600 STATE BOARD OF AGRICULTURE. 



burn the foliage, and it is cheap. To prepare it, dissolve four ounces of 

 arsenate of soda and eleven ounces of acetate of lead, each in a gallon of 

 water. On mixing the two solutions together we shall get a milky pre- 

 cipitate, which should be stirred into 100 gallons of water. It is now 

 ready for spraying. Of course, larger or smaller quantities may be made 

 in the same proportion, and if this preparation does not seem strong 

 enough, it may be applied much stronger with safety. 



Its action is slower than that of Paris-green, but the fact that it does 

 not readily burn foliage is an advantage when spraying various kinds of 

 trees with one mixture. 



CONTACT INSECTICIDES, FOR INSECTS WHICH SUCK THEIR FOOD. 



The most effective contact insecticides are kerosene-emulsion and 

 whale-oil soap. Kerosene-emulsion may be used against all lice (except 

 bark-lice), bugs, etc., which do not succumb to the internal poisons. To 

 be effective it must be very carefully made and conscientiously applied. 



Flace two gallons of ordinary kerosene in a warm place, either in a 

 warm room or in the sun, and allow it to become as warm as possible 

 without danger from Are. Boil one pound of laundry soap or whale-oil 

 soap in a gallon of soft water until completely dissolved. If the water 

 is the least bit hard, "break" it with washing soda. Remove the soap 

 solution from the fire, and while still boiling hot add the kerosene and 

 agitate for ten minutes, or until the oil is emulsified, with a spraying- 

 pump by forcing the liquid back into the vessel from which it was 

 pumped. 



When the liquid is perfectly emulsified it will appear creamy in color 

 and will flow evenly down the side of the vessel. Care should be 

 taken to completely emulsify the oil, and this is accomplished much 

 more easily when the mixture is hot. This strong emulsion may 

 now be readily diluted with water and used, or it may be stored away for 

 future use. When cold it becomes like sour milk in appearance, and 

 should be dissolved in three or four times its bulk of hot water before 

 diluting with cold water. 



Small amounts of this emulsion may be made by using the ingredients 

 in small quantities, but in the same relative proportion. 



It should be diluted ten times for most insects, but many plants are 

 able to resist a stronger mixture, which is usually more effective. 



WHALE OIL SOAP. 



This insecticide is rapidly coming into favor. It may be used at the 

 rate of one pound to from four to six gallons of water for plant-lice and 

 many other insects. For winter spraying it is used at the rate of two 

 pounds to a gallon of water. This is the most effective remedy known 

 against the San Jose" scale. 



Whale-oil soap should cost about four cents per pound when bought 

 in quantity. It requires no preparation other than dissolving in water, 

 and ordinarily is easily applied. Care should be observed to get an 



