154 CHEMISTRY OF THE PROTEIDS CHAP. 



It is perhaps more correct to follow Kossel, 1 and also to consider 

 the second mode of union, such as we see it in arginin, as essential 

 for the conception of an albumin. According to this view we would 

 have to define albumins as acid-imines composed of a-amino-acids 

 and including also arginin. 



This definition will cover, without doubt, all peptones, and 

 also the more complex peptids ; further, the protamins, which 

 latter ought not to be put into a separate class, if we consider 

 what broad chemical and genetic transitions exist between them 

 and the other albumins. A classification on a physiological basis, 

 as has been attempted by Low 2 and by Hofmeister, 3 has, according 

 to Cohnheim, great disadvantages, and is not permissible, since 

 it has become probable that the animal body can build up its proteids 

 from all nitrogenous compounds, provided that these can be acted 

 upon by its ferments. Kossel 4 believes, however, and the author 

 thinks rightly, that from the physiological standpoint we are, nowa- 

 days, not justified in believing that rneat-albumin possesses the same 

 nutritive value as milk -albumin or the albumin of maize. These 

 substances differ in their chemical constitution, and therefore they 

 must also play different parts in nutrition. Kossel has looked on 

 this matter from still another point of view. He draws attention to 

 the fact that arginin up till now is the only dissociation-product which 

 has been found in all albumins, and that certain albumins exist, namely, 

 the protamins, in which arginin forms the main bulk of the dissocia- 

 tion-products, and that the protamins appear relatively simple, because 

 of the smaller number of compounds composing them. Wheresoever the 

 other amino-acids increase in number and complexity, arginin diminishes 

 in amount. He therefore considers arginin as the nucleus of the 

 albumin-molecule, or rather as the nucleus round which the individual 

 complexes of albumoses group themselves in building up the albumin- 

 molecule. Attention is drawn once more to the fact that the most 

 resisting element in albumins, which Siegfried succeeded in isolating by 

 means of careful treatment with trypsin and acids, namely, the kyrins, 

 are bases, consisting for the greater part of arginin and lysin. 



THE CARBOHYDRATE RADICALS OF ALBUMINS 

 That either a carbohydrate, or some radical resembling a carbo- 



1 A. Kossel, Ber. d. deutsch. chem. Ges. 34. III. 3214 (1901) ; Bull, de la Soc. 

 chim. de Paris, 3eme ser., 1. 29, Nr. 14, Juli 1903. 



2 0. Low, Holy's Jahresber. 1900, p. 18. 



3 F. Hofmeister, Ergehnisse der Physiologic, I. 1. 1902, p. 759. 



4 A. Kossel, Berl. Win. Wochenschr. 41. 1065 (1904). 



