Bacilli Resembling the Typhoid Bacillus 68 1 



white rats. He has also obtained a poisonous protein of 

 which 50 mg. were fatal for white rats, and which immu- 

 nized them against highly virulent hog-cholera organisms 

 when administered by repeated subcutaneous injection. 



De Schweinitz* has also separated a slightly poisonous 

 base which he calls "sucholotoxin," and a poisonous protein 

 that crystallizes in white, translucent plates when dried over 

 sulphuric acid in vacua, forms needle-like crystals with pla- 

 tinic chlorid, and was classed among the albumoses. 



Pathogenesis. The bacillus is disappointing in its 

 effects upon hogs. When it is subcutaneously or intra- 

 venously introduced into such animals or fed to them, they 

 sometimes show no signs of disease; sometimes show fever 

 and depression, but rarely sicken enough to die. Animals 

 thus made ill do not communicate the disease to others. 



Smith found that 0.75 c.c. of a bouillon culture injected 

 into the breast muscles of pigeons would kill them. 



In Smith's experiments one four-millionth of a cubic 

 centimeter of a bouillon culture injected subcutaneously 

 into a rabbit was sufficient to cause its death. The tem- 

 perature abruptly rises 2 to 3 C., and remains high until 

 death. Subcutaneous injection of larger quantities may 

 kill in five days. Injected intravenously in small doses the 

 bacillus may kill rabbits in forty-eight hours. 



Agglutination. Pitfieldf found that after a single in- 

 jection of a killed bouillon culture of the bacillus into a 

 horse, the serum, which originally had very slight agglutina- 

 tive power, showed a decided increase. If the horse be 

 immunized to large doses of such sterile cultures, the serum 

 becomes so active that with a dilution of i : 10,000 a typical 

 agglutination occurs in sixty minutes. 



McClintock, Boxmeyer and SifferJ found that the serum 

 of normal hogs agglutinates strains of ordinary hog-cholera 

 bacilli in dilutions occasionally as high as i : 250, and con- 

 sider reaction in a dilution of less than i : 300 without 

 diagnostic value. 



"Medical News," 1900, p. 237. 

 f "Microscopical Bulletin," 1897, p. 35. 

 J "Jour, of Infectious Diseases," March i, 1905, vol. n, No. 2, p. 351. 



