104 ESSENTIALS OF BACTERIOLOGY. 



Roux and Yersin, in 1888, discovered that the injection of the 

 filtered culture bouillon (that is, freed of all diphtheria bacilli) 

 gave rise to the same palsies as when the bacilli themselves were 

 introduced. 



Toxalbumen of diphtheria. Brieger and Friinkel filter the 

 bouillon culture, evaporate (in vacuo at 27 C.) to ^ volume, 

 then treat with 10 volumes of alcohol and acetic acid the pre- 

 cipitate redissolved in water and re precipitated with the acidu- 

 lated alcohol until a clear aqueous solution is obtained ; this is 

 then dialyzed for 72 hours, and again precipitated with alcohol, 

 and dried ; a white amorphous body results, giving all the re- 

 actions of an albumen, and called by them toxalbumen. 



Immunity. Brieger and Frankel, by injecting 10 to 20 c.cm. 

 of a three weeks' old culture of diphtheria bacilli, which had 

 been heated at 70 C. for one hour, produced an immunity in 

 guinea-pigs against the virulent form. 



Behring found several ways to make animals immune. One 

 method was to infect them with diphtheria and then inject tri- 

 chloriodine into them, which prevented them from dying, and 

 they were then immune. 



Site of Bacilli. Bacilli are usually found in the older portions 

 of the pseudo-membrane very near to the surface. The secre- 

 tions of the throat of a diphtheritic child produced bacilli three 

 weeks after the temperature was down to normal. 



Streptococcus in Diphtheria. Streptococci have been found 

 quite constant in diphtheria, but they resemble the strepto- 

 coccus pyogenes, and have no specific action. 



Bacillus of Typhoid or Enteric Fever. (E berth-Gaff ky.) 



Origin. Eberth found this bacillus in the spleen and lym- 

 phatic glands in the year 1880, and Gaff ky isolated and cultivated 

 the same four years later. 



Form. Rods with rounded ends about three times as long as 

 they are broad. Usually solitary in tissue-sections, but in arti- 

 ficial cultures found in long threads. Flagella on the side. 



Properties. They are very motile ; they take the aniline dyes 

 less deeply than some similar bacilli. Spores have not yet been 

 found ; small oval spaces appear in some of the degenerated 

 bacilli just at one end, but these bacilli are less resistant than 

 those without tins so-called spore ; they do not liquefy gelatine. 



