880 WASTE OF THE BODY AUGMENTED 



are united with the different organs is expended, 

 they successively fall from their places,* when 

 they are taken up by the absorbents, conveyed 

 into the general circulation, and thence through 

 the lungs, where the greater part of their carbon 

 and hydrogen is given off, in combination with 

 oxygen. In the mean time, the compounds of 

 nitrogen, oxygen, soda, lime, and other salts, 

 together with the small remainder of carbon and 

 hydrogen not employed in respiration, pass off 

 chiefly through the kidneys in the form of urine, 

 and partly through the bowels and skin. From 

 which it follows, that every muscular contraction, 

 every thought, feeling, or emotion of the brain, is 

 attended with a loss of the vital heat by which all 

 the organs are enabled to perform their respective 

 functions, and of the substance by which they 



tween its particles, as that it is generated by muscular contrac- 

 tion, secretion, nutrition, or any other species of vital action. 

 Moreover, as the power of an organ when once exhausted, cannot 

 be again restored, without an additional supply of animal heat 

 from the blood, so has it been found, that when the ductility of 

 iron has been diminished or destroyed by forcing out a portion of 

 its latent caloric by hammering, it cannot be restored until resup- 

 plied with what it had lost by exposing it to the fire. 



* The extent to which the vital cohesion of the solids is dimi- 

 nished by violent exercise, is strikingly illustrated by the fact, that 

 the flesh of a stag hunted to death is far more tender than if bled 

 to death, and undergoes putrefaction in a much shorter time, as 

 stated by John Hunter. And it was observed by Autenreith, that 

 a muscle taken from an animal before its irritability had ceased, 

 putrified much sooner if stimulated to frequent contractions, than 

 if left at rest. (Miiller's Elements, p. 52.) 



