CHEMICAL CONSTITUTION AND PHYSIOLOGICAL ACTION. 725 



lethal activity of iodide of dimethyl-conium is greatly less than that of either 

 conia or methyl-conia. That the character of the symptoms it produces is also 

 different, will be seen from the following experiment. 



Experiment XCVIII. — Having dissolved three grains of iodide of dimethyl- 

 conium in forty minims of distilled water, we injected the solution under the skin 

 of a rabbit, weighing four pounds. The animal remained sitting quietly for more 

 than half an hour, during which time no symptom was observed. In thirty-two 

 minutes, however, it became restless, and faint tremors occurred. Soon, it had 

 difficulty in moving about; and after some endeavours to maintain a sitting 

 posture, it lay down on the abdomen and chest. In forty-one minutes, the head 

 rested on the table ; and at this time the respirations were shallow, and at the 

 increased rate of 144 in the minute. The rabbit remained quietly in this position 

 until one hour and four minutes, when it succeeded, after some efforts, in rising 

 on its limbs, but, being unable to support itself thus, it again lay down on the 

 abdomen and chest, with the head resting on the table. The respirations were 

 now eighty-four in the minute. In one hour and eleven minutes, slight tremors 

 again occurred, and then the rabbit became perfectly flaccid, and the respirations 

 infrequent and laboured. In one hour and twelve minutes, the respirations were 

 mere gasps, occurring at the rate of about twelve in the minute ; and soon after 

 they became so shallow as to be hardly visible. In one hour and fifteen minutes, a 

 few twitches occurred in the muscles of the face, and in a few seconds the rabbit 

 was dead. 



In the autopsy, the motor nerves and muscles were found active, twelve 

 minutes after death ; but at this time the exposed heart was found to be contract- 

 ing irregularly and feebly. 



In this experiment, we frequently tested the reflex excitability, but never 

 observed the slightest evidence of its being increased. 



We shall now briefly describe the experiment in which we administered five 

 grains. 



Experiment C. — A solution, containing five grains of iodide of dimethyl- 

 conium, in fifty minims of distilled water, was injected under the skin of a rabbit, 

 which weighed three pounds and six ounces and-a-half. As in the previous 

 experiment, the first effects observed were a number of restless, uneasy move- 

 ments, which occurred in eleven minutes. Soon afterwards, paralytic symptoms 

 appeared ; and in twenty minutes, these had so far advanced that the rabbit lay 

 flaccid on the abdomen, chest, and lower jaw, while irritation of the skin was 

 followed by extremely feeble movements of the head, or one or other of the 

 extremities. In twenty-four minutes, the head fell over on the side, and rested 

 thus on the table ; and the respirations were infrequent, shallow, and laboured. 

 After this, the respirations became greatly more infrequent and laboured, until 

 they altogether ceased, thirty -one minutes after the injection of the poison. 



VOL. XXV. PART II, 9 C 



