MOTOR EXCITANTS. 95 



are increased, as is also the body temperature to a 

 slight degree. Full doses dilate the pupils, relax the 

 arterioles, lower blood pressure, produce spasmodic 

 respirations, twitching of the muscles, and jerking of 

 the extremities. Toxic doses, especially if given on 

 an empty stomach, rapidly produce tonic spasms, par- 

 ticularly of the extensor muscles, rapidl}^ succeeding 

 each other on the least irritation, with intervals of 

 repose (differential diagnosis from tetanus, where the 

 spasm is constant) . 



Death takes place very rapidly in one or two 

 hours, according to the size of the dose. Very large 

 doses kill almost instantly, death taking place by CO^ 

 poisoning, as the respiratory muscles become com- 

 pletely paralyzed. 



Str^^chnine exalts all the functions of the cord. If 

 given in larger doses there is over-stimulation; in 

 further increased doses the entire cord is suddenly 

 paralyzed — i.e., the spinal functions are destroyed at 

 one blow. Strychnine is absorbed more rapidly from 

 the rectum than from the stomach, and still more 

 rapidly from the bronchi and cellular tissues. It is 

 slowly excreted in an unchanged condition in the 

 urine. 



Therapeutics. — Nux vomica and strychnine are 

 among the very best of the respiratory, cardiac, 

 muscular, and nerve stimulants and tonics. Strych- 

 nine is a powerful antagonist in poisoning by opium 

 or morphine. In anaemia, chlorosis, and con- 

 vales cence from debilitating diseases, strychnine 

 combined with iron and quinine; tetanus; atonic 



