245 



tion, continuance, and suspension of living action in 

 the inferior classes of animals. The phenomena of 

 incubation, and the evolution of viviparous animals, 

 would next have engaged his attention ; and these 

 would have been succeeded by an endeavour to ex- 

 plain the phenomena of respiration, as connected 

 with the appearances and properties of the blood, 

 and the distribution and maintenance of animal heat. 

 A short view of some pathological states of the sys- 

 tem, arising immediately out of the preceding discus- 

 sions, would then have concluded the whole. 



This enumeration, it is obvious, comprehends 

 some of the most curious and important problems 

 in physiology j and many of them are of such a na- 

 ture as not to admit, in the present state of science, 

 of completely satisfactory proof. All, therefore, 

 that could be hoped for, would be a probable ex- 

 planation, essentially different, indeed, from all the 

 theories which have been hitherto proposed, but 

 perfectly consistent with the view already ta- 

 ken, and supported and illustrated by the aid of 

 such additional facts and experiments as a farther 

 prosecution of the subject would necessarily intro- 

 duce. 



As, however, the whole of the author's reason- 

 ing would be founded on the principles which, in 

 this publication, he has attempted to establish, it is 

 evident that the truth or falsity of the principles 

 themselves, ought first to be ascertained. With 

 this view, he submits them to the judgment of the 

 public in their present form. If they shall be fa- 

 vourably received, and the author be in consequence 

 encouraged to proceed, he will endeavour to exe- 



