TYPHOID FEVER. 83 



The injection of mallein would probably supply 

 information which would be obtained more easily and 

 quickly, and would be more conclusive. 



TYPHOID FEVER. 



Typhoid fever is caused by a bacillus which is 

 variable in length, though usually short (about half 

 as long as a tubercle bacillus) and thick, its length 

 being only about three times its breadth. It does not 

 form spores, and it does not stain by Gram's method. 

 It is actively motile ; when a culture of the organism 

 in a fluid medium is examined under the microscope 

 the bacilli can be seen darting rapidly about in all 

 directions. It owes its motility to the possession of a 

 large number of long wavy flagella, which can only be 

 seen after special and difficult staining processes. 



The bacillus coli communis, the most plentiful organ- 

 ism of the intestine in man and animals, bears a very 

 close resemblance to the typhoid bacillus, and can only 

 be distinguished therefrom by the application of several 

 cultural and chemical tests, the performance of which 

 takes a considerable amount of time. This renders it 

 very difficult to diagnose typhoid fever by methods 

 similar to those which are in use for the other diseases 

 mentioned, i.e., by the demonstration of the specific 

 organism. Suppose for instance, that we were to 

 attempt to determine the nature of a case of diarrhosa 

 by a search for the typhoid bacillus in the stools. For 

 every typhoid bacillus which we should encounter we 

 should find a great many colon bacilli, and we should 

 only be able to distinguish the one from the other by 



G 2 



