236 



THE FLORIST. 



with the surface wnped, so as to take off some of the waxy covering, 

 and others with the surface in the natural state : — 



Similar results, and even more marked, were obtained when one of 

 the leaves was washed with soap and water, care being taken to note 

 the weight before and after the washing, for it sometimes happens that 

 a small quantity of water enters through the epidermis covering the 

 ribs, and through the stomata. 



The following table shows the results : — 



Names of Plants. 



Lilac 



Entire-leaved Cle- 

 matis . 



Sycamore . 

 Red Valerian . 

 Panicled Phlox 

 Siberian Stachys 



Weight of 

 Natural Leaves. 



"Washed 



with soap 0.67 



Natural 0.67 



Washed 



Natural 



Washed 



Natural 



Washed 



Natural 



Washed 



Natural 



Washed 



Natural 



0.47 

 0.47 

 4.00 

 4.00 

 1.30 

 1.30 

 050 

 0.50 

 0.71 

 0.71 



Weight 



after 



Washing. 



0.70 



0.52 

 4.50 



Weight 



after 15 hours 



exposure 



to air. 



0.20 

 0.45 

 0.14 

 0.21 

 1.85 

 3.10 

 0.30 

 040 

 0.32 

 36 

 0.19 

 0.55 



Loss. 



0.38 

 0.22 

 33 

 0.26 

 2 15 

 90 

 100 

 0.90 

 18 

 0.14 

 0.52 

 016 



These experiments, although undertaken with a different end in 

 view, conclusively show how necessary it is to keep leaves clean, and 

 they likewise point out what may have often been partially overlooked, 

 the very great importance of well washing the under sides as well as 

 the upper. It would also appear that the waxy or fatty matter of the 

 skin has a marked effect in preventing too copious exhalation ; but this 

 more especially applies to plants in warm countries. Next, therefore, 

 to securing a healthy root action, take care to keep the leaves clean, and 



