M. H. Bleibtreu on Cumarine. 487 



In per-centage, — 



Carbon 40*00 



Hydrogen .... 2*64 



II. 0-8237 grm. of the salt gave 0-3287 silver. 



III. 0-5181 grm. salt gave 0*2049 silver. 

 In per-centage, — 



II. Silver . ♦ . . 39-90 



III. Silver .... 39'55 



Mean number . 39*72 



These results correspond exactly with those of Delalande 

 and give the following formula, AgO, C 18 H 7 5 . The calcu- 

 lated and experimental numbers are as follows : — 



Theory. Experimental. 



39*86 



2*58 



17-72 



39-84 39-72 40-00 



3386-51 100-00 



Formation of Cumaric and Salicylic Acid from Cumarine. 



From the above experiments it is evident that the formula 

 given by Delalande to cumaric acid must be regarded as the 

 correct one. The representation however of the formation of 

 this acid, to which this chemist was led by the incorrect for- 

 mula of cumarine, requires correction. The formation of 

 cumaric acid depends upon no decomposition of water, the 

 oxygen of which is added to the elements of cumarine, but 

 simply on the assumption of 2 equivalents of this body, ex- 

 actly analogous to the formation of benzilic acid from benzile, 

 or isatinic acid from isatine. 



C* H 10 O 4 +2HO = HO, C 28 H n 5 



V , 1 V , ( 



Benzile. Benzilic acid. 



C 16 H 5 N0 4 + 2HO = HO,C ie H 6 NO s 



Isatine. Isatinic acid. 



C 18 H 6 4 +2HO = HO,C 18 H 7 5 



* v j < — - — , ■ 



Cumarine. Cumaric acid. 



It is not requisite even to fuse the cumarine with caustic 

 potash : by the employment of an alcoholic solution of po- 

 tassa it is also transformed, though very slowly, into cumaric 



