METHYL SALICTLiVTE I. 105 



« 



ing in a flask with refliix condenser attached, on a steam bath, with a 

 large excess of strong caustic alkali solution. 



After saponification is complete, half an hour usually being sufficient, 

 the condenser is detached and the heating is continued untU all of the 

 chloroform is expelled. The solution is then diluted to a known volume 

 and the salicylic acid determined in alicjuot portions. The followiag 

 quantitative experiments serve to show the manipulation and the accuracy 

 of the method. 



1.02.50 grams methyl salicylate were dissolved in 50 cubic centimeters of 

 cliloroform and 10 cubic centimeter portions saponified with 10 cubic centimeters 

 of a 25 per cent solution of caustic potash. After evaporation of the chloroform, 

 the residue was diluted to 100 cubic centimeters and 2 cubic centimeter portions 

 made acid with sulphuric acid (1 to 3) and extracted four times with small 

 amounts of chloroform. The chloroform was evaporated in a vacuum desiccator, 

 and the residue dissolved in 100 cubic centimeters hot water. The salicylic acid 

 determined colorimetrically " in this solution gave 1.0640 grams methyl salicylate. 



1.2277 grams treated as above gave 1.2667 grams. 



0.156S grams dissolved in 10 cubic centimeters of a 25 per cent solution of 

 sodium hydroxide gave — 



I. ,11. 



0.1499 gram. 0.1565 gram. 



THE HYDEOLYSIS OF METHYL SALICYLATE WITH SODIUM CARBONATE 

 AND SODIUM HYDROXIDE.^^ 



N N 



Solutions of sodium hydroxide, approximately — and — , were made 



by dissolving clean, metallic -sodiimi in distilled water from which the 

 gases had been exjDelled by boiling. These were agitated in bottles with 

 an excess of methyl salicylate and 10 cubic centimeter jDortions were 

 removed and titrated at intervals.^'' The reactions were all carried 

 on at 30°, with variations not exceeding ±1°. This is the prevailing 

 temperature in this locality. 



In the following tables, t is the time expressed in hours, v the volume 



N 

 of — sulphuric acid used to neutralize 10 cubic centimeters of the reac- 

 tion solution at time t, and x is the percentage of sodium hydroxide 

 which has been used in the reaction. 



^■' Color comparisons made with a wedge colorimeter. 



^^ More extended investigation of the hydrolysis of methyl salicylate with 

 acids, alkalies and water and the catalytic action of tropical sunlight is being 

 carried on and will probably be presented in a later paper. The cases of sodium 

 carbonate and hydroxide are here taken up merely to show the basis of the 

 analytical methods. 



•" Ostwald-Luther : Physiko-Chemische Messungen, Leipzig (1902), 447. 



