W00'RALI POISON. Since the original publication of the article Cunani, which is one of the synonyms of this substance, the physiological actions of this fearful poison has been carefully studied by Drs. Weir, Mitchell, and Hammond, of,thet United States; i and the essay in which their joint labors are recorded is published in Physiological Memoirs (1863). This essay is so valuable, and contains so much original mat ter regarding two other allied poisons whose native names are corroval and rao, that we shall give a brief abstract of its contents; premising that for th e best account of the history of this remarkable poison, the reader should consult Bernard's Loons les Effets des Oubstances Toxiques (1857, p. 238). We shall notice the physical and properties of this poison before describing its physiological action. The best of the earlier investr gations of the poison is that of Roulin and Boussingault in 1828, who obtained from the crude "woorala" an alcoholic extract, to which they gave the name of curarin. This curarin was a solid transparent mass, of an excessively bitter taste, and possessed in an emiuent degree of all the virulence of the woorali. Heintz has subsequently examined the precipitate which tannic acid throws down from the watery solution of the poison, but only found that it contained no nitrogen, and 'was composed of apparently inert sub stances, as sugar, gum, resin, extractive matter, tannic and gallic acids, etc. He sought in vain for strychnine in it. Among the chief experimenters on the subject may be mentioned De la Condamine (Hem de 'Academie des Sciences, 1745, t. 62, p. Brock lesby (Philosophical Transactions, 1747, vol. xliv. p. 408); Trans actions, 1751-52, vol. xlvii. p. 75), who killed a bear with a poisoned arrow in less than five minutes; and nearly killed himself and a small boy who was evaporating an aque ous solution of the poison; both, however, recovered under the influence of fresh air, a pint of wine, and a quantity of sugar; Fontana (1781), who showed that (notwithstand ing the above experiment) the vapor is not deleterious, and that the state of the stomach at the time when the poison was inhaled modified the result, an animal with a full stomach being able to resist the action of a dose that would prove fatal to one of the same size when fasting; Brodie (Philosophical Transactions, 1811-12); Virchow and Mnnter (published in vol. i. of Schoinburgk's Reisen in Britisch G (liana), who, inter alia, showed that the poison, even after being kept dry for five years, is still intensely active— that its physiological action corresponds with the result of analysis in showing the absence of strychnine, and that it rather belongs to narcotic than to tetanic poisons— and that death takes place not from any direct result of the poison, but indirectly, by causing the cessation of the respiratory process; Bernard and Pelouze (Compt. Rend., 1850, t. xxxi. p. 534); Vulpian (Uompt. Rend., 1854, t. i., 2d series, p. 73); and Kiilliker (Proceedings of the Royal Society, 1857), who, among other important conclusions, arrives at the following: (1) That the strari (as he terms it) causes death very rapidly when injected into the blood or inserted into a wound; and that when introduced by way of the mucous membrane, its effects are slow, and require a large dose for their production; when applied to the skin of frogs, it is inoperative; (2) it acts through the blood, and destroys the excitability of the motor nerves, while the sensory nerves are hardly at all affected; (3) when artificial respiration is carried on in animals under its influence, many of the secretions are increased, owing to the paralysis of the vascular nerves, and the consequent dilatation of the vessels; (4) that in mammals, the poison causes death by the paralysis of the respiratory nerves and suppression of the respiration, which brings on convulsions as a collateral effect.
The late researches of Weir, Mitchell, and Hammond, on the two hitherto nude scribed varieties of the poison, named woorara, variety corroval, and woorara, variety vao, lead to the following results: The corroval, which is asserted to be the strongest arrow poison, but of whose mode of manufacture they could learn nothing, was in large lumps of a brownish-black color, resembling vegetable extracts of that tint. From its aqueous solution they obtained a substance possessing all the qualities of an alkaloid, and in an eminent degree the poisonous properties of the corroval, to which they assign the name corrovalia. Hence it differs materially in its chemical composition from ordinary woorali. From a large number of experiments on living birds, mice, cats, frogs, and alligators, they find (1) that corroval differs essentially from any variety of woorali hitherto described in its physiological results; (2) that it acts primarily on the heart through the medium of the blood, producing an arrest of the heart's action; (3) that the annihilation of voluntary and reflex movements is a secondary result of its action, depending primarily on the cessation of the heart's action; (4) that it acts upon the nerves from the surface to the center, and abolishes both the sensory and motor functions; (5) that it destroys muscular irritability; (6) that it paralyzes the sympathetic nerve, this being one cf its primary effects; (7) that it is absorbed both from the intestinal canal and skin of frogs; and (8) that its poisonous effects are due to an alkaloid hitherto undescribed. The authors devote 42 pages to a history of their experiments on vao or boo; but as they are of opinion that vao is only a weaker variety of corroval, it is unnecessary to follow their researches in this direction. It is obvious that in corroval and vao we have a fear ful poison, quite distinct from ordinary woorali; and we have entered into further detail on this subject than we should otherwise have done, because, so far as we know, they have not yet been noticed by any English author.