470 VEGETABLE DRUGS 



rise of pulse rate, force and tension, by stimulation of the 

 cardiac muscle and vasomotor centres. 2. Large doses are 

 followed by slowing and weakening of the pulse. The 

 vagus centre is stimulated and the heart muscle depressed. 

 3. Towards the end of fatal poisoning the pulse becomes 

 weak, thread-like, rapid and irregular from paralysis of the 

 heart muscle, vagus endings and vasomotor centres. It 

 sometimes- happens, however, that the pulse remains weak 

 and slow in this stage because the paralyzing influence of 

 the substance on the heart muscle prevents quickening of 

 the heart even after the removal of inhibitory control. The 

 heart is dilated and irresponsive to galvanism, after death, as 

 are also the voluntary muscles. 



Respiration. — Lethal doses paralyze the respiratory 

 centres and death occurs from respiratory arrest. The 

 breathing may be quickened by small doses of veratrine, 

 owing to transient stimulation of the respiratory centres and 

 vagus nerve endings in the lungs. 



Toxicology. — The symptoms of poisoning are referable 

 to the action of veratrine on the digestive, nervous and 

 muscular apparatus, heart, and respiratory organs. They 

 include nausea, salivation, clammy sweating, excessive vomit- 

 ing in dogs, cats and cattle, attempts at vomiting in the 

 horse, abdominal pain, severe purging, muscular twitchings 

 or convulsions (excited by external stimuli), loss of muscular 

 power and paralysis. The pulse, at first weak and infrequent, 

 becomes thready, rapid and irregular. The temperature is 

 reduced and the respiration is weak and slow. Death occurs 

 in convulsions or paralysis. One-sixteenth of a grain has 

 caused alarming symptoms in man. The minimum fatal 

 dose is about one grain for dogs. One grain subcutaneously, 

 or five to six grains by the mouth, produce poisonous 

 symptoms in horses. 



Treatment. — External heat; respiratory and cardiac 

 stimulants should be employed subcutaneously. Potassium 

 carbonate and demulcent ' drinks are to be given in- 

 ternally. 



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