a nature suitable to the constitution of a plant un- 
der culture, it is sometimes not only difficult to 
obtain, but altogether impossible. We allude to 
atmosphere. 
The density and weight of the atmosphere varies 
on the surface of the earth, in proportion to the alti- 
tude of the situation. Upon the animal frame its 
weight acts as a bandage, and most persons of ob- 
servation know, that when its pressure is greatest, 
which is indicated by the increased height of the 
barometer, a constringing effect on the system is 
produced; and an increased circulation of the 
blood, and more active flow of the animal spirits is 
the consequence. Persons who have ascended ex- 
ceedingly high mountains have experienced diffi- 
culty of breathing and other unpleasant sensations, 
showing clearly, that either from a difference in the 
quality of the air they breathed, or from the loss 
of a due atmospheric pressure on the system, health 
would quickly be impaired. Vegetables, like ani- 
mals, may be said to breathe and perspire — oper- 
ations which, as a matter of course, are greatly under 
the influence of the atmosphere in which they live, 
whence it may be concluded that the want of suc- 
cess in the culture of some alpine plants arises 
from atmospheric influence, which admits of no 
amelioration from the assiduity of the cultivator. 
The Onosma setosum may be increased by cut- 
tings ; but plants raised from seed, in the place in 
which they are to remain, succeed best. The soil 
should be light, and if mixed with broken limestone 
it will the better imitate that of its native places. 
A sheltered and shady situation should be chosen. 
Don’s Syst. Bot. v. 4, p. 315 
