284 GENERAL VIEWS, 



sorbing powers of the parts above ground suffice for 

 their support. Of this number are the succulent plants, 

 whose fibrous root only serves to hold them in their 

 places ; and the moisture of the atmosphere is inhaled 

 and retained by the spongy parts above. Thus in the 

 vast plains that receive the waters from the eastern 

 declivity of the Andes, when the scorching heat of 

 summer has consumed the grasses and other herbaceous 

 kinds which the rainy season had brought forth, we still 

 find some lingering Cacti, which, under their dry, 

 thorny coats, conceal a cellular system, by which an 

 abundant sap has been imbibed and preserved. But in 

 countries where the atmosphere holds but little mois- 

 ture in evaporation, either because the soil is wholly 

 destitute of water, or by reason of the coldness of the 

 temperature, we find no plants at all, or such only as 

 are of dry, hard texture. The sands of Africa, water- 

 ed by no river, are found to be utterly barren. Spitz- 

 berg, Nova-Zembla, Kamschatka, &.c. where the in- 

 fluence of the sun is only felt for two months in the year 

 at most, and where, consequently, the air is habitually 

 dry, furnish a very scanty portion of herbaceous plants 

 only, or some dwarf shrubs, with a narrow leathery fol- 

 iage. It is true that drought is not in these instances 

 the sole cause of the degenerated state of vegetation, 

 but it would of itself be sufficient to produce it : for it 

 is a fact, that plants acquire height of stem and breadth 

 of foliage, only in proportion to the abundance of nu- 

 triment they meet with in the atmosphere, and that nu- 

 triment is water reduced into vapour, and held in sus- 

 pension by the atmosphere. 



When vegetables^are deprived of light, they extend 

 in length, shoot up pale, lank stalks are of a lax fibre, 

 and of no substance : in short, they spindle themselves 



