And so much of the abuse of Mercury: I hope it will be a good warning unto many, so that they will not so easily billet such a tyrannical guest in any ones house, whereby the ruine thereof of necessity must follow. And that cure deserveth no praise at all, whereby one member is cured with the hurt of two or three other members. As we see by the Pox, when one infected member is cured by Mercury, and that but half, and not firm at all, that all the rest of the body is endangered thereby for the future. And therefore it would be much better that such crude horse-physick might be severed from good medicaments, and such used instead of them, as may firmly, safely, and without prejudice to other parts perform the cure, of which kind several are taught in this book. But in case that you have Patients, which have been spoiled by such an ill-prepared Mercury, then there is no better remedy to restore them, than by medicines made of metals, wherewith Mercury hath great affinity, as of gold and silver: for when they are often used, they attract the Mercury out of all the members, and carry it along with them out of the body, and so do rid the body thereof. But externally the precipitated Mercury may more safely be used, than internally, in case there be nothing else to be had, _viz._ to corrode or eat away the proud flesh out of a wound. But if instead of it there should be used the corrosive oyl of Antimony, Vitriol, Allome or common salt it would be better, and the cure much the speedier; and it would be better yet, that in the beginning good medicaments were used to fresh wounds, and not by carelesness to reduce them to that ill condition, that afterwards by painful corrosives they must be taken away. But such a Mercury would serve best of all for souldiers, beggers, and children that go to school; for if it be strewed upon the head of children, or into their cloathes, no louse will abide there any longer. In which case Mercury must by his preparation not be made red, but onely yellow, and it must be used warily, and not be strewed on too thick, lest the flesh be corroded, which would be the occasion of great mischief. _Of Aqua fortis._ Out of Salt nitre and vitriol, taking of each a like quantity (or if the water is to be not altogether so strong) two parts of vitriol to one part of salt nitre, a water distilled is good to dissolve metals therewith, and to separate them from one another; as gold from silver, and silver from gold, which in the fourth part punctually shall be taught.