HOW TO FIGHT POTATO ENEMIES. 63 



Stir constantly while adding the lime. Add water to make the 

 amount desired. 



Much time may be saved by preparing stock solutions. While 

 any proportions can be used, the following was found in the 

 spraying experiments made by the Station a convenient way : 



The stock solution of copper sulphate is made by weighing 

 out 50 pounds of copper sulphate, placing it in a bag and sus- 

 pending it in the top of a barrel containing 30 gallons of water. 

 The copper sulphate dissolves completely in a few hours. The 

 stock solution of the lime is prepared by slacking 50 pounds of 

 lime, and adding water so as to make up to 30 gallons and 

 straining through No. 50 brass screen cloth. To slack and strain 

 this amount of lime takes less than one-half hour. For use, 3 

 gallons of each solution and 44 gallons of water make up the 

 formula give above. The stock solution of lime should be kept 

 well covered and be thoroughly stirred before dioping out. 



Formula 3. bordeaux mixture and paris green. 



Paris Green y 2 pound 



Bordeaux Mixture 50 gallons 



Make a paste with the Paris green and a little water. Add to 

 the Bordeaux mixture and stir thoroughly. 



Formula 3a. bordeaux mixture and lead arsenate. 



Lead Arsenate or Disparene 1 pound 



Water 50 gallons 



Formula 4. paris green. 



Paris Green ^2 pound 



Lime (unslacked) 3 pounds 



Water 5° gallons 



The standard remedy for the destruction of insects which eat 

 the foliage or fruit The lime is added to prevent the Paris 

 green from burning the foliage. Slack the lime in a little water, 

 make into a thin paste and strain. Wet up the Paris green with 

 a little water into a thin paste. Mix the lime and Paris green 

 and add the remainder of the water. A stock solution of lime 

 can be made as described under formula 2. 





