343 VEGETABLE DRUGS 



of the nervous system — especially the medulla, spinal centres, and peri- 

 pheral sensory and motor nerves — describe the general effect of aconite. 



Respiration. — Following primary stimulation, with increased depth 

 and frequency of breathing, the breathing of animals under the influence 

 of aconite resembles that observed after section of the vagi. The res- 

 piration is slow and labored; the expiration is prolonged, and is suc- 

 ceeded by a considerable interval before the next inspiration. This 

 condition is brought about by depression of the medullary respiratory 

 centres. 



Temperature. — The bodily heat is reduced by aconite in fever, after 

 medicinal doses, and in poisoning by the drug. Heat loss is due to stimu- 

 lation of the heat regulating centres which reduce a febrile temperature 

 to normal; to diminished action of the heart; and to sweating, if it 

 occurs. 



Skin. — Aconite sometimes produces slight diaphoresis, due to stimu- 

 lation of the nerve endings in the sweat glands and to dilation of the 

 peripheral blood vessels. 



Kidneys and Elimination.* — Aconitine is chiefly eliminated in the 

 urine. 



Toxicology. — The minimum fatal dose of aconite is about 3i for 

 the horse ; gr.xx for paedium sized dogs ; and gr.v-vi for cats. The 

 smallest fatal dose recorded in man is a teaspoonful of tincture of aconite 

 (U. S. P. 1890), equivalent to about gr.xxx of the crude drug. The 

 minimum lethal quantity of aconitine is gr. -^ for man, and about the 

 same for cats, lor dogs it is from gr. 14 to gr. %. " The writer has 

 found that cats will live from fifteen minutes to half an hour after re- 

 ceiving the smaller deadly doses under the skin, but large doses produce 

 death immediately by paralyzing the heart. Large therapeutic doses 

 cause, in horses, restlessness, pawing the ground, shaking of the head, 

 champing of the jaws, increased secretion of salivary mucus, and at- 

 tempts at swallowing probably owing to the peculiar sense of irritation 

 produced by the drug in the throat. Nausea and retching are observed 

 in all animals, while vomiting occurs in dogs and cats. The pulse and 

 respiration are weakened and generally retarded. After lethal doses 

 these symptoms are intensified. We observe violent retching, frequent 

 and difficult attacks of swallowing, ejection of frothy mucus from the 

 mouth, copious sweating in horses ; pulse first weak and infrequent, later 

 rapid, running and almost imperceptible; respiration slow, interrupted, 

 and shallow, and reduction of temperature. Death is preceded by mus- 

 cular twitchings in the horse and loss of strength, so that the subject 

 falls and is unable to rise; or in the case of cats and rabbits, the animals 

 jump vertically into the air, topple over backwards and go into convul- 

 sions, lying helpless on their side. The labial muscles are retracted, and. 

 the lips drawn back, showing the teeth covered with foam. The face is 



*While a time-honored remedy in veterinary practice recent experiments by 

 Mackensie, Price, and Rudolf and Cole, independently, have failed to find that 

 aconite lowers pulse or fever in usual medicinal doses. 



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