'204 CULTURE OF THE GRAPE. 



hundred- weight) of gypsum to an acre which he recom- 

 mends to be applied annually for such crops. The amount 

 of sulphate of lime needed for an acre of grape-fruit must 

 much exceed two hundred-weight per annum, if the state- 

 ment of Mr. Downing, that the fruit yields thirteen per 

 cent of sulphuric acid, is not altogether wrong. Lime, we 

 know, exists in the wood in a much larger proportion. 

 It would seem reasonable to conclude that an application 

 of at least two hundred-weight per annum of sulphate 

 of lime in some form would be not merely desirable, but 

 necessary. 



According to Johnson, coal-ashes contain about ten 

 per cent of sulphate of lime. This undoubtedly refers to 

 ashes of the English coal, and is probably a larger per- 

 centage than is contained in our anthracite coal-ashes. 

 At this rate, ten per cent of fifty bushels of coal-ashes 

 'would be equal to five bushels of gypsum, which would 

 be a suitable dressing for an acre. Wherever coal-ashes 

 are on hand, they should be tried, not because they con- 

 tain any considerable amount of potash, but more espe- 

 cially because of the sulphate of lime which they may 

 contain. 



Upon this subject of furnishing the specific food for the 

 vine, recognizing the desirableness of a change of diet at 



