THE SCIENCE OF HAPPINESS 



destruction of a portion of organic tissue, and by 

 elaborate chemical transmutations. Such chemical 

 changes, stated in the least technical language, con- 

 stitute a virtual burning of fuel. Oxygen, brought 

 from the lungs by the red blood corpuscles, unites with 

 certain matter of the tissues, with a resulting liberation 

 of energy, partly measurable as muscular force, and 

 partly as heat. 



The product of this oxydation ashes of this com- 

 bustion are no longer available for the purposes of 

 bodily nourishment or energy-production; indeed, 

 they are not merely useless, they are positively detri- 

 mental. If allowed to accumulate in the tissues or the 

 blood, they are noxious poisons, quickly overpowering 

 the organism and destroying life. The uraemic poison- 

 ing of certain kidney diseases furnishes a well-known 

 case in point. 



It is familiar experience that the body may exist for 

 long periods without exerting the muscles; so it would 

 be possible, on this score, to reduce the necessity for 

 fuel almost indefinitely though not quite indefinitely, 

 since heart muscles and the muscles of the respiratory 

 and digestive systems are perpetually active. But, 

 however inactive, the organism is of necessity giving 

 off heat (unless kept in a medium at a temperature that 

 would be unendurable) and this heat must be supplied 

 by the burning of fuel, else the bodily temperature as a 

 whole would quickly sink below the level at which life 

 may be maintained. 



One of the most remarkable of physiological facts 

 is the narrow range of temperature maintained by the 



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