ALBUMINS OR PROTEINS. 269 



principally present in cases of sarcoma formations in the bone marrow 

 (Sarcomatosis ossium). It is usually found only in the urine, the epi- 

 thelia of the glomeruli permitting this substance to pass through, at the 

 same time retaining all the serum-albumins. It might be thought that 

 the Bence-Jones albumin represents a lower albumin, and consequently 

 diffuses through the urinary passages. 1 This assumption is, however, in- 

 correct, because this albumin contains all of the usual amino acids, which 

 seems to indicate that the albumin has not in any way undergone much 

 decomposition. Tyrosine is one of these amino acids, and this amino 

 acid, as is well known, is very easily split off from the rest of the molecule. 

 The objection might be raised, of course, that the tyrosine-is linked in a 

 different manner in the Bence-Jones albumin from that in other varieties 

 of albumin. There is at present no ground for such an assumption. 

 According to its content of amino acids, the Bence-Jones albumin does 

 not correspond to either of the two serum-proteins, and may be con- 

 sidered as one of the tissue-albumins, which, without being broken down 

 or changed into one of the serum-albumins, is transmitted to the blood, 

 and then is probably eliminated as an albumin foreign to the blood 

 although suitable for the body. It would be interesting to investigate 

 other analogous albuminous excretions from the kidneys. 



Although such products are only found under specific conditions, normal 

 urine, nevertheless, contains other complicated compounds, whose nature 

 has not yet been determined, but which, from their elementary composition, 

 must be closely related to albumin-metabolism. Their high percentage 

 of oxygen stamps them as albumin oxidation products. Their presence 

 indicates the possibility that the disintegration of the albumin molecule 

 may proceed in different ways, and that our assumption, that albumin is 

 broken down in cell-metabolism through the amino acid stage, does not 

 apply to all albumin decomposition. It is indeed possible that a part of 

 the albumin is oxidized in a manner unknown to us without undergoing 

 previous cleavage. It is not impossible that, for this kind of albumin 

 decomposition, those complexes come into consideration which, as we 

 have seen, strongly resist the action of the proteolytic ferments. At all 

 events, we shall expect that when these products are explained, we shall 

 receive further insight into the intermediate metabolism. Here we can 

 only mention the names of these various compounds, and assert that no 

 proof exists of their individuality. Bondrizyski and Gottlieb 2 distinguish 



1 E. Abderhalden and O. Rostoski: Z. physiol. Chem. 46, 125 (1905). Cf. A. 

 Ellinger: Deut. Arch. klin. Med. 62, 255 (1899). A. Magnus-Levy: Z. physiol. Chem. 

 30, 200 (1900). F. Reach: Deut. Arch. klin. Med. 82, 390 (1905). 



3 St. Bondzyriski and Gottlieb: Zentr. Med. Wiss. (1897) No. 33, 577. St. Bondzyriski 

 and Panek: Bull, de 1'Acad. d. sciences de Crascovie, Oct. 1902. St. Bondzyriski, St. 

 Dombrowski, and K. Panek: Z. physiol. Chem. 45, 83 (1905). F. Pregl: Pfluger's Arch. 

 76, 87 (1899). 



