276 THE UNFERTILISED EGG AS A [pt. hi 



to hydrolysis by pepsin than by trypsin (see later under enzymes and 

 antitrypsin). For its properties see the papers of Morner and Neu- 

 mann. Both the glucoproteins have twice as much sulphur as ovo- 

 albumen. Their carbohydrate content has been the subject of a great 

 amount of discussion and experimental work. Berzelius was the 

 first to draw attention to certain similarities between the breakdown- 

 products of sugars and proteins when acted upon by boiling acids. 

 In 1876 Schiitzenberger asserted that the ovoalbumen molecule 

 contained a carbohydrate group, basing his views on positive results 

 with Trommer's test after total hydrolysis. In later years a number 

 of workers supported the view that the carbohydrate was glucose, 

 using in different cases methods of varying reliability, e.g. Kruken- 

 berg in 1885, Hofmeister and Kravkov in 1897, and Blumenthal ; 

 Blumenthal & Mayer and Mayer in 1898 and 1899. Spencer and 

 Morner, however, failed to get any evidence of a carbohydrate 

 group after hydrolysis, and reported their negative results in 1898. 

 Weiss, about the same time, thought he could identify a methyl 

 pentose among the hydrolysis products, but he was never confirmed. 

 Seemann was the first to announce that the carbohydrate was glucos- 

 amine, and his discovery was quickly confirmed by Frankel and 

 Langstein. These later workers began to attempt quantitative estima- 

 tion of the sugar, and their figures are given in Table 15. Pavy, 

 using the then recently discovered osazone technique, made a study 

 of a variety of proteins, and showed, as might be expected, that the 

 yield from ovoalbumen was always greatly less than from ovomucoid. 

 Eichholz obtained glucosazone from ovoalbumen, ovom.ucoid and 

 ovomucin, but not from either serum albumen or casein. On the 

 whole, it is most likely that ovoalbumen contains extremely 

 little glucosamine, and the figures recorded in the literature for 

 this are probably due to contamination with ovomucin. This is the 

 view of Osborne, Jones & Leavenworth, for neither they nor 

 Osborne & Campbell obtained any glucosamine from their very 

 carefully purified ovoalbumen. Komori has prepared from ovo- 

 mucoid, and Frankel & Jellinek from ovoalbumen, polysaccharide- 

 like substances which they regard as the prosthetic group containing 

 all the glucose. Following this up Levene & Mori have prepared a 

 trisaccharide containing glucosamine and mannose from egg-white. 

 Ovoalbumen contains 0-26% of this substance, coagulated egg-white 

 1*9%, and ovomucoid 5*1%. According to Levene & Rothen the 



