296 ' MICROSCOPICAL TECHNIQUE. 



All the above are soluble in, or miscible with water in every 

 proportion. In using them the material is thrown on the liquid, 

 and floats or sinks according to its specific gravity. — Natmial 

 Druggist. 



The Action of the X-Rays on Micro. Organisms. —Minck * 



exposed several agar plates which were inoculated with Eberth's 

 bacillus to the action of the X-rays. The time of exposure was 

 half-an-hour. The plate was put into the incubator at the same 

 time as two others which were used as "tests." At the end of 

 fourteen hours there was no difference in the number of colonies 

 that had grown on the three plates. 



In another experiment the quantity of culture sown on the 

 agar was less abundant, and the duration of the exposition was 

 thirty-five minutes. The colonies which developed on the plates 

 submitted to the rays were less abundant and thinner than 

 on the test plates. This led Minck to believe that the duration 

 of exposure was too short. Other plates prepared in the same 

 manner were submitted during a period of from two to eight hours 

 to the rays, and were then placed in the incubator. After fifteen 

 hours there was no difference in the aspect or the number of 

 colonies which had grown on the plates. 



These experiments seem to prove that the X-rays have no 

 special action on the bacilli, which excludes the idea of using 

 them as a therapeutic agent, at least in infectious diseases. 

 Similar negative results have been obtained by F. Barton, who 

 submitted the diphtheria bacilli to the action of the rays for six- 

 teen, thirty-two, and sixty-four hours. The vitality and the 

 virulence of the bacilli remained in their integrity. — Bulletin of 

 the Pasteur I?istitute, 1897. 



Diphtheria Bacilli can be very successfully cultivated upon a 

 new medium recommended by Kanthack and Stephens, in Ce?i- 

 tralblattfiir Bakteriologie, May 8, 1896. It is simple, inexpensive, 

 transparent. It resists the development of staphylococci and the 

 colon bacillus surprisingly well ; and yet it surpasses all other 

 media for the rapid cultivation and isolation of the diphtheria 



* Munch. Med. IVockenschrifi, p. 202, 1896. 



