156 VETERIKARY MATERIA MEDICA. 



quency of the pulse when continued for some time. 

 It at times causes considerable depression, muscular 

 weakness, nausea, and vomiting. Large doses make 

 the pulse very small, rapid, and almost imperceptible, 

 and frequently cause gastro-enteritis. Respiration is 

 not nearly so much affected as by aconite. Toxic 

 doses cause a fatal cardiac paralysis, preceded by 

 coldness of surface, impaired vision, constant vomit- 

 ing, and sometimes partial unconsciousness. 



Jervine partly represents the depressant action on 

 the circulation and on the central nervous system, 

 while it does not affect the vagus, and but very 

 slightly the voluntary muscles or motor nerves. It 

 irritates the motor centres in the brain, causing con- 

 vulsions; it lowers the functions of the cord, of the 

 centres in the medulla, especially the vasomotor, 

 and those of the cardiac ganglia, slowing the heart by 

 direct depression either of the cardiac muscle or its 

 motor apparatus. It always causes salivation, but 

 never vomiting or purging ; it kills by asphyxia, the 

 heart beating after respiration has ceased. 



Veratroidine always causes emeto-catharsis, pro- 

 duces less violent convulsions, stimulates the vagus 

 centre, and paralyzes the vagus ends ; depresses the 

 cord and paralyzes the respiratory centre, but at the 

 same time increases the excitability of the vasomotor 

 centre. The result is a great slowing of the pulse 

 rate and of respiration, lowering of the blood pressure, 

 until the carbonized blood irritates the vasomotor 

 centre, when blood pressure greatly rises. 



Veratrum album contains a very powerful alkaloid, 



