1 8 Vegetable Staticks. 



favour of the eminent Mr. Wife. This 

 vine was prepared with a cover, as the Sun- 

 flower was. Its greateft perfpiration in 12 

 hours day, was 6 Ounces + 240 grains; its 

 middle perfpiration 5 ounces -p 240 grains 

 — to 9- cubick inches. 



The furface of its leaves was 1820 fquare 

 inches, or 12 lquare feet -f- 92 fquare 

 inches ; whence dividing 9- cubick inches, 

 by the area of the leaves, it is found that 

 ■^y part of an inch in depth, perfpires offin 

 12 hours day. 



The area of a tranfverfe cut of its ftem, 

 was equal to \ of a fquare inch : hence the 

 fip's velocity here, to its velocity on the fur- 

 face of the leaves, will be as 1820 x 4 = 

 7280: 1. Then the real velocity of the fap's 

 motion in the ftem is == 7 **f = 38 inches 

 in twelve hours. 



This is fup poling the ftem to be a hollow 

 tube: but by drying a large vine-branch, (rn 

 the chimney corner) which I cut off in the 

 bleeding feafon, I found the folid parts were 

 | of the ftem ; hence the cavity thro' which 

 the lap pafies, being fo much narrowed, its 

 velocity will be 4 times as great, vkti. 152 

 inches in 12 hours, 



But 



