RUST ON GRAPES. 57 



it is the application of sulphur to the pipes or flue 

 about the time the grapes come into bloom. I was led 

 to suspect this some time ago, by observing that in 

 houses where the foliage was affected with a sort of 

 green warty excrescence on the back of the leaf of 

 which more hereafter the very day sulphur was 

 applied to the pipes these green warts, if I may term 

 them such, became black, and killed, to all appearance. 

 Here, then, was a case where the sulphur was affecting 

 organised vegetable matter. This led me to suspect it 

 might be the cause of rust, in as far as it was as likely 

 to be able to affect the young and tender skin of the 

 embryo grape as that of the parts of the leaves referred 

 to ; and I was confirmed in this belief by the following 

 circumstances : In a house of vines, where we also 

 grew French beans and strawberries, red spider was 

 very troublesome, and before the grapes came into 

 bloom I had the pipes painted with sulphur. This 

 house was the only one on the place where sulphur was 

 used till after the grapes were set some time, and the 

 only one w^here they had rust on them. This year 

 (1862) I applied no sulphur to the pipes till the grapes 

 were stoning, and they are perfectly free from rust ; 

 and as they have been treated in every other respect 

 exactly the same as formerly, I have satisfied my own 

 mind that sulphur, applied to hot pipes in a house 

 where vines are in bloom, is sure to cause rust on the 

 berries, especially in the case of such tender-skinned 

 grapes as black Hamburgs.* 



* Farther experience confirms the opinion expressed in this chapter about 

 sulphur being the fertile source of rust. 



