ON THE INFLUENCE OF CLIMATE ON PLANTS. 
131 
kept through the winter in the greenhouse, or succulent-house, with very little 
water, and a temperature just high enough to exclude frost. They should never 
be pruned, for when they become old and straggling it is better to throw them 
away at once, having previously raised a stock of young plants to supply their 
place. 
The annual species, such as M. crystallinum, and others, require very little 
attention, as it is only necessary to collect the seed as soon as it is ripe, and sow it 
in a very light soil, keeping it in an airy part of the succulent-house till it vegetates, 
and afterwards potting the young plants singly into small pots, and treating them 
according to the preceding directions with regard to soil, situation, and water. 
Thus treated, there are few plants which reward the cultivator with a greater 
profusion of showy blossoms than the numerous species and varieties of this genus, 
and they are equally within the reach of the nobleman and the amateur, and may 
be successfully cultivated in the garden of either, provided due attention is given 
to the subjects of light, soil, and watering, as here detailed. 
REMARKS ON THE INFLUENCE OF CLIMATE ON PLANTS. 
ARTICLE II.— THE INFLUENCE OF LIGHT— (continued). 
To the inquiring gardener or cultivator of plants, no subject is more replete 
with interest, or more calculated to afford him information and instruction relative 
to the principles on which these charming productions of nature should be treated 
or managed, than an investigation into the peculiar effects which the various atmo- 
spheric influences produce upon them, with a view to his guidance in the regulation 
and modification of those influences in practical cultivation. If we reflect upon the 
fact, that, in the absence of a due degree of light and heat, and of a free and constant 
supply of the more immediate aerial elements, plants and vegetables would cease to 
exist, we shall at once perceive, that certain proportions of each of these atmospheric 
principles are indispensable to the cultivation and reproduction of every description 
of plants. But, if we pursue our inquiries, and endeavour to ascertain the par- 
ticular degree of these elementary constituents which each tribe of plants or indi- 
vidual species requires, we shall speedily discover that it is a question too intricate 
for the human mind to solve, a subject almost too impalpable and too complicated 
for human observation, and indeed it is one of which the most eminent individuals 
have, after devoting their whole lives to its consideration, been obliged to confess 
that they had learnt comparatively nothing. It is sufficient, then, for each succeed- 
ing age to know something more of this subject than their predecessors, and to 
approach a little nearer the goal which all have in view, viz. a perfect knowledge 
of the nature, manner, and extent of atmospheric agency in plants. It would 
doubtless be highly interesting to many of our intelligent readers, were we, in 
resuming the consideration of the subject of the present article, to treat of it in a 
chemical point of view ; but as we seldom introduce to our pages any remarks of 
