98 CULTURE OF THE GRAPE. 



quantity as of least importance, while quality is the sine 

 qua non. Again : it will be noticed that the hillsides 

 flanking a river are universally esteemed. The deeper 

 these valleys, the farther north the culture of the vine 

 may be successfully extended. This is the secret of suc- 

 cess in the Rhine Valley, the grape being planted even 

 upon the northern slopes of this high latitude of fifty-one 

 degrees. In these valleys the air becomes heated during 

 the summer much more so than in the open plain. In 

 addition, a moderate humidity is preserved by the mist 

 arising from the flowing river. It will be noticed that 

 the Rhine lands are described as having a large propor- 

 tion of clay. It should be borne in mind that this is 

 freely intermixed with calcareous and silicious gravel, 

 while the sharp pitch of the hill will insure quick drain- 

 age and a warm soil. As a rule, we observe that pref- 

 erence is given to a loose, warm soil ; limestone and silex 

 being both considered as desirable elements. On the 

 plains, more sand is required than on the hills : a heavy 

 clay or loam, at all inclined to dampness, is unfavorable. 

 Sufficient clay to give strength to a dry, gravelly hillside, 

 or a sandy plain, would be a valuable addition. Just that 

 degree of richness should be sought that will insure 

 health and a fair degree of vigor, in order to the full 



