May.] hot-house — op repotting, etc. 147 
of heat naturally to quicken them to an active state when 
they are encouraged ; and, thirdly, being thus in new soil 
while dormant, they have a yellow and sickly aspect until 
they begin to grow ; and the foliage, thus deprived of its 
natural vigour, will not appear so healthful again : whereas, 
if they are shifted or repotted in this or next month, at 
which season they are between two stages of growth, 
they immediately, on receiving fresh assistance, and by the 
increasing heat of the summer, make new growths, are 
perfectly ripened before the approach of winter, and never 
lose that vernal appearance they have attained. These are 
our reasons, acquired from a close practice and observation, 
and are not influenced by the doings of others which are so 
much aside. No practical operator especially, nor, in fact, 
any individual, ought to be governed by custom in regard 
to the treatment of planrs, without having any idea as to why 
and wherefore, founded on the principles of nature, and 
governed by her unerring results. 
As many are desirous of having a knowledge of plants 
before they order them, and likewise which are the finest 
flowerers and their general character, especially those who 
are at a great distance, and seldom have the privilege of 
seeing what is most desirable, our descriptions will be limit- 
ed, but still will convey some accurate idea of the article 
described. 
Acacias. — Several of these are desirable in the hot-house 
for the grandeur of their foliage, beauty of flower, and a few 
of them as specimens of valuable medicinal plants. A. 
Houstoni, now Anncsleia Houstoni, is one of the most 
magnificent of the Mimosa tribe, blooming from August to 
November in large terminal spikes of a crimson colour, 
stamens very long and beautiful, leaves bipinnated in pairs. 
A. grandifldra, likewise given to Anncsleia, and similar to 
the former in colour, has very large compound bipinnate 
leaves, with from twenty to forty pairs. A. Catechu, flowers 
yellow, wood spiny, leaves bipinnated, about ten pairs. The 
inner wood of this tree is of a brown colour, from which the 
Catechu used in medicine is prepared. It is disputed 
whether A. vera or A. ardbica produces the gum Arabic. 
We are inclined to think it is the latter, which grows prin- 
cipally on the Atlas mountains. The gum exudes spon- 
taneously from the bark of the tree in a soft half fluid state. 
