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ance of their skins, which have, in fact, become thick 

 and indurated. Some think it arises from their being 

 handled, or the hair of the head touching them ; but 

 the disease is often too general to admit of this topical 

 explanation. We believe it to arise from an over- 

 heating of the vinery, however unintentional, whilst 

 the grapes were young, and thus tending to force 

 them to a premature rapidity of growth. Any ex- 

 cessive pressure upon the cuticle, whether from within 

 or from without, causes its thickening. This consi- 

 derable elevation being succeeded by as sudden re- 

 duction of temperature, will almost certainly induce 

 the disease. 



One writer thinks that this, or whatever causes 

 the rust, occurs whilst very young, for he states that 

 he never saw grapes with this disease, but dark spots 

 were to be observed on the bunches before they were 

 in bloom. He adds, that if the diseased berries ap- 

 pear to have a more oily appearance, until nearly the 

 size of a pea, and the pollen adheres to them as dust 

 does to anything fresh painted, whether syringed, 

 thinned, or not, there is nothing will prevent them 

 from having the rust that season. (Gard. Chron. 

 1842, 805.) We can only say, that we have not ob- 

 served these phenomena, and that we are convinced, 

 if the temperature to which the bunches are exposed 

 is not subjected to sudden vicissitudes, the rust will 

 not appear upon their berries. 



