upon the Animal System. 5. 



of carbonic acid sufficient to extinguish a lighted paper instantly, 

 and to destroy animal life in a few seconds. 



But, when the contents of the oxygen jars were tested after 

 the continued respirations of animals in them, an extinguished 

 taper was uniformly re -illuminated ; and other animals, then 

 placed under the jars, continued to live some time, and very 

 much as those did which were originally immersed. Small 

 collections of the gas were made, for the purpose of testing the 

 contents of the jars with a lighted taper; and, when the gas 

 was no longer required, the main bulk of the oxygen, also, was 

 similarly tested, and with the same results, as to the proportion 

 remaining being sufficient for the support of life and combus- 

 tion ; although, when portions were washed with lime-water, 

 they exhibited the presence of some carbon, by a white turbid 

 appearance. 



Having premised these circumstances, I shall now proceed 

 to detail some of the principal experiments which I made at 

 different periods, and which were undertaken entirely indepen- 

 dent of any previous anticipation of the results, and uncon- 

 nected with a wish to support any theory whatever upon the 

 subject ; and rather, indeed, as a mere matter of curiosity, to 

 endeavour to place upon a more satisfactory footing certain 

 points which have appeared to myself and others to be imper- 

 fectly understood hitherto. 



JSXPERIMENT I. 



A kitten, of about ten or twelve days old, was immersed in 

 pure oxygen, and suffered no apparent inconvenience during 

 the first hour, but afterwards its respirations were quickened, 

 and the sanguiferous system was much accelerated. To this 

 succeeded a state of debility, and gradually a total insensibility, 

 with depression of the voluntary powers, and ultimately the 

 entire loss of them. The eyes became glazed ; and, after long 

 and slow inspirations, the diaphragm alone was seen to contract 

 slowly and feebly at distant intervals. Having continued some 

 time in this state, the animal was then removed, and very 

 shortly recovered in the open air — having been immersed three 

 hours, the quantity of gas being about one gallon. Some hours 

 elapsed before its strength was regained, but it ultimately reco- 

 vered altogether. 



B 2 



