A course of chemistry containing an easie method of preparing those chymical medicins which are used in physick : with curious remarks and useful discourses upon each preparation, for the benefit of such who desire to be instructed in the knowledge of this art / by Nicholas Lemery, M.D.

Remarks.

The Acidity of Vinegar consists in an Essential, or Tartareous Salt, which being heavier than the Phlegm rises last; but you must evaporate this Phlegm very gently, because the Acid Spirit of Vinegar will easily sublime with it.

I do use an earthen pan, rather than a Cucurbite, that the Phlegm of Vinegar finding a large open passage may evaporate the more easily.

It would be no great fault, if you should distil the Vinegar without dephlegmating it first; for the separating the phlegm from it is not of so much consideration, as to make it as clear as pure water, that it may not bestow any particular tincture to the ingredients that are to be dissolved in it.

The Spirit of Vinegar is much less fixed than many other acids, because it partakes of the Sul∣phureous Spirits of wine which still remain in it.

Common Vinegar keeps its strength a longer time than the distilled, because it contains a more Ter∣restrious Salt, that doth not Volatilize so easily. And for this reason, you should rather chuse to use Vinegar newly distilled, than that which hath been kept a good while. All Acids do prove Cordial, and good against malignity of humors, when it is caused by too great a commotion, because it fixes and Coagulates them, moderating their motion. Thus in places where the Air is corrupted, and Pestilential, Vinegar is a good Preservative; you may every morning take half a Spoonful of it Fast∣ing; but in diseases which proceed from a Tarta∣reous

humor, as the Hypochondriack melancholy, it is rather hurtful than good, because it fixes the humors the more.

Some having dried and calcined the sweet ex∣tract that remains at the bottom of the Cucurbite, after the distillation of Vinegar, and having by Solution, Filtration, and Coagulation, separated from it an Alkali fixt salt, much like to that which is drawn from Tartar, they do mix it with Spirit of Vinegar, and distil and cohobate it divers times, until, say they, the spirit has carried off all the salt, and then will needs have it called Spirit of Vinegar Alkalized, or Radical Spirit of Vinegar, and they affirm that this being much more pure, and entirely united with its proper salt, is much the more powerful in dissolving Metals. But the distilled Vinegar is so far from becoming the stronger through this Preparation, that I can de∣monstrate that it breaks and loses the greatest part of its edges in contending with the Alkali salt, with which it is mixt, for it is the property of this salt to sweeten Acids.

Neither is it necessary to believe that by distilla∣tions is so drawn the Alkali salt of Vinegar, for it remains fixt at bottom of the Retort with the acids it is impregnated with; so that this same Spirit of Vinegar to which so many great names and uses have been appropriated, is properly the more Phlegmatick part of distilled Vinegar.