Note 587 — PHARMACOLOGIA. (continued 5)

The discovery of an alkaline body in opium induced the French and German chemists to examine the composition of other active vegetables, with a view to detect the existence of an analogous principle; and their labours have been rewarded with unexampled success. They have accordingly obtained Strychnia from the nut of the Strychnos nux vomica;—Brucia from the bark of the Brucea Anti-dysenterica (False Angustura Bark) Veratria from the Veratrum album, V. Sabadilla and Colchicum Autumnale;—Cinchonia from the bark of the Cinchona Oblongifolia (Red Bark);—Quina (or Kina) from that of the Cinchona Cordifolia (Yellow Bark);—Emeta from the Callicocca Ipecacuanha;—Delphia, from the Delphinium Staphisagria;—Picrotoxa from the Menispermum Cocculus;—Solana from the Solanum Nigrum, and S. Dulcamara; Gentia, from Gentiana lutea;—Atropia from the Atropa Belladonna;—Hyoscyama, from Hyoscyamus Niger. Besides which, Capsicum, Piper nigrum, and Senna, have been said to yield analogous principles of a salifiable character. With respect to most of these alkaline bodies farther experiments are required to establish our confidence; it is more than probable that several of them will turn out to be disguised modifications of each other; it has already been questioned whether Quina and Cinchonia be not varieties of one alkali; indeed it is possible that all these bodies may have the same alkaline base, and that they differ from each other in consequence of their combination with other principles, derived from the vegetable in question, and impressing upon the salt its characteristic virtues; and this idea receives material support from the fact, that they are neutralized by a very small proportion of acid. (See a paper on this subject in the 70th number of the Edinburgh Med. and Surg. Journ.)

They have all many properties in common, such as a degree of bitterness varying in intensity in different species; they are inodorous; are not altered by air or light, but are decomposed by a moderate heat; most of them enter into fusion, but at different temperatures, some for instance at below 212° Fahr. others not until they are about to be decomposed; Hyoscyama will even resist a low red heat. They are very sparingly soluble in water, but they are in general rendered more so by the presence of resinous matter. They are nearly all highly soluble in alcohol. Æther readily dissolves Delphia, Veratria, Emeta, Quina, and Gentia; but Morphia, Cinchonia, and Picrotoxa, are very sparingly soluble: and Strychnia and Brucia are nearly insoluble in it; they combine with the acids; and, in general, form neutral salts; but it appears that Veratria and Emeta always unite with an excess of acid. All the combinations with the mineral acids, excepting the salts of Picrotoxa, are exceedingly soluble in water; and, with the exception of Nitrate of Cinchonia, and all the salts of Veratria, they are crystallizable. The acetates too, with a few exceptions, are also soluble, and they are disposed to form super-salts. All the oxalates, except that of Picratoxa, which is the most soluble of its salts, and all tartrates, are rather insoluble, and have likewise a tendency to unite with an excess of acid. The action of concentrated nitric acid on these alkaline bodies is very peculiar, converting the greater number of them into artificial tannin; but it appears to peroxidate Morphia, Strychnia, and Brucia, rendering them less powerful as salifiable bases, and diminishing or destroying their action on the animal body. See Edinburgh Med. & Surg. Journ. supra citat.

By analysis, with the deutoxide of copper, these alkalies yield carbon, hydrogen, and oxygen; but no azote, unless they have been obtained by precipitation with ammonia, as in the process of Sertuerner.

It would appear that these bodies exist in their native plants, in combination with peculiar acids; some of them are found in the state of Malates.

With respect to their physiological action it may be stated, that they would appear to concentrate in themselves the characteristic properties of the vegetables to which they belong, and yet, although their effects are much greater than those of the undecomposed vegetables, the same quantity of alkali is not so powerful in its pure form, as in its natural state of combination. Thus one grain of morphia produces no more effect than two grains of Turkey opium, which do not contain more than a sixteenth part of the alkali. To explain this loss of efficacy which usually attends our attempts at concentration, the reader is referred to the observations which have been already offered upon this subject in the first part of this work, page 153.