[ 345 ] 



XXVII. 



SEARCH FOE, THORIUM IN CANCEROUS GROWTHS. 

 By J. JOLT, Sc.D., F.R.S. 



[Eead June 23, 1914. Published January 7, 191S.] 



In a recent number of the Proceedings of the Royal Society (vol. Ixxxv B, 

 p. 170, and in The Practitioner (March, 1914)), Dr. Lazarus-Barlow records 

 observations showing the presence in some cases of abnormally large quan- 

 tities of radium in morbid tissues. His experiments refer to cancerous and 

 malignant growths of various kinds. 



These results may be very significant, for, of course, the radiations from 

 the radioactive derivatives of radium are involved, and it has been shown by 

 observation that feeble y radiation may accelerate the growth of such morbid 

 tissues. Nor is it difficult to perceive d priori reasons for the influence of the 

 rays when their remarkable ionising powers are considered in connexion 

 with the chemical activities involved in metabolism. 



Dr. Lazarus-Barlow's results are, however, bj' no means uniformlj? posi- 

 tive. The amount of radium present cannot, in every case, be claimed as 

 abnormal. This fact suggested tlie desirability of seeking for the presence 

 of thorium in such growths. 



The element tliorium is, so far as we know, much moi-e abundant in 

 Nature than radium. In the sedimentary rocks (which may be taken as 

 covering the greater part of the earth's surface) there is on the average ten 

 million times as much thorium as radium. In radioactivity, however, the 

 amounts present of the two series — i.e. of the radium series of element and 

 of tlie thorium series — do not differ seriously. Indeed the aggregate energy 

 emitted in transmutation by each, series, as determined by the heating effect, 

 is rather greater for the radium series than for the thoiium series in average 

 sedimentary material. We may assume, then, that if these elements — 

 radium and thorium — are taken into the body, in amounts proportional to 

 their relative abundance in the surface materials of the earth, their radio- 

 active influence upon growth, etc., will be much alike in importance — be this 

 little or great — and, if by any processes segregation of these elements is 

 equally promoted in any special organ, the effects will be similar in kind and 



SCIENT. PEOO. E.D.S., VOL. XIV, NO, XXVII. 3 K 



