Which is also to be seen by children, that are troubled with worms, if there be given unto them 4, 6, 8. to 12. or 16. grains of the finest filings of steel or iron, that all the worms in the body are killed thereby, their stomach and guts scowred very clean, and their stools also turned black. But this must be observed by children, when the worms are killed, and yet remain in the guts (because that the iron in a smal quantity is not strong enough for to expel them, but only make the body soluble) that a purge must be used after, for to carry them out; for else if they do remain there, others will grow out of their substance. But to those that are more in years, you may give the Dose so much the stronger, as from ℈ i. to ʒ i. that the worms also may be carryed out, they being better able to endure it than little children, and although sometimes a vomit doth come, yet it doth no hurt, but they will be but so much the healthier afterward. And thus Iron may be used, not only against worms, but also against all stomach-agues, head-ach, and obstructions of the whole body, without any danger and very successfully, as a grateful or very acceptable medicine to Nature; for after a powerful magnetical way it doth attract all the ill humors in the body, and carrieth them forth along with it. Of whose wonderful vertue and nature, there is spoken more at large in my Treatise of the Sympathy and Antipathy of things. Which some Physitians perceiving and supposing by Art to make it better, they spoiled it, and made it void of all vertue: for they taking a piece of steel, made it red-hot, and held it against a piece of common Sulphur, whereby the steel grew subtle, so they did let it drop into a vessel filled with water; then they took it out, and dryed it, and made it into powder, and used it against obstructions, but to no effect almost; for the Iron was so altered by the sulphur, and reduced to an insoluble substance (which ought not to have been so) that it could perform no considerable operation: But if they had made the steel more soluble (whereas they made it more insoluble) than it was of it self before, then they had done a good work: for he that knoweth sulphur, doth know well enough, that by no _Aquafortis_ or _Aqua Regis_ it can be dissolved; and how could it then be consumed by an animal humor? Hitherto it hath been proved sufficiently, that in some men, especially in those that are of a Melancholick constitution there is an acid humor, which can sufficiently dissolve all easily soluble metals and stones: and that therefore it is needless to torture, and dissolve pearls, corals and the like with corrosive waters before they be administred to patients: but that the Archeus of the stomach is strong enough by the help of the said humors to consume those easily soluble things, and to accept of that which serveth his turn, and to reject the rest.