BiocHEMiCAL Bulletin 



Volume II JULY, 1913 No. 8 lfbrar' 



New Vr;;.: 



ßOTA ■ 



AN INVESTIGATION TO DETERMINE THE ACCU- t. 



RACY OF A MODIFIED MEIGS METHOD FOR 



THE QUANTITATIVE DETERMINATION OF 



FAT IN MILK, WITH A DESCRIPTION 



OF AN IMPROVED FORM OF 



APPARATUS 



WALTER LEWIS CROLL 



(wiTH PLATE 7) 



(Robert Hare Chemical Lahoratory, University of Pennsylvania) 



Owing to the importance of determining accurately and quickly 

 the amount of fat in a given quantity of milk, special efforts have 

 been made to devise a method that would embody both these requi- 

 sites. These efforts have resulted in methods based upon many 

 principles, and some are brilliant examples of chemical and mechan- 

 ical ingenuity. The Separation of the fat has been accomplished by 

 the use of differences in specific gravity, by saponification, extrac- 

 tion with ether, colorimetry, and absorption; but, to the present 

 time, no rapid method, which is sufficiently accurate for legal, 

 pediatric and biological work, has been devised. Today the most 

 accurate method and, indeed, the only one suitable for most legal 

 ' work, is the Adams paper-coil method, with the Soxhlet extraction » 



apparatus. This method, while extremely accurate, requires at least 

 twenty-four hours for its execution and considerable care in its 

 manipulation. 



A COMPARISON OF WELL KNOWN METHODS 



The Adams method. In this investigation the Adams method 

 was carried out as follows: First a homogeneous mixture was 



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