128 OPEN AIR GKAPE CULTURE. 



cal limit to this law that is, that the distance to 

 which the sap may be propelled exceeds any limits to 

 which it is ever necessary to carry it. 



&quot; If the shoots of the vine are trained along a con 

 siderable extent of wall, the branches spread out much 

 wider, and the berries attain a larger size. This 

 property of the vine, although known to experienced 

 gardeners, is not taken advantage of as it ought to be. 

 A vine might be trained horizontally under the cop 

 ing of a wall to a great distance, and by inverting the 

 bearing shoots, the spaces between the other fruit- 

 trees and the top of the wall could readily be filled 

 up, and if different vines were inarched to the hori 

 zontal branch, the south wall of a large garden might 

 be furnished with a variety of sorts from the stem 

 and root of a single plant, the roots of which would 

 not encumber the border in which the other fruit- 

 trees are growing. I have an experiment of this kind 

 now in progress in my garden. &quot;Within a few years 

 past, I have gradually trained bearing branches of a 

 small black cluster grape, to the distance of near 

 fifty feet from the root, and I find the bunches every 

 year grow larger, and ripen earlier as the shoots con 

 tinue to advance. 



&quot; According to Mr. Knight s theory of the circula- 

 lation of the sap, the ascending sap must necessarily 

 become enriched by the nutritious particles it meets 



