144 ADDITIONAL NOTES. 



February 5. 1821. 



A guinea-pig was placed under the bell-glass 

 employed in my experiments on animal heat. 

 The bell-glass was left open above, while a small 

 retort containing sulphuric ether was adapted to 

 the tube communicating with the lower part of 

 the apparatus. A lamp was placed below the 

 retort, so as to make the ether boil. The vapour 

 of the ether thus became mixed with the air in 

 the bell-glass, a portion of it becoming con- 

 densed on the inner surface of the latter, and 

 on that of the wooden stand on which it was 

 placed. 



In two minutes after the experiment was 

 begun the animal moved about briskly, as if 

 affected by the first symptoms of intoxication. 

 In two minutes more he lay on one side in a 

 state of insensibility, but still breathing. He 

 continued in this state, breathing at longer and 

 longer intervals, for six minutes, when respira- 

 tion had entirely ceased. After two minutes 

 more he was removed from underneath the bell- 

 glass. Though he was apparently dead the heart 

 could be felt beating feebly through the ribs. 

 An opening having been made in the trachea, 

 the lungs were now artificially inflated. Only a 

 few seconds had elapsed before there was a spon- 

 taneous effort to breathe, and the pulsations of the 

 heart were more distinct. When the artificial 

 respiration had been kept up for some minutes 

 longer it was discontinued. The animal now 

 breathed naturally, and gave some slight indica- 



