252 
SUCCULENT PLANTS. 
majority of them, where they are always found in exposed places, and generally 
grow in a very sandy soil. The knowledge of these two facts is of great value to 
the culturist. From the first, he is made aware that no degree of light which in 
this country is ever afforded, even if unmodified by intermediate protective 
substances, can ever furnish more than half the quantum of this element they there 
receive; and through this he learns that everything which unnecessarily obstructs the 
passage of the solar rays to his charge, does them a positive injury. 
But the inferences to be deduced from the other circumstance recorded are 
much more complex and remote, and therefore less likely to be detected by any 
but the most acute gardener. It is true that on the surface of it there is a hint that 
the soil employed for these sorts of succulents should be of a sandy nature : and of 
that we shall have something further to say hereafter. Still, it is usually forgotten 
that a sandy earth will not retain much moisture ; that, in consequence of the 
peculiar intensity of light in those regions, acting on such a soil, the plants can never 
be really wet ; and that, for a considerable proportion of the year, an actual dryness 
is maintained. Let these considerations be placed against the condition of Aloes 
and their congeners in our gardens, and the disparity will be strongly apparent. 
If the compost used for these plants in Britain were exactly (or as nearly as 
possible) similar to that in which they naturally thrive, the inferior amount of solar 
agency exerted upon them, would render a more sparing administration of water, 
compared with that furnished by their native climate, desirable ; but, in the existing 
methods of management, with a soil of which loam is the principal constituent, they 
are watered so profusely as very commonly to perish from too great dampness. 
Brick rubbish is certainly very generally incorporated with the loam and heath soil 
in which they are potted : yet nature and experience unitedly attest that such a 
material is not adapted for the purpose ; for where a great degree of aridity is to 
be preserved, and the plants are not capable of enduring the extreme drought to 
which Melocacti may freely be subjected, the earth, unless it contain a large 
quantity of sand, which will admit the diffusion of water in a manner nearly 
analogous to blotting-paper, becomes hard and impervious, and the resources of the 
plant are so drained that its leaves turn flaccid, and positively wither, if not timely 
prevented by the renewal of the soil. Without dwelling longer on this point, which 
will again come beneath our notice, w 7 e may enforce the propriety of consulting the 
wants of these species with respect to light. And here the most strenuous 
observations that we have made on the utility of solar influence to the other tribes 
of succulents, may be more than reiterated. For though it might be reckoned 
superfluous to advance so much on a question which has been before insisted upon, 
light is even more essential to the species now under remark than to any kinds of 
Cacti, inasmuch as these last are nearly always favoured with an artificial tempera- 
ture, which is, to some extent, equivalent to solar agency at particular periods of 
their growth. Aloes, on the other hand, requiring only the temperature of a green- 
house, need a greater natural stimulus to elaborate the nutriment with which they 
