As we find, upon the Examination of Opium, by chemical Analysis, that it contains a very large Proportion of a volatile Salt, and corrosive Oil, Alkalies will undoubtedly encrease the Volatility of the one, and Corrosivity of the other, and thereby assist their Expansion. On the other Hand, Acids condense Volatiles, and destroy their Power; and furthermore, will prevent the Expansion of the corrosive Oil, by checking the Activity of the Salts. We see, by putting the mineral Acids to volatile Spirits, they destroy their Volatility, and produce fixt Bodies. _Vide Boerhave, de Regeneratione Salis Armoniaci, &c. process. 20. Partis 3. de Operationibus Chemiæ._ Likewise by a vegetable Acid, thus, when distilled Vinegar is poured to the Volatile Spirit of Sal Armoniac, the Volatility is destroyed, as in making the Spiritus Mindereri. The Antients, sensible of this, used frequently to prepare Opium with vegetable Acids, to correct its Power; and by that Means could give it in larger Doses; but this Practice, being in many Cases inconvenient, was laid aside. Acids are of two Sorts, either Mineral or Vegetable; the Mineral are the stronger, and very corrosive, being drawn from Fossils by the Help of intense Heat, as Vitriol, Nitre, _&c._ the Vegetable are Native, in Fruits, as Citrons, Oranges, Limons, Limes, _&c._ in some Plants, as Sorrell, &c. or produced by Fermentation, as Tartar and Vinegar. Opium being a vegetable Production, replete with a volatile, urinous Salt, what can be more efficacious to counteract the Power of it, than a vegetable Acid, which is not of a corrosive Nature, so as to prevent the taking of it, even alone, into the Stomach without Injury? and this surely cannot be said of a mineral Acid. _Wedelius_, Lib. I. Sect. 2. p. 53. strenuously asserts the Use of Acids, _Acida enim Sulphura tum Salium tum aliorum obtundunt, præcipitant, invertuntque ac exhalationem et resolutionem remorantur, quod infinitis Experimentis Chimicis demonstrari posset_. And, he further says, p. 59. "That Vinegar is a most powerful Remedy for such as are poisoned with Opium, that it will correct the Acrimony and Heat of it, and thereby the volatile Parts will become mild, and as it were fixed." The Affect of Opium upon the Nerves, being by Stupefaction, and a subsequent Relaxation, what Principle can so readily restore them, as light fermented Acids, and so soon promote, by their gentle Pungency, a Disposition to Sweat? The crude Acids of Fruits and Herbs are more sharp and contracting, than those by Fermentation; nor can they be used with Safety in such Quantities, though they stand particularly recommended. I prefer, therefore, the Acetum Stillatitium, or distilled Vinegar, it being an Acid of sufficient Strength, and of a pure Nature, which, joined with nervous and cordial Medicines, has fully answered my Expectations.