SECT. I. INTRO-SUSCEPTION. Q3 



to be regarded as the greatest ; but if it retained its 

 verdure longest with the under surface applied to 

 the water, then the absorbing power of the under 

 surface was to be regarded as the greatest. The 

 experiment was made in the spring and autumn, the 

 temperature being between five and ten of Reaumur; 

 and the leaves employed being such as were fully 

 expanded. The result was as follows : 



Out of fourteen herbs of different genera selected On the de- 

 forthe purpose of experiment, the leaves of six the }^ ve e s of 

 Arum maculatum. Kidney Bean, Sun-flower, Cab- herbs - 

 bage, Spinach, and small Mallow were indifferent 

 to the mode in which they were applied to the water, 

 and were found to retain their verdure equally long 

 whether moistened by the upper or under surface. 

 The rest the Plantain,, white Mullein, great Mallow, 

 the Nettle, Cockscomb, purple-leaved Amaranth, 

 Marvel of Peru, and Balm were not indifferent to 

 the mode in which they were applied to the water, 

 but retained their verdure longest when moistened 

 by the upper surface. 



The following are the most remarkable examples 

 of the relative capacity of their different surfaces : 

 The leaf of the Nettle when moistened by the upper 

 surface lived two months, but when moistened by 

 the under surface only three weeks. The leaf of 

 the Amaranth when moistened by the upper surface 

 lived three months, and when moistened by the 

 under surface only seven or eight days. The leaf 

 of the Mullein when moistened by the upper surface 



