154 THE AMERICAN MONTHLY [May 



STERILIZATION OF GELATIN WITH ONE ROILING. 



Dec. 29, 1896 



Feb. 19. 1S97 



.\f«r. iS. 1S97 



Do 



Mar. 23. 1897 



Do 



Mar. J5, 1S97 



^ JS 



3 ;= 

 = 



Q 2 



II 



Left at room temp for 14 clays 



Contained a spore bearing 

 bacillus belonging to the H. 

 tubtilia group. 



If spore bearing bacilli are [>resent in large numbers 

 more difficulties might be experienced. But ordinarily 

 if the medium is prepared with proper care and distrib- 

 uted as soon as filtered, in sterile tubes and boiled at ome 

 very few contaminations are likely to occur. 



The time that must elaspe before the medium can be 

 safely used is not so much slioi-ter than when the custom- 

 ary method is employed but the time actually spent in 

 sterilizing is much shorter. In a crowded laboratory tliis 

 is important. It probably is not necessary to leave the 

 media in the incu}>ator from five to seven days as I havp 

 indicated in the above tables for in every case of con- 

 tamination the growth took place within the first twenty 

 four hours. 



1 am not prepared to say that this method is the best 

 or that it is safe for all kinds of work, but it has proved 

 to be well adapted to the needs in a student laboratory 

 and to save much valnai)le time for both the student and 

 trie tcachei'. 



Prof, llankine, one of the leaders in sanitary work 

 in India, contracted plague a few weeks ago, but fortu- 

 nately the attack was not severe and lie recovered. He 

 was inoculated with Hati'kine\ serum. 



