ORGANIC PRINCIPLES. 09 



malia at all periods of life. He extracted about three-fourths 

 of a grain from the perfectly healthy lungs of a female who 

 was guillotined. It has not been found in other situations. 



Its function is connected with respiration. The carbon- 

 ates and bicarbonates of the blood, in passing through the 

 lungs, are in part decomposed by pneumic acid, a certain 

 portion of the carbonic acid in the expired air being evolved 

 in this way. 



Pneumate of Soda is produced by the action of pneumic 

 acid upon the carbonates of soda in the blood, and is found 

 in the blood which passes through the lungs. It is not dis- 

 charged from the body, undergoing in the system some 

 transformation with which we are unacquainted. 



ORGANIC NITROGENIZED PRINCIPLES. 



Principles of this class differ essentially from all the other 

 constituents of the body. They are the only elements en- 

 dowed with what are called vital properties, and upon them 

 depend all the phenomena which characterize living struc- 

 tures. This important fact cannot be too fully insisted upon. 



All the vital phenomena which take place in the l)ody 

 depend primarily upon organic nitrogenized principles, which 

 are the only elements in the organism endowed with life. 



By a tissue or fluid endowed with life is meant : 



A combination of proximate principles ivhich has the prop- 

 erty, under certain conditions, of appropriating materials for 

 its nourishment and regenerating itself, to repair the continual 

 destruction or waste to which all living bodies are subject. 



This, which is the great process of NUTRITION, is going 

 on from the beginning to the end of life; its phenomena 

 are distinct from those which take place in inert com- 

 pounds, and are called vital. Take, for example, the nutri- 

 tive processes which take place in the muscles or the bones. 

 In common with all parts of the body, these tissues are 

 continually undergoing waste. The circumstances under 



