368 BOARD OF AGRICULTURE. [Pub. Doc. 



arsenic compounds, would be of no value. From the nature 

 of their feeding habits they are not as active as the biting; 

 insects, and often remain fixed in one place for a long time, 

 thus rendering their destruction easy through those insecti- 

 cides which kill by contact. The general effect of contact 

 insecticides is to suffocate the insects by closing the breath- 

 ing pores, either by coating them over with a film or induc- 

 ing an irritation which closes them. The most practical and 

 hence most prominent insecticide of this class is kerosene 

 emulsion, the formula for which as given by Professor Fer- 

 nald is presented herewith : — 



Kerosene Emulsion. 



This most useful insecticide is prepared in the following man- 

 ner : One-quarter of a pound of common bar soap is dissolved in 

 two quarts of boiling water, and while still hot four quarts of 

 kerosene oil are added and the whole mixture churned through a 

 small hand force-pump with the small nozzle turned into the pail. 

 This churning must be continued about five minutes, until the 

 whole forms a creamy-white mass which becomes jelly-like when 

 cool. Care must be taken to have the soap solution hot when the 

 kerosene is added to it and the churning done, but it must not be 

 near a fire. 



Before applying the emulsion to plants it should be diluted with 

 water in the proportion of one quart of the emulsion to nine quarts 

 of water, which must be thoroughly mixed. The above will make 

 sixty quarts of insecticide ready for use, but the emulsion will 

 keep for a long time without injury and may be diluted at the time 

 of using. This insecticide is said to be one of the best substances 

 for the destruction of vermin on domestic animals and in hen 

 houses. 



The dissolving of the soap requires considerable time, and 

 I find that the emulsion when needed for immediate use may 

 be prepared more expeditiously and equally as effectively 

 by use of the same or a little greater quantity of any good 

 soap powder in place of the bar soap. The common soap 

 powders readily dissolve in hot water, thus obviating the 

 necessity of cooking the mixture over a stove, and so far as 

 I have observed make an excellent emulsion. Samples pre- 

 pared four weeks ago are as permanent as when made, and 

 I see no reason why they may not keep as well as the emul- 



