Vegetable Stanch. i j 



viz. 2160 fquarc inches, the quotient is 

 4- part of a cubick inch perfpired off a fquare 

 inch in twenty four hours. Therefore in 

 equal furfaces and equal times the man per- 

 fpires fr, the plant t-Jt* or as 50 : 15. 



Which excefs in the man is occafioned 

 by the very different degrees of heat in each : 

 For the heat of the plant cannot be greater 

 than the heat of the circuna-ambient air, 

 which heat in fummer is from 25 to 35 de- 

 grees above the freezing point, (vide Exp. 

 20.) but the heat of the warmeft external 

 parts of a man's body is 54 fuch degrees,* 

 and the heat of the blood 64 degrees 5 

 which is nearly equal to water heated to 

 fuch a degree, as a man can well bear to hold 

 his hand in, ftirring it about j which heat is 

 fufficient to make a plentiful evaporation. 



§lu. Since then the perfpirations of equal 

 areas, in a man and a Sunflower, are to each 

 other as 165 : 50. or as sf : 1 > and jflnce the 

 degrees of heat are as 2 : 1, muft not the fum 

 or quantity of the areas of the pores lying 

 in equal furfaces, in the man a$d Sunflower, 

 be as \6 : 1 \ for it feems that the quantities 

 of the evaporated fluid will be as the degrees 

 of heat, and the fum of the areas of the pores 

 taken together. 1 Dr. 



