60 THE ALBUMINS. 



or alkalies. In every case their formation is preceded by the dena- 

 tnrization of the original molecule. 



Collectively the albumoses, which are derived from the true albu- 

 mins in contradistinction to those which are obtained from the albu- 

 minoids, are termed proteoses. According to their origin, we dis- 

 tinguish between globulinoses, vitelloses, caseoses, myosinoses, 

 keratinoses, elastoses, gelatoses, etc. During the process of diges- 

 tion primary albumoses first result, which then give rise to secondary 

 albumoses, and these in turn to simpler products, which collectively 

 are termed peptones. Of primary albumoses, at least three are known, 

 viz., proto-albumose, hetero-albumose, and gluco-albumose (synal- 

 bumose, Hofrneister). The secondary albumoses are designated as 

 deutero-albumoses, and of these again several varieties exist (see 

 Products of Digestion). 



In their quantitative composition the albumoses do not differ ma- 

 terially from the original albumins ; their molecular weight, however, 

 is materially less. Most likely they represent depolymerization- 

 products of the albumins, and occur preformed in the original mole- 

 cule, as has been suggested (page 43). 



The albumoses give the same color-reactions as their mother-sub- 

 stances. With the biuret test, however, instead of the original violet, 

 a beautiful rose color is obtained. Their final decomposition-prod- 

 ucts are in general those of the original albumins ; there are certain 

 differences, however, largely of a quantitative character, which are 

 very important. These are shown in a subsequent table (see 

 page 202). Noteworthy is the absence of the glucosamin complex 

 in the proto-albumose and hetero-albumose, and its presence in the 

 gluco-albumose ; further the large amount of sulphur in the thio- 

 albumose ; then the presence of 39 per cent, of the total nitrogen, in 

 the form of diamino-acids in hetero-albumose, as compared with 25 

 per cent, in proto-albumose, etc. 



Unlike the albumins, the albumoses are not entirely indiffusible, 

 and it appears that the power to pass through animal membrane 

 increases as they become structurally further and further removed 

 from their mother-substances. 



As a class the albumoses are much more readily soluble than the 

 albumins. Most of them are soluble in water or in dilute saline 

 solutions, and also in dilute acids and alkalies. From their solutions 

 they are readily precipitated by neutral salts, notably ammonium 

 sulphate, which precipitates all albumoses when added to saturation, 

 the reaction being slightly acid. Most of them, indeed, are thrown 

 down when the salt is added to the extent of 75 per cent. Each 

 albumose, in fact, appears to possess certain special limits of pre- 

 cipitation with ammonium sulphate which renders possible the sep- 

 aration of the individual substances from each other, and also from 

 other albumins which may be present at the same time. Zinc sul- 

 phate behaves in a similar manner. Sodium chloride when added 

 in substance to saturation causes a partial precipitation of the 

 albumoses from their neutral solutions, while a fairly complete sep- 



