That thou mayest understand what I intend, it is to discover in a general way of the manifest virtues of medicines.

I say of the manifest virtues, and qualities, viz. Such as are obvious to the senses, especially to the taste and smell: for it hath been the practice of most Physicians, in these latter ages as well as ours, to say, when they cannot give, nor are minded to study a reason, why an herb, plant, &c. hath such an operation, or produces such an effect in the body of man: It doth it by an hidden quality, for they not minding the whole creation, as one united body, not knowing what belongs to astral influence, not regarding that excellent harmony the only wise God hath made in a composition of contraries (in the knowledge of which consists the whole ground and foundation of physic) are totally led astray by Tradition.

It is the manifest qualities of medicines that here I am to speak to, and you may be pleased to behold it in this order.

SECTION I.

Of the Temperature of Medicines.

Herbs, plants, and other medicines manifestly operate, either by heat, coldness, dryness, or moisture, for the world being composed of so many qualities, they and only they can be found in the world, and the mixtures of them one with another.

But that they may appear as clear as the sun when he is upon the meridian, I shall treat of them severally, and in this order