This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Iris; a perennial plant with long narrow sword-like leaves, (landing edgewife to the stalk; and large naked flowers, divided deeply into six segments, of which, alternately, one is erect and another arched downwards, with three smaller productions in the middle, inclosing the stamina and pistil: the roots are tuberous, irregular, and full of joints.
1. Iris vulgaris germanica five silvesiris C. B. Iris germanica Linn. Flower-de-luce, common iris or orrice: with blue flowers, whofe arched fegments are bearded with a yellowish matter, Handing several on one stalk higher than the leaves. It is a native of the mountainous parts of Germany, common in our gardens and flowers in June.
The roots of this plant have, when fresh, a disagreeable smell, and an acrid naufeous taste. They are a strong irritating cathartic; in which intention, their expressed juice has been given in hydropic cases, from one or two drams to three or four ounces, diluted largely with watery or vinous liquors, to prevent its inflaming the throat. The remarkable differences in the dose, as directed by different practical writers, appear to have proceeded from hence; that some employed the juice in its recent turbid state, loaded with the acrimonious cathartic matter of the root; others, such as had been depurated by settling, and which had deposited, along with the feculencies, a great share of the active parts. By gently inspissating the juice, it is rendered less violent in cathartic power, and less liable to irritate and inslame; but becomes at the same time too precarious in strength to be depended on: by inspiffation to perfect drynefs, its purgative virtue is almost, if not altogether, destroyed. The root itself loses also, in drying, its ossenfive smell, and its naufeous acrimony, and along with these its cathartic quality: in this date, it discovers a slight and not disagreeable pungency and bitter-ifhnefs, accompanied with a kind of aromatic flavour, nearly of the same kind with that of the following species, but weaker and less grateful.
The bluish expressed juice of the flowers changes on being inspissated, especially if a little lime-water is added, to a fine green; and in this form is directed, in foreign pharmacopoeias; for tinging some of the unctuous compositions called odoriferous or apoplectic balsams,
2. Iris Pharm. Lond. Iris slorentina Pharm* Edinb. & Linn. Iris alba florentina C. B. Florence orrice; supposed to be only a variety of the foregoing occasioned by difference of climate; distinguishable from it in our gardens, by the flowers being white, and the leaves inclining more to bluish. The shops are sup-plied from Italy with dried roots superiour to those of our own growth; in oblong slattish pieces freed from the fibres and brownish bark, externally of a whitish colour with brownish specks, internally inclining to yellowish, easily reducible into a farinaceous yellowish white powder.
This root, in its recent state, does not seem to differ much from the preceding; being, like it, nauseous, acrimonious, and purgative, though not quite in so great a degree; and losing these qualities on being dried. The dry root, as met with in the shops, has an unctuous, bitterish, pungent taste, not very strong, but very durable in the mouth: and a light agreeable smell, approaching to that of violets. It is used in perfumes; in sternutatory powders; for communicating a grateful flavour, some-what like that of raspberries, to wines and to spirits; and medicinally in disorders of the bread, for attenuating viscid phlegm, and pro-moting expectoration. Its smell.and taste arc extracted both by water and rectified spirit, most perfectly by the latter. In distillation, it gives over with water the whole of its peculiar flavour, its bitterness and a slight acrimony remaining in the inspiffated extract: the distilled water smells very agreeably, but no essential oil is obtained though some pounds of the root be subjected to the operation at once. Rectified spirit brings over a part of its violet smell, but little or nothing of its warmth or taste: the infpiffated extract is a pungent, bitterifh, balsamic mass, glowing in the mouth like pepper; its quantity is about one fifteenth of the weight of the root.
3. Iris palufiris Pharm. Edinb. Iris pa-lujlris lutea Ger. Gladiolus luteus. Acorus vulgaris Pharm. Auguftan. Acorus adulterinus C. B. Pseudoacorum Matth. Pseudoris Dod. Butomon Cluf. Iris Pseud-Acorus Linn. Yellow water-flag, baftard acorus, sedge: with reddish roots, yellow unbearded flowers standing several on one stalk, and the middle ribs of the leaves prominent. It is common by the sides of rivers and marshes, and flowers in June.
The roots of this species are, when fresh, rather more acrid, and more strongly cathartic, than either of the preceding, The expressed juice, given to the quantity of eighty drops every hour or two, and occasionally increafed, has, in some instances, produced plentiful evacuations, after jalap, gamboge, and mercurials had failed (a): but however successful it may have sometimes been as a sraftic purgative, it is accompanied, like the other irises, with a capital inconvenience; its strength being so precarious, or so variable in different dates, that it is by no means fit for general ufe. The juice, both of this and of the other kinds of iris, has been employed also externally for clearing the skin of serpiginous eruptions; and sometimes snufTed up the nose as a strong errhine: even for these purposes it is to be used with caution, being subject, by its great acrimony, to inflame or vesicate the parts.
The dry roots are much weaker and less agreeable than those of either of the preceding species of iris. They have scarcely any smell; and when chewed in subslance, discover very little taste. An extract made from them by rectified spirit is likewise weaker and more nauseous, though its quantity is less, amounting only to one twenty-fourth of the weight of the root: it has nothing of the flavour or aromatic warmth of those of the other two, but an ungrateful austere bitterishness and a. kind of saline pungency. It is the root in this dry state that the writers on medicines mean, when they speak of the yellow water-flag root as being astringent and stomachic: it does not, however, appear to have any great claim to these virtues, and among us is no otherwise made use of than as an ingredient in the officinal arum powder, in which it is said to be employed only in deference to the original of Birckmann first published by Quercetanus.
(a) Edinburgh medical essays, vol. v. art, 8.