_Of drawing Medicines._
The opinion of physicians is, concerning these, as it is concerning
other medicines, viz. Some draw by a manifest quality, some by a
hidden, and so (quoth they) they draw to themselves both humours and
thorns, or splinters that are gotten into the flesh; however this is
certain, they are all of them hot, and of thin parts; hot because the
nature of heat is to draw off thin parts that so they may penetrate to
the humours that are to to be drawn out.
Their use is various, _viz._
_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.