328 



PROCEEDINGS OP THE AMERICAN ACADEMY. 



Clearly, then, the growing presence of hydrobromic acid must be the 

 cause of the abnormal loss of speed in the original time-curve. But in 

 what manner can the substance effect this change ? 



The next step was to study in great detail the actual effect of hydro- 

 bromic acid of varying strengths. 



IV. The Effect of Hydrobromic Acid. 



The following series give a basis for more certain conclusions con- 

 cerning the action of hydrobromic acid. Series IV is merely a repeti- 

 tion of Series I with a somewhat more dilute solution of oxalic acid, 

 Series V contained a few centigrams of hydrobromic acid, and Series 

 VI contained about twice as much of this acid. In each the total vol- 

 ume was 59.30 cubic centimeters, containing at the start 1.495 grams of 

 anhydrous oxalic acid and 0.1536 gram of un-iouized bromine. 



As before, the temperature was 23°. 0. 



SERIES IV. 



