442 



AN ECO NU MIC K.XJ'OMOLUG Y. 



Allied to the lime, because of their caustic action, come the 

 various combinations of Ihnc and sulphur, with or without salt, 

 formed by boiling, by using the heat of the slaked lime alone or 

 by using caustic or sal soda to aid the union. The result is a 

 sulphide of lime which is very corrosive, an absorl)enl of moisture, 

 and which decomposes slowly, setting free a poisonous vapor. 

 This is suitable for winter use only, on dormant trees ; is particu- 

 larly applied against scale insects, and, in the Kast, almost exclu- 

 sively against the pernicious or San Jose scale. 



The wash is originally a Californian preparation, and a generally 

 accepted fornnila is : 



Lime 50 pounds 



Sulphur 25 pounds 



Stock salt iS pounds 



Water suflicii iit to make 100 ji^ailons 



The proportions vary greatly in different localities, but long 

 continued, thorough boiling is always insisted on. There is no 

 doubt that on the Pacific coast these combinations, properly made 

 and applied, are entirely successful, and, incidentally, they have 

 proved us(;fnl in the control of certain fungous tliscases. In the 

 East, a great variety of f.x])i'riiii(nls have been made under cpiite 

 different climatic conditions, and contradictory results have been 

 obtained ; but, as the net product of all the e.xj)erience, it seems a 

 fair conclusion that under favorable conditions the linie-sul|)hur 

 combinations are reasonably certain in their effects on the scale 

 insects, and safe on all varieties of trees when fnllv doiinaiit. 



Chemically, it reciuires less than one i)oun(l of lime to combine 

 one pound of sulphur, and anything more than is necessary is 

 mere whitewash ; but a slight excess is not harmful, antl the 

 fornnila that I have found most satisfactory is : 



Lime stone or shell 50 pounds 



Sulphur — flowers or ground 50 jwunds 



Salt 50 i)ouuds 



Water 150 j^^allons 



Slake the lime with warm water enough to do it thoroughly, 

 and during the process add the sulphur, preferably made into a 

 thin paste. Hoil one hour with water enough to jjrevent burning, 

 and until the mixture becomes a deep amber color. Dissolve the 



