PHYSOSTIGMINE 391 



of the inferior cornua. This has been abundantly and 

 directly proved by application of the alkaloid to the spinal 

 cord; and, indirectly, by dividing the inferior from the 

 superior portion of the cord, by stopping the blood supply 

 to the latter part, when the drug caused loss of motor power 

 and abolition of reflex action in the inferior portion, while 

 reflex phenomena were undisturbed in the superior portion 

 (Frazer). The superior columns are finally depressed ; per- 

 ception of pain is wanting, but that of touch persists. The 

 sensory nerves are not aff'ected, and the motor nerve trunks 

 bat slightly. The muscular tremors are due to stimulation 

 of the voluntary muscles themselves, or to the motor nerve 

 endings. These are characteristic of physostigma poisoning 

 in animals — not in man — and are probably due to calabarine, 

 which should not be present in pure physostigmine. The 

 involuntary muscles throughout the body are stimulated, 

 including those of the stomach, intestines, bronchial tubes, 

 heart, blood vessels (?), spleen, uterus, bladder and iris. In 

 the case of some of these organs, it has not been decided 

 whether the muscles themselves, or the motor nerve termi- 

 nations, are affected. 



Respiration. — The respiration is not disturbed by medi- 

 cinal doses. Toxic quantities at first quicken, and then 

 retard the respiratory movements, and death occurs from 

 asphyxia, before cessation of the heart, owing to paralysis 

 of the medulLiry and spinal respiratory centres. The accel- 

 eration of breathing is due to the stimulation of the pulmo- 

 nary vagal endings, and possibly to constriction of the 

 unstriped muscle of the bronchial tubes. 



Secretions. — Secretion is generally increased, including 

 that of the salivary, gastric, intestinal, sudoriparous and 

 lachrymal glands. In this respect eserine is antagonistic to 

 atropine. 



Eye. — Physostigmine is a myotic, applied locally or 

 administered internally. Intraocular tension is diminished 

 and there is spasm of accommodation. In all probability 

 contraction of the pupil is brought about by stimulation of 



