98 



PROCEEDINGS OF SECTION B. 



and then distilled ; the resulting anhydride was con- 

 verted into the ethyl ester and twice crystallised from, 

 carbon tetrachloride. Distillation of the final eater 

 product gave long crystals of an anhydride with M.P. 

 190 deg. The crudest product of the commercial acid 

 promised to be measurable, but the pure product was 

 not. 



4. TetracMorfhthalic Anhydride. — Obtained by distillation of 



commercial acid ; hydrated too rapidly for measurement. 



C. — Other organic anhydrides — 



5. Brombenzoic ; 6. Naphthalic ; 7. Alantic. — Schuchardt 



samples used in each case, but all velocities too great 

 for measurement. 



8. Isohutyric Anhydride. — Commercial sample purified by 

 distillation. B.P. 177-179 deg. under 762 mm. Hy- 

 dration of this anhydride proceeds very moderately, 

 15 to 20 minutes being available for measurements. 

 Table III. contains the summarized results at 25 deg. 



9. Isovalerianic Anhydride. — The procedure used with other 

 liquid anhydrides gave in this case results which indicated 

 that the anhydride was practically insoluble as such. 

 The rate measured was therefore the rate of solution of 

 a very fine emulsion, invisible when present in very 

 minute amount, and not the rate of hydration. Figures 

 were quoted in proof of this conclusion. 



