viii, a, i Gibbs, Williams, Galajikian: Methyl Salicylate IV 



19 



If we take the values K 2 =0.0053 and K 3 =0.0223, K=6.36 and 

 K 1 =0.1605. This value of K agrees very well with the value 

 calculated by Goldschmidt. His whole calculations, however, 

 ignore the possibility of any saponification of sodium methyl 

 salicylate taking place. While such a supposition was not jus- 

 tified by any facts at his command, yet it proved to be nearly 

 true. That is, the reaction velocity constant of the saponifica- 

 tion of sodium methyl salicylate proves to be only about 0.1605 

 or about 1/40 of that of methyl salicylate. His error, therefore, 

 did not prove great enough to invalidate his mean numerical 

 value for Kx, although the constancy of his values left much 

 to be desired. 



It is rather startling to find that sodium methyl salicylate is 

 saponified so extremely slowly as compared with the free ester. 

 In the following paper, 17 an investigation is described which 

 throws some light upon these facts. 



VI. HYDROLYSIS OF METHYL SALICYLATE WITH SODIUM CARBONATE 



Methyl salicylate was saponified with a pure, freshly prepared 

 solution of 0.3998 normal sodium carbonate. The temperature 



> 30 eo so no no no go ko zk 300 



330 



360 



3SO 



420 



4S0 



400 



m 



S40 



sn 



So 















..t 





























* / 





























































* / 

























































































































I /: 





























































tH 

















!#■* 

























IK 













s@ 



1' 



























> 













"^7, 



,lh)l 



ill". 



'lii- 







































Tb>* 













































«9 















ttM 











































































































































































































































































































t 





























1700 UK HOO 3C60 4100 4300 SW tOOO SSOO JIM 1800 3400 



10200 10800 11*00 



Fig. 3.— Saponification of methyl salicylate and benzoate with NaOH (above) 



and Na 2 C03. 



" Gibbs and Pratt, This Journal, Sec. A (1913), 8, 33. 



