722 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



0.3 



1.8 



i.3 



Figure 1. 



A study of the above table 

 will show that there is appar- 

 ently a considerable amount 

 of unreduced antimony in 

 solution, and that all the 

 antimony taken is not ac- 

 counted for, except in Series 

 D, in which it is less than the 

 amount apparently found. 

 Though the impurities in the 

 zinc were probably too slight 

 to influence the reaction in 

 any way, yet the amount of 

 zinc, which was purposely 

 small in order to avoid the 

 introduction of large quan- 

 tities into the solutions to 

 be titrated, was perhaps in- 

 sufficient for reduction. It 

 is not unfair to suppose that 

 a more complete reduction 

 would have given the same 

 ratios between the precipi- 

 tated antimony and that 

 evolved as hydride. As to 

 the inequality between the 

 amounts of antimony taken 

 and found, we think that 

 this may be explained by the 

 errors in the titration of such 

 small amounts. 

 In spite of these criticisms of the above results, it seems to us that 

 the study points to the conclusion that practically all of a small amount 



