CALABAR BEAN. The seed of Physo stigma renenosn at. a twining. half-shrubby plant. native of western Africa. of the natural order Leguminosi•, nearly allied to the kidney-bean, hut of a genus distinguished by the hood.shaped stigma and the deeply furrowed hit= 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 brownish-red, pale chocolate, or ash-gray color. Irregularly kid ney-shaped. with two flat sides. and a furrow running longitudinally along its convex margin, ending in an aperture near one end of the seed. Within the shell is a kernel. consisting of two cotyledons. weighing on an average about 46 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 im perfectly to water." It is used in the form of an emulsion by the natives of Africa, as an or deal when persons are suspected of witchcraft. It is believed that if one vomits them he is in nocent: if they are retained and death occurs, he is guilty. If the accused person is innocent he will usually eat a large number without hesitation, and so cause vomiting; if he hesi tate: and takes little, this does not occur. In 1$55 Dr. Christian very nearly fell a victim to his zeal for science in experimenting on some specimen: of this bean which had been sent. to Edinburgh by some African missionaries. dan gerous symptoms having been produced by 12 grains of the kernel which he swallowed. In ISG1 Dr. Thomas R. Fraser tried the effects upon himself of doses of 6. S, and 10 grains. The general symptoms were epigastri• uneasi ness. great feebleness. dimness of vision, saliva
tion. giddiness, and irregular. feeble. and slow heart's action. When placed on the eyeball, this substance contracts the pupil. decreases infra ocular tension, and produces near-sightedness. In 1S64 fifty children were poisoned by eating these beans, which, were swept out, of a ship at Liverpool. A boy aged 6 years, who ate six beam, died very speedily. The- chief symptoms in these cases were griping, vomiting, and eon t•acted pupils; the face was pale, the eyes bright and yrotruding, and in trying to walk the chil dren staggered, as if they were drunk. The bean contains two alkaloids—physostigmine, or eser ine, which represents the- chief activity of the drug; and ealitharing. which has a tetanizing action like strychnine. It has been used medic inally, in small duos, in chorea. tetanus, and strychnine poisoning. It is employed to coun teract the dilatation of the pupil caused by at ropin•. to. lessen intraocular tension in glau •oma. and to alternate with atropine in breaking up in iritis. Being now a recognized medicinal agent, it ie satisfactory to know that the dangerous and even fatal effects of exces sive doses may be prevented by administering Belladonna (nightshade). or its active princi ple. atropine. Belladonna has also an oppo"site action on the eye to that of this substance. When the pupil is contracted by Calabar bean, it may he dilated to its normal size or larger by belladonna: and when it is dilated by bella donna, it may be reduced to its, normal' size or smaller by Calabar bean: but the action of eserine is not as durable as that of atropine.