BACILLUS TYPHOSUS 285 



dilution of 1 to 250 and that the agglutinative power was much incrased 

 after inoculation with hog-cholera vaccine; it could be shown that 

 the intraperitoneal injection of such vaccines was usually followed by 

 the production of large quantities of agglutinins. The amount of 

 the vaccine, however, had no relation to the amount of agglutinins 

 formed. Giltner has recently published a preliminary report on a 

 series of experiments which show that the serum of hogs hyperim- 

 munized against hog cholera by the Dorsett-Niles method has a 

 very high agglutinative value for the hog-cholera bacillus. He found 

 values as high as 1 in 2000. The blood serum of immune hogs 

 (which had not yet been hyperimmunized) agglutinated in dilutions 

 as high as 1 in 1000. These results are really not very astonishing 

 when the fact is considered that hog-cholera bacilli are, as a rule, 

 found in the blood and organs of animals sick from hog cholera. 

 For this reason, an animal which survives an attack of the disease 

 may be expected to possess a certain amount of immunity against 

 the hog-cholera bacillus as well as against the invisible filterable 

 virus. The presence of a large amount of agglutinins against the 

 cholera bacillus in hyperimmunized animals can likewise be easily 

 accounted for by the fact that with the large amount of virulent, 

 blood injected for hyperimmunization a considerable number of 

 hog-cholera bacilli are also injected. The agglutination tests with 

 the hog-cholera bacillus are made as macroscopic tests, and the 

 method is identical with that employed in the case of the glanders 

 bacillus. According to a circular of the United States Department of 

 Agriculture the Bruschettini Hog-cholera Vaccine and the Bruschettini 

 Hog-cholera and Swine-plague Serum are without value whatsoever. 

 The department reported that healthy pigs were injected with the 

 serum and were exposed after twenty-four hours by being placed 

 in the same pens with hogs affected with the disease. All the hogs 

 treated with the Bruschettini serum contracted hog cholera within 

 the usual period of time after exposure and finally died, exhibiting 

 typical lesions of hog cholera at autopsy. 



BACILLUS TYPHOSUS. 



Occurrence. The best known of the microorganisms of the group 

 under discussion is the typhoid bacillus. It is the cause of typhoid 

 fever, also called abdominal typhoid or enteric fever in man. While 

 pathologic changes and death can be produced in experimental 

 animals by the inoculation of typhoid bacilli, none of the lower 

 animals are susceptible to a natural typhoid infection. In man, 

 typhoid fever is, as a rule, contracted through the drinking water 

 or food which has directly or indirectly become contaminated with 

 the excrements of patients suffering from the disease. The bacillus, 

 after ingestion with water or food, multiplies enormously on and in the 



