MOTOR EXCITANTS. 107 



less delirium is producecl, with hallucinations, mental 

 disorder, and a tendency to irregular movements 

 caused by a selective action of the drug upon the cells 

 of the gray matter. The spinal cord is stimulated 

 from the second cervical to almost the last dorsal ver- 

 tebra, resulting finally in paralysis of both central 

 and peripheral motor nerves, locomotory power being 

 first lost in the posterior extremities. Sensation is 

 somewhat impaired, but muscular irritability is un- 

 affected. By the increased circulation metamor- 

 phosis is greatly promoted, which, together with the 

 increased respiration, raises the temperature. A 

 scarlatina-like rash (seldom discernible in the lower 

 animals) with d^^sphagia and sore throat, is occasion- 

 ally produced by belladonna on the skin and fauces, 

 and is due to capillary congestion resulting from the 

 increased circulation. Belladonna is rapidly diffused 

 and rapidly eliminated, which process is accom- 

 plished chiefly by the kidneys. Large doses dimin- 

 ish the excretion of urine, while small doses seem to 

 be without effect in that particular. Since atropine 

 is eliminated in an almost unchanged form, the urine 

 of an animal under its action will dilate the pupil of 

 another animal. The herbivora are not so profoundly 

 affected by belladonna as the carnivora, the goat be- 

 ing accredited with the ability of consuming quanti- 

 ties of the leaf with impunity. On the dog the car- 

 diac action of the drug is more apparent, while in 

 the horse the cerebral action predominates. 



Antidotes and Antagonists. — Belladonna has 

 been thought to have no direct physiological antago- 



