This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Asa Foetida Pharm. Lond. & Edinb. Laser. Laserpitium. Sylphium. Asafetida: the fetid concrete juice of a large plant, growing in the mountains of the provinces of Cho-rafaan and Laar in Persia, called by Kaempfer umbellifera levistico affinis, etc. "The umbel-"liferous plant akin to lovage, with branched "leaves like those of piony, a very large full "stalk, and naked solitary foliaceous seeds like "those of parsnep or cow-parsnep, yielding "afafetida from its root." It is the Ferula Assa Foetida of Linnaeus. The root of the plant, when grown to a proper age and size, is bared of earth at the top, skreened from the fun by the leaves that have been pulled off, after some days cut horizontally, and again carefully skreened: the juice gradually rises, and in a day or two is accumulated on the surface; and being thence collected, the superficial part of the root, that has become dry, is cut off, to allow an exit to the remainder of the juice. A particular detail of this process may be seen in Kaempfer's amaenitates exoticae. This juice, as it first issues from the root, is liquid and white like milk: on being exposed to the air, it turns brownish, and gradually acquires different degrees of consistency. It is brought to us in large irregular masses, composed of various shining little lumps or grains, which are partly whitish, partly of a brownish or reddish, and partly of a violet hue. Those masses are accounted the best, which are clear, of a pale reddish colour, and variegated with a great number of fine white tears.
This juice has a strong fetid smell approaching to that of garlic, and a nauseous bitterish biting taste. It is by much the strongest of the deobstruent warm fetid gums; and is given not only against hysterical complaints, flatulent colics, and obstructions of the breast; but in most of the disorders called nervous, in which it frequently acts as an antispasmodic and an anodyne: in some cases musk, and in some opium, are usefully joined to it. It is sometimes used also as an anthelmintic, and said by Hoffman to be one of the capital medicines of that class. It is most commodiously taken in the form of pills; from a few grains to a scruple or half a dram. It loses with age of its smell and strength; a circumstance to be attended to in dosing it: Kaempfer informs us, from his own observation, that a single dram of the recent juice smells more than an hundred pounds of such as is commonly fold in Europe.
Asafetida is composed of a gummy and a re-sinous substance, the first in largest quantity. Its smell and taste reside in the resin; which is readily dissolved and extracted by pure spirit, and, in great part, along with the gummy matter, by water. The tincture made in pure spirit is of a transparent yellow colour; that made in proof spirit, and the watery infusion, is turbid. A tincture in rectified spirit is kept in the shops; whereof two drams contain nearly all the virtue of fifteen grains of the asafetida †: and another, in which two ounces of asafetida are dissolved in one pound of dulcified spirit of sal ammoniac‡.
In distillation with water, it impregnates the aqueous fluid highly with its scent, and yields a small portion of a pale-coloured essential oil which smells exceeding strongly: the remaining decoction, inspissated, leaves'a weakly nauseous bitterish extract, of very little smell. Rectified spirit distilled off from the tincture made in that menstruum, proves likewise considerably impregnated with the flavour of the afafetida, though much less so than the distilled water; the remaining extract smells moderately, and tastes strongly of the juice.