400 Diseases of Greenhouse Crops 



(b) The following proportions of materials for 

 TOO gallons of spray are used: 



1. Five gallons of hot water. 



2. One and one-half pounds of Ivory soap. 

 (Six 5-cent cakes or three lo-cent cakes.) 



3. One gallon of raw linseed oil. 



(c) Steps in the preparation of stock solution 

 follow: 



1. Put the required amount of hot water in the 

 container. 



2. Shave the Ivory soap into this and stir until 

 completely dissolved. 



3. If at this time the temperature of the soap so- 

 lution is too hot for the hand to bear, dilute with 

 one gallon of cold water and let it stand until about 

 body temperature or lukewarm. The cooling of this 

 solution is necessary in order to prepare a permanent 

 emulsion ; otherwise the oil will come to the surface 

 on standing (see No. 6). It also prevents the chemi- 

 cal and physical killing properties of the linseed oil 

 from being changed by heat. 



4. Add slowly, while stirring vigorously, one gal- 

 Ion of linseed oil. 



5. Completely emulsify by using the bucket 

 pump and turning the stream back into the container 

 again, keeping the nozzle below the surface of 

 liquid. Five minutes' vigorous pumping should 

 completely emulsify this solution. 



6. Set aside for a few minutes while preparing 

 spray tank in order to see that oil does not come 

 to the surface. 



