Spraying with Lime-Salt-Sulphur Spray in Fall. 283 



"This wash was cooked without the direct use of external heat. First tlie 

 sulphur was made into a paste with hot water and was then emptied into a 

 barrel containing forty pounds of lime, which was started to slake with twelve 

 gallons of boiling water. During the slaking process the barrel was covered to 

 prevent the loss of heat. Occasionally the wash was stirred to secure a more 

 uniform distribution of the sulphur in the whitewash. In twenty minutes after 

 the time that the lime first commenced to slake, enough boiling water was added 

 to make the required sixty gallons of mixture ; after which the salt was added 

 and stirred until dissolved. The wash was then strained and applied hot. 



LIME-SULPHpR WASH. 



(Formula III.) 



Lime 15 pounds 



Sulphur 15 pounds 



Water 50 gallons 



"This mixture was made in the same manner as the boiled lime-sulphur-salt 

 wash, except that the salt was omitted. 



SELF-BOILED LIME-SULrHUR-CAUSTIC SODA WASH. 



(Formula IV.) 



Lime 30 pounds 



Sulphur 15 pounds 



Caustic soda 6 pounds 



Water 50 gallons 



"In preparing this wash the lime was started to slake with six gallons of 

 water, and. as soon as the slaking commenced the sulphur, which had .iusr 

 previously been made into a thin paste with hot water, was added and thoroughly 

 mixed in with the slaking lime. To prolong the boiling of the wash, the caustic- 

 soda was then used, with water as needed, and the whole mixture was kept thor- 

 oughly stirred. As soon as the cnemical action had ceased the required amount 

 of water was added, when the mixture was ready for use. The soda used in tht^ 

 preparation of this wash is a powdered 74 per cent caustic soda, sold by the I'enn 

 Chemical Works, 1.S22 Washington Avenue, Philadelphia, I'enn. It sells for 

 4 cents a pound and is contained in 50-pound cans. 



"A modification of this method is discussed later on in this article. 



BOILED LniE-SUIiPHUR-CAISTIC SODA WASH. 



(Formula V.) 



Lime 30 pounds 



Sulphur 15 pounds 



Caustic soda Q pounds 



Water 50. gallons 



"This was prepared in the same manner as the self-boiled lime-sulphur-caustic 

 soda wash, after which the mixture was boiled for one to two hours over a 

 flre. 



"In each experiment with each variety of fruit the number of trees was 

 divided as evenly as possible for treatment by the different sprays. Compara- 

 tive tests were made of the above described washes in all of the orchards with 

 the exception that the self-boiled lime-sulphur-salt wash was omitted in two 

 orchards, and the self-boiled lime-sulpliur-caustic soda wash in one. 



"All the trees were examined carefully early in May and several times dui'ing 

 the summer to determine the effect of the treatment. All the washes proved 

 equally destructive to the scales, and as effctive as spring treatments upon simi- 

 lar trees. This was true not only of San Jose scale, but also of the scurfy bark 

 louse, which infested many of the trees in one orchard. On all trees with smooth 

 bark practically all the insects were killed, whether few and scattered or so plen- 

 tiful that portions of the trees were encrusted with a layer of the scales so 

 closely crowded that the bark could not be seen. On trees with naturally rough 



