180 DRS CRUM BROWN AND FRASER ON THE CONNECTION BETWEEN 



In the autopsy, the heart was seen acting, one minute after death, at the rate 

 of 160 beats per minute, and the intestinal peristalsis was found to be normal. 

 The motor conductivity of the sciatic nerves was retained at three minutes after 

 death, but it had disappeared in other four minutes ; while the idio-muscular 

 irritability was not lost until more than sixty minutes after death. 



For internal administration, we followed the plan already described. No 

 symptom whatever was observed when the large dose of twenty grains was 

 introduced into the stomach of a rabbit. We did not, accordingly, consider it 

 advisable to continue this method of administration any further. 



As we have already stated, and as the experiments we have narrated clearly 

 show, the principal effects that are caused by codeia are convulsions and hypno- 

 tism. In our experiments with rabbits, the latter effect was manifested only when 

 large doses were introduced into the stomach. It was not seen when this alkaloid 

 was administered by subcutaneous injection, probably because sleep was then 

 prevented by the spasmodic starts and convulsions that were so prominently 

 caused. We learn from our experiments that the iodide and sulphate of methyl- 

 codeium have a very different action from codeia. We have never observed any 

 hypnotic effect follow their administration, and, in place of convulsions, we have 

 seen that they produce paralysis. This, indeed, is the only marked symptom that 

 follows their administration, and it is apparent that it does not depend on an 

 effect on the muscles, nor on the cerebral lobes. We endeavoured to determine 

 the exact cause of this paralysis by experiments with localised poisoning on frogs. 



Experiment XCVIII. — Having tied the right sciatic artery and vein of a 

 frog, weighing 722 grains, one grain of sulphate of methyl-codeium, dissolved in 

 distilled water, was injected into the abdominal cavity. In fifteen minutes, 

 voluntary movements had disappeared, and the frog was lying on the abdomen, 

 in a flaccid state. In thirty minutes, pinching of the skin with a pair of 

 forceps excited movements in all the limbs, but these were most energetic in 

 the right posterior extremity. In one hour and thirty minutes, similar stimula- 

 tion excited no movement except in the right posterior extremity (where the 

 vessels had been tied). The application of an interrupted galvanic current to the 

 exposed trunk of the left sciatic nerve was now followed by active movements 

 of the right leg, but of no other part ; while, at the same time, the muscles in the 

 poisoned regions freely responded to galvanic stimulation directly applied to them. 

 In two hours and forty minutes, the condition was the same, and, judging from 

 the cardiac impulse, the heart was contracting at the rate of thirty-five per minute. 

 We need not again enter into the reasons for concluding from such an experi- 

 ment that the paralysis caused by sulphate of methyl-codeium is due to an action 

 on the motor nerves. As has been already done with the corresponding sub- 

 stances treated of in the previous portion of this paper, we, in the next place, 

 determined what portion of the motor nerve — trunk or periphery — is acted on. 



