Medical writers have generally treated of various substances as stimulating diaphoretics, which, though they undoubtedly will occasionally promote the perspiratory function, when aided by warm dilution, have quite as great a tendency to other excretory functions, especially that of the kidneys, and are used more as alteratives than in reference either to their diaphoretic or diuretic powers. Such are sarsaparilla, guaiac, mezereon, and sassafras. These have all been fully considered among the alteratives (II. 432 to 444), where, I think, they belong more strictly than to the present place.

Prickly Ash

Xanthoxylum. U. S We have, in the bark of a small indigenous tree, the Xanthoxylum fraxineum or prickly ash, a medicine closely analogous, in its properties and effects, with those just mentioned, particularly with guaiac and mezereon, and, like them, sometimes used in chronic rheumatism. it is usually given in decoction; an ounce of it being boiled with three pints of water to a quart, of which one-half may be administered, in divided doses, through the day.

Virginia Snakeroot

Serpentaria. U. S This might also rank with the stimulating diaphoretics; but has been treated of among the tonics, to which it more especially belongs (i. 299). As its properties and uses as a diaphoretic are scarcely separable from those which rank it with the tonics, they have been already sufficiently considered, and it is only necessary here simply to call attention to them.

Most substances having a stimulant influence on the circulation, and capable of being absorbed into the blood, may be made to operate as diaphoretics by directing their action towards the surface of the body; and prove more or less serviceable by this property. But in all these, when considered elsewhere, this particular property, and their uses in reference to it, have been sufficiently treated of, and to repeat the same statements here would be a useless waste of space.

In treating of diaphoretics, it is scarcely proper to pass without notice, an indigenous product, which has been considerably employed by American physicians with a view to this effect, and probably possesses diaphoretic powers. I allude to the root of the butterfly-weed or Asclepias tuberosa, which has a place in the secondary catalogue of our Pharmacopoeia under the name of Asclepias.