CHAPTER VI 



EXPERIMENTS WITH RADIUM AND CULTURE MEDIA 



Experiments with glycerine and liquid air — Dr. Gladstone's 

 glycerine crystals — Culture produced by radium salts in 

 gelatin bouillon — Other globular bodies produced by gum 

 and gelatin — Eeasons for supposing radiobes are not bacteria 

 — Negative experiments with cyanogen — Pfliiger's theory — 

 Nature of the cyanogen molecules and of the radium mole- 

 cules — Dubois' vaeuolides not radiobes — Sachs's theory of 

 colloid bodies : that they are crystals asymmetrically 

 arranged — Experiments of Leduc, Biitschli, and others — 

 Discussion of Pasteur's results and their bearing on the 

 present experiments — Eadiobes and primitive hfe. 



In the course of my previous work on phosphor- 

 escence I was induced to try whether the molecular 

 groupings which, it was supposed, were formed 

 during phosphorescence, by exciting sources, could 

 also be produced in other organic bodies, whether 

 they become luminous or not, so long as they 

 are similarly acted upon. The precise reasons 

 for this hypothesis will appear when we come to 

 deal with the phenomena of phosphorescence and 

 fluorescence. 



The first attempt was to bring about the con- 



