Page:Treatise on poisons in relation to medical jurisprudence, physiology, and the practice of physic (IA treatiseonpoison00chriuoft).pdf/645

 CHAPTER XXXIII.

OF POISONING WITH NIGHTSHADE, THORN-APPLE, AND TOBACCO.

The first group of the narcotico-acrids comprehends these whose principal symptom in the early stage of their effects is delirium. All the plants of the group belong to the natural order Solanaceæ, and Linnæus's class Pentandria Monogynia. Those which have been particularly examined are deadly nightshade, thorn-apple, and tobacco. Of Poisoning with Deadly Nightshade.

The deadly nightshade, or Atropa belladonna, is allied in physiological and botanical characters to the hyoscyamus and solanum formerly mentioned; and by the older writers, indeed, was confounded with the latter. It is a native of Britain, growing in shady places, particularly on the edge of woods. The berries, which ripen in September, have a jet-black colour. Their beauty has frequently tempted both children and adults to eat them, although they have a mawkish taste; and many have suffered severely. It is not the berry alone which is poisonous; the whole plant is so; and the root is probably the most active part. From one to four grains of the dried powder of the root will occasion dryness in the throat, giddiness, staggering, flushed face, dilated pupils, and sometimes even delirium. The juice of the leaves is very energetic, two grains of its extract being, when well prepared, a large enough dose to cause disagreeable symptoms in man. It is a very uncertain preparation, unless when procured by evaporation in vacuo; for some samples from the Parisian shops have been found by Orfila to be quite inert.

It contains a peculiar alkaloid, named atropia. In the belladonna Brandes obtained a volatile, oily-like, alkaloidal fluid, of a penetrating narcotic smell, and bitterish, acrid taste, which he supposed to be the active principle of the plant. The ulterior researches of Geiger and Hesse, however, as well as the simultaneous analysis of Mein, have proved that this fluid is not the pure alkaloid of belladonna, and that the real atropia is a solid substance, forming colourless, silky crystals, soluble in ether and alcohol, sparingly so in water, slightly bitter, liable to decomposition under contact with air and moisture, volatilizable, but with some decomposition, a little above 212°, and capable of forming definite crystallizable salts with acids. The aqueous solutions of its salts exhale during evaporation a narcotic vapour, which dilates the pupil, and causes sickness, giddiness, and headache.

The ordinary extract of belladonna in the dose of half an ounce will