Dr. Willis's practice of physick being the whole works of that renowned and famous physician wherein most of the diseases belonging to the body of man are treated of, with excellent methods and receipts for the cure of the same : fitted to the meanest capacity by an index for the explaining of all the hard and unusual words and terms of art derived from the Greek, Latine, or other languages for the benefit of the English reader : with forty copper plates.

3. Common Precipitate Mercury.

Take of pure Mercury ℥ij. of Aq. fortis ℥ iv. and having dissolved it, put it into an earthen glazed Vessel, wherein let it evaporate first over a gentle fire till the moisture he all spent; * 1.1 then increase the fire, and let it calcine even till the Vessel be red hot, still stirring i•…•… with an Iron Instrument till it gain a ruddy colour: Let the matter when taken out and powdered, be first sweetned with frequent washings in sweet water, and after that again kindle Spirit of Wine, and pour upon it, and so keep it for your use. The Dose is gr. iij. to v. or vj. It works violently enough by Vomit, and causeth spitting more certainly than any other Pr•…•…cipitate of Mercury.

If you enquire into the reason of this Chymical attempt, I say, that the Mercury is dissolved by the Aqua fortis, in as much as the saline particles of the Menstruum [or * 1.2 Dissolver] meeting with the Salts of the Metal, do presently snatch such Salts to them, and consequently, when by the dissolution of the mixture all the other particles are set at liberty, and expanded every where lie lurking in the pores of the menstruum; but afterward when the moisture is consumed, the saline particles that are left, and expo∣sed to view, do quite take off the force of the Mercurial ones within them, which

are mixt in every part. Now the reason why Mercury being precipitated on this fashion with Aqua fortis, or Aqua Regia, grows red, and of another colour than when it is prepared with Oil of Sulphur or Spirit of Vitriol, is partly from the Nitre that always gives it a Flame colour (for Nitre is an ingredient of the former menstruum, * 1.3 though not of these later) and partly from the Mercury it self, whose particles when it is dissolved, so long as they are free and not hid in others, are of their own nature red, as you may see in Mercury precipitated by it self, and in the dissolving of it in Oil of Tartar, wherein it leaves a ruddy, that is, a Mercurial Powder.

This Medicin consisting of Salts that are very corrosive, as well as Mercurial par∣ticles * 1.4 that are dissolved, in as much as it extreamly provokes the fibres of the Stomach, causes most violent Vomiting, so that it is rarely given alone for this end. But if at any time it be taken, and having passed the Stomach and those first passages, it be carried into the bloud; in as much as the native Salts thereof are thereby very much fermented, and with them the Mercurial particles being plentifully infused, and throughly mingled, are so entangled, that they can be discharged again no way better than by the Ductus Salivales, or Spittle-passages (as I have elsewhere shewn) for that reason this Medicin causeth spitting in many People before any other.

Notes

• * 1.1

  Mercury preci∣pitated with corrosi•…•…e liq•…•…rs
• * 1.2

  The reason of this Pr•…•…aration
• * 1.3

  Why it grows red in this case.
• * 1.4

  How Mercurial Medicins work upon the Sto∣mach.