8^ Effects of Oxygen and other Gases 



very weak, and apparently losing its sensibility. Nearly a 

 quart of oxygen was added during the experiment, to makeup 

 for the rising of the water. About seven, having been in the 

 gas nearly six hours, it was convulsed and expired, and was 

 removed in five minutes without any sign of motion. On 

 opening the chest, the heart was in full action, and the dia- 

 phragm still. No venous blood was perceptible. The gas 

 remaining after the experiment rekindled a blown-out taper. 



N. B. In all these experiments the surface of the lungs ap- 

 peared much injected. The blood, also, was observed to be 

 very transparent, and to coagulate remarkably quick. The 

 right side of the heart was always much more filled than the 

 left. I am not aware of any other circumstances omitted to 

 be noticed as belonging to the experiments detailed. 



Some of the principal experiments undertaken for the purpose 

 of ascertaining the nature of the influence exercised by oxygen, 

 in its unmixed state, over the animal functions, having been thus 

 described, it will be perceived that, in some respects, my results 

 confirm those of others, but are yet opposed to many, and afford 

 also rather a novel view of the subject. At least, the authorities 

 into which I have looked do not appear to have anticipated 

 some of my conclusions. I may here observe, that experi- 

 ments, of the nature which I have cited, should not be 

 confined to small animals, such as mice, and birds of the 

 size of sparrows ; for they are not so well calculated as larger 

 animals to afford satisfactory and clear demonstrations when 

 their internal organs are to be examined. Therefore, feeling 

 it constantly necessary to appeal to the internal state of the 

 animal, I have selected accordingly rabbits, kittens, and gui- 

 nea-pigs, as the best adapted to my purposes, these being at 

 once sufficiently large and manageable. Many of the older 

 experimenters, as Dr. Priestley and others, deduce their con- 

 clusions from mice. Dr. Priestley found, that if the tempera- 

 ture of the bath was kept up, the mice lived longer than when 

 surrounded by a medium of a low degree ; and hence he drew 

 this inference — that the oxygen itself is not destructive. This, 

 however, appears to me to be an unwarranted inference, for 

 I did not find (although latterly the weather was extremely 

 severe) that the preservation of an elevated temperature made 



