36 THE THEORY OF IONS 



glycerine. In the digestion of fat by animals, the 

 fats are split up into a glyceryl radical and a fatty 

 acid radical ; the glyceryl radical is joined by 

 OH ions and forms glycerine ; the fatty acid radical 

 unites with ions of Na, K, or Mg, and forms stearate, 

 oleate or palmitate of those elements, in which 

 condition they are absorbed. After their diffusion 

 into the blood-stream or while in the interior of 

 cells forming a part of the alimentary system, the 

 glycerine and soap are again dissociated and their 

 radicals reunite to form fat. 



In biological processes heat is disengaged during 

 chemical action just as it is observed to be in 

 non-biological processes. Metabolism consists of 

 anabolic and catabolic changes in which the heat 

 disengaged is measurable in calories or heat units. 

 The consumption and oxidation of proteid, fat, and 

 carbohydrate results in the liberation of known 

 quantities of heat. Other chemical processes in an 

 organism also result in the liberation or consumption 

 of heat and energy which is not always considered 

 in problems of metabolism. The neutralisation of 

 an alkali, the conversion of organic acids to alkaline 

 carbonates, the reduction of proteids to urea or 

 other waste products, of fat to carbonic acid and 

 water, are all attended by the disengagement or 

 absorption of heat. This is in accordance with the 

 physical law that matter and energy are indestruct- 

 ible. When a chemical action takes place between 

 two substances the total quantity of matter and 

 energy remains the same. The equation C + 2 = 

 C0 2 shows only the rearrangement of the atoms, 

 i.e. that when 12 grammes of carbon are united 



