201 



is as yot practically unknown. In our earlier invest i<j:at ions " upon the 

 losses which meats sustain when cooked in hot water it was observed 

 that the sum of the proteids. Ilesh l)ases. fat, and ash in clear hroths 

 as obtained by analysis was in all cases considerably less than the 

 amount of total solids obtained by the direct eva])oration, and this 

 quantity of unknown extractives was designated ''other substances." 

 The projiortion of the undetermined material or "other substances" 

 ranged from 19.9 to 43.4 per cent, and averaged 34.2 per cent of the 

 total solids of the clear broth; or, stated in another way, the jiropor- 

 tion of unidentified substances in the broth varied from 0.3 to 1.1 per 

 cent, and averaged O.S per cent of the total weight of the fresh meat. 



Much time has been devoted in tliis laboratory to the study of unde- 

 termined sul)stances in liroths, but tlie publication of the detailed 

 results is withheld until further investigations can be made. It is evi- 

 dent from the experimental results so far obtained that this material 

 contains consideral)le lactic acid, some glycogen, more or less inosite 

 and xanthin bases, and traces of acetic and butyric acids. 



In the investigations reported in the later publication referred to 

 above,'' notwithstanding the fact that all the determinations of proteids, 

 flesh bases, and ''other substances" were carefully made, it was then 

 considered more satisfactory in calculating the material lost in cook- 

 ing meats to combnie the flesh bases and the so-called "other sub- 

 stances" under the name of "extractives," a term wliich has often 

 been used in that sense.'" 



Recent studies in connection with these nutrition investigations 

 have shown that the cold-water extracts of meats also give results 

 similar to those obtained in the analysis of ])roths, namely, that the 

 sum of the nitrogenous matters, fat, and mineral matter determined 

 by direct analysis is in ever}^ case decidedly less than the total solid 

 residue obtained by direct evaporation. This difference ma}^ be seen 

 by noting the ]:)roportion of the nonnitrogenous organic extractives 

 in Tables 98-104, pages 99-115. 



Composition of Clear, Filtered ]\1eat Broths. 



The methods (see p. 15) used in the determination of the losses 

 involved in the cooking of meats in hot w^ater make it necessary to 

 separate the constituents of the original complete broths into those 

 which exist in the form of suspended matter and those wliich occur 

 dissolved in the clear filtered broth. Broths are so frequently served 

 clear that it seems desirable to present the available data regarding the 



oU. S. Dept. Agr., Office of Experiment Stations Bills. 102, 141. 



b U. S. Dept. Agr., Office of Experiment Stations Bui. 141. 



c Mitchell's Flesh Foods, pp. 7, 45, and 48. See also Allen's Commercial Organic 

 Analysis, vol. 4, Philadelphia, 1898, pp. 270 and 335; and Halliburton's Textbook of 

 Chemical Physiology and Pathology, 1891, p. 418. 



