upon the Animal System, 13 



A rabbit of two or three weeks old was immersed in nitrogen, 

 and fell dead, after gasping and struggling, in about thirty, 

 seconds. Two or three minutes having elapsed, it was removed, 

 and the blood vessels of the lungs and brain were collapsed, 

 the right ventricle of the heart was full of dark blood, and its 

 irritability was not extinct. Coagulation in all these cases 

 occurred, but not immediately. Another rabbit of the same 

 brood fell dead also in about thirty seconds, and, being removed, 

 was resuscitated and lived. 



From the phenomena exhibited in these experiments, it 

 appears, that undiluted nitrogen is quickly fatal to animal life, 

 suspending the functions of the brain almost instantaneously, 

 as soon as a few waves of blood have passed through that 

 organ ; but, that the lungs are perfectly capable of receiving 

 and circulating the gas during a few seconds, until the sensibi- 

 lity of the nervous system becomes destroyed. It is neverthe- 

 less known, that nitrogen is largely separated from the atmos- 

 pheric air absorbed in ordinary respiration, and that its supply 

 is necessary to the animal economy. 



Ill, EXPERIMENTS WITH CHLORINE. 



Some glass vessels being charged with chlorine, several mice 

 were successively immersed in this gas, and they fell dead in 

 less than thirty seconds. On opening these animals, the heart 

 was found palpitating in each, and the peristaltic motion of 

 the intestinal canal continued, and was kept up by irritating ifc 

 with a probe. The vessels of the brain were collapsed. The 

 lungs were tinged with the yellow colour of the gas, and the 

 peculiar odour of chlorine was perceptible throughout their 

 structure. Several sparrows were similarly immersed and ex- 

 hibited the same phenomena. Coagulation took place as usual 

 under ordinary circumstances. 



A rabbit of two or three weeks old was immersed in chlorine, 

 and it died in less than half a minute. On opening the thorax 

 the heart was found acting freely, and on puncturing the aorta 

 the blood jetted forcibly out to a considerable distance. The 

 peristaltic motion of the bowels was also going on. The vessels 

 of the brain were in a collapsed state. The lungs were very 

 much distended, and they were tinged with yellow ; and when 

 removed from the chest to, a distance they emitted the odour of 



