242 CASTOR-OIL PLANT. 
been effected by means of ether, but the process is too 
expensive for common use. A simple method of form- 
ing tubes of it is to split a piece of cane and to put 
between the pieces a slip of whalebone. If the Indian 
rubber be cut into slips, and twisted closely round the 
cane, and the heat of boiling water be applied, the whole 
will become united into one piece or tube, from which 
the whalebone first, and afterwards the cane, may easily 
be separated. 
It has been proved that cloth of all kinds may be 
made impenetrable by water, if impregnated with the 
fresh juice of the Indian rubber tree; and tnat boots, 
gloves, and other articles, made of cloth thus prepared, 
may be joined without sewing, and only by moistening 
the edges with the juice. These are not only more 
durable, but retain their shape better than such as are 
made of the juice without any connecting substance. 
It has lately been ascertained that, in Prince of 
Wales's Island, and also in Sumatra, there are trees of a 
class and order totally different from that above de- 
scribed, which yield a juice similar to this, and applic- 
able to all the same purposes. 
254. The CASTOR-OIL PLANT (Ricinus palma christi) 
is a native both of the East and West Indies, and has a stem 
from Jive to fifteen or sixteen feet in height, and large bluish- 
green leaves, divided into seven lobes, serrated and pointed, 
tlie footstalks long, and inserted into the disk. 
The Jioice.rs are produced in a terminating spike, and the 
seed-vessels aic covered with spines, and contain each three 
Cattish oblong seeds. 
It is to the seeds of this plant that we are indebted 
for the drug called castor-oil. This is sometimes obtained 
by pressing the seeds, in the same way as is practised 
with respect to oil of almonds (152). But the mode 
chiefly adopted in the West Indies, whence we princi- 
pally import it, is first to strip the seeds of their husks 
or pods, and then to bruise them in a mortar ; after- 
