832 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



COLLATED DATA CONCERNING SPEED OF REACTION. 



It is reasonable to suppose that the effect of the hydrobromic acid will 

 be eliminated if we compare speeds of reaction in solutions containing 

 equal concentrations of hydrobromic acid. It is true that the cause of the 

 retarding action of this substance may affect its available concentration, 

 but clearly a first approximation may be reached in this way. We should 

 expect to find the residual difference in rate to be due to the bromine 

 alone, and hence be able to discover at once to what type the bromine 

 reaction belongs. 



It is easily seen that Series IV contained 124 milligrams of hydrohromic 

 acid after 240 minutes, while Series V contained the same amount after 

 only 89 minutes. Now the amounts of bromine present in these two 

 cases were respectively 32 and 98 milligrams, while the rates were 



