520 THE CHEMISTRY OF TUMORS 



Sulpluir is readily split ofl' liy alkalies, reacting with lead acetate to produce 

 lead sulphide (Boston). 



After standing in alcohol, by which llie body is precipitated, it loses its solu- 

 bility (differing in this respect from albuuiosc). 



As to the exact nature of the body, little can be said at the present 

 time. Since protoproteoses, deiiteroproteoses, and peptone are split 

 off on digestion with pepsin, the molecule is evidently larger than 

 that of any of the albumoses. The Avell-purified substance is free 

 from phosphoms, and hence contains no nueleins ; but it contains con- 

 siderable sulphur (between 1 and 2 per cent.), which is readily split 

 off. Like casein, it contains no hetero-group (lack of heteroproteoses 

 on digestion), but differs in containing a carbohydrate group (in small 

 amount) and in the absence of phosplionis. On hydrolysis ^Nlagnus- 

 Jjexy ^s obtained glutaniinic acid, tyrosine, and leucine, but no glyco- 

 coll. He found the nitrogen distributed as follows: amid-nitrogen, 

 9.9 per cent. ; humin-nitrogen, 9.8 per cent. ; diamino-nitrogen, 6.4 

 per cent. — which last was composed of: histidine, 0.9 per cent.; 

 arginine, 2.4 per cent. ; lysine, 3.0 per cent. The extensive analytic 

 studies of Hopkins and Savory °° show that the amino-acid grouping is 

 that of a typical protein, with a high proportion of aromatic radi- 

 cals, similar proteins not being found in the tumors or muscles of a 

 typical case. In fact, the amino-acid content, as given below, indi- 

 cates that Bence-Jones protein is as distinct from other proteins in 

 chemical composition as in its physico-chemical properties. The 

 amino-acids, in round numbers, were isolated in the following per- 

 centage proportions of the entire protein : Valine-leucine fraction, 

 14 ; glutamic acid, 8 ; aspartic acid, 2 ; proline, 2.7 ; phenylalanine, 4.8 ; 

 tyrosine, 4.2 ; tryptophane, 0.8 ; cystine, 0.6 ; arginine, 6 ; histidine, 0.8 ; 

 lysine, 3.7; sulphur, 1.2. An important point in this work is the 

 agreement in composition of the proteins from two different cases, 

 being identical within the limits of the analytic methods, showing that 

 the protein is of constant and characteristic properties. 



Occurrence of "Myelopathic Albumosuria." — ^Not all cases of mul- 

 tiple myeloma show the presence of Bence-Jones protein in the urine, 

 however, and it is present occasionally in other conditions. Multiple 

 bone involvement by other tumors does not often cause "albumo- 

 suria. ' ' *'° There is no evidence that it occurs in the normal body, even 

 in the bone-marrow, or that it is produced as a step in the splitting of 

 any form of proteins. A few cases of supposed osteomalacia have 

 been reported, with the Bence-Jones body in the urine, but on more 

 careful investigation these seem to have been unrecognized myelomas 



58Zeit. phvsiol. Cheni., 1000 '.30\ 200. 



r-oJour. of Physiol., Iflll (42). 180. 



60 A case of this kind has, however, been described by Oerum (Ugeskrift f. 

 Lager., 1004, No. 24), in which the bone tumors were multiple metastases of a 

 gastric carcinoma. See also Boggs and (inttiric, .\mcr. .Tour. !\Icd. Sci., 1012 

 (144), 803. 



