This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Assafetida is a concrete juice, derived from the root of Nar-thex Assafoetida, an umbelliferous herb, from six to nine feet high, growing in the interior mountainous regions of Persia, and neighbouring countries.
It is obtained by twisting the leaves from the root, digging the earth from about it, then slicing off the top of it transversely, and scraping the juice from the surface as it exudes: the leaves being employed to shelter the wounded root from the sun. When the exudation ceases, another slice is removed; and so on, till the root is exhausted.
The juice thus collected is allowed to concrete in the sun, and is then taken to Bushire, whence it is carried in vessels to Bombay, and from that port is distributed over the world.
Assafetida is in irregular lumps or masses, often softish in the interior as first imported, but gradually becoming hard and brittle. The colour is brownish externally, but, upon the freshly broken surface, is whitish or variegated, quickly becoming red on exposure to the air, and ultimately changing to brown. The lumps are sometimes homogeneous or nearly so; but usually consist of smaller portions aggregated, or of whitish tears imbedded in a darker paste. The odour is strong and extremely fetid, so as to have acquired for the drug the name of stercus diaboli. Yet it sometimes becomes tolerable by habit; and it is not requisite to go so far as the East Indies to find individuals who are even fond of it. The taste is bitter and subacrid. In certain parts of Hindostan, the inhabitants use it habitually as a luxury; and the streets of Surat are said to be sometimes redolent of the drug. Both the smell and taste are diminished by drying, and by age; and, in the recent condition of the juice, the former is said to be intensely offensive. Assa-fetida softens by heat, but cannot be quite melted. It is very inflammable.
In chemical constitution it is a gum-resin, consisting of gum, resin, and volatile oil. The odour is owing to the oil, the medical virtues to that and the resin conjointly, and the gum is inert. When rubbed with water, the gum-resin forms a white milky emulsion; the resin and oil being suspended by the intervention of the gum. This emulsion often assumes a pinkish hue on exposure. Alcohol dissolves all the active matter, forming a transparent tincture, which becomes turbid on the addition of water, in consequence of the separation of the resin.
Effects on the System Assafetida stimulates the stomach and the circulatory system moderately, and the general nervous system powerfully, is somewhat expectorant and often laxative, and is believed by some to have emmenagogue and anthelmintic properties. In moderate medicinal doses, it produces a feeling of warmth in the stomach, somewhat increases the frequency of the pulse and the heat of skin, often more or less exhilarates the spirits, and is said also to excite the genital organs, and sometimes to bring on the menstrual flow in women. When rather freely taken, it occasionally produces slight vertigo or headache, but never intoxication or stupor. It not unfrequently operates as a cathartic, but not so uniformly as to deserve to rank in that class of medicines. In large doses it disturbs the stomach, and may even excite nausea and vomiting; but these are rare effects when that organ is quite sound. That it should cause offensive eructations is a necessary result of its fetid odour and carminative properties.
The volatile oil of assafetida is certainly absorbed. A sufficient proof of this is the fetid odour of all the secretions under its use, of the breath, the perspiration, the urine, and, as has been asserted, of the discharges from ulcerated surfaces. As the oil is probably the main active principle, the drug no doubt produces its constitutional impression through the circulation; though it is highly probable that the offensive odour may sometimes also act favourably on the cerebral centres, through the sense of smell.