PROTEOSES AND PEPTONES. 129 



KUHNE and his pupils, who have conducted extensive investiga- 

 tions on the proteoses and peptones, classify the various proteoses accord- 

 ing to their different solubilities and precipitation properties. In the 

 pepsi n digestion of fibrin 1 they obtained the following proteoses : (a) 

 Heteroproteose, insoluble in water but soluble in dilute salt solution; 

 (6) Protoproteose, soluble in salt solution and water. These two pro- 

 teoses are precipitated by NaCl in neutral solutions, but not completely. 

 Heteroproteose may, by being in contact with water for a long time 

 or by drying, be converted into a modification, called (c) Dysproteose, 

 which is insoluble in dilute salt solutions, (d) Deuteroproteose is 'a pro- 

 teose which is soluble in water and dilute salt solution and which is 

 incompletely precipitated from acid solution by saturating with NaCl, 

 .and is not precipitated from neutral solutions. This precipitate is a 

 combination of the proteose with acid (HERTH 2 ). The deuteropro- 

 teose is essentially the same thing that BRUCKE has designated as peptone. 



The proteoses obtained from different protein bodies do not seem 

 to be identical, but differ in their behavior to precipitants. Special 

 names have been given to these various proteoses according to the 

 mother-protein, namely, albumoses, globuloses, vitelloses, caseoses, myo- 

 sinoses, elastoses, etc. These various proteoses are further distinguished, 

 as proto-, hetero-, and deuterocaseoses, for example. CHITTENDEN S has 

 suggested the common name proteoses for the products formed inter- 

 mediary between the proteins and peptones in the digestion of animal 

 and vegetable proteins. We have made use of it in this sense in pref- 

 erence to the word albumose (which is used in the German and by some 

 other writers), but which will be used in this book as indicating the 

 intermediary products in the hydrolysis of albumins and not as a gen- 

 eral term. Certain proteoses have also been obtained in a crystalline 

 state (SCHROTTER). 



NEUMEISTER 4 designates as atmidalbumose that body which is obtained by 

 the action of superheated steam on fibrin. At the same time he also obtained a 

 substance called atmidalbumin, which stands between the albuminates and the 

 proteoses. 



Of the soluble proteoses NEUMEISTER designates the protoproteose 

 and heteroproteose as primary proteoses, while the deuteroproteoses, 



1 See Kiihne and Chittenden, Zeitschr. f . Biologic, 20. 



2 Monatshefte f. Chem., 5. 



3 Kiihne and Chittenden, Zeitschr. f. Biologic, 22 and 25; Neumeister, ibid., 23; 

 Chittenden and Hartwell, Journ. of Physiol., 11 and 12; Chittenden and Painter, 

 Studies from the Laboratory, etc., Yale University, 2, New Haven, 1887; Chittenden, 

 ibid., 3; Sebelien, Chem. Centralblatt, 1890; Chittenden and Goodwin, Journ. of 

 Physiol., 12. 



4 Zeitschr. f. Biologic, 26. See also Chittenden and Meara, Joura. of Physiol., 

 15, and Salkowski, Zeitschr. f . Biologic, 31 and 37. 



