Their use is various, viz.
Project Gutenberg EPUB3 edition
Culpeper, Nicholas
Use 1. That the bowels may be disburdened of corrupt humours.
2. Outwardly used, by them the offending humour (I should have said the peccant humour, had I written only to scholars,) is called from the internal parts of the body to the superfices.
3. By them the crisis of a disease is much helped forward.
4. They are exceedingly profitable to draw forth poison out of the body.
5. Parts of the body over cooled are cured by these medicines, viz. by applying them outwardly to the place, not only because they heat, but also because they draw the spirits by which life and heat are cherished, to the part of the body which is destitute of them: you cannot but know that many times parts of the body fall away in flesh, and their strength decays, as in some persons arms or legs, or the like, the usual reason is, because the vital spirit decays in those parts, to which use such plaisters or ointments as are attractive (which is the physical term for drawing medicines) for they do not only cherish the parts by their own proper heat, but draw the vital and natural spirits thither, whereby they are both quickened and nourished.
They are known almost by the same tokens that attenuating medicines are, seeing heat; and thinness of parts is in them both, they differ only in respect of quantity, thinness of parts being most proper to attenuating medicines, but attractive medicines are hotter.