PATH0GE2SnC BACTKRIA. 



279 



acid in forty-eight hours. The reaction of the bouillon sub- 

 sequently becomes alkahne. The growth may form a pelHcle 

 over the surface of the bouillon. It has also been successfully 

 cultivated on various media to which egg-albumen has been 

 added. 



It is killed by a moist heat at 58° C. in ten minutes. It 

 resists desiccation well. 



Bacteriological Diagnosis oj Diphtheria. — In many large 

 cities the bacteriological diagnosis 

 of diphtheria is undertaken by 



•Vv , 





v;t' 



Fig. 82. — Bacillus of Diphtheria 

 Stained by Neisser's Method. (X 

 1000.) 



Fig. 83. — Swab and Citl- 

 tijre-tttbe used in the 

 Diagnosis of Diph- 

 theria. 



boards of health. The methods used differ somewhat in 

 detail, but are similar in the main, and are based upon the 

 procedure devised by Biggs and Park for the Board of Health 

 of New York City. Two tubes are furnished in a box. The 

 tubes are like ordinary test-tubes, about three inches in length, 

 rather heavy and without a flange. Both are plugged with 

 cotton. One contains slanted and sterilized LofHer's blood- 



