What medicine is appropriated to the purging of such a humour, for seeing the offending matter is not alike in all, the purging medicine ought not to be the same to all. I shall speak more of this anon. As also of the divers ways whereby medicines draw out or cast out humours, viz. by lenifying, cleansing, provoking nature to expulsion, and (which is stranger than the doctor's hidden quality) some purge by binding, but indeed, and in truth, such as are properly called purging medicines, which, besides these faculties, have gotten another, by which they draw or call out the humours from the most remote parts of the body, whether these do it by heat or by an hidden quality, physicians are scarce able to determine, it being very well known to modern physicians, though the ancients denied it, that many cold medicines purge.

There is this faculty in all the purges of Galen's model, (because he gives the whole simple which must needs consist of divers qualities, because the creation is made up of and consists by an harmony of contraries) there is (I say) this faculty in all purges of that nature, that they contain in them a substance which is inimical both to the stomach and bowels, and some are of opinion this doth good, namely, provokes nature the more to expulsion; the reason might be good if the foundation of it were so, for by this reason nature herself should purge, not the medicine, and a physician should help nature in her business and not hinder her. But to forbear being critical, this substance which I told you was inimical to the stomach, must be corrected in every purge.