230 MATERIA MEDICA AND THERAPEUTICS. 



cardiac centre is first stimulated, so that the heart beats more 

 powerfully and less frequently ; but at last, or after large doses, 

 depression ensues. Therewith the intracardiac branches of 

 the vagus are probably stimulated at first, and the ganglia 

 paralysed at last. The blood pressure rises with the increased 

 cardiac action, and falls later on. Whether there is any direct 

 action of eserin on the vaso-motor apparatus is unsettled. 



Contraction of the pupil and spasm of accommodation are 

 striking and highly important effects of eserin, whether it be 

 given internally or applied locally. Both phenomena are due 

 to irritation of the fibres of the third nerve, aud not to central 

 disturbance as in the contraction caused by opium, or to 

 paralysis of the sympathetic. These effects are accompanied 

 by fall of the intraocular tension, and can be removed by 

 atropia. The salivary secretion is increased through the centre 

 of the chorda, but ceases after large doses from arrest of the 

 circulation in the glands. 



The specific uses of calabar bean depend on its action on 

 the cord and the eye. It has been frequently given in tetanus, 

 and other convulsive diseases referable to irritation or disease 

 of the spinal centres, and apparently with success, although 

 many of these cases recover spontaneously, and others resist 

 the eserin. The alkaloid should be given subcutaneously in doses 

 of gr. ^<7 to T \ in solution ; or gr. ^ of the extract may be given 

 subcutaneously, or gr. 1 by the mouth, repeated in two hours, 

 and followd by doses of gr. T V to 5 every few hours. For the 

 convulsions of strychnia poisoning calabar bean is of little or 

 no use. Neither is it of much real service in the treatment of 

 poisoning by atropia or chloral, as was once expected. 



In diseases of the eye eserin is now much used. A drop of 

 a solution of the sulphate (2 gr. to 1 ounce of water) is 

 applied locally to diminish intraocular pressure in glaucoma, 

 perforating keratitis, etc. ; in paralysis of the iris and ciliary 

 muscle, e.g. after diphtheria (^ gr. to 1 ounce) ; to counteract the 

 effects of belladonna ; or to diminish the entrance of light in 

 painful diseases of the eye, photophobia, etc. 



4. REMOTE LOCAL ACTION. 



Eserin is excreted by the liver and salivary glands, but has 

 never been found in the urine. 



Araroba GOA POWDER. A concretion from 

 clefts in the stem of Andira Araroba ( Angeliun Amar- 

 gosa) imported from Brazil chiefly into India. (Not 

 ojjicinal.} 



