CORRELATION OF PHENOMENA 73 



a matter of degree. It is by the presence of a sub- 

 stance which acts as a nucleus that these changes 

 are brought about, without the nucleus apparently 

 partaking in the actual combinations of the process, 

 whilst the last state of the nucleus is neither better nor 

 worse, but the same as the first ! Thus, as in the case 

 of catalytic phenomena, the influence of impurities 

 forms a very important part in the production of phos- 

 phorescence, as also does the presence of nuclei, and 

 their behaviour is like that of enzymes in more com- 

 plicated molecular interactions. The extraordinary 

 behaviour of solid solutions in exhibiting phos- 

 phorescences and thermo-luminescences, gives at 

 the outset a clue which cannot be ignored as to 

 the probable catalytic nature of these phenomena.^ 



That a nucleus takes part in the process of 

 luminosity, and that it resembles in many ways, in 

 its behaviour, the part played by enzymes in highly 

 complex organic and vital processes, is a point of very 

 great importance in the correlation of these facts. 



We shall, in conclusion, have to deal with experi- 

 ments on the influence of radium and other sub- 

 stances on gelatin and other colloid bodies, and to 

 dwell upon the remarkable effects thus produced, of 

 the organic bodies spontaneously developed in such 

 media, notwithstanding all previous sterilisation and 

 re-sterilisation. 



The unstable nature of the radium emanation 

 resembles in many ways the behaviour of unstable 



1 Electrician, 26 Sept. 1902. Brit. Assoc. Bep., Belfast, 1902. 

 See also Phil. Mag., March and April, 1901. 



