418 VEGETABLE DRUGS 



Nervous System and Micsdes. — Medicinal doses do not 

 cause any functional disturbance of the nervous system, but 

 very large doses excite the spinal motor tract and reflex 

 centres and cause convulsions in frogs, succeeded by spinal 

 depression and paralysis. The latter is due in part to an 

 influence on the muscles themselves. Tremors occur occa- 

 sionally in man and the domestic animals in poisoning. 

 The nerves escape unscathed. The involuntary muscles are 

 stimulated throughout the body, owing to the direct action 

 of the drug upon them and their motor nerve terminations. 



Skin. — Moderate doses of pilocarpine stimulate but 

 slightly the secretion of sweat in the lower animals, but in 

 man the secretion is enormous (1 pt.). The salivary secre- 

 tion appears to supplant that of the skin in the domestic 

 animals, unless very large doses are employed (H., gr.vii.- 

 xii.), which cause diarrhoea, salivation and loss of body 

 weight (40 to 60 lbs.), and may entail pulmonary oedema 

 and heart failure. The secretory nerve terminations and 

 glandular cells are both stimulated. The secretion of tears, 

 nasal mucus and milk are slightly increased in the same 

 manner, and the growth of hair is rendered more luxurious. 



Temperature. — The temperature is reduced by evapora- 

 tion from the skin, if there is much sweating. 



Genito Urinary Organs. — Pilocarpine exerts a slight and 

 uncertain oxytocic action on the pregnant uterus and has 

 sometimes precipitated parturition in pregnant animals at 

 full term. The unstriped muscle of the spleen and bladder 

 is stimulated, and micturition is frequent. Pilocarpine, in 

 repeated small doses, augments the flow of urine and prob- 

 ably increases tissue waste and the excretion of urea by its 

 general action on the secretions. It is eliminated unchanged 

 in the urine. 



Eye. — Pilocarpine contracts the pupil when applied to 

 the eye; it also increases tension of the eyeball and impairs 

 the sight temporarily, owing to action on the retina. The 

 myosis is due to stimulation of the peripheral oculomotor 

 nerve endings. When the alkaloid is given internally it 



