This to be so may easily be proved; for it is notorious, that melancholick folks, hypocondriaques, and others do often cast up a great quantity of acid humor, which is so sharpe that no vinegar is comparable to it, and doth set their teeth on such an edge, as if they had eaten unripe fruit. What remedy now? take away the cause and the disease is taken away. If you could take away the peccant matter by purgings, it would be well, but it remaineth obstinate and will not yield to them. By vomit it may be diminished in some measure. But because that not every one can abide vomiting, it is therefore no wisdome to turn evil into worse. Shall then this tartar be killed and destroyed by contraries, which indeed in some sort may be effected; as when you use vegetables or animals, whose vertue consisteth in a volatile salt: such are all species or sorts of cresses, Mustard-seed, horse-radish, scurvy grass, also the spirit of Tartar, of Harts-horn, and of urine and the like, which by reason of their penetrating faculty pass through all the body, finding out the Tartar thereof, destroying the same, as being contrary unto it; and in this combat two contrary natures is kindled, a great burning heat, whereby the whole body is throughly heated and brought to sweating; and whensoever by these contraries a sweating is caused, there is always mortified some of this hurtful Tartar. But because that of that acid humor but a little at a time can be mortified and edulcorated by contrary volatile spirits, and that therefore it would be required to use them often, for to kill and expell all the Tartar; and because also (as hath been mentioned before) a strong sweat always is caused by every such operation, whereby the natural spirits are much weakened, so that the patient would not be able to hold out long thereby, but by taking away of one evil, another and greater one would be occasioned. And therefore such things must be offered to that hungry acid humour, by which the corrosive nature thereof, may be mortified and grow sweet, with that proviso nevertheless, that those things be such as are not contrary or hurtful to the nature of man, but grateful and friendly, as are corals, pearls and crabs eyes, _&c._ For amongst all stones none are more easily to be dissolved than Pearls, Corals, Crabbs-eyes, and other stones of fishes. But the truth of this, _viz._ that every corrosive is killed by feeding upon pearls and corals, and thereby can be made sweet; and besides, how a sowre coagulated Tartar, by the help of corals or pearls may be reduced to a sweet liquor (a pleasant and acceptable medicine to the nature of man) which never can be coagulated again by any means, shall be afterwards proved and taught when I shall come to treat of Tartar.