COMMENTS ON THE ANALYSIS OF BABBITT METAL ^ 



By J. C. Witt 



{From the Laboratory of General, Inorganic, and Physical Chemistry, 



Bureau of Science, Manila, P. I.) 



The analysis of Babbitt metal has always offered considerable 

 difficulty to chemists, particularly those who are engaged in 

 commercial testing. Although many excellent papers have been 

 published on the subject, most of the methods given are either 

 too long and involved for commercial purposes, or else they are 

 not sufficiently accurate and reliable in the hands of the average 

 analyst. There has been a wonderful advance in electrolytic 

 analysis, and many of the methods now being published are 

 along these lines. While this system is very close to the ideal 

 with the right equipment, there are many laboratories doing 

 general chemical work where the expense of installing suitable 

 electrical equipment is hardly justified. 



There is scarcely any other material which has so large a 

 range of composition as Babbitt metal. The lead or the tin 

 content may vary from to 90 per cent, and there is often 

 a great variation in the other elements present. Some of the 

 varieties have special names, but as a rule the average consumer 

 calls almost any white metal used for antifriction purposes a 

 babbitt. Besides the metals actually called for in the formula, 

 there are invariably impurities present which in some cases are 

 in sufficiently large amounts to cause trouble in the analysis. 

 Persons submitting such samples seldom seem to realize that 

 while some samples are simple others are exceedingly difficult 

 and cannot be completed without a great deal of labor if results 

 are to be dependable. 



An object of this paper is to point out that there is no 

 general method that may be equally well applied to all samples. 

 Many methods are published which show accurate results with 

 one class of babbitts, but fail with others. Until a good general 

 method is devised, the chemist must keep well in mind the limits 

 of whatever method he may favor and be constantly on the 

 alert to modify it to suit the circumstances, or to substitute a 

 different one if necessary. 



The present work has been done with babbitts having the 



' Received for publication September 9, 1915. 



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