OP ARTS AND SCIENCES. 187 



VI. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



ON THE ACTION OF CHROMIC SUPERFLUORIDE ON 

 BENZOIC ACID. 



By C. Loring Jackson and George T. Hartshorn. 



Communicated May 13, 1885. 



As the chromic superfluoride is instantly decomposed by water with 

 the formation of chromic anhydride and hydrofluoric acid, we under- 

 took the experiments described in the following paper in the hope that 

 organic compounds containing hydro xyl would act in a similar way ; and 

 since Mallet's* determination of the vapor-density of hydrofluoric acid 

 obliges us to assign it the formula H^F^, that thus we might obtain 

 organic substances, in which the oxygen of the hydroxyl was replaced 

 by two atoms of fluorine, as in fluosilicic acid. This hope has not 

 been realized in the case of benzoic acid, with which we began our 

 experiments, as the chromic superfluoride left the hydroxyl entirely 

 unaltered ; but, on the other hand, it has led us to a very interesting 

 result, as the products of the reaction were chromic fluoride (Cr^F^) 

 and a difluorbenzoic acid, and therefore we have achieved for the first 

 time, so far as we can find, the direct substitution of the hydrogen in 

 an organic substance by fluorine. Preliminary experiments with acetic 

 acid and benzol seem to show that the reaction is a general one, — in 

 both cases the chromic superfluoride was reduced to a lower fluoride 

 of chromium, — and there is good promise, therefore, that it will prove 



of service in addinij new members to the class of fluorine or<ranic com- 

 es o 



pounds, as yet so meagrely represented. 



We have not made a complete study of the difluorbenzoic acid, 

 but have contented ourselves with doing enough to characterize it 

 thoroughly, as we are anxious to avoid any interference with Paterno, 

 who has already begun the investigation of organic bodies in which 



* Am. ChcMii. J., iii. 189. 



