78 BIO-RADIOACTIVITY, EOBES, RADIOBES 



cultures. He considers them not bacteria, and not contaminations, 

 but "highly organized bodies." They have "nuclei," subdivide 

 when a certain size is reached, and " the larger ones appear to have 

 sprung from the smaller ones, and they have all probably arisen -in 

 some way from the invisible particles of radium." He regards them 

 as colloidal, rather than crystalling, "of the nature of 'dynamical 

 aggregates' rather than of * static aggregates,' " and coins for them 

 a new name, radiohes. This forms the experimental basis for a 

 volume of 351 pages. 



With reference to these discoveries, Dubois ^^ claims priority over 

 Burke, and rejects his term radiobe in favor of eobe, because these 

 bodies may be obtained with non-radioactive substances. 



A few months after Burke's announcement Rudge ^^' -^ showed 

 that the alleged growths were " nothing more than finely divided 

 precipitates of insoluble barium salts." He was unable, in a prep- 

 aration similar to the one described by Burke, to observe anything 

 like cell-division, and believes that an occasional grouping of the 

 particles in pairs must be purely fortuitous. The appearance of 

 growth of the radiobes is explained as due to a diffusion of the pre- 

 cipitate through the gelatine from a point of concentration where the 

 radium salt was in contact with the gelatine. Salts of barium, lead, 

 and strontium produced ejects exactly similar to those caused by 

 radium preparations. 



Again repeating Burke's experiments, Rudge'^'' was unable to 

 secure the radiobes when agar-agar was substituted for gelatine and 

 distilled water was used. If tap-water was employed a slight growth 

 resulted, while the addition of a soluble sulfate resulted in a very 

 dense growth. An examination of 30-40 samples of gelatine showed 

 that they all contained enough H^SO^ to give a distinct, sometimes a 

 dense precipitate with barium chloride in the presence of HNO3. 

 This precipitate was found, on analysis, to be BaSO^. Gelatine was 

 then prepared free from sulfates and gave no growth. Negative 

 results were obtained with salts of uranium, thorium, pitchblende, 

 and metallic uranium, thus clearly indicating that there is not the 

 slightest connection between the formation of the radiobes and radio- 

 activity. 



A sample of gelatine from which HgSO^ had been removed was 

 sealed with a radium salt from June until September. At the end of 

 that time no growth appeared, but when a soluble sulfate was added 

 to a portion of this gelatine the growth began at once. 



