Adulteration—We may point out that the roots of Mandragora microcarpa, M. officinarum, and M. vernalis Bertoloni are very nearly allied to the root under notice, both in external appearance and in their structure. They are not likely to be confounded with Belladonna root, their mother plants being indigenous in the South of Europe.
FOLIA BELLADONNÆ.
Belladonna Leaves; F. Feuilles de Belladone; G. Tollkraut.
Botanical Origin—Atropa Belladonna L. ([p. 455]).
History—Belladonna Leaves and the extract prepared from them were introduced into the London Pharmacopœia of 1809. For further particulars regarding the history of belladonna, see the preceding article.
Description—Belladonna or Deadly Nightshade produces thick, smooth herbaceous stems, which attain a height of 4 to 5 feet. They are simple in their lower parts, then usually 3-forked, and afterwards 2-forked, producing in their upper branches an abundance of bright green leaves, arranged in unequal pairs, from the bases of which spring the solitary, pendulous, purplish, bell-shaped flowers, and large shining black berries.
The leaves are 3 to 6 inches long, stalked, broadly ovate, acuminate, attenuated at the base, soft and juicy; those of barren roots are alternate and solitary. The young shoots are clothed with a soft, short pubescence, which on the calyx is somewhat more persistent, assuming the character of viscid, glandular hairs. If bruised, the leaves emit a somewhat offensive, herbaceous odour which is destroyed by drying. When dried, they are thin and friable, of a brownish-green on the upper surface and greyish beneath, with a disagreeable, faintly bitter taste. Of fresh leaves 100 lb. yield 16 lb. of dried (Squire).
Chemical Composition—The important constituent of belladonna leaves is Atropine. Lefort (1872)[1679] estimated its amount by exhausting the leaves previously dried at 100° C. by means of dilute alcohol, concentrating the tincture, and throwing down the alkaloid with a solution of iodohydrargyrate of potassium. The precipitate thus obtained was calculated to contain 33·25 per cent. of atropine. Lefort examined leaves from plants both cultivated and growing wild in the environs of Paris, and gathered either before or after flowering. He found cultivation not to affect the percentage of alkaloid,—that the leaves of the young plant were rather less rich than those taken at the period of full inflorescence,—and that the latter (dried) yielded 0·44 to 0·48 per cent. of atropine.
Larger percentages are recorded by Dragendorff;[1680] as much as 0·95 per cent. of atropine as obtained from the dried unripe fruits, 0·83 from the dried leaves, 0·21 from the root. The estimation was performed in nearly the same way as that followed by Lefort.
Belladonna herb yields Asparagin, which according to Biltz (1839) crystallizes out of the extract after long keeping. The crystals found in the extract by Attfield (1862) were however chloride and nitrate of potassium. The same chemist obtained by dialysis of the juice of belladonna, nitrate of potassium, and square prisms of a salt of magnesium containing some organic acid; the juice likewise affords ammonia.[1681] The dried leaves yielded us 14·5 per cent. of ash consisting mainly of calcareous and alkaline carbonates.