Q The Philippine Journal of Science 1913 



is not split by boiling in dilute acid solution. This proves that 

 the carbon dioxide is a result of the alkaline hydrolysis and 

 probably from salts, rather than from the ester itself. 



A further proof of this statement is found in the following 

 experiment. A sealed tube containing salicylic acid and N/10 

 sulphuric acid was heated on a steam bath in the dark for eight 

 months without the formation of any color and with no appre- 

 ciable internal pressure. The absence of color is an indication 

 that no carbon dioxide is split off. If phenol were formed, it 

 is probable that some color would be produced by the oxidation 

 of phenol to quinone. 12 The extent to which the splitting of car- 

 bon dioxide takes place in alkaline solution is so small as to render 

 carbon dioxide formation a negligible factor of the rate of sapon- 

 ification at ordinary temperatures. 



II. THE FORMATION OF SODIUM METHYL SALICYLATE AND ITS 



HYDROLYSIS 



The influence of sodium methyl salicylate on the rate of sapon- 

 ification depends upon the degree of hydrolytic dissociation of 

 the salt in water solution. Goldschmidt has calculated the value 

 for r in the following equilibrium equation to be 0.001. 



C'NaOH X OceEU-OH-COOCH 



«? a* 



Cc 6 H 4 -ONa-COOCH 3 



His method was to determine the affinity constant of the phenol 

 group of the ester and to obtain the hydrolytic constant of the 

 salt from the relationship 



K 



w 



K XK" 

 B E 



in which K , K , and K are the affinity constants of water, 



w B E 



the base (diethylamine), and the ester, respectively. It was 

 thought advisable to determine the hydrolytic constant of sodium 

 methyl salicylate by a more direct method. If methyl salicylate 

 be dissolved in pure aqueous sodium hydroxide, after the first 

 moment of time, the following substances are present, the con- 



" The compounds which cause the red color in phenol, by Gibbs, This 

 Journal, Sec. A (1908), 3, 361, and The oxidation of phenol, ibid. (1909), 

 4, 133. 



