Nine books of physick and chirurgery written by that great and learned physitian, Dr Sennertus. The first five being his Institutions of the whole body of physick: the other four of fevers and agues: with their differences, signs, and cures.

CHAP XXII. Of the manner of finding out the vertue of Medi∣cines.

WE come to the knowledge of the faculties of these Medicines two wayes, by reason, and Experience; * 1.1 and indeed especially by experience; for the force of some Medicines, as acting in their whole substan••, is found out only by experience and although reason may seeme to per∣swade some things, yet unlesse it be confirmed by experience it is to be rejected; truly those indications are not plainly to be rejected which are taken from externall passions of things, from the place, and Aire, from colours, and smells, and remarkeable signes, yet in many things they faile, unless experience be joyned: nay experience alone often sufficeth, for those things which are cleerly manifest to our senses, leave nothing of doubt, yet if that which is found by experience,

can be confirmed by reason, * 1.2 that is, by much the most cer∣taine knowledge, but when reason seemes to be adverse to experience, tis better to cleave to experience, yet experi∣ence ought not to be taken rashly, nor to be taken from one example but many observations, and those are choicely to be collected, which may be done if the medicine acting, and the body or subject suffering, be diligently considered.

In medicines, especially such as are taken from Plants, the substance, quantity, quality, age, time of gathering, na∣tive place, and such like, are to be considered, and especially to be regarded, whether it have got any strange, and acqui∣red quality, but it ought to have its owne vertue whole and entire.

The subject is mans body, and all medicines are said to be such, not absolutly, nor in respect of other things, but in re∣gard of mans body, whence it comes to passe, that experience ought to be made, of the primary qualities in a temperate man; in others for the most part, especially those that are sick, and those that are affected with me simple discase, and not a compound, least experience should be put out of its course, nor is it enough, that experience be made once, or in one body, but observation ought to be made in many that are alike in Temperament, age, sex, structure of body; it is also to be considered whether any Medicine, performes any thing primarily, and by its selfe, or by accident.

Notes

• * 1.1

  How the vertues of Medicines may be found out:
• * 1.2

  Manner of experi∣ments.