54 MEAT EXTRACTS. 



E. Kemmerich a made a study of South American meat extracts 

 and peptones, and divides the proteid bodies of these substances into 

 three groups, depending on their action in the presence of various per- 

 centages of alcohol : (1 ) gelatin substances precipitated by 50 per cent 

 alcohol; (2) albumoses precipitated by 80 per cent alcohol; (3) the 

 peptones remaining in solution. The extractives are also in solution 

 with the peptones. The author suggests a separation based on the 

 fact that the extractives and salts dialyze while the other bodies 

 do not. 



Frentzel and Schreuer 6 fed meat extracts to dogs and compared 

 the results with those obtained when meat was fed. These authors 

 believe that the proteid-free extractives of meat, to one-third of their 

 total, take part in metabolism in that they produce heat and energy. 



Dr. J. Forster c discusses Valentine's meat juice, and considers it 

 of no more value than Liebig's as a food — that is, it is of value as a 

 condiment. 



Dr. R. Sendtner d gives analyses of some 12 meat extracts and 

 bouillon extracts. He considers the original Liebig process extract to 

 be the best and cheapest. Many of the bouillons and juices are 

 diluted meat extracts. 



Frentzel and Schreuer e have studied the calorific value of meats 

 and meat meal. Dogs were used in the experiments. His results 

 agree with Ilubner's in showing that the calorific value of meat is 

 higher than that of meat powders and extractives. 



Dr. Jung' in an article on meat extracts and peptones discusses the 

 various constituents of these bodies and methods for separating the 

 same. The author believes that large amounts of gelatin and gelatin 

 hydration products are present in some extracts, being included under 

 the term ''proteid" since no method for separating gelatin and its 

 hydration products from the various proteid bodies is known. 



CONCLUSION. 



It is commonly assumed that proteids, gelatinoids, and the simpler 

 amids have very different nutritive values, and, while all authorities 

 would agree in assigning the highest value to the first of these, there is 

 probably no small difference of opinion as to the order in which the sec- 

 ond and third should be rated. In considering such a question, there 

 should be separately taken into account relative digestibility or solu- 



oZts. physiol. Chem., 1893, 18A09. 

 b Biedermann's Centrbl. Agr. Chem., 1902, «?/:391. 

 cZts. Biol., 1876, 12:475. 

 ^ d Arch. Hyg., 1897, 6:253. 



cArch. Anat. Physiol., 1901, p. 284. 

 /Chem. Ztg., 1900, 94 : 732. 



