38 THE THEORY OF IONS 



ascertainable, and is called the heat of neutralisation, 

 as in the following thermo-chemical equation. 



HC1 + NaHO = NaCl + H 2 + 13736 or 13'736 calories. 



When glycero-phosphoric acid is neutralised by 

 sodium hydroxide there is developed + 14-95 

 calories for the first equvialent, +13-75 for the 

 second, and +0-1 for the third equivalent; when 

 potassium hydroxide is substituted the values are 

 + 15-9, +13-9 and +0-4 calories for the same 

 equivalents ; and when phosphoric acid is used the 

 caloric equivalents are practically the same.* 



In all biological processes heat is developed in a 

 similar manner, that is by the transformation of 

 the energy possessed by ions in excess of that 

 retained by the combined molecules. When 

 1 gramme of fat is oxidised to C0 2 and water, the 

 potential energy of the fat is transformed into 

 kinetic energy, and is equivalent to the chemical 

 force necessary to form C0 2 and water + 9, 300 or 

 9-3 calories or units of heat. Proteid and carbo- 

 hydrate are not directly reduced to the low stage of 

 chemical constitution in which they leave an 

 organism ; but the amount of energy lost in the 

 form of heat is the same as if they were directly 

 transformed. 



Under the influence of living matter, substances 

 more complex than sugar or starch are formed. 

 Organic compounds arise which contain N, S, P, 

 and other elements in more and more complex 

 combination, until finally protoplasm is formed. 

 But the formation of nitrogen compounds can only 



* Imbert and Belugon : Compt. Eendus, 1897, cxxv., 1040. 



