oil will not rise to the top, but will re- 

 main incorporated with the liquid. This stirring is best done by use 

 of a force pump — pumping back into the vessel containing the liquid. 

 When we are ready to use this, stir in enough water to make fifteen 

 pints in all — that is, one-fifteenth of the liquid applied would be ker- 

 osene oil." 



The following formula has been used by the members of the 

 Division of Entomology in the United States Department of Agri- 

 culture for making this emulsion, and has been found to give the best 

 general results. It is generally known as Hubbard's formula, because 

 first used by that gentleman in his experiments with orange insects: 



