726 DRS CRUM BROWN AND FRASER ON THE CONNECTION BETWEEN 



In this experiment, likewise, we failed in discovering the slightest evidence of 

 exaggeration in the reflex excitability, or any spasmodic symptom. 



These descriptions are sufficient to show that iodide of dimethyl-conium acts 

 simply as a paralysing agent, and that it does not produce any spasmodic effects 

 in rabbits. 



The general symptoms that appear in frogs after the administration of a fatal 

 dose are illustrated in the following experiment. 



Experiment CVII. — Having dissolved one-tenth of a grain of iodide of dimethyl- 

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

 at the right flank of a frog, weighing 150 grains. In two minutes and thirty 

 seconds, a slight degree of paralysis was observed in the anterior extremities, 

 which were scarcely able to support the chest ; and the jumping movements 

 were now less active than before. Quickly, the paralysis became more decided ; 

 until at six minutes, the frog was lying on the abdomen and the lower jaw. The 

 respiratory movements of the chest had now ceased, while those of the throat 

 continued for several minutes longer. In nine minutes, irritation of the skin 

 produced merely feeble movements in the posterior extremities ; and in thirty 

 minutes, it was impossible to excite any reflex movement whatever, even by 

 severe irritation of the skin. The right sciatic nerve was now exposed in the 

 thigh, and stimulated by an interrupted galvanic current, but no muscular con- 

 tractions were thereby produced, although the muscles contracted actively when 

 the electrodes were directly applied to their surfaces. At this time, the heart's 

 impulse was of fair strength, and the beats occurred twenty- two times in the 

 minute. 



On the following day, the frog was found to be in the condition last noted : 

 but on tbe third day, the contractility of the muscles had disappeared, and the 

 heart's contractions had ceased. 



In many other experiments on frogs, the same general phenomena were 

 observed. The spasmodic symptoms to which we have drawn attention in our 

 description of the effects of conia and of methyl-conia were entirely absent in 

 our experiments with iodide of dimethyl-conium; and, accordingly, the symptoms 

 we observed were those of paralysis only. We made several experiments to 

 determine what structures are influenced in the production of this paralysis. 



Experiment CVIII. — Immediately after ligaturing the blood-vessels at the 

 upper part of the right thigh of a frog, weighing 192 grains, we injected three- 

 twentieths of a grain of iodide of dimethyl-conium, dissolved in four minims of 

 distilled water, under the skin of the left flank. In one minute thereafter, the 

 movements of the frog had become somewhat feeble, the poisoned extremities 

 being obviously weakened. In two minutes and thirty seconds, the frog lay on 

 the abdomen and lower jaw, apparently unable to execute any voluntary move- 

 ments with any part of the body except the right (non-poisoned) posterior 



