200 THE PRODUCTS OF ALBUMINOUS DIGESTION. 



albuniose, but the precipitate redissolves in an excess of the reagents. 

 Sodium chloride brings about complete precipitation only in feebly 

 acid solution, on complete saturation. With ammonium sulphate 

 the limits of precipitation are the same as for the hetero-albumose. 

 In dilute alcohol proto-albumose dissolves with ease ; precipitation 

 begins in the presence of 80 per cent, (separation from hetero-albu- 

 mose), and only becomes complete when a mixture of alcohol and 

 ether is added. 



The elementary composition is C= 55.64, H = 6.8, N = 17.66, 

 S = 1.21, O18.69. It is a hemi-body and accordingly readily 

 digested further ; it yields much deutero-albumose of the A fraction, 

 some deutero-albumose B and peptone B, but no deutero-albumose 

 C or peptone A. Like hetero-albumose, it contains no carbohydrate 

 group and hence does not give the Molisch reaction. On hydrolysis 

 it yields 25 per cent, of its nitrogen in basic form (diamiuo-acids), 

 much tyrosin and tryptophan, but little leucin and glycocoll. 



The remaining albumoses are not known so well as the two that 

 have been described ; the most noteworthy data follow : 



Gluco-albumose. The gluco-albumose (synalbumose) is obtained 

 together with the deutero-fraction B on complete saturation with 

 ammonium sulphate, the reaction being neutral. It can be separated 

 from the deutero-fraction B by careful treatment with alcohol (see 

 below). Its elementary composition is C == 48.72, H = 7.03, 

 N = 13.61-14.77, S -f O == 30.49. There is but little loosely 

 combined sulphur. The substance gives an intense Molisch re- 

 action and is the only primary albumose containing a carbohydrate 

 group. This can be split oif by means of acids and yields an osazon, 

 which in appearance resembles glucosazon and melts between 182 

 and 184 C. On further digestion it yields Pick's peptone A ; the 

 intermediate products have not been isolated. 



Deutero-fraction A. The deutero-fraction A is precipitated on 

 62 per cent, saturation with ammonium sulphate. By treating this 

 fraction with 60-70 per cent, alcohol it can be further resolved into 

 two fractions, of which the one (thio-albumose) is precipitated, while 

 the other, deutero-albumose A, passes into solution. The thio- 

 Mumose derives its name from the large amount of sulphur which 

 it contains, viz., 2.97 per cent., and which is present almost entirely 

 in loosely combined form (cvstin). The elementary composition of 

 this portion is: C = 48".96, H = 6.9, N 16.02, S = 2.97, 

 O 25.15. 



The deutero-albumose A contains much less sulphur, which is 

 also present in loosely combined form. Its composition is C = 53.11, 

 H = 7.16, N = 17.86, 8 = 0.8, and O = 21.07. 



Neither fraction probably contains the carbohydrate group, while 

 the Millon reaction, the xanthoproteic and biuret reactions are posi- 

 tive. On fusion with caustic alkali indol is obtained. 



Deutero-fraction B. This fraction is obtained together with the 

 gluco-albumose on complete saturation with ammonium sulphate in 



