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PROCEEDINGS OF THE AMERICAN ACADEMY 



the acetate till the reaction was stopped by dilution with water, while 

 in the other columns, under the name of each substance the amount 

 of bromine removed is given, — first in grammes, and second in per- 

 centages of the total amount of side-chain bromine. 



Table I. 



On representing the percentages of the total side-chain bromine 

 removed by curves, in which horizontal distance represents time, ver- 

 tical per cents, it is found that those given by the para and meta com- 

 pounds are comparatively regular, but that the ortho curve is decidedly 

 irregular. The same fact is brought out by the following table, in 

 which the amount of bromine removed from the ortho and meta com- 

 pounds in each experiment is given in percentages of the amount 

 derived from the para compound in the same experiment. 



The differences between the relative amounts of bromine removed 

 from the meta compound in the first three experiments, tabulated 

 above, fall within the limit of error of the process, which amounts to 

 over five per cent when the numbers are given in this form ; and, 

 although the amount of bromine removed during thirty minutes is 

 somewhat larger, the difference between this and the highest of the 

 other numbers is only four per cent. It is probable, therefore, that 

 the relative rate of decomposition for the para and meta compounds 

 remains constant in the interval of time between five and thirty min- 

 utes ; and that the slight increase in the numbers with the time in the 

 experiments at 5, 20, and 30 minutes, is entirely accidental, alihouyh 



