CHAP 5. Of Medicines opening the Mouths of the Vessels.
THese Galen thought to be hot, but of thick parts and biting.
Let none admire that thickness should be attributed to Medicines of an opening substance, seeing thick∣ness seems rather to stop than to open. For answer to this, you must consider the manner of opening obstructions, and of opening the mouths of the Ves∣sels is different, Obstructions require cutting Medi∣cines by which the thickness of the matter obstruct∣ing is made thinner, therefore the Medicine ought not to be thick, but of thin substance that it may the better penetrate (I do not mean of a thin Body, like water, for that causeth Obstructions rather then take them away, but of thin parts, viz. Making thin) But those Medicines which are said to open the mouths or passages of the Vessels, are of thick parts, that they may not only penetrate, but also strengthen the passages by which they pass, therefore Galen be∣sides heat, appointed thickness of parts and sharpness, or biting, as Pepper bites, for such a sharp heat is very effectual to penetrate, and cannot stop in the least; for although the Skin be easily contracted by gentle Medicines, the Vessels cannot be shut but by things vehemently binding, and therefore let these Medicines of thick substance be also moist, for moi∣sture cannot so forcibly bind as to stop the mouths of the Vessels.
The Use of opening Medicines may be easily ga∣thered* 1.1 from the use of the Vessels to be opened, for seeing their use is to hold Blood, which sometimes offend in quantity, sometimes in quality, such infir∣mities are to be remedied by opening Medicines.
They are easily known by tast, being sharp and piercing, and bite the tongue, but such as are stop∣ping, are cold and binding, and contract the tongue in tasting of them.