714 DRS CRUM BROWN AND FRASER ON THE CONNECTION BETWEEN 



appeared, the respirations had become mere infrequent gasps, but the heart was 

 contracting at the rate of 120 beats in the minute. Death occurred thirty-two 

 minutes after the administration. The pupils were frequently observed ; they 

 retained the same diameter during the experiment as they had immediately 

 before it, but on the occurrence of death they contracted considerably. 



After death, galvanic stimulation of the left sciatic nerve caused active move- 

 ments in the left leg, and also well-marked reflex movements in the right. The 

 exposed heart was contracting, six minutes after death, in proper rhythm, and 

 at the rate of 100 beats in the minute. 



In our experiments with frogs, we found that a dose equivalent to the 44 * 00 t fa 

 of the weight of the animal was sufficient to cause death. In the two experi- 

 ments with Dr Christison's conia, which we shall now describe, somewhat 

 larger doses than that above mentioned were administered, the complete physio- 

 logical action being but slowly developed with small doses. 



Experiment LXI.— One-tenth of a grain of hydrochlorate of Dr Christison's 

 conia was dissolved in four minims of distilled water, and injected under the skin 

 at the right flank of a frog, weighing 300 grains. The frog jumped about actively 

 until five minutes after the administration, when it appeared to experience some 

 difficulty in moving about, and it was observed that this difficulty was chiefly 

 due to tonic spasm of the anterior extremities. This spasm, though by no means 

 powerful, was sufficient to retain the extremities in a constrained perpendicular 

 position, and in extreme extension, during the five minutes that succeeded its 

 first appearance. In ten minutes, the frog was unable to jump, and it lay on the 

 abdomen and chest ; while the respirations had now ceased. In twenty-five 

 minutes, it was perfectly flaccid, and the head rested on the table, but the heart's 

 impulse was still well marked, and the rate of its contractions was forty per 

 minute. At frequent intervals, the two posterior extremities were somewhat 

 suddenly pushed out to extreme extension, and after remaining in this posi- 

 tion, for one or two seconds, again partially flexed. In fifty minutes, these 

 extension movements of the posterior extremities ceased, and irritation of the 

 skin now caused merely faint twitches of the toes. In one hour and thirty 

 minutes, it was impossible to excite any reflex movement whatever; and on 

 applying galvanic stimulation to the trunk of a sciatic nerve, it was found that 

 the motor conductivity was completely suspended. The heart was at this time 

 contracting thirty-seven times in the minute, and the contractility of the striped 

 muscles was unimpaired. On the following day, the frog was still in a flaccid and 

 motionless state. The heart was contracting twenty-two times in the minute, 

 and the nerves and muscles were in the condition last described. On the morning 

 of the third day, rigor mortis was established. 



In the next experiment, one limb was protected from the direct influence of 

 the poison. 



