ABSORPTION OF LEAVES. 147 



more than five days when supplied by the upper sur- 

 face, while such as floated on their backs continued 

 in perfection near six months. The Vine, the Poplar, 

 (probably Populus nigrd), and the Walnut, were no 

 less remarkable, for fading almost as soon, when fed 

 by their upper surface, as when left without any water 

 at all. Many of the other trees imbibed water as well, 

 or better, by their footstalks than by their upper sur- 

 faces. Hazel-tiut and Rose leaves, when laid with 

 their backs upon the water, imbibe sufficiently to nou- 

 rish other leaves on the same branch ; so will one 

 leaflet of a French bean supply its neighbour that does 

 not touch the water. 



Those who wish to repeat these experiments should 

 be careful to choose full-grown healthy leaves, all as 

 nearly as possible of the same age and vigour. It is 

 also desirable that the precise species of plant should 

 be recorded by its scientific name. For want of this, 

 Bonnet, who despised method and nomenclature, has 

 left us in uncertainty concerning several of the plants 

 he examined. We ought to have been accurately in- 

 formed what species of Poplar differed so remarkably 

 in its power of absorption from the Aspen, another of 

 the same genus. We ought likewise to have been told 

 what Sun-flower, what Nettle, Amaranth and Mallows 

 were examined ; for want of which information the 

 authority of such experiments is much impaired. 



From the foregoing observations we learn the im- 

 portance of shading and watering plants newly re- 



