_Ispaghúl Seeds_, _Spogel Seeds_.
=Botanical Origin=—_Plantago decumbens_ Forsk. (_P. Ispaghula_
Roxb.),[1795] a plant of variable aspect, from an inch to a foot in
height, erect or decumbent, with linear lanceolate leaves which may be
nearly glabrous, or covered with shaggy hairs. The flower-spikes differ
according to the luxuriance of the plant, being in some specimens
cylindrical and 1½ inches long, in others reduced to a globular
head. The plant has a wide range, occurring in the Canary Islands,
Egypt, Arabia, Beluchistan, Afghanistan, and North-western India.
Stewart[1796] says it is common in the Peshawar valley and Trans-Indus
generally up to 2000 feet; also on the plains and lower hills of the
Punjab, but that he has never seen it cultivated in the latter region.
It is said to be cultivated at Multan and Lahore, also in Bengal and
Mysore.
=History=—The seeds which are found in all the bazaars of India and
are held in great esteem, are generally designated by the Persian word
_Ispaghúl_; but they also bear the Arabic name _Bazre-qatúná_, under
which we find them mentioned by the Persian physician Alhervi[1797]
in the 10th century, and about the same period or a little later by
Avicenna.[1798] Several other Oriental writers are quoted by Ibn
Baytar[1799] as referring to a drug of the same name, which may
possibly have included the seeds of other species, as _Plantago
Psyllium_ L. and _P. Cynops_, having similar properties, and known to
have been used from an early period.
J. H. Linck, whom we mentioned in our article on Oleum Cajuputi (p.
278), described in 1719 the seed under notice, yet without knowing its
name; it further attracted the notice of Europeans towards the close of
the last century,[1800] and has been often prescribed as a demulcent in
dysentery and diarrhœa. It was admitted to the _Pharmacopœia of India_
of 1868.
[1795] After the examination of numerous specimens, we adopt the
course taken by Dr. Aitchison (_Catalogue of the Plants of the Punjab
and Sindh_, Lond. 1869) of uniting _P. Ispaghula_ to _P. decumbens_.
The union of species in this group may probably be carried still
further.—For a fig. see Bentley and Trimen, _Med. Plants_, part 21
(1877).
[1796] _Punjab Plants_, Lahore 1869. 174—also MS. note attached to
specimens in Herb. Kew.
[1797] _Liber Fundamentorum Pharmacologiæ_, ed. Seligmann, Vindobonæ,
1830. 40.
[1798] Lib. ii. tract. 2. c. 541. (Valgrisi edition, 1564. i. 357.)
[1799] Sontheimer’s transl. i. (1840) 132.
[1800] Fleming, _Catal. of Indian Med. Plants and Drugs_, Calcutta,
1810. 31.
=Description=—The seeds, like those of other species of _Plantago_, are
of boat-shaped form, the albumen being deeply furrowed on one side and
vaulted on the other. They are a little over ⅒ of an inch in length
and nearly half as broad, and so light that 100 weigh scarcely three
grains. Their colour is a light pinkish grey with an elongated brown
spot on the vaulted back, due to the embryo, which at this point is
in close contact with the translucent testa. From this brown spot the
thick radicle runs to the top of the seed. The hollow side of the seed
is also brown and partially covered with a thin white membrane.
The seeds are highly mucilaginous in the mouth, but have neither taste
nor odour. Those of the allied _P. Psyllium_ have nearly the same form,
but are shining and of a dark brown hue.
=Microscopic Structure=—This can be best investigated by immersing
the seed in benzol, as in this medium the mucilage is insoluble. When
thus examined, the whole surface is seen to consist of polyhedral
cells, separated by a very thin brown layer from the albumen, which
on the back of the seed is only 70 mkm. thick. The albumen is made up
of thick-walled cells, loaded with granules of matter which acquire
an orange hue on addition of iodine. The two cotyledons adhere in a
direction perpendicular to the bottom of the furrow; their tissue is
composed of thin-walled smaller cells, containing also albuminous
granules and drops of fatty oil.
If the seed is immersed in water, the cells composing the epidermis
instantly swell and elongate, and soon burst, leaving only fragments of
their walls. When examined under glycerin, the change is more gradual,
and the outer walls of the cells yielding the mucilage display a series
of thin layers, which slowly swell and disappear by the action of
water. The mucilage is consequently not contained within the cells, but
is formed of the secondary deposits on their walls, as in linseed and
quince pips.
=Chemical Composition=—Mucilage is so abundantly yielded by these
seeds, that one part of them with 20 parts of water forms a thick
tasteless jelly. On addition of a larger quantity of water and
filtering, but little mucilage passes, the greater part of it adhering
to the seeds. The mucilage separated by straining with pressure does
not redden litmus, is not affected by iodine, nor precipitated by
borax, alcohol or ferric chloride. The fat oil and albuminous matter of
the seed have not been examined.
=Uses=—A decoction of the seeds (1 p. to 70 p. of water) is employed in
India as a cooling, demulcent drink. The seeds powdered and mixed with
sugar, or made gelatinous with water, are sometimes given in chronic
diarrhœa.