lo Effects of Oxygen and other Gases 



of threie minutes ihduces restoration of their action and re- 

 covery of animation. 



VI. EXPERIMENTS WITH CARBURETTED HYDROGEN. 



In order to ascertain the effects of this gas, I placed a kitten 

 of about a fortnight old under a glass vessel carefully charged. 

 It made two or three rapid gasps, and fell dead in *a few seconds. 

 Having removed it, artificial respiration was employed, and it 

 Recovered. Another kitten of the same brood was similarly 

 affected ; but, being left about three minutes in the gas, it was 

 not resuscitated. On opening the thorax the heart was still, 

 the blood dark, the right ventricle full, the vessels of the brain- 

 nearly empty, and the lungs collapsed. Several sparrows im- 

 mersed exhibited . similar phenomena. This gas also appears 

 to enter into the circulation, darkening the blood, and destroy- 

 ing sensibility after a few waves of the deteriorated blood have 

 passed through the brain. 



VII. EXPERIMENTS WITH NITROUS GAS. 



Several sparrows were immersed in nitrous gas, and after a 

 few rapid gasps they fell dead. The heart was still, and did 

 hot contract on being irritated. Mice placed in the gas exhi- 

 bited the same phenomena. A young rabbit lived only a few 

 seconds in this gas. The blood appeared to have lost much 

 of its arterial character, the right ventricle was distended, and 

 the vessels of the brain and lungs were collapsed. 



The nitrous gas, as might be expected, seems to act directly 

 upon the centre of the nervous system, while it appears also to 

 suspend the contractility of the involuntary organs of motion. 



VIII. EXPERIMENTS WITH CARBONIC ACID GAS. 



Several sparrows being immersed in this gas, they died iii 

 somewhat less than three minutes, having gasped and struggled 

 violently. Upon disse.ction the brain and lungs appeared to be 

 collapsed, the right ventricle was distended with dark blood, 

 and the circulation was still. Some kittens of about a fortnight 

 old were next made the subjects of experiment. None of 

 them shewed any signs of life after three minutes' exposure to 

 the influence of the gas. At first they gasped and breathed in 

 a hurried manner, and then "fell insensible and motionless, after 



