494 THE CHEMISTRY OF TUMORS 



tive proliferation of the epitlieliuni, but witliout metastasis, and re- 

 trogressing: when the irritant is discontinued.'"' The influence of vari- 

 ous salts on cell o;ro\vth has also been a])plied to cancer patholofjy, and 

 while we have abundant evidence that chemical substances may either 

 stimulate or check cell growth, as well as regulate it, our biological 

 chemistry has not yet given us any very substantial facts on these 

 problems/ 



Nevertheless, numerous observations have been made concerning the 

 chemistry of tumors, which, although they do not as yet throw any 

 important light on the fundamental problems of tumor pathology, 

 are of much interest. These may be briefly summarized as follows : 



A. CHEMISTRY OF TUMORS IN GENERAL 



(1) Proteins. — Earlier studies showed that tumor growths contain 

 the same sorts of proteins as do normal tissues, and apparently in 

 about the same proportions, and in spite of certain contradictory re- 

 ports this statement seems to be correct. 



In all probability the nucleoproteins of tumors share the specific 

 characteristics of the nucleoproteins of the tissues from which they 

 arise — at least this is the case with the nucleoproteins of lymphosar- 

 coma, according to Bang.- The characteristic constituent of lymph- 

 glands, spleen and thymus is a compound of nucleic acid and histon 

 {Jiistmi nudeinate) . If to a watery extract of an organ a few drops 

 of CaCL solution are added, the formation of a precipitate indicates 

 the presence of a lymphatic tissue. If this precipitate is soluble in 1 

 per cent. NaCl, it is a nucleinate corresponding in type to that of the 

 lymph-glands and spleen ; if not soluble, it is of the type of the 

 thymus or leucocytes. Extracts from no other organs give a pre- 

 cipitate with calcium chloride. Spindle-cell sarcomas were found not 

 to give this reaction, but round-cell sarcomas of lymphatic origin do, 

 for they contain the specific nucleinate abundantly. Bang believes 

 that this reaction can be used to distinguish sarcoma arising from 

 lymphoid tissue. This seems to have been confirmed by Bcebe," who 

 found nucleo-histon only in lymph-gland tissue, but the distinction be- 

 tween thymus and lymph-gland nucleohistou is probably not so easily 

 made as Bang intimates. 



Because of their richly cellular structure cancers may contain move 

 nucleoprotein than the tissues from which they arise. Thus Petry ^^ 

 found 50 per cent, of nucleoprotein in carcinoma of the mannuary 

 gland, as against 30 per cent, in normal tissue, which is perhaps ve- 



«b;Mitt. Med. Oosollsch., Tokio, 1910 (im) . 1. 



7 A thoory of foil division in cancor as a icsuK of (.'kH'tric forces is uivon by 

 JoRsup et ah, Tlioc-licm. Jour., 1909 (J), 19]. 

 « TTofinoistcr's Boitr., 199.3 (4), 36H. 

 t> Anipr. Jour. Phvsiol., 190r) (1.3), 341. 

 loZeit. physiol. Chem., 1899 (27), 398. 



