576 



MANUAL OF POISONOUS PLANTS 



Fig. 316. Coca-tree {Brythroxylon coca). Furnishes the coca of 

 commerce. (After Faguet). 



vessels is not very marked, except in poisoning. The alkaloid is, hov/ever, a slight cardiac 

 stimulant in moderate doses, increasing the pulse-rate and tension. The action upon the 

 heart is caused by depression of the cardio-inhibitory centres, and sometimes as well by 

 depression of the cardiac inhibitory ganglia. Vascular tension is increased because of stim- 

 ulation of the medullary vasomotor centres, smooth muscle of the walls, and because of 

 the increased action of the heart. On the other hand, both minute and large doses may 

 diminish the pulse rate. 



Cocain is a respiratory stimulant in medicinal doses, but a paralyzant in toxic amounts. 

 The respiratory centres are first stimulated and the breathing is made deeper and quicker. 

 Depression and paralysis of the respiratory centres follow; cyanosis supervenes, and the 

 respirations are shallow and irregular. Death occurs from asphyxia. In man, an amount 

 of cocaine exceeding gr. ^ should not be employed under the skin, or upon mucous mem- 

 branes, and death has occurred in susceptible patients from even smaller doses. The most 

 powerful action follows the use of cocain in very vascular parts, as about the face. One 

 half a grain of cocain given subcutaneously to a girl eleven years old, was followed by a 

 fatal result in 40 seconds, and the writer has seen violent convulsions produced by the in- 

 stillation of a few drops of a 2 per cent, solution into the eye of a man. On the other hand, 

 spontaneous recovery has obtained in the human subject after the ingestions of 22 grs. of 

 the alkaloid. In the horse, the toxic dose of cocain causes restlessness and excitement, 

 dilated pupils and salivation, culminating within an hour in a state of acute mania and 

 intense excitement. These symptoms are followed by gradual recovery after a lapse of a 

 few hours.1 Three grains of cocain given under the skin, will sometimes induce nervous 

 excitement in susceptible horses. The treatment of dangerous forms of cocain poisoning, 

 with respiratory and heart failure, consists in the use of rapidly acting stimulants, — as 

 nitroglycerin upon the tonguCi and strychnin, atropin and brandy subcutaneously. 



Families of Geraniales 



Flowers regular or nearly so, petals present usually as many as the sepals; 

 flowers perfect; leaves not punctate. 



