248 



SCIENCE. 



[N. S. Vol. XX. No. 503. 



action upon the bacteria. Details are given 

 in the following table. 



The action of radium rays upon the diph- 

 theria bacillus (B. diphtherias) was next 

 studied, the methods employed being the same 

 as with B. coli. This organism was selected 

 (1) because it may be regarded as a typical 

 pathogenic microbe; and (2) because it has 

 been suggested that radium, on account of its 

 germicidal action, may be conveniently applied 

 in the treatment of diphtheria. In such treat- 

 ment the radium is to be encased in special 

 tubes (to be obtained from dealers in radium) 

 and these tubes inserted in the throat, where- 

 upon, it has been claimed, the organisms will 

 be destroyed. It has even been hinted that 

 radium may replace antitoxin in medical prac- 

 tice. 



Two cultures of B. diphtherice were experi- 

 mented upon — one a laboratory culture of sev- 

 eral generations since isolation, the other a 

 recently isolated, virulent culture. As with 

 B. coli the length of the exposure to the action 

 of radium varied considerably, and in all cases 

 the results were negative, as will be seen from 

 the table. 



No experimental evidence whatever was ob- 

 tained which would indicate that any degree 

 of success can be hoped for in treating diph- 

 theria by destroying the specific micro-organ- 

 isms by means of radium rays. 



A few experiments were also made to de- 

 termine the action of radium on fungi other 

 than bacteria, and for this purpose domesti- 

 cated yeast (Saccharomyces cerevisice) was 

 employed as a type of the blastomycetes. The 

 method differed from that used with B. coli 

 and B. diphtherice only in the fact that a wort- 

 gelatine medium replaced nutrient agar, and 

 that the plates were incubated at 25° instead 



of at 37°. As in the experiments with bac- 

 teria, negative results only were obtained, the 

 most careful scrutiny failing to reveal any 

 destruction, or even any inhibition, of the life 

 or growth of the micro-organisms. 



These experiments and the conclusions to 

 be drawn from them may be summarized by 

 the following statements. 



-1. Radium rays have no effect upon fresh 

 cultures of B. coli, B. diphtherice, or Saccharo- 

 myces cerevisiw at a distance of one centi- 

 meter when the time of exposure is less than 

 ninety minutes. 



2. Any advantages derived from the thera- 

 peutic use of radium must be explained in 

 some other way than by the direct weakening 

 or destruction of the micro-organisms of dis- 

 ease. 



3. The use of radium tubes in the treatment 

 of diphtheria can not be recommended or re- 

 garded as a substitute for antitoxin. 



In conclusion, I desire to express my obliga- 

 tion to Dr. F. H. Williams for the opportunity 

 to carry on these experiments, and for many 

 helpful suggestions. S. C. Prescott. 



The Biological Laboeatokies, 

 Mass. Inst. Technology, 

 July 30, 1904. 



A wheat-rye hybrid. 

 To THE Editor of Science : A few prelimi- 

 nary notes as to distribution of parental char- 

 acters observed in the above type of hybrid 

 grown by the writer during the present season 

 may be interesting. The cross was obtained 

 in May, 1903, by using a Eussian variety of 

 rye as the pollen- and Jones' Winter Fife as 

 the seed-parent. No reciprocal crosses were 

 attempted. Several seeds resulted, of which 

 a few showed apparent xenia, the blue-gray 

 color of the rye seed-coat being very evident 



