2 The Philippine Journal of Science 1913 



drogen carbonate is negligible since the concentration of sodium 

 hydroxide in the solution is very small. 4 



Preliminary comparisons of the rate of saponification of the 

 ester with sodium hydroxide, sodium carbonate, and sodium 

 hydrogen carbonate showed that the first was fairly rapid, the 

 second was very slow, and the last had an almost infinitesimal 

 speed. 



Calculations, by means of the formula, 5 



, /dC\ , /dC\ 



IN - logC v -logC v ' 



from two different sets of data, gave the values 0.994 and 1.028, 

 average 1.011, which signified that the reaction between an 

 excess of methyl salicylate and sodium hydroxide was of the 

 first order. The velocity constants obtained were very un- 

 satisfactory and since, at that time, they were not necessary 

 for the purposes in hand, they were not mentioned and no 

 explanation was attempted. In this paper much of the pre- 

 liminary work has been repeated with greater accuracy, the 

 investigation extended to include methyl benzoate and the methyl 

 ether of methyl salicylate, and explanations of the peculiar 

 phenomena involved are offered. 



Methyl salicylate is capable of a variety of reactions, several 

 of which occur simultaneously in alkaline solution, and affect 

 the velocity of saponification more or less markedly. Of these, 

 the following have been noted and studied, and are doubtless 

 the most important if not the only reactions occurring in alkaline 

 solution: (1) The splitting of the carboxyl group with for- 

 mation of carbon dioxide, methyl alcohol, and phenol; (2) the 

 formation of a colored compound in presence of sunlight and 

 oxygen; 6 (3) the substitution of a metal atom for the hydrogen 

 of the phenol group with formation of a salt of the methyl ester, 

 which in water solution is capable of a considerable hydrolysis. 



The splitting with formation of carbon dioxide is a reaction 

 which salicylic acid undergoes very readily at higher temper- 

 atures, 7 but which had not been noted in the case of the methyl 



* The significance of the concentration of sodium salt of methyl salicylate 

 in the solution will be pointed out later in this paper. This factor is 

 negligible in the analytical separation. 



' Van't Hoff, Vorlesungen fiber theoretische und physikalische Chemie. 

 Braunschweig (1901), 1, 194. 



* Methyl Salicylate III, loc. cit. 



'Meyer u. Jacobson, Org. Chem. (1894), 2, 629. 



