70. Iris florentina, Linn.—Florentine Orris.
Sex. Syst. Triandria, Monogynia.
The orris root (radix iridis florentina) of the shops consists of the rhizomes of three species of Iris; namely, I. florentina, I. pallida, and I. germanica. [According to Savi, orris root is collected in Italy indiscriminately from the three species named in the txt. (F. G. Hayne, Getreue Darst. u. Beschreib. der in der Arzneykunde gebraucht. Gewächse, Bd. xi. 1830.] They acquire their well-known violet odour while drying. They are brought to us in the decorticated state, in casks, from Leghorn and Trieste.
Orris root consists, according to Vogel, [Journ. de Pharm. i. 481.] of volatile oil, acrid resin, astringent extractive, gum, starch, and ligneous matter. Raspail [Chim. Organ.] detected in it crystals, which he considered to be those of oxalate of lime. The starch of orris root consists of elliptical shaped particles, which form interesting objects for the polarizing microscope. Some of them consist of two mullar shaped particles applied base to base. Most of them are cracked at the hilum, and even at their edges. Schleiden [Principles of Scientific Botany, pp. 15-16, translated by Ed. Lankester, M. D., 1849.] describes the starch particles of Iris florentina and kindred species as being perfectly hollow, and apparently cup-shaped. [The following measurements, in parts of an English inch, of particles of starch of orris root, were made for me by Mr. George Jackson:— Particles. 1. Length. 0.0011. breadth. 0.0010. 2. 0.012. 0.0006. 3.* 0.0009. 0.0006. 4. 0.0006. 0.0004. 5. 0.0004. 0.0004. 6. 0.0003. 0.0002. 7. 0.0002. 0.0002. The most prevalent-sized particle is marked thus *.]
Orris root is an acrid substance, and in full doses causes vomiting and purging. It is principally used on account of its violet odour. Thus hair and tooth powders, perfumed oils, &c, are frequently scented with it. Issue peas (pois d'iris) have been made of it. During teething, infants are sometimes permitted to rub their gums with, and bite, the rhizome; but the practice is objectionable, since it is not unfrequently attended with irritation of the mouth, and disorder of the stomach and bowels. Forthermore, the danger of the rhizome getting into the oesophagus or trachea is not to be overlooked. One fatal case of this kind is recorded. [Kraus, Heilmittellehre, S. 541.] Powdered orris root is sometimes used as an errhine.
A tincture of orris root (tinctura iridis florentinae), prepared by digesting one part of powdered orris root in eight parts of rectified spirit, is used as a scent, and is frequently sold as essence of violets, or eau de violettes.