This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Viola Pharm. Lond. & Edinb. Viola martia purpurea flore simplici odoro C. B. Viola-ria. Viola odorata Linn. Violet: a low creeping plant, without any other stalk than the pedicles of the leaves and flowers: the leaves are roundish, somewhat heart-ihaped, obtusely cre-nated about the edges: the flower consists of five irregular petala, of the deep purplish blue called, from the name of the plant, violet colour: the fruit is a little capsule divided into three cells, full of small roundish seeds. It is perennial, grows wild in hedges and shady places, and flowers in March.
The flowers of a different species, greatly in-feriour to the above, are frequently substituted in our markets. This sort may be readily dis-tinguished; the herb, by its having stalks, which trail on the ground, and bear both leaves and flowers, and by the young leaves being hairy; the flower, by the three lower petala being spotted with white, and by their want of smell.
The officinal violet flowers have a very agreeable smell, and a weak mucilaginous bitterish. taste. Taken to the quantity of a dram or two, they, are said to be gently laxative or purgative; and the seeds, which have more taste than the flowers, to be more purgative, and sometimes emetic. The flowers give out to water both their virtue and their fine colour, but scarcely impart any tincture to rectified spirit, though they impregnate the spirit with their fine flavour, and probably also with their purgative quality. An infusion of two pounds of the fresh flowers in five† or eight‡ pints of boiling water, passed through a fine linen cloth without pressure, is made in the shops into a syrup, which proves an agreeable laxative for children. Both the flowers themselves and the syrup lose their colour in being long kept: acids change them instantly into a red; alkalies, and sundry combinations of acids with earthy and metallic bodies, to a green: perfect neutral salts, or those compounded of an acid and alkali, make no alteration. Some have been accustomed to communicate to syrups a violet colour with materials of greater durability than the violet itsef, or than any other blue flower: these sphist cated preparations may be distinguished by their colour withstanding alkalies and acids, or being affected by them in a different manner.
* Viola tricolor Linn, Pansies, or hearts-ease: this well known plant has lately been recommended by a German physician, Dr. Strack, as a specific in the crusta lactea of children. He directs a handful of the fresh, or half a dram of the dried leaves to be boiled in half a pint of milk, which is to be (trained for use. This dose is repeated morning and evening. He ob-serves, that when it has been administered eight days, the eruption usually increases considerably, and the patient's urine acquires a smell like that of cats. When the medicine has been taken a fortnight, the scurf begins to fall off in large scales, leaving the skin clean. The remedy is to be peristed in, till the skin has resumed its natural appearance, and the urine ceases to have any particular smell.
Syr. violar. † Ph. Lond. ‡ Ph.Ed.