Insects of Interest to Fruit Groicers. 71 



kerosene emulsions, and in the course of his remarks read the following from 

 the advance sheets of his forthcoming report : 



"It can not be too strongly impressed upon all who use kerosene as an 

 insecticide, that it can be considered a safe remedy only when properly 

 einulsilied. The formula for the kerosene and soap emulsion, as found most 

 satisfactory by Mr. Hubbard, is as follows: 



"Kerosene 2 gallons = 67^. 



Common soap or whale-oil soap ^ pound | „„ , 



Water 1 gallon J ~ '"' 



"Heat the solution of soap and add it boiling hot to the kerosene. Churn the 

 mixture by means of a force-pump and spray-nozzle for five or ten minutes. The 

 emulsion, if perfect, forms a cream, which thickens on cooling, and should adhere 

 without oiliness to the surface of glass. Dilute, before using, one part of the emul- 

 sion with nine parts of cold water. The above formula gives three gallons of 

 emulsion, and makes, when diluted, thirty gallons of wash. 



" The kerosene and soap mixture, especially when the latter is warmed, 

 forms upon very moderate agitation, an apparent union ; but the mixture i& 

 not stable, and separates on standing or when cooled or diluted by the addi- 

 tion of wat^r. A proper emulsion of kerosene is obtained only upon violent 

 agitation. It is formed, not gradually, but suddenly ; in short, to use a fa- 

 miliar phrase, 'it comes ' like butter. The time required in churning de- 

 pends somewhat upon the violence of the agitation, but still more upon the 

 temperature, which, however, need not be much above blood heat. 



" When obtained, an emulsion of kerosene and soap is known by the per- 

 fect union of the ingredients, and the absence of oiliness, so that the liquid 

 clings to the surface of glass or metal. It resembles a rich cream, more or 

 less thickened according to the proportion of soap used in the mixture. 



" These details have been fully set forth in previous reports, but it seems 

 necessary to again refer to them, because, while the value of the kerosene 

 emulsions as insecticides has been widely acknowledged, the important 

 point of thorough emulsification has not been sufficiently recognized, and 

 the agricultural press of the country in the discussion of this new applica- 

 tion of an old remedy have very generally omitted to mention the methods 

 by which a perfect emulsion may be secured. 



" Thus in a horticultural journal of wide distribution we find the follow- 

 ing: 'Mr. E. L. Sturtevant, director of the experimental farm at Geneva, 

 N. Y., says that an emulsion, composed of one ounce of common soap, one 

 pint of kerosene oil, and one and one-half gallons of water, kept continually 

 stirred while using to prevent the oil floating on the surface, and used through the 

 rose of a water-pot, will destroy all worms (on cabbage) that get thoroughly 

 wet with the mixture,' etc. The italics, which are our own, sufficiently in- 

 dicate the unstable nature of the mixture, to which this writer wrongly gives 

 the name emuUion. 



"An officer of another State institution, having become a discoverer of the 



