Description: Natural Order, Iridaceae. This is the pretty blue flag of the American swamps and bogs, blooming in May or June. The genus is peculiar in having three stigmas which look like large bluish-white petals, the three inner divisions of the perianth being of the same appearance as the stigmas, and the three stamens lying below the stigmas and above the inner divisions of the perianth concealed between the two. The flowers are large and showy, borne on the summit of a peduncle a foot or more in length, which rises directly from the root-stock, is flattened, and has two long and sword-shaped leaves. The root is a creeping, tough rhizoma, half an inch or more in diameter, brownish-scaly without and whitish within. Fruit a three-sided and three-celled capsule, two inches long, with numerous flat seeds.
The root of this plant is medicinal. When fresh, it is acrid and stimulating; but when dried at a moderate temperature, it loses this property, and then possesses little taste, though retaining its virtues. Age impairs it, and it requires to be kept in air-tight jars. Water extracts much of its virtues; alcohol, and diluted alcohol, act on it more effectually, extracting an oily and a resinous material.
Properties and Uses: This root is relaxing and stimulating, the stimulating property predominating. It acts upon the whole series of secernent organs, exciting the glandular system, and arousing the secretion of saliva, bile, urine, etc. Full doses act upon the liver and bowels quite decidedly and promptly, procuring rather thin discharges, and exhausting the frame if continued too freely. Small doses act with sufficient force to secure the usual glandular effects of a general stimulating alterant. Combined with diuretics, or the aqueous infusion used alone, it manifests a rather distinct impression upon the kidneys. It is rarely used alone as a cathartic, being too active for ordinary purposes; but is commonly added in small proportions to alterative compounds designed for secondary syphilis, mercurial cachexy, low grades of scrofula, leprous and chronic skin affections, and similar cases of marked depression and secernent inefficiency. It has, for the same reason, been commended in low forms of dropsy and chronic rheumatism; and may also be used in chronic liver complaints and jaundice. It is usually given in very limited quantities with such relaxants as suit the case in hand–the iris itself bearing toward the glandular system much the same stimulating relations that capsicum bears to the arterial system. It is not a suitable agent to administer in sensitive and irritable conditions of the frame, but is suited to languid and unimpressible states. Its field of action is thus quite limited, but in that field it is powerful and reliable. The dose ranges from two to five grains, three times a day, as a glandular stimulant; and ten to twelve grains as a cathartic. Roots (powdered) of different ages, may vary much in strength; and an inferior article would call for the use of larger doses. Dr. Bigelow and Prof. Rafinesque were among the first to direct the attention of the profession to tills article. It is usually combined with such articles as sarsaparilla, arctium, scrofularia, and rumex. Prof. Rafinesque says that one part of iris and three parts of eryngium yuccaefolium, (about the same as eryngium aquaticum,) are very efficient in curing dropsy, when used in doses not sufficient to more than regulate the bowels. It is an ingredient in the Compound Sirup of Stillingia. As heat impairs its virtues, it is customary to add the tincture when the sirup has been completed.
Pharmaceutical Preparations: I. Tincture. Finely crushed roots of blue flag, three ounces; alcohol of eighty percent, one pint. Macerate for two weeks, express and filter. This is used in doses of from ten to twenty drops three times a day, as an alterant; and forty to sixty drops as a cathartic. It is usually added to alterant sirups–four to eight ounces of the tincture to each gallon. When intended to be added to sirups, it should be prepared on fifty percent alcohol; as the resinoid will separate from a stronger alcoholic tincture, when added to water.
II. Extract. A hydro-alcoholic extract is made from the coarsely-powdered roots, after the manner of extracts of this class. This is a rather powerful preparation, seldom used; but may be used in pills in obstinate cases. It is pretty sure to excite rather persistent ptyalism; and by its action on the rectum may arouse the uterine function. Alterative dose, half a grain; cathartic dose, two to four grains.
III. Fluid Extract. Mix one pound of finely-crushed blue flag with twelve fluid ounces of absolute alcohol and four ounces of ether; transfer to a percolator, and add a similar quantity of the menstrua; after it has ceased dripping, add diluted alcohol till a quart has passed. Evaporate this spontaneously to ten fluid ounces, in the mean time adding diluted alcohol till twenty-four fluid ounces have passed. Evaporate this to ten fluid ounces, and mix the two products–using a little absolute alcohol to dissolve any resinous material that may fall. Alterative dose, three to five drops; cathartic dose, twenty to twenty-five drops.
IV. Iridin. This is virtually an oleo-resinous extract, obtained by treating the root with ether and absolute alcohol till exhausted, and then evaporating. It can not be reduced to a solid form. It is a very concentrated article, and not much used. Cathartic dose, one-fourth of a grain every three, hours till it operates. Some druggists prepare iridin by the precipitation of a concentrated alcoholic tincture, as in podophyllin. On the addition of water, it falls as an oleo-resinous mass; which slowly oxidizes by long exposure to the air, and then may be brought to the powdered form by the admixture of a small part of the powdered root or of magnesia. The dose of this preparation is about one grain.
The Physiomedical Dispensatory, 1869, was written by William Cook, M.D.
It was scanned by Paul Bergner at http://medherb.com