210 III. DIGESTIBILITY OF FATS 



ether; the fatty material remains after evaporation of the petroleum 

 ether. 



Severance 41 reported that identical data on digestibility were obtained 

 by the use of several procedures, provided, of course, that the appro- 

 priate factors were used in each case as a correction for metabolic lipid. 

 Her results are summarized in Table 6 (p. 208). 



Holt et al. 42 reported a practical procedure for the determination of fat 

 in dried feces which makes use of the Roese-Gottlieb method employed 

 in determining fat in dried and condensed milks, as reported by Patrick 

 and Boyle. 43 



b. Methods Employing Wet Feces. These include a large number of 

 procedures which have been suggested for the determination of lipids, 

 chiefly in feces, but also in tissues, in which the wet sample is employed. 42-57 

 Most of these are used clinically for the determination of fat, but some of 

 them may be sufficiently precise for research. 



According to van de Kamer and associates, 44 estimations of fat based 

 upon microscopical examination are unreliable, and fail to be quanti- 

 tative. Likewise, the calculation of fat excretion from the weight of a 

 random sample of dried feces is equivocal, since considerable variations 

 occur in the proportion of dry matter in feces, irrespective of the fat 

 present. 44 ' 57 - 58 



41 E. J. Severance, The Digestibility of Some Peanut Oils in the Rat, Thesis, Univ. 

 So. Calif., Dept. Biochem. Nutrit., Jan., 1952. 



42 L. E. Holt, A. M. Courtney, and H. L. Fales, Am. J. Diseases Children, 17, 38-42 

 (1919). 



43 G. E. Patrick and M. Boyle, U. S. Dept. Agr., Bu. Chem., Bull. No. 105, Proc. 23rd 

 Annual Convention Assoc. Official Agr. Chemists, Washington, Nov., 1906, pp. 106-109 

 (1907). 



44 J. H. van de Kamer, H. ten Bokkel Huinink, and H. A. Weyers, J. Biol. Chem., 177, 

 347-355 (1949). 



46 L. von Liebermann and S. Sz6kely, Arch. ges. Physiol. (Pfluger's), 72, 360-366 

 (1898). 



46 E. Polenske, Arb. kaiserl. Gesundh., S3, 563-579 (1910-1911). 



47 G. J. Saxon, /. Biol. Chem., 17, 99-102 (1914). 



48 F. S. Fowweather, Brit. J. Exptl. Pathol, 7, 7-14 (1926). 



49 F. S. Fowweather and W. N. Anderson, Biochem. J., 40, 350-351 (1946). 

 60 G. Rosenfeld, Biochem. Z., 200, 280-288 (1928). 



51 P. Muller, Nederl. Tijdschr. Geneesk., 79, 3960-3962 (1935). 



52 H. C. Tidwell and L. E. Holt, Jr., /. Biol. Chem., 112, 605-613 (1935-1936). 



53 F. C. Gephart and F. A. Csonka, /. Biol. Chem., 19, 521-531 (1914). 



54 G. Nielsen, Acta Paediat., 31, 225-234 (1943). 



55 M. Kumagawa and K. Suto, Biochem. Z., 8, 212-347 (1908). 



56 R. Inaba, Biochem. Z., 8, 348-355 (1908). 



67 R. Goiffon, Manuel de coprologie clinique, 5th ed., Masson, Paris, 1949. 

 58 W. T. Cooke, J. J. Elkes, A. C. Frazer, J. Parkes, A. L. P. Peeney, H. G. Sammons, 

 and G. Thomas, Quart. J. Med., n.s., 15, 141-155 (1946). 



