134. _The TRUE or OFFICINAL RHUBARB_ (Rheum palmatum) _is a medicinal
root which grows wild in various parts of Asia._
_The leaves which issue from this root are large, and deeply cut into
lobes; and the whole plant has a general resemblance to what in our
country are called docks. The stem is erect and six or seven feet high.
The leaves stand on footstalks, that are somewhat grooved above, and
rounded at the edge. Those which proceed from the stalk supply at the
joints a kind of membraneous sheaths. The flowers terminate the branches
in clusters._
The importance and the properties of this _root_ in medicine are
universally known. Rhubarb is usually imported from Turkey, but it is
occasionally also brought from Russia, China, and the East Indies. Dr.
Woodville states that the _Turkey rhubarb_ is brought over in oblong
pieces, flattish on one side, and rounded on the other; and that it is
compact, hard, heavy, and internally of a dull colour, variegated with
yellow and white. The _Chinese rhubarb_ is in roundish pieces, each with a
large hole through the centre. It is softer than the former, and exhibits,
when broken, many streaks of bright red colour.
In some of the mountains of Tartary, rhubarb plants are found in great
abundance. The roots, when first dug out of the ground, are thick, fleshy,
externally of yellowish brown colour, and internally of bright yellow
streaked with red veins. When they have attained sufficient size, they are
dug up and cleansed; and the small fibres and the rind being cut off, they
are divided into pieces of proper size. Each piece is then perforated in
the middle, and they are strung on cords in such manner as not to touch
each other, and are suspended to dry, either upon adjacent trees, or in the
tents.
The sum expended for the importation of this drug is said to exceed
200,000_l._ per annum, a great proportion of which, it is presumed, might
be saved to the country by cultivation of the plants in Great Britain. This
was first attempted, about sixty years ago, by Dr. Hope, in the botanic
garden at Edinburgh, and with such success as to prove that the climate
even of Scotland would be no obstacle to its increase. In 1791, Sir William
Fordyce received from the Society for Encouragement of Arts, Manufactures,
and Commerce, a gold medal, for having raised more than 300 plants of the
true rhubarb from seed. And, in 1783, Mr. Davis, of Minehead, in
Somersetshire, brought to perfection as many plants as yielded three
hundred pounds' weight of dried rhubarb. Since this period, rhubarb has
been grown, in different parts of England, to great extent; and has so far
flourished, that some of the roots have weighed seventy pounds and upwards.
The principal difficulty has attended the curing of it; but this, after
numerous experiments, has at length been performed in such manner, that the
English drug has been found equal, or nearly equal, to that which is
imported from Turkey and China.
The _bark_ of rhubarb has been used for tinctures, and found, in every
respect, as efficacious as the best part of the roots: and the _seeds_
possess nearly the same qualities. The _leaves_ impart an agreeable
acidity, somewhat similar to that of sorrel; and a marmalade, which may,
with advantage, be adopted for children, is made from the fresh _stalks_,
by stripping off the bark, and boiling the pulp with an equal quantity of
sugar.
135. _The COMMON RHUBARB_ (Rheum rhaponticum), _is a plant which is
cultivated in kitchen gardens, and has large, blunt and smooth leaves,
and the leaf-stalks furrowed on the upper side, and rounded at the edge._
This species of rhubarb grows wild on the mountains of Rhodope, in Thrace,
whence it was first propagated in other parts of Europe, about the year
1630. It is chiefly in request for the _footstalks of the leaves_, which
are used, (in the early part of the year, when there is little fruit) for
pies and tarts. The _root_ has some of the qualities of the true rhubarb,
and has occasionally been imposed upon purchasers for that drug.
----