CHEMICAL CONSTITUTION AND PHYSIOLOGICAL ACTION. 709 



In the autopsy, it was found that the sciatic nerves retained their afferent 

 (motor) and efferent (sensor) conductivity for at least fifteen minutes after death, 

 and that the heart had ceased to contract previous to twenty minutes after this 

 event. 



These general effects very closely resemble those that have been described in 

 the experiments with the iodide of methyl-atropium. We shall see from the 

 following experiment that the effects on frogs of this ethyl derivative are like- 

 wise the same in character with those of the methyl derivatives. 



Experiment LIL— We injected under the skin of the left flank of a frog, 

 weighing 290 grains, three-twentieths of a grain of iodide of ethyl-atropium, 

 dissolved in eight minims of distilled water. In six minutes, the frog was per- 

 fectly motionless and flaccid ; and so complete was the paralysis, that even severe 

 irritation of the skin did not cause any reflex movement. The heart was now 

 contracting in regular rhythm, at the rate of thirty-nine beats in the minute. In 

 seven minutes, the right sciatic nerve was exposed, and it was found, by galvanic 

 stimulation, that its motor conductivity was completely suspended. The muscles, 

 at this time, contracted vigorously when the electrodes were applied to their 

 surface. This condition of the motor nerves and of the muscles was retained for 

 other two days; but on the second day the cardiac impulse was weak, and the 

 beats occurred at the diminished rate of twenty in the minute, while, on the 

 third day, no cardiac impulse could be observed. On the fourth day, the muscles 

 had become rigid. 



These symptoms are in all essential characters the same as those we have 

 described, with fatal doses of iodide of methyl-atropium. We have besides, given 

 a dose considerably below the minimum fatal, and have observed a temporary 

 stage of complete paralysis of the motor nerves, which was recovered from with- 

 out the occurrence of the slightest spasmodic or convulsive symptoms. This ethyl 

 derivative of atropia, therefore, resembles the methyl derivatives, in that it does 

 not possess the well-marked convulsant action of atropia. 



We have seen from the last experiment that the paralysis is accompanied by 

 total suspension of the conductivity of the motor nerves. It is important that we 

 should now discover whether the sensory nerves and spinal cord are also impli- 

 cated in the production of this paralysis. This may readily be determined by 

 experiments in which certain limited regions are protected from the direct action 

 of the poison — as has been done in experiments with the methyl derivatives of 

 atropia. 



Experiment LI. — Having ligatured the blood-vessels in the lower third of the 

 right thigh of a frog, weighing 301 grains, we injected three-twentieths of a grain 

 of iodide of ethyl-atropium, dissolved in ten minims of distilled water, under the 

 skin of the left flank. Paralysis very quickly supervened ; and in two minutes, 

 stimulation of the skin anywhere was followed by vigorous movements of the 



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