ABSORPTION OF LEAVES. 145 



decidedly be of a morbid nature*. That >;vax is also 

 an exudation from the leaves of plants, appears from 

 the experiments recorded by Dr. Thomson in his Che- 

 mist ri/, %). 4. 298, and it has been long ago asserted 

 that wax may easily be gathered from the leaves of 

 Rosemary. On this subject I have not made any ex- 

 periments to satisfy myself. 



With respect to the absorbing power of leaves, the 

 best observations that have been made are those of 

 Bonnet, recorded in the beginning of his Recherches 

 sur r Usage des Feuilles. His aim was, by laying leaves 

 of various plants upon the top of a jar of water, some 

 with their upper, and others of the same species with 

 their under, surfaces applied to the water, to discover 

 in which situation the leaves of each plant continued 

 longest in health and vigour, and also how far diffe- 

 rent species differed from each other in this respect. 

 The results were in many instances highly curious. 



Of fourteen herbaceous plants tried by this philoso- 

 pher, six lived nearly as long with one surface applied 

 to the water as with the other ; these were the com- 

 mon Arum inaculatum, the French Bean, the Sun- 

 flower, Cabbage, Spinach, and the Small Mallow. By 

 the last I presume is mesLUt Malva rotiindijblia, EngL 

 Bot. t. 1092. Six others, Plantain, White Mullein, 



* I do not mean to dispute the accuracy of Mr. Curtis's excellent 

 paper, Tr, of Linn. Soc. v. 6, written to prove honey-dew to be tlie 

 dung of AphUlcs. I only contend that there are more than one kind *f\ 

 honey-dew. 



