$16 Dr, Davy’s observations and experiments , &c. 
deserving of particular attention. The theory which is now 
most generally adopted, is recommended by its simplicity, but 
is not well supported by the analogies and facts of physio- 
logy, which seem to favour the doctrine of the absorption of 
oxygene into the blood, and the evolution of carbonic acid ; 
and that , perhaps, not in the air-cells of the lungs alone, but 
likewise along the whole tract of the primae viae, and over 
the whole of the external surface of the body. 
Fort Pitt, Chatham, June 17, 18Z3. 
