JXOh'dAMC COX^TITLEXTS OF TUMOUH 499 



cancer o;rowth ; apparently lecithin inhibits gi-o\vth and cholesterol 

 stimulates/'' However, Bullock and Cramer *^'' found much more 

 cholesterol in a slowly jifrowing- mouse carcinoma than in a rapidly 

 growing one. somewhat more phosphatid in the latter, much more 

 phosphatid in a sarcoma than in the carcinoma, and* cerebrosides only 

 in the latter; in necrotic portions of tumors they found an increase in 

 simple fats. These tigiires are based on too few observations to be in- 

 terpreted as yet. 



(3) Inorganic Constituents. — These have been studied under ex- 

 ceptionally favorable conditions, in that the age of the tumor could be 

 accurately estimated, in the inoculable carcinoma of mice (Jensen), 

 by Clowes and Frisbie.^^ They found that rapidly growing tumors 

 contain a high percentage of potassium and little or no calcium, 

 whereas in old, slowly growing, relativel}' necrobiotic tumors the rela- 

 tion is reversed, the potassium decreasing greatly while the calcium in- 

 creases. Magnesium is present only in traces, while the proportion of 

 sodium fluctuates much less, but is usually greater than either the 

 potassium or calcium, although in very old tumors the latter may be- 

 come excessive. The most rapid growth, however, seems to occur in 

 tumors in which both calcium and potassium arfe present in the ratio of 



K 2 3 

 — = - or - 

 Ca 1 2 



Beebe ^'' analyzed a number of human tumors with the following 

 results: PhosphoTOS was found in proportion to the amount of nu- 

 clear material, varying from 0.139 per cent, (uterine fibroid) to 1.06 

 per cent, (sarcoma). Iron varied from 0.013 per cent, to 0.064 per 

 cent., probably depending on the amount of blood and nucleoproteins. 

 Calcium is most abundant in old degenerated tumors, and potassium in 

 rapidly growing tumors. These results, supported by Clowes and 

 Frisbie's findings, indicate the importance of potassium for cell 

 growth. Injection of potassium salts into mice increases their suscep- 

 tibilitj' to inoculation (Clowes),""^ while calcium decreases cancer 

 growth (Goldzieher).'*" A greater proportion of potassium was found 

 in primary than in secondary growths by Mottram ; '*^ sodium was the 

 same in each ; there is more potassium in squamous cell carcinoma 

 than in round cell sarcoma. Robin ^^ states that in cancerous livers 

 the cancer tissue contains more inorganic matter than the normal liver 



43 See Robertson and Burnett. Jour. Exp. Med., 1013 (17), 344; 1916 (23), 

 631; Sweet et al.. Jour. Biol. Cliem., 1915 (21), 309. 

 43aProc, Roval Soc, London (B), 1914 (87), 236. 

 4*Amer. Joiir. Physiol., 190.5 (14), 173. 

 45 Amer. Jour. Plivsiol., 1904 (12), 167. 

 48 British Med. Joiir., Deo. 1, 1906. 

 4TVerhandI. Deiit. Path. Gesellsch., 1912 (15), 283. 

 48 Arch. Middlesex Hospital, 1910 (19), 40. 

 49Conipt. Rend. Acad. Sci., 1913 (156), 334. 



