The Dissohition of a7i Isotropic Solid. 



179 



would furnish 1145 cc. of hydrogen at 750 mm. pressure 

 and 15° C. The sphere was acted upon by sufficient acid to 

 produce this quantity of gas. 



The numbers in columns A are the cubic centimeters 

 of gas given off, the numbers in columns B the times in 

 seconds required for the evolution of the corresponding 

 volume of gas. If we subtract 561 from 649, the difference 

 is 88, this number of seconds has elapsed while 50 cc. of 

 gas were given off; if we subtract 649 from 731 the differ- 

 ence is 82 ; therefore, in this interval, the velocity has been 

 greater than in the former one ; if we examine the succes- 

 sive intervals we shall not find a greater velocity than this. 

 Suppose then that we commence our observations after the 

 lapse of 649 seconds, we then derive the numbers given in 

 columns A and B of the following table. 



