METHYL SALICYLATE II. 



359 



cubic centimeters of water, conductivit_y 2.8X10"" at 30°, and 0.6 cubic 

 centimeter of methjd salicylate, which was agitated in a sealed tube at 

 30° ±1°. This determination is probably as reliable as any that have 

 been made and represents a fairly accurate average. Electrodes were 

 sealed into this cell and measurements of the conductivity of the aqueous 

 phase showed that it had changed but little during the last seven days 

 of the ten days' agitation. 



N 

 Table II. — Soluiility of methyl sahcylate in — sulphuric acid solution (tem- 

 perature, 30°) . 



No. 



T 



S 



Q 



1 



66 



10 



0.077 



2 



139 



10 



.077 



3 



354 



10 



.076 



4 



978 



5 



.078 



It is to be expected that the solvents will show a constantly increasing 

 capacity for dissolving the ester as the hydrolysis proceeds, owing to 

 the slowly increasing concentration of the methyl alcohol, one of the 

 products of the hydrolysis. The rate of the increase in the concentration 

 of the ester is very slow as shown from the tube of distilled water which 

 had been agitated for three months with the solute. The concentration- 

 of the methyl salicylate had increased to 0.093, and from the determina- 

 tion of the salicylic acid the concentration of the meth3'l alcohol in the 

 aqueous solution was found to be approximately 0.03 gram per 100 

 cubic centimeters. Since the rate of hydrolysis in acid solutions is more 

 rapid than in water, it is probable that the increase in the concentration 

 of the ester will be more rapid in the former than in the latter. 



SUMMAEY. 



N 



sul- 



The solubilities of methyl salicylate in pure water and in 



phuric acid solution at 30° have been determined. The average of a 

 number of determinations is 0.074 gram per 100 cubic centimeters for 

 the former solvent and 0.077 for the latter. 



Slight improvements in the colorimetric method for determining 

 methyl salicjdate as given in the first paper are described. 



