24 



LIBERATION OF ENERGY 



The value ioiiiul by direct combustion is 3-7, a considerably higher 

 figure. A difiiculty, however, occurs with proteins. 



In the case of carbohydrates and fats the end-products are 



Fig. 3. — Bertlielot-Mahler Bomb Calorimeter. 

 A. Boint) or autoclave (see Fig. 102). 

 H. Insulating vessel. 



G. Manometer on stand with union.s to fix to oxygen cylinder and to bomb (at S, Fig. 102). 

 D. A steel mould for making pellets from the material to be burned. 



those of complete oxidation, but in the case of proteins, the 

 final results of metabolism are not substances of the lowest 

 energy content, i.e. protein is not completely oxidised. Further, 

 these protein end-products are eliminated in solution, and this 



