Wright. — Clionical Composition of Meat -extract. 5 



bases have been isolated from meat-extract in recent years — namely, ignotin, 

 oblitin. methylguanidin, carnomuscarin, neosin, novain, alanin, leucin, and 

 glycocoll ;* these are present in extremely small quantities, and it is im- 

 possible with our present knowledge to determine all of the meat bases in 

 meat-extracts. 



The meat bases are the products of the breaking-down of proteins in the 

 vital processes of the body, and are excreted for the most part unchanged, 

 and have little use as tissue-builders ; neither do they produce heat or 

 energy ; they are therefore not foods. 



Recent experimentsf show that meat bases furnish relief to fatigued 

 muscle, and are powerful exciters of gastric secretion. They are thus most 

 valuable, in that they create an appetite and prepare the system for food 

 and aid its digestion. The custom of preceding a meal with soup which 

 contains these bases has therefore a strong physiological warranty. 



Ammonia when in (|UHntity indicates some degree of putrefaction. 

 Probably some of the ammonia present is in combination with acids of the 

 fatty series. 



Recently preparations made from yeast have been placed on the market 

 as substitutes for and adulterants of meat-extracts. While as far as the 

 taste and appearance are concerned they resemble meat-extracts, they show 

 marked chemical differences, and are in no sense true substitutes, since 

 they lack the valuable constituents and stimulating properties of meat- 

 extracts, and their salts and bases. 



Yeast on hydrolysis yields extractives somewhat similar to those 

 obtained from meat, and when evaporated by the open-pan process darkens 

 and looks like extract of meat. Caramel is sometimes added to darken 

 the colour. 



The following is the analysis of a sample of this class of product sold in 

 this country : — 



As in the case of the meat-extracts examined, no natural peptones were 

 found. 



* Zts. Nahr. Genusam., 1902, p. 193 ; 1905, p. 528. Zts. Physiol. Chem., 1906, 

 p. 412. 



t Joiirn. Physiol., 1907, p. 163; Medicin-chir. Centrbl., 1893. p. 653: ''The Work 

 ol the Digestive Glands," Pawlow, trans, by W. H. Thompson, 1902. 



