CALABAR BEAN, a very remarkable medicinal agent, width has been introduced into the new edition of the British Pharmacopceia (1867). It is the seed of physom'igma vereenomn, a twining, half-shrubby plant, a native of western Africa, of the natural order lerminowe, sub-order papilionacee, nearly allied to the kidney bean, but of a genus distinguished by the hood-shaped stigma, and the deeply-furrowed bikini of the seed. The following are the leading characters of the bean itself: "About the size of a very large horse-bean, with a very firm, hard, brittle, shining integument, of a brown ish-red, pale chocolate, or ash-gray color. Irregularly kidney-shaped, with two flat sides, and a furrow running longitudinally along its convex margin, ending iu an aper ture near one end of the seed. Within the shell is a kernel, consisting of two cotyledons. weighing on an average about 40 grains, hard, white, and pulverizable, of a taste like that of the ordinary edible leguminous seeds, without bitterness, acrimony, or aromatic flavor. It yields its virtues to alcohol, and imperfectly to 'water." It is used in the form of an emulsion by the natives of Africa, as an ordeal when persons are suspected of witchcraft. About twenty years ago, Dr. Christison very nearly fell a victim to his zeal for science in experimenting on some specimens of this bean which bad been sent to Edinburgh by some African missionaries, dangerous symptoms having been produced by 12 grains of the kernel which he swallowed. In 1801, Dr. Thomas R. Fraser tried the effects upon himself of doses of 6, 8, and 10 grains. The general symptoms were epigastric uneasiness, great feebleness, dimness of vision, salivation, giddiness, and irre gular, feeble, and slow heart's action. About the same time, he made the interesting discovery, that when placed on the eyeball this substance contracts the pupil, and pro duces near-sightedness; and it is now frequently employed for these purposes by ophthal mic surgeons. In 1864, 50 children were poisoned by eating these beans, which were
swept out of a ship at Liverpool. A boy aged six years, who ate six beans, died very rapidly. The chief symptoms in these cases were griping, vomiting, and contracted pupils; the face was pale, the eyes bright and protruding, and in trying to walk, the children staggered as if they were drunk. Dr. Fraser, in it paper which he communi cated to the royal society of Edinburgh in 1866, maintains that, in mammals. death is generally produced by a combination of syncope (faintness) with asphyxia (suffocation); the symptoms of the one or the other depending on the (lose, which, when large, at once destroys the heart's action. It has been used medicinally in small (loses (one to ten grains of the powder, or to of a grain of the extract) in chorea, tetanus, general paralysis of the insane, and other diseases of the nervous system. Being now a recog niz.ed medicinal agent, it is satisfactory to know that the dangerous and even fatal effects of excessive doses may be prevented by administering belladonna, (night-shade). or its active principle, atropin, as a counter-poison. This fact has been established by Dr. Fraser in a communication to the royal society of Edinburgh, embracing the results of 500 experiments on dogs and rabbits. So unmistakable is the power of the antidote, that it can prevent even three times a fatal dose of time kernel from caus ing death in those animals. Belladonna has also an opposite action on the eye to that of this substance. as it dilates the pupils and produces leng•sightedness. When the pupil is contracted by Calabar bean, it may be dilated to its normal, or to a greater, size by belladonna; and when it is dilated by belladonna, it may be reduced to its normal, or to a less, size by Calabar bean.