PROLONGATION OF LIFE DUE TO X-RAYS 455 



tenth day, the highest death rate of JC was lower than tfie 

 lowest death rate of the controls. 



During the first seventeen days of the experiment, group JD 



MAM 



(200 — at 50 KV.) had a higher death rate than the controls. 



After the seventeenth day the death rate of group JD was less 



than that of the controls. After the twentieth day the death 



rate of JD was identical with that of JC. When divided into 



two equal subgroups, as described above, it was found that after 



the twenty-second day the highest death rate of group JD was 



less than the lowest death rate of the controls. 



During the first twenty-nine days of the experiment the 



MAM 



death rate of group JE (300 at 50 KV.) was greater than 



25^ 



that of the controls. After the twenty-ninth day the death rate 



of JE was less than that of the controls. 



MAM 



The death rate of group JF (400 — at 50 KV.) was at all 



times greater than that of the controls. 



These results are shown graphically in figure 3. Figure 4 

 contains an analysis of these same curves by means of prob- 

 ability paper, showing that, as in the case of experiment A, the 

 curves are composed of accurate portions of probability curves 

 placed end to end. 



All of the above results seem to be a direct confirmation of 

 the curves given in the previous paper (loc. cit.). The effect of 

 concentrated single doses is not nearly so marked as the effect 

 of a series of small 'homeopathic' doses. This seems to be much 

 the same law as is already well known in serum therapy and in 

 the action of certain drugs. In the case of serum therapy, this 

 law has been shown to be identical with the law of adsorption. 

 If it could be rigorously shown that the effects of exposure to 

 x-rays follow the same general law, we should conclude that the 

 x-rays are responsible for the production of some substance, 

 perhaps in the blood, which is later adsorbed. 



