422 



THE UNIVERSE. 



an ounce and three drachms of Avater; that is to say, it 

 transpired double its weight in twenty-fovu' hours — results 

 which were far from being expected. 



When on a burning summer day, exhausted and stream- 

 ing with perspiration, we see in the by-nook of a parterre 



-'^%'. 



229, Transpiration in Plants. Guettard's experiment. 



the garden sun-flower, we admire its heavy floral crown 

 turned towards the luminary which it ceaselessly accom- 

 panies in its course, and its ample and motionless leaves; 

 but this apparent calm vails a most unexpected vital energy. 



Who indeed would think that the pers^^iration exhaled 

 by the leaves of the plant is more copious than that which 

 moistens our foreheads? Yet science has proved this; 

 after demonstrating the existence of vegetable transpira- 

 tion, it has dared to estimate comparatively the product 

 of it. 



An old physician of Padua, Sanctorius, Avhose origin- 



