720 



cleaned Jena vessels by carbon dioxide and the dissociation thereof 

 is practically repelled by the fatty acids. 



The constant given above for^wopropylacetic acid (= 1.68) has 

 been found equal for both the commercial and synthetic product. 

 As the former is contaminated with methylethylacetic acid and as 

 the constant thereof does not differ much from that of the pure 

 2.9övalerianic acid ^), this was to be expected. 



The measurements of the hydratation velocity were executed in 

 the same manner as those described previously. ^) The anhydride 



mean : .4343 k^ = 0.00700. 



1) BiLLiTZER, Sitz. Ber. Ak. Wien 1899, p. 416. 



2) Rec. 31, 80 (1912). 



