SUCCULENT PLANTS. 251 
The sand of No. I., that had been burned, will exhibit a greater volume of blue 
than will the solution obtained from the raw earth : that fluid, indeed, will be 
tinged ; but the blue will separate from the first, and fall to the bottom of the glass. 
Still, the test should be applied by the strip of glass to the surface of each liquid 
till it effect no further change of tint. 
Another process remains to complete the analysis, and solve the mystery arising 
from the circumstance just mentioned. — The raw soil, after the action of the acid 
and subsequent filtration, should be carefully dried and burnt as was No. 1 ; its loss 
of weight noted ; and then be subjected a second time to the action of acid in the same 
way as before, omitting the nitrous, and doubling the quantity of oil of vitriol. 
Reduce the quantity by heat, and after twenty-four hours' standing in the vessel, 
add water, strain, and edulcorate as directed ; then add the test drop by drop. A 
fresh and still more copious deposition of blue will be occasioned, affording proof 
undeniable and self-evident, that iron is revealed, if not formed by the action 
of fire on decaying vegetable matter. We now leave these facts, subject to 
the acumen of the enlightened reader, and to the criticism of the philosophic 
chemist. 
SUCCULENT PLANTS. 
{Concluded from p. 229.) 
The last class of succulents whose cultivation we at present propose to discuss, 
comprehends the numerous species of Aloe*, Agave, Gasteria, Haworthia, and their 
allies ; with a portion of the genus Euphorbia, and the whole of Echeveria, 
Mesembryanthemum, Crassula, and the different divisions into which the latter 
genus has been separated. Our arrangement of the entire tribe into these distinct 
groups may seem arbitrary and unnatural ; but it will be admitted that there is a 
dissimilarity in the habitude of each assemblage which entitles them to be considered 
apart from the rest. We thus have what may be called the Mammillaria class, the 
Epiphyllum class, and the class of which Aloe may be regarded as the type. And 
if Euphorbias are supposed not properly to belong to the latter, our reason for 
ranking them therewith is, that they are too often kept in a house of high 
temperature, where, in supplying them with the requisite moisture, the foundation 
of disease is laid. Perhaps, too, we might have more correctly reserved Stapelice 
for this article. 
By far the greater part of the plants here brought together are from the same 
country, or the same kind of locality. The Cape of Good Hope gives birth to the 
* Both these words, Aloe and Agave, are frequently pronounced as if there were no final e. The 
former, especially, is almost invariably so. To the botanic student or orthoepist, we need hardly say that 
such a mode of pronunciation is grossly inaccurate ; as every botanical word that terminates in e is sounded 
as a distinct syllable. 
