24 
OXALIS SENSITIVA. 
must be planted out as early in the season as 
possible, to be safe from frost. 
It belongs to the natural order of Sola- 
naceas ; and in the Linnasan arrangement to 
Pentandria monogynia. 
HEATING DISTINCT BUILDINGS. 
It is not very difficult to imagine that if a 
pipe, to convey hot water, were to go a very 
long distance either underground, or exposed 
above ground in the open air, the water would 
be very much cooled before it reached its des- 
tination. This, however, is easily obviated by 
placing around the pipe any non-conductor 
of heat. The more certain mode of doing this, 
is to have a wooden trough made large enough 
to give an inch of room all round the pipe ; 
this trough is to be fixed so that the pipe shall 
occupy the centre, and the vacancy round it 
is to be stuffed with pumice stone pounded, 
and then be covered, so that there shall be an 
inch of pounded stone all round the pipe, en- 
closed in a wooden case. It matters but little, 
comparatively speaking, whether this extends 
a hundred inches or a hundred yards, the heat 
of the water will be very little diminished by 
its passing ; and I am not quite sure whether 
boiling water may not be conveyed a much 
further distance than has been imagined with- 
out losing any important quantity of its heat ; 
nor does it matter much whether this be car- 
ried on in the earth or above it. G. 
CUTTINGS FOR STRIKING. 
Foe many years the commonly received 
notion has been that all slips of plants for 
striking should be cut up to the under part of 
a joint, and thousands act upon it to this day; 
yet many hard-wooded plants strike as well in 
the middle between two joints. Upon this 
principle Mr. Fairburn struck Camellia ja- 
ponica from pieces containing only one 
joint to grow the plant from, and a 
piece of the plain wood left below the 
joint, from the bottom of which, all round, 
the fibres shot in abundance to form a root : 
cuttings thus struck had fine roots when the 
plants had hardly started. It has been said 
that this originated at Mr. Kelley's, of Black- 
heath, and had prevailed for very many years 
before the present branch of the family be- 
came possessed of the nursery. Whether it 
be so or not, it is worth any body's notice to 
try the effect upon any hard-wooded species. 
We are informed by one cultivator, that he 
has succeeded beyond his expectation with 
Fuchsias, and with layers of Rhododendron and 
Azaleas; and it is of the utmost importance to 
be able to obtain plants from a single, instead 
of at least two joints ; for without one above 
to give the growth, nothing can be done; 
whereas, upon the ordinary plan of striking 
cuttings, there was necessarily a joint at the 
bottom, so that a branch of six joints would 
make six plants one way, and only three the 
other. Let this fact be impressed on the mind 
of amateur Horticulturists. 
OXALIS SENSITIVA. 
(LinncEtts.) 
THE SENSITIVE WOOD SORREL. 
Tins is quite a small plant, and well suited, 
both from its size and interesting properties, for 
a Wardian case. It is not showy by any means, 
but its leaves are remarkably sensitive, and 
fold up on being touched, like those of the 
common sensitive Mimosa. Indeed, Rum- 
phius states, that in Amboyna, this property is 
possessed by it in so extraordinary a degree, 
that the leaves cannot bearthat the wind should 
blow on them, or even that they should be 
breathed upon ; at the least irritation they close 
up, and the plant looks as if dead. This pro- 
perty is not possessed in so marked a manner 
as this, by the plants cultivated in this country, 
but they are certainly quite sensitive. 
The plant is an annual ; it has a dwarf 
stem, from which a tuft of pinnated leaves 
proceeds; these have from eight to twelve pair 
of oval leaflets, from among these rise nume- 
rous flower-stems, having several small yellow 
flowers at the top of each. It is found wild 
all over the tropics of Asia. It was raised 
in the Horticultural Society's garden, from 
seeds sent from China, by Mr. Fortune ; and 
is also cultivated at Kcw. It often springs 
up in mould received among plants from the 
East Indies. 
It is of very easy culture in the hothouse, 
where it, no doubt, will prefer a shady place, 
similiar to that in which our native wood- 
