236 CULTURE OF THE GRAPE. 



of foliage, and exudation of viscid matter, upon which the 

 fungus may fasten, is done wisely. Upon the second 

 point, namely, a state of the atmosphere in which mildew 

 will cease to grow, we shall have little to say. That mil- 

 dew delights in a warm and muggy air is beyond doubt. 

 It is equally clear, that, though the vines have become 

 debilitated, and in condition to receive, and have actually 

 received, the seeds, yet, if the weather becomes warm, dry, 

 arid clear, the fungus will perish. It cannot grow in a 

 clear, dry air. However important this fact may be, it is 

 one over which we have very little control. In a glass 

 house, we can control the atmosphere ; and I have no 

 doubt that by this means alone we could check the 

 growth and spreading of the fungus. In the open air, we 

 must be content with the slight modification of the tem- 

 perature, and the material diminution of the humidity of 

 the air, which result from a warm, well-drained soil. 



The third and last remedy consists in destroying the 

 life of the fungus by poison. In England, it is found that 

 caustic lime, and also common salt, are destructive to the 

 Puccinia graminis, the species of mildew which attacks 

 grain. In Johnson's " Essay upon Salt," 3d ed. p. 52, is an 

 account of the application of salt, by Rev. Edmund Cart- 

 wright, upon a field of wheat which was badly mildewed. 



