732 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



with the standards and the amount of antimony read off. From the 

 amount in the aliquot portion, the amount in solution was calculated. 



Very often the mirror obtained from a given portion of the solution 

 will be found too small or two large for estimation. In this case one 

 can readily determine the proper amount of solution to be used. 



The following table shows the results of these analyses : 



TABLE II. 



The results are as good as can be expected, considering the small 

 amounts of antimony under estimation and the difficulty of reading the 

 mirrors more accurately than within 0.002 or 0.003 mgr. The demand 

 on the method made by these analyses is much more severe than would 

 occur in actual practice. It is safe to say that the method will give a 

 close approximation to the amount of antimony present in a given 

 product, within the limits for which it is intended. It will serve also 

 as a means of quickly, though roughly, estimating amounts which would 

 require the ordinary analytical methods for an exact determination. 



