The plant producing the Ordeal Bean of Calabar. A large perennial climber. Nat. Ord. LeguminosAe, inhabiting Old Calabar.
Med. Prop. and Action. The bean or seed, the Ordeal Bean of Old Calabar, is an energetic poison. Administered internally, it appears to exert a sedative influence on the spinal cord, producing paralysis or the lower extremities, and death by asphyxia; or, if given in large doses, death by paralysis of the heart. J Prof. Christison§ tried it on his own person in minute quantities: the prominent symptoms were vertigo, a sense of extreme prostration, and syncope, whilst the action of the heart and circulatory system was rendered very weak, tumultuous, and irregular; the mental faculties, however, were unimpaired. Further experiments on rabbits, &c., demonstrated its powerfully poisonous qualities. Recently a number of children at Liverpool have been poisoned, and one has died, from eating the Beans. A full detail of these interesting cases is furnished by Dr. Cameron.|| It is not to its poisonous effects, however, that we would call attention in this place, but principally to the extraordinary power possessed by its active principle, in the form of alcoholic extract, of inducing, when locally applied, contraction of the iris and ciliary muscle. This property of inducing contraction of the pupil, and restoring the power of accommodation, has rendered it a most useful application in certain Diseases and Injuries of the Eye. Thus, it is of especial value when the power of accommodation is lost from paralysis, or after the use of Atropine in ophthalmoscopic examinations. Dr. Argyll Robertson,¶ from experiments made with the Extract, draws the following conclusions: - 1. Its application induces a condition of short-sightedness, which may be relieved by the use of concave glasses. 2. It occasions contraction of the pupil of the eye to which it is applied, and sympathetic dilatation of the pupil of the other eye. 3. Atropine possesses the power of counteracting its effects, and vice versa, i. e. it is capable of overcoming the effects produced by Atropine. The first symptom noticed after its application is dimness of distant vision, and shortly after the pupil becomes contracted. These symptoms subside in the same order, - first the derangement of accommodation, and then the affection of the pupil. The observations of Drs. Fraser and Stewart, Messrs. Bowman, Wells, and others, confirm the statements regarding its anti-mydriatic powers. Mr. Daniel Hanbury** has published two excellent papers on this Bean, from which it appears, (1) that it will yield upwards of 4.5 per cent. of Extract, and that probably more may be obtainable, as the residuum after its extraction continues to possess poisonous properties; (2) that the Extract in aqueous solution is a turbid, inelegant form, and likely soon to spoil. It has been prepared of several strengths, so that one minim may represent i, 1, 2, or 4 grains of the Bean; (3) Glycerine is a preferable menstruum, less irritating to the eye, and not liable to change by keeping; (4) it may be advantageously applied by means of bibulous paper or gelatine, in the manner advised by Messrs. Streatfeild and Hart for Atropine (q. v.). It has been prescribed internally in certain affections of the nervous system. A case of Traumatic Tetanus, in which the Extract of Calabar Bean dissolved in gelatine was administered, is recorded by Mr. Holmes Coote.* The patient took in all 14 minims of Bell and Co.'s Extract, equal to 56 grains of the powder. He ultimately recovered, but it was doubtful whether recovery could be attributed to the Bean. The powdered Bean has also been prescribed with apparent benefit by Professor Harley, of University College, in Chorea, in doses of gr. iij., gradually increased to gr. vj.
* Quoted by Pereira, vol. i. p. 349.
Garrod, Ess. Mat. Med. and The-rap., p. 35.
Ibid., p. 189.
§ Pharm. Journ., 1855, vol xiv. p. 472.
|| Med. Times and Gaz., Oct. 18, 1864, p. 406. ¶ Edin. Med. Journ., March 1863. ** Pharm. Journ., June and July, 1863.