Where the substance is in a solid form, and acts by absorption, we should be very cautious how we favour its solution; while, if it exists in a liquid state, our object must be to render its active portion insoluble; this problem involves a series of questions which are wholly _chemical_. In order to prevent, or retard, the absorption of the active matter, we must, to a great degree, depend upon the agency of _vital_ adjuvants; this latter indication however does not apply to _Corrosive Sublimate_ and other substances which act upon the stomach locally, and are not absorbed; copious dilution also, in such cases, will frequently disarm the poison of its virulence,[226] but it should be followed as quickly as possible by vomiting. In cases where the poison requires to be absorbed, before it can display its energies, it would be generally unsafe to administer any solvent. Nothing therefore can be less true as an aphorism, nor more dangerous as a precept, than the unqualified assertion of Boerhaave, “_Aqua omnia venena enervat, quæ cum aqua misceri possunt_.” (Prælect. in Instit: T. vi. p. 289.) _Alkaline_ solutions and _Magnesia_, in cases of the ingestion of arsenic, accelerate its fatal effects, by promoting its solution,[227] whereas _Lime_, or its _Carbonate_, has as an opposite tendency,[228] in consequence of the insolubility of _Arsenite of Lime_; so again, Orfila has shewn that the pernicious qualities of the _Muriate of Baryta_ are counteracted by the administration of any soluble _Sulphate_, which renders the former substance _insoluble_. In cases where _Verdegris_ has been swallowed, the administration of vinegar greatly increases its virulence, as M. Drouard has ascertained, by converting the substance into a soluble _acetate of copper_. This view of the subject will explain why the pure earth _Baryta_ is so slow, and comparatively inert, in its effects upon the system, while its _muriate_ is distinguished by the extreme rapidity and virulence with which it operates. The propriety of administering _vinegar_, _lemonade_, and different acid potations, in order to counteract the baneful effects of _Opium_, which has been so often questioned, will thus also receive ample explanation; it must appear that, if any quantity of the substance of opium remain in the primæ viæ, acid, or mucilaginous drinks will, by favouring its solution and absorption, accelerate its fatal effects;[229] but should it have been previously ejected from the stomach, that then the anti-narcotic influence of a vegetable acid[230] may remove the consecutive stupor and delirium, and thus realize the expectations which Virgil has so poetically raised. “Media fert tristes succos tardumque saporem Felicis Mali: quo non præsentius ullum (Pocula si quando sævæ infecere novercæ Miscueruntque herbas, et non innoxia verba) Auxilium venit, ac membris agit atra venena.”