PROTEOSES AND PEPTONES. 127 



which stand in connection with their strongly marked acid nature. Dilute 

 solutions of alkalies act more energetically on proteids than do acids 

 of corresponding concentration. In the first case a part of the nitro- 

 gen and often also the sulphur, is split off, and from this property we may 

 obtain an alkali albuminate by the action of an alkali upon an acid albu- 

 minate; but we cannot obtain an acid albuminate by the reverse reac- 

 tion (K. MoRNER 1 ). This does not exclude the possibility that, by 

 a more severe acid treatment, products can be obtained which perhaps 

 correspond to those products obtained by a more mild alkali treatment. 



The preparation of the albuminates has been given above. The 

 corresponding albuminate obtained by the action of alkalies or acids 

 upon a proteid solution may be precipitated by neutralizing with acid 

 or alkali. The washed precipitate is dissolved in water by the aid of a 

 little alkali or acid, and again precipitated by neutralizing the solvent. 

 If this precipitate, which has been washed in water, is treated with 

 alcohol and ether, the albuminate will be obtained in a pure form. 



In the preparation of acid as well as of alkali albuminates, proteoses and the 

 closely related albuminates are formed. The " alkali albumose " obtained by 

 MA AS 2 belongs to this class. The lysalbinic acid and protalbinic acid obtained 

 by PAAL 8 from ovalbumin are likewise alkali albuminates. These have been 

 carefully studied by SKRAUP and his co-workers. 4 



Desam.inoalbuminic acid is an alkali albuminate which SCHMIEDEBERG 6 obtained 

 by the action of such weak alkali that a part of the nitrogen was evolved but the 

 quantity of sulphur remained the same. The proteid combination obtained by 

 BLUM 6 by the action of formol on proteid and called by him protogen, has similarities 

 with the alkali albuminates in regard to solubilities and precipitation, but is not 

 identical therewith. 



2. Proteoses and Peptones. 



Peptones were formerly designated as the final products of the decom- 

 position of protein bodies by means of proteolytic enzymes in so far as 

 these final products are still true proteins, while the intermediate prod- 

 ucts produced in the peptonization of proteins, in so far as they are 

 not substances similar to albuminates, were designated as proteoses 

 (albumoses, or propeptones) . Proteoses and peptones may also be 

 produced by the hydrolytic decomposition of the proteins with acids 



1 Pfltiger's Arch., 17. 



2 Zeitschr. f. physiol. Chem., 30. 



3 Ber. d. d. chem. Gesellsch., 35. 



4 Hummelberger, Lampel and Woeber, Monatsh. f . Chem., 30. 

 6 Arch. f. exp. Path. u. Pharm., 39. 



6 Blum, Zeitschr. f. physiol. Chem., 22. The older investigations of Loew may 

 be found in Maly's Jahresber., 1888. On the action of formaldehyde see also Benedi- 

 centi, Arch. f. (Anat. u.) Physiol., 1897; S. Schwarz, Zeitschr, f. physiol. Chem., 30; 

 Bliss and Novy, Journ. of Exper. Med., 4, 



