mucilage will be dissolved, or swim in the water; while a starch perfectly wholesome and nutritious will subside, and may be advantageously used as food; by a similar species of address the French prepare from the acrid _Arum_ the harmless, but highly prized cosmetic, called _Cyprus powder_. There are many substances which receive a much pleasanter mode of operation by having their solubilities increased or diminished; thus the griping occasioned by several drastic purgatives is obviated by the addition of some alkali: and the nauseating tendency of _Camboge_, which arises from its too easy solubility, is prevented by incorporating it with some insoluble body; as in the _Pilulæ Cambogiæ Comp:_ but the farther consideration of this question will be resumed in the fourth section of the Analysis. (iv. c.) Numerous attempts have been made to correct the inconvenient effects of _Opium_, such as nausea, head-ache, and costiveness, by removing the resinous element, upon which such evils have been supposed to depend, and we have accordingly been at different times presented with a variety of _Formulæ_ for the accomplishment of so desirable an object; (_see Opium_). More recently, opium has been discovered to possess _two_ active principles, viz. _Morphia_ and _Narcotine_, which would appear from the researches of M. Majendie to exert very different powers upon the animal system; the former imparting to opium its _soporific_, the latter, its _exciting_ property; whence it is proposed to remove this latter principle in order to render the operation of opium milder, and at the same time to divest it of those objectionable properties which so greatly limit its medicinal utility. _See Opium._ B. _By adding some substance capable of guarding the stomach, or system, against its deleterious effects._