vii OXIDATION-PRODUCTS 243 



On comparing the ratio of loosely-bound acid-amide-nitrogen and 

 the oxalic acid of the kyro-proteic acid A : 



Total nitrogen : acid-amide-N : oxalic acid. 

 1 : i : \ 



In kyro-proteic acid is sufficient loosely-bound N to allow us to 

 assume that the whole of the oxalic acid is contained in kyro-proteic acid 

 as oxamide groups NH . CO . CONH . . . NH . CO . CO . NH. 



On treating egg-white or other albuminous solutions with large 

 amounts of potassium permanganate in strongly alkaline solutions at 

 room temperature, a part of the albumin is very quickly dissociated. 

 Albumoses and peptones are formed which, by fractional precipita- 

 tion with ammonium sulphate, can be shown to be the same fractions 

 as are obtained by peptic digestion. They show towards precipitants 

 the same behaviour as do such albumoses and peptones as are obtained 

 by digesting albumin, but there is one exception : they are for some 

 curious reason not precipitated by picric acid, although the other 

 alkaloidal reagents give positive results. 



This whole class of bodies gives a well-marked biuret-reaction, and 

 also Millon's reaction, except in the case of the analogue of peptone B, 

 which also does not give it. Negative results are obtained with the 

 lead sulphide- and xantho-proteic reactions, and also with the tests of 

 Millon and Adamkiewicz. 



In addition to these albuminous substances are also found simple 

 disintegration-products, which is not remarkable if one considers how 

 susceptible albumins are to the action of all alkalies and how oxidation 

 by means of potassium permanganate may produce a rise of tempera- 

 ture of 12-16. 



With Ehrmann l we may assume that oxidation will produce in 

 the albumin-molecule, if it is built up according to Hofmeister's theory 

 (see p. 139), the following changes : 



NH . CH . CO NH . CH . CO when oxidised gives rise to 



I I 



E R 



NH . CH . CO NH . CH . CO by splitting off of C0 2 

 CQOH CQOH f rms 



Nil . CH. 2 . CO NH . CH 2 . CO by further oxidation 

 NH . CO . CO NH . CO . CO results. 



1 Ehrmann, Uber die Peroxyprotsauren, Inaugural Dissertation, Strassburg, 1903. 



