124 THE HOP. 



persons interested in the sale of the substance, when 

 carefully tested by an agent of the United States De- 

 partment of Agriculture in the field in Oregon in 1893, 

 proved less effective than the kerosene emulsion and 

 than the best of the fish- oil soaps, and it is probable that 

 the disrepute into which the kerosene emulsion early 

 fell was due to improper preparation and consequent 

 destruction of foliage. 



The standard kerosene soap emulsion formula is 

 made as follows: 



KEROSENE EMULSION 



Kerosene 2, gals. 



Whale-oil soap (or I qt soft soap). . .| Ib. 

 Water i gal. 



Dissolve the soap in boiling water and add the hot 

 solution, away from the fire, to the kerosene. Agitate 

 violently for five minutes by pumping the liquid back 

 upon itself with a force pump until the mixture assumes 

 the consistency of cream. In this condition it will keep 

 indefinitely and should be diluted only as wanted for 

 use. For plant lice and other soft-bodied insects, dilute 

 the above to 15 or 20 gallons. For scale insects and 

 beetles use seven to nine parts of water. 



Fish-oil soap is made in the following way : Take 

 potash lye, I pound; fish oil, 3 pints; soft water, 2 gal- 

 lons. The lye is dissolved in the water, and when 

 brought to the boiling point the oil is added. The 

 batch is boiled for about two hours. Enough water is 

 filled in to make up the evaporation by boiling, and 

 the result will be about 25 pounds of soap, which, when 

 cold, may be cut and handled in cakes. This is enough 

 for 150 gallons of effective wash and will cost from 20 

 to 25 cents in Oregon. 



Additional experiments were made in 1893 with 

 resin wash and the results were very satisfactory. The 

 formula used by the agent, Mr. Koebele, that year was 

 as follows : One pound of caustic soda dissolved in two 



