viii, a, i Gibbs, Williams, Galajikian: Methyl Salicylate IV 13 



revolutions per minute. The ester in this case did not emulsify, 

 but remained in one large globule, which at each revolution 

 rolled from one end of the tube to the other. 



A second experiment using five times the theoretical equivalent 

 of ester was carried out simultaneously with hydroxide solution 

 of the same strength and at the same temperature, 30°. These 

 tubes were revolved at the rate of 120 revolutions per minute, 

 which was sufficiently vigorous to break up the ester into fine 

 globules which for the most part remained suspended in the 

 aqueous solution. The following results were obtained on 

 titration : 



■t- . ,. T.T i Experiment No. 2. 



Experiment No. 1. Five times the equiva- 



Eqmvalent amount of l t amount of 



ester; 20 revolutions 120 revolutions 



per minute. per minute . 



(a) 0.0278 0.0280 



(b) 0.0280 0.0283 

 Average 0.0279 0.02815 



While the amount transposed in experiment 1 was found to be 

 slightly less, the difference is not greater than experimental 

 error. Contact action is therefore excluded. 



V. THE SAPONIFICATION OF METHYL SALICYLATE 



When methyl salicylate is shaken with aqueous sodium hydrox- 

 ide, there exist in solution the following substances, the con- 

 centrations of which are represented by the symbols following 

 them: Free base (n), free ester (e), sodium methyl salicylate 

 (m), di-sodium salicylate (d), and mono-sodium salicylate (s). 

 If such a reaction mixture is titrated with a strong acid, using 

 Congo red as an indicator, all the sodium which exists in the 

 carboxyl group will be titrated as combined, while that existing 

 as free base or substituted in the phenol group will be titrated 

 as free. 13 That is, if a represents the total sodium and x the 

 combined sodium, 



x =s -f d (3) 



a — x = m — n — d. (4) 



We have also established the relationships 



(l) 

 = r=0.03 (3) 



rn 

 ns 

 ~8 

 e =0.005 (7) 



" Poirrier blue is the only known indicator for the acidity of phenol. 

 Imbert et Astruc, Compt. rend. Acad. sci. (1900), 130, 35. 



