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Page:Illustrations of Indian Botany, Vol. 1.djvu/105

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ILLUSTRATIONS OF INDIAN BOTANY.

which hence got the name of Viola ( Ionid'mm J lpecacuana, and in Brazil they are said to be in common use as emetics. Those of this country are not stated by Ainslie to have any such properties, but he speaks of the leaves and young shoots as being demulcent, and adds, that formed into a liniment with oil, the natives esteem them a cooling application to the head after exposure to the sun, and I am informed that the leaves and young shoots are eat as a cure for ardor urinae and gonorrhoea. On the continent of Europe, decoctions of the sweet smelling and pansy violets, are extensively employed for the cure of cutaneous affections, particularly of children: whether our alpine violets, of which our hills produce several species, will be found suited for such purposes remains to be determined.

M. Boullay (Jour. de Pharm. X, 23 J discovered in the Viola odorata an alcaloide, so analogoHS to emetine, that he called it emetine de violette, or violine. He considers it not as identical with that procured from Ipecacuana, but as a species of the same genus. He obtained it in two states ; 1st. Impure violine, combined with malic acid, in form of yellowish brown deliquescent scales, very soluble in alcohol. Of this a pound of violet roots treated with alcohol, furnished about 4 drachms. 2d. Pure violine. The taste is bitter, very acrid, and disagreeable; it is in form of a white powder; little soluble in water, but more so than emetine, less soluble on the contrary than it in cold alcohol, insoluble in aether, and in the fixed and volatile oils. It combines with acids but does not form well characterized salts. It possesses strong emetic and purgative properties, but was found when tried, very uncertain in its operation, and was never admitted into practice : but the fact of one of the least active of the order being endowed with such properties, affords strong grounds for inferring that most of the others possess them in a greater or less degree.

Remarks on Genera and Species. As there are only two genera of this order found in Southern India, a species of each of which is here figured to show their distinctive characters, it appears unnecessary to advert here to their generic characters. Specific characters however are not so easily made out, owing to their disposition to vary, under this conviction, I was at first led to conclude that the species here figured, was one of the numerous varieties of Viola Patrinii, and it was not until I had examined, with much care, a great number of specimens, pro- cured from different localities, I became sensible of my error, by observing that, however much they varied in other respects, they all agreed in having winged-leaf stalks. The absence of that character, combined with the whole under surface of the leaves of this one, being covered with short hairs, (in V. Vatrinii they are confined to the veins only,) aided by its remote place of growth (Ceylon) induced me to take a different view, and consider it a new species. Viola Patrinii except in the characters above alluded to is most variable. In some of my specimens the petiols are shorter, others longer than the limit of the leaf, and the leaves in place of being always truncated are occasionally cordate at the base, in others the petiols are nearly a foot long, surmounted by triangular leaves, not above an inch and a half in their largest dimension, while in a third form the leaves more nearly approach to lanceolate, that is, they taper at the base ; but still the winged petiol is invariably present. These various forms are derived from the Neilgherries, Pulney mountains, and Shevaroy hills — the very large ones are from the last named station. The relative length of leaves and peduncles do not afford good distinctive marks, the one being sometimes longer, sometimes shorter, than the other. To the species here figured may probably be referred the Viola hastafa of Moon (Gal. Ceylon plants). The species variously named Viola serpens, V. aspera, V. crenata, V. Wightiana, and V. palmaris, are I suspect only varieties of one species, and feel almost certain, that my collection presents representatives of each, though I am unable to distinguish two well marked species among the whole, without however wishing for the present to do more than call attention to the subject, I may observe, that characters taken from the comparative lengths of petiols and peduncles, are scarcely fit to determine specimens of the same plant for they vary in their relative proportions on different parts of the same specimen, neither do I think, are good characters to be obtained from the stipules or bractioles, which appear to be nearly the same through the whole series. The degree of hairiness is equally variable even on the same plant, apparently depending on different degrees of luxuriance, the early leaves, expanded under the influence of a moist soil and atmosphere, being sometimes nearly glabrous, while others developed at a latter period, probably during dry weather, are decidedly hairy. Again they