2C M. Thouin's Description of a Bank, 8$c. [Appendix. 



.quickly in this light black soil, the moisture which they have 

 absorbed during the night : but the returning sun which excites 

 them to action, also melts the snow above, the waters of which 

 trickling down to their roots, give immediate refreshment. The 

 sun, disappearing, these little vegetables are no longer exhausted 

 and a continuance of moisture would even be hurtful ; accord- 

 ingly the snow resuming its solid consistence with the cold of 

 the night, this natural irrigation ceases, with a degree of exact- 

 ness that the most careful gardener cannot perform. 



From the above remarks, it will easily be deduced, that Alpine 

 plants should have no water at all during winter and moist 

 weather : on the contrary, that they should be kept perpetually 

 moist during hot sunshine, by water dribbling through the soil 

 to their roots, without wetting their leaves, which immediately 

 evaporating by the heat, will cool the air just above them. In 

 fact, it is only by a close imitation of the process of nature, that 

 these vegetables of cold regions can be successfully cultivated in 

 botanic gardens. 



The last essential point relative to Alpine plants, is to cover 

 them up on the approach of frost : this may appear a strange pre- 

 caution to some, but when winter commences in their native soil, 

 being immediately covered with snow to the depth of seven 

 inches, they never feel a greater degree of cold than that of the 

 freezing point, the soil itself being hardly frozen. The best 

 covering is that of Fern, ( Pteris Aquilina,) w hich does not absorb 

 moisture so quickly, as most other sorts of haum. 



