vpon the Animal System, flf 



such a difference in the experiment as was sufficient to account 

 either for the final result, or the general phenomena presented 

 to my notice. Both in the experiments conducted at a distance 

 from the fire, and without heating the bath, during a severe 

 frost, and in those wherein the temperature was kept up, the 

 action of the sanguiferous system continued some time after the 

 motion of the diaphragm had ceased, and a similar progressive 

 insensibility occurred. Possibly the final termination of life 

 may be quickened somewhat by extreme cold in and around 

 the bath, as the means of increasing the force of the debili- 

 tating cause. 



Another inference in Dr. Priestley's experiments is, that the 

 carbonic acid generated by the animal respiring oxygen, has 

 less effect upon a second animal placed under the glass than 

 on the first, from the greater vigour of the former coming fresh 

 out of the atmospheric air. But upon reference to my expe- 

 riments, this does not appear, no appreciable difference being 

 noticed. 



Lavoisier observed, in his early experiments, some indica- 

 tions of increased vascular action, but none in his latter inves- 

 tigations, nor indeed any change whatever. His first conclu- 

 sions, however, are most probably correct. 



Messrs. Dumas and Richerand observed a great degree of 

 pulmonary excitement when animals breathed oxygen during a 

 long time ; and M. Richerand remarks, that they consume no 

 more oxygen than when immersed in so much common air. 

 From the experiments of Dr. Beddoes, however, this conclu- 

 sion is controverted. And I am disposed to coincide with this 

 last author in the opinion he entertains, that the fact is not as 

 M. Richerand supposed, and that animals confined in the gas 

 become completely, as it were, oxygenated. Dr. Beddoes 

 observed the very florid injection of the lungs and pleura, 

 the long retention of contractility in the heart, the rapid coa- 

 gulation of the blood, and the very slight deterioration of the 

 gas, — all of which facts were so obvious in my experiments. 

 1 do not, however, feel disposed to refer the state of the lungs 

 and pleura to inflammation, as this author does ; but rather to 

 congestion, from inefficient respiratory action. 

 - Sir Humphry Davy also employed mice, and found that 

 they ultimately died when immersed in oxygen ; but he 



