OF ARTS AND SCIENCES. 



309 



On the Acidity of the substituted 3faIonic Esters, Acetacetic Ester, 

 and Ketones described in the preceding Papers. 



In order to determine the relative acidity of these substance*, their 

 action with the following reagents was studied: acid sodic carbonate, 

 sodic carbonate, ammonic hydrate, sodic hydrate. Each reagent was 

 added in aqueous solution to the solid organic substance, and, after 

 observing what took place, alcohol was added, and any change in the 

 behavior of the substance noted. All these experiments were tried at 

 the same time, great care being used to make the conditions as nearly 

 the same as possible. The results can be divided into those which 

 were perfectly definite, that is, where the differences consisted in the 

 fact that one compound formed a salt with the reagent, and another 

 did not ; and those depending to a certain extent upon my judgment, 

 in which the differences were only in the amount of salt formed, as 

 shown by the depth of color, or iu the quantity of alcohol necessary 

 to produce the salt. The differences of the first class can be described 

 most cleai"ly and succinctly by the following table, in which the sub- 

 stances are arranged in the order of their acidity, beginning with the 

 most acid. The columns correspond to the reagents, and the word 

 " Salt " indicates that a salt was formed, as shown by the color imparted 

 to the solution, or solid. 



* No salt was obtained from IV. with aqueous sodic carbonate, but I ascribe 

 this to a mistaken observation, probably due to the difficulty in moistening the 

 ketone with the aqueous solution. 



