380 AMERICAN GRAPE CULTURE. 



restore the normal activity of the plant, by the 

 application of the principles elsewhere ex- 

 plained. 



At the same time we must have recourse to 

 some remedy that will destroy the active cause 

 of the disease. Remedies without number have 

 been suggested, but, after long trial, only one 

 has proved so effectual as to commend itself to 

 general use, and that is sulphur. It should be 

 applied directly to the parts affected, but espe- 

 cially to the under side of the leaves. The 

 sulphur should be in the finest state of powder, 

 and dry; and it should be applied with con- 

 siderable force, at least to the under side of the 

 leaves, so as to penetrate the furze which gener- 

 ally covers this part of the leaf. Sulphur ap- 

 plied in this state, being acted upon by the sun's 

 heat, would seem to combine oxygen enough to 

 form sulphurous acid, the vapor of which de- 

 stroys the mildew. We have found consider- 

 able advantage in adding a portion of finely 

 powdered lime, which increases the action of 

 the sulphur. In this case, sulphite of lime is 

 formed. 



Various contrivances have been invented for 

 applying sulphur, one of the simplest of which 

 is the bellows of De la Vergne, which resembles 



