BETWEEN THE CONDITIONS OF A CHEMICAL CHANQE AND ITS AMOUNT. 215 



Table XII. (continued). 

 2. Second set. 



The actual readings of the burette are given above instead of the amounts per cent., 

 in order to show more clearly what is the practical limit of error in this mode of expe- 

 rimenting. The earlier series of numbers in the first set (Table VIII.) are omitted, 

 because they are not sufiiciently prolonged to be characteristic. Of the second set 

 that corresponding to three proportions of sulphuric acid is perfectly geometric, while 

 those on either side of it, corresponding respectively to one and to four proportions of 

 acid, are not. It will be shown that this curious circumstance depends upon the existence 

 of a particular relation between two of the three rates. 



The foregoing experiments prove that the reaction here examined is of a complex 

 character, and thus unsuited to the purpose with which we entered upon this investiga- 

 tion. The law that the amount of chemical change in a unit of time is proportional 

 to that of each of the substances reacting, rather serves to explain these results than is 



