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the powder, grs. v to 9j ; of the infusion or decoction, f3j ; in large do-ses all the forms are liable to produce nausea. Form. 58. OfficinalPrep. Infusum Cusparite. L. Tinct. Bonplandia Trifoliate. E. Tinet. An-gusturce. D. Adulterations. There is found in the market a particularbark, which has been called Fine Axgustura, hut which is of a differentspecies, and is a very energetic poison. This bark is characterized by_having its epidermis covered with a matter which has the appearance ofrust of iron, and which, moreover, possesses certain chemical proper-ties of this metal ; for if water acidulated with muriatic acid be agitatedin contact with its powder, it assumes a beautiful green colour, and af-fords with an alkaline prussiate. (Hydro-cyanate of Potass) a Prussianblue precipitate. Late researches have detected the presence of an al-kaline element in this bark, on which the name of Bruciu. has been be-stowed. When this alkali is dissolved in boiling alcohol, and crys-tallized by spontaneous evaporation, it yields colourless and transparentcrystals in the form of oblique quadrangular prisms.

DATURA STRAMONIf HERBA. E. D.The Herbaceous part of the Thorn Apple.Qualities. Odour, foetid and narcotic, occasioning head-ache and stu-por ; Taste, bitter and somewhat nauseous. Chemical Composition.Gum, resin, and carbonate of ammonia ; the recent experiments of M.Brandes have also developed an alkaline element of activity, to which thename of Daturia has been assigned ; it appears to exist in native combi-nation with malic acid ; when in an imcombined state it is nearly insolu-ble in water, and in cold ilcohol, but boiling alcohol dissolves it. It hasbeen obtained with difficulty in the form of quadrangular prisms. Solu-bility. The medicinal powers of the herb are alike extracted byaqueous and spirituous menstrua. Incompatible Substances. The in-fusion is precipitated by the salts of lead, silver, mercury, and iron ; themineral acids would also appear to produce some essential changes whichmay diminish its efficacy. Acetic acid increases its powers, although itrelieves the effects of an over-dose, if administered after the stomachhas been emptied. This apparent anomaly is easily explained when weconsider, that in the first Case its operation is purely chemical, increasingthe solubility of the active principle of the plant, while in the latter caseit operates as a vital agent, restoring to the nervous system that energywhich has been suspended by (he narcotic influence of the vegetable.Medicinal Uses. It is narcotic, and has been regarded by many authorsas eminently antispasmodic ; Dr. Barton, an American physician, madevery extensive trials of its efficacy in Mania, the result of which is high-ly favourable to its use- Dr. Marcet first noticed its salutary eflects inchronic diseases attended with violent pain ; he found it to lessen power-fully, and quickly, sensibility and pain, and to produce a sort of nervousshock, attended with a momentary affection of the head and eyes, with adegree of nausea, and with phenomena resembling those which are pro-duced by intoxication. It seems to be more particularly beneficial inchronic rheumatism, sciatica, &c. Its root, smoked in the manner of to-_bacco, has been much extolled as a remedy in the paroxysms of spasmod-ic asthma ; this practice however, is not unattended with danger ;* the* It is said to have been introduced into this couufry from Ceylon. See the obserrations made upon the subject of the narcotics used by the [ndians, m page 9.

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