INSECTICIDES 15 



trees in winter, and must be used with care and dis- 

 cretion in order not to kill the trees. It is to be 

 sprayed on until the bark is thoroughly moistened, 

 but spraying should cease before the kerosene begins 

 to run down the branches. The Vermorel nozzle with 

 one-twentieth-inch aperture is recommended for this 

 work. Apparently there is especial danger of injury 

 to the trees in the case of the peach. 



Kerowater Sprays During the last few years 

 considerable progress has been made in the making 

 of apparatus for applying kerosene in mechanical 

 mixture with water. Essentially this consists in 

 having the kerosene in one receptacle and the water 

 in the other and bringing the two together at the 

 nozzle in such a way that the two will combine in 

 the spray applied. In much of the apparatus now 

 upon the market, the two liquids enter the same hose 

 at the pump so that there is an opportunity for more 

 or less separation before the nozzle is reached, a fact 

 which leads to inequality in the percentages of ker- 

 osene in the spray at different times. The longer and 

 larger the hose the greater the danger. Consequently 

 the small bucket and knapsack kerosene and water 

 machines are much more likely to give satisfaction 

 than the large barrel machines. 



As a matter of fact the kerosene and the water 

 should reach the nozzle through separate lines of 

 hose so that there will be no opportunity for such 

 inequalities as the present system involves. In some 

 of the best types of barrel sprayers this principle is 

 now adopted. 



There is no question that these kerowater sprays 

 have many advantages, and are very useful in de- 

 stroying many sorts of insects. 



Kerosene Emulsion According to the Riley- 

 Hubbard formula in general use this is prepared by 



