Page:Treatise on poisons in relation to medical jurisprudence, physiology, and the practice of physic (IA treatiseonpoison00chriuoft).pdf/699

 He took it in the form of infusion, and the dose was only three-quarters of a liqueur-glassful; yet he was seized with nausea, pain in the stomach, a sense of fulness in the head, giddiness, ringing in the ears, and obscurity of vision, followed by stiffness of the limbs, great pain on every attempt at motion, locked-jaw, and impossibility of articulating. These symptoms continued two hours; and abated under the use of ether and laudanum.

Some interesting experiments were made by Emmert with this poison to show that it acts on the spine directly, and not on that organ through the medium of the brain. If an animal be poisoned by inserting the extract of false angustura bark into its hind-legs after the spinal cord has been severed at the loins, the hind-legs as well as the fore-legs are thrown into a state of spasm; or if the medulla oblongata be cut across and respiration maintained artificially, the usual symptoms are produced over the whole body by the administration of it internally or externally,—the only material difference being that they commence more slowly, and that a larger dose is required to produce them, than when the medulla is not injured. On the other hand, when the spinal cord is suddenly destroyed after the symptoms have begun, they cease instantaneously, although the circulation goes on for some minutes.

The true angustura bark has a finer texture than the other, and is darker coloured, aromatic, pungent, and less bitter. The ferrocyanate of potass causes in a muriatic infusion of the false bark a precipitate, which is first green and then becomes blue; and the same reagent converts into blue the reddish powder which lines the bark. No such effects are produced on the true angustura bark. Nitric acid renders the rusty efflorescence of the spurious bark deep dirty blue, but has no such effect on the true bark; which, besides, never exhibits a yellow efflorescence.

With the preceding poisons Orfila has arranged also some poisons used by the American Indians; but, as in Europe they are mere objects of curiosity, it is scarcely necessary to treat of them particularly here.

The most interesting and best known of them is the wourali-poison of Guiana, variously called woorara, urari, or curare, by different authors. It is believed to have been traced by Martius to a new species of strychnos, the S. guianensis, and more recently by Dr. Schomburg to a different species, the S. toxicaria of that traveller. But the action it exerts does not correspond exactly with what would be expected of a plant belonging to that genus.

The effects of wourali have been investigated by Sir B. Brodie in the Philosophical Transactions for 1811-12, in Orfila's Toxicology, in Magendie's Memoir on Absorption, and in Fontana's Traité des Poisons. But the most detailed inquiry is that by Emmert, published in 1818. It produces, not convulsions or spasm of the mus-*