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and have noticed the diminution of bulk which it 

 suffers in respiration : we have attempted to ascer- 

 tain the volume of air ordinarily inspired by man, 

 and to appreciate the relative proportions which ex- 

 ist in the lungs in the different states of those or- 

 gans : we have laboured to prove, that the actual 

 bulk of air in the lungs must, and does vary, accord- 

 ing to the various conditions of the system, to the 

 circumstances in which respiration is carried on, the 

 composition of the air itself, and the mode in which 

 it is breathed ; deducing from the whole, that the 

 bulk of residual air in the lungs, at any period of 

 life or of death, must be calculated always with re- 

 ference to these considerations. We have spoken 

 generally against the entrance of any part of the in- 

 spired air into the blood-vessels of the lungs, by the 

 function of absorption, as unsupported by anatomi- 

 cal fact ; and have held its supposed attraction by the 

 Mood through the coats of those vessels as inconsis- 

 tent with the acknowledged laws of chemical affinity : 

 we have denied that any proof exists of air being, at 

 any time, present in healthy blood, and have demon- 

 strated its fatal effects whenever it gains admission 

 into thaf fluid : we have examined the experiments 

 and arguments of Mr Davy, in favour of an absorp- 

 tion of aeriform fluids by the blood, and have found 

 them wholly insufficient, and leading to conclusions 

 which are completely at variance with the established 

 laws of the animal system. Lastly, we have adduced 

 arguments against the possibility of the inspired air 

 being decomposed during the circulation of the 

 blood ; and have assigned reasons in proof of its ac- 

 tual decomposition in the lungs, and even in the 



