228 SCIENCE PROGRESS 



of them which will bear scientific investigation. What I have 

 said with regard to diet as a possible cause of cancer applies 

 even more forcibly to diet as a cure. Diet may be among the 

 causes of cancer but when once a group of cells has become 

 malignant, it is quite obvious that no change of diet can destroy 

 them. The cancer cells derive their nourishment from the cells 

 forming the body of the organism in which they exist. The 

 cancer cells have been shown experimentally to possess a 

 vitality at least as great as and in some respects greater than 

 that of the somatic cells, so any change of diet must affect the 

 cells through which the nourishment of the cancer cells passes 

 before it affects the cancer cells. There is nothing that suggests 

 that any particular form of diet could act upon the somatic 

 cells in such a manner as would cause them to produce any- 

 thing which would act in a selective manner upon the cancer 

 cells and cause them to die out without affecting any of the 

 other cells which form the body. Everything we know which 

 bears upon this, point suggests that such an effect could not 

 be produced in such a manner. However, in spite of the 

 extraordinary improbability that diet could affect the growth 

 of cancer to any material extent, I made some experiments upon 

 mice suffering from cancer in order to make sure of this point. 

 Some were given a mixed diet of bread, water, milk and meat ; 

 others were kept upon a diet of rice and water only. According 

 to certain claims that have been made from time to time, meat 

 is one of the principal articles of diet which is to be avoided 

 in cases of cancer. The tumours in all these mice grew at 

 about the same rate. The great difference between the two 

 sets was that the mice fed on a mixed diet thrived whilst 

 those on a rice diet did not. 



Radium and X-rays have been much used in cases of cancer 

 and in some cases have been successful ; there is, however, 

 no evidence to show that these exert any specific action upon 

 the cancer cells. The effect in both cases probably is to kill 

 the cells which are exposed to the treatment, whether they 

 be malignant cells or not. The form of malignant growth in 

 which such treatment has been most successful is rodent ulcer. 

 But rodent ulcer is successfully treated by purely mechanical 

 means such as scraping, though more scarring is thus pro- 

 duced. There is therefore nothing in the effect produced in 

 these cases which suggests selective action nor is there in 



