EXPERIMENT STATION BULLETINS. 331 



for use. The arsenic in this mixture is equivalent to four ounces of 

 Paris green." 



*'The pot, jug, etc., must never be used for any other purpose after 

 using it for making this mixture." 



"If an additional pound or two of lime be added to the mixture, it 

 will help to make the application permanent and conspicuous without 

 in any way interfering with its effects. In using it the extra lime should 

 be added." 



ARSENATE OF LEAD. 



This poison is coming into general use throughout the country, and 

 has several advantages; it shows where it has been applied; and it does 

 not easily burn the foliage. 



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

 does not readily burn the foliage is an advantage when spraying various 

 kinds of delicate trees with one mixture. It is used at the rate of from 

 one to five pounds to fifty gallons of water or Bordeaux — or the lime 

 sulphur sprays. 



CONTACT INSECTICIDES, FOR INSECTS THAT SUCK. 



KEROSENE EMULSION. 



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

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

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

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

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

 and agitate vigorously 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 when 

 allowed to do so. 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. If the water is at 

 all hard, "break" it by adding a little sal-soda before putting in the 

 soap. 



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

 in small quantities but in the same relative proportion. It is used at 

 the rate of eight or ten parts of water to one part of emulsion. 



STRONG LIME-SULPHUR FOR DORMANT TREES AND SHRUBS. 



This is a contact insecticide which should be used preferably just be- 

 fore growth starts, in any case, before the buds swell in the spring. If 

 used when foliage is on the trees, the foliage will be killed. It is made 

 in several ways, one of which is as follows : 



