120 EXPERIMENT STATION. [Jan. 



METHODS FOR FAT ANALYSIS. 



BY E. n. HOLLAND, M.SC. 



During the past ten years the Massachusetts experiment 

 station has conducted a series of feeding experiments, to as- 

 certain, among other things, the effect of different concentrates 

 upon the composition of the resulting butter fat. In connection 

 with this work, which required a great many fat analyses, it 

 was found necessary to study the methods thoroughly in order 

 to simplify when possible, to bring to a like basis and above 

 all to insure uniform results under known conditions of manip- 

 ulation. The intent of this article is to give only the methods 

 adopted, with a few supplementary notes. What originality 

 there may be is reasonably evident if one compares the methods 

 stated with those usually prescribed. It has been largely, how- 

 ever, the adapting of valuable suggestions from many careful 

 analysts ^ though few references are cited. 



Apparatus was one of the first things that required attention, 

 especially flasks. A form and size were desired that would be 

 suitable for all ordinary tests, and a 300 cubic centimeter Er- 

 lenmeyer flask, of uniform height and cork requirement, has 

 satisfactorily filled that need. Such a flask occasionally calls 

 for a slight increase in quantity of solvent, but that is to be 

 expected. Normal graduated ware on the basis of the true cubic 

 centimeter at 4° C. was adopted as the standard. The flasks 

 are graduated for capacity and the burettes and pipettes for 

 delivery at 20° C, and all graduations are verified. 



The solutions are standardized at 20° C. and are brought to 

 that temperature before being used. Tempering should be 

 carefully observed, especially with alcoholic and acetic acid solu- 

 tions having a high coefficient of expansion. 



1 Allon, Brown, Blyth, Leach, LeflFmann and Beam, TjCwkoAvitsch, Prescott, Sadtler, 

 Sherman, Wiley, Wright, Zulkowski and others. 



