B2 On rainitw Trees, 



to 



Art. XIII. On raining Trees. By John Murray, Esq. 

 F.S.A. F.L.S. F.G.S. &c. 



Sir, 



The secretions of trees form a curious part of their phy- 

 siology, but the influence of vegetation on the atmosphere 

 seems to have been entirely overlooked, at least as far as it 

 regards its meteorology. 



In the case of that curious genus of plants the Sarracen/«, 

 in which, the S. adunca is most conspicuous, the foliaceous 

 pouch is a mere reservoir, or cistern, to catch and retain the 

 falling dew or rain. In the iVepenthes distillatoria, or pitcher 

 plant, the case is different ; and analysis proves it to be an 

 evident secretion from the plant itself, independent altogether 

 of the fact that it is found in the pitcher before the lid has 

 yet opened. I may here state, en passant^ that the results I 

 obtained from a chemical examination of this liquid differ 

 materially from those of Dr. Edward Turner. The Cornus 

 mafscula is very remarkable for the amount of fluid matter 

 which evolves from its leaves, and the willow and poplar, 

 when grouped more especially, exhibit the phenomenon in 

 the form of a gentle shower. Prince Maximilian, in his 

 Travels in the Brazils^ informs us that the natives in these 

 districts are well acquainted with the peculiar property of 

 those hollow leaves that act as recipients of the condensed 

 vapours of the atmosphere ; and, doubtless, these are sources 

 where many tropical animals, as well as the wandering savage, 

 sate their thirst " in a weary land." The Tillandsi<2 exhibits 

 a watery feature of a different complexion : here the entire 

 interior is charged with such a supply of liquid, that, when cut, 

 it affords a copious and refreshing beverage to man. That 

 these extraordinary sources of " living springs of water " are 

 not unknown to inferior creation, is a fact interestingly conr 

 firmed to us in the happy incidents detailed by Mr. Camp- 

 bell, in his Travels in South Africa, where a species of mouse 

 is described to us, as storing up supplies of water contained 

 in the berries of particular plants : and, in Ceylon, animals 

 of the »Slmia tribe are said to be well acquainted with the 

 Nepenthes distillatoria, and to have frequent recourse to its 

 pitcher. The mechanism of the " rose of Jericho" (Anasta- 

 tica hierochuntina) shows the susceptibility of plants to mois- 

 ture in a very remarkable manner ; and I have submitted some 

 experiments made with this extraordinary exotic, the inhabi- 

 tant of an arid sandy soil, to the Horticultural Society of 

 London. That succulents should be found clothing in patches 



