DISEASES. 205 



It is well to wash the stems of all vines in gardens with 

 potash water every winter, as it would destroy insects that 

 make their nests in the crevices of the bark. That portion 

 of the solution that falls upon the ground is not wasted, 

 because it furnishes the vine with potash, which is one of 

 the most valuable ingredients of all manures. 



There are several other species of vine scale or coccus 

 which may be occasionally found. The Coccus adonidum^ 

 or Mealy Bug, sometimes attacks the vine when grown un- 

 der glass, but it generally confines itself to other plants. 

 Diluted soft-soap, or potash dissolved in water, will usually 

 destroy all kinds of vine scale. 



DISEASES. 



The diseases to which the grape is subject in this coun- 

 try are not numerous or very destructive, except in some 

 particular localities, and these are confined mainly to the 

 fruit. The instances are very frequent where whole vine- 

 yards are destroyed by allowing them to over-bear ; and 

 without doubt more vines are annually destroyed from this 

 cause than from any other. But this should not be called 

 disease, nor the effects of an uncongenial climate, but corn- 

 pulsatory suicide, just as much as it would be to make a 

 prisoner lift at a dead weight until he broke his own back. 

 At least eight tenths of all the failures with our native 

 grapes have been from this cause, and probably one tenth 

 fail from planting unsuitable varieties, and only the other 

 tenth from actual disease. 



The case is now becoming quite different, as in the rap- 

 dly increasing number of varieties there will, without 

 doubt, be many which are naturally diseased ; and when 

 such varieties have been through a course of forced propa- 

 gation for several years, it would not be strange if we 

 should have some that would baffle the skill of the best 

 cultivators. 



