Q Trariftacfio/is. 



The low content of kreatin and kreatinin and the presence of the piirin 

 bases are characteristic of yeast-extracts. 



Another characteristic is that the filtrate from the zinc-sulphate precipi- 

 tate is cloudy in the presence of yeast-extract, whereas with true meat- 

 extract the filtrate is clear. "^ 



According to Mickof the distribution of the purin bases is different in 

 meat and in yeast extracts : in meat-extracts xanthin and hypoxanthin 

 predominate, while in yeast-extracts adenin and guanin predominate. 



Formerly it was supposed that meat-extracts represented the whole 

 nutritive value of the meat from which they were prepared, but from a 

 consideration of their chemical composition as shown by more exact 

 analytical procedure it is difficult to see whence their food-value could 

 come. 



Liebig's views are clearly stated by himself, as followsj : " Neither tea 

 nor extract of meat is nutriment in the ordinary sense ; they possess a 

 far higher importance by certain medicinal properties of a peculiar kind. 

 . . . It is surely a grave offence against all the laws of physiology to 

 compare tea, coffee, and extract of meat with the more common articles of 

 food, and, because they are not that, to draw the inference that they are 

 nothing at all." 



It is thus clear that extract of meat was never intended by Liebig 

 to be regarded as a concentrated food, having but comparatively little 

 nutritive value. It is only fair to state, however, that many manufacturers 

 make no claim as to its food-value. 



There is little doubt that extract of meat is most valuable as a dietary 

 adjunct, in that it arouses appetite and aids the digestion of any food with 

 which it is taken, by acting as an excitant of gastric secretion ; it further 

 acts as a rapid and powerful restorative, in condition of muscular fatigue. 

 These are its true functions both in health and in disease. 



For permission to publish these results the author desires to express 

 his thanks to the Christchurch Meat Company (Limited), in whose chemical 

 laboratory most of the work in connection with this investigation was 

 carried out. 



* Arab. Pharm., 1904, vol. 242, p. 537. 



t Ber. dent. Chem. Ges., 1894, vol. 27, p. 499. 



t The Times, 1st October, 1872. 



