ALBUMINOSE, OK PEPTONES. 265 



the residue consisted of a yellowish-white substance, resem- 

 bling desiccated white of egg. The dry residue is soluble in 

 water, when it regains its characteristic properties ; but it is 

 entirely insoluble in alcohol. 



The observations of Lehmann on albuminose, or pep- 

 tones, were more extended. He found a great similarity 

 between the substances resulting from the digestion of the 

 various albuminoid bodies, and even those produced by the 

 digestion of gluten, chondrine, and gelatinous tissues. He 

 was unable to obtain the peptones free from mineral sub- 

 stances. In the condition of k greatest purity in which they 

 have been obtained, they have been found to be white 

 amorphous bodies, odorless, having a mucous taste, very 

 soluble in water, and insoluble in alcohol. Their watery 

 solutions redden litmus. They combine readily with bases, 

 forming neutral salts which are soluble in water. 1 The 

 differences between the various peptones are not, as yet, 

 very well defined. Lehmann states that they always con- 

 tain the same proportion of sulphur that existed in the albu- 

 minoid substance from which they are formed. 



According to Lehmann, the gastric juice transforms the 

 various nitrogenized alimentary principles into these liquid 

 suBstances, which are not easily coagulable, and which pre- 

 sent slight differences in chemical composition and gen- 

 eral properties, varying with the principles from which they 

 are formed. Those which have been most particularly de- 

 scribed are fibrin-peptone, albumen-peptone, and caseine- 

 peptone. It does not appear, however, that the differences 

 between the substances resulting from the digestion of the 

 various nitrogenized bodies are sufficiently definite to estab- 

 lish a rigorous distinction between them ; and until we are 

 better acquainted with their distinctive properties, it is best, 

 perhaps, to preserve the name albuminose, applying it to 

 the substance resulting from the action of the gastric juice 

 upon the albuminoids. "We are as yet too little acquainted 



1 LEHMANN, Physiological Chemistry, Philadelphia, 1855, vol. i., p. 451. 



