TYPHOID FEVER. 195 



allowed to remain for about ten minutes in a i-5th per cent, 

 solution of corrosive sublimate and then stained by Gram's 

 method, the bacilli are most deeply stained, although Fraenkel 

 and others state that the colour is invariably discharged if 

 Gram's method be used. They may also be prepared by 

 Kiihne's method of first allowing them to remain in a con- 

 centrated watery solution of oxalic acid, washing them 

 carefully and afterwards staining with methyl blue dissolved 

 in a I per cent, solution of ammonium carbonate. Sections 

 may also be stained for twenty-four hours in Loffler's alkaline 

 methylene blue, after which they are rinsed in water, which 

 removes sufficient of the colour ; the water is driven out with 

 aniline oil, the sections are allowed to dry on the slide and 

 mounted in Xylol Balsam. 



The bacilli are found in the adenoid follicles, or lymphatic 

 tissue of the intestine, in the mesenteric glands, in the spleen, 

 and in the liver, and more rarely in the kidneys. They are 

 usually collected in little clumps, and single bacilli are seldom 

 if ever met with. These clumps, although readily enough 

 recognized when seen, are as a rule so sparsely scattered 

 through the tissues that it is often a difficult matter to find 

 them, even in characteristic cases, and as Fliigge says, " It is 

 only after the examination of a large number of sections that 

 one or several of these deposits can be found." Gaffky, 

 working in the Hygienic Institute in Berlin, was first able to 

 make pure cultivations of this bacillus, and in 1884 he gave 

 a very complete description of the bacilli that he was able to 

 examine or to cultivate in twenty out of twenty-two cases of 

 typhoid fever of which the examination was committed to his 

 charge. The bacilli, when obtained pure, and cultivated in 

 fluid, grew out into very long threads, both threads and short 

 bacilli apparently being motile, having a peculiar wavy motion ; 

 quite recently this motion has been found to be due to the 

 presence of groups of lateral flagella which, waving back- 

 wards and forwards, impart to the organism its peculiar 

 snake-like movement. The bacillus can grow perfectly well 

 both in the presence of free oxygen and also when oxygen is 

 cut off, but, as in the case of the cholera organism, it appears 

 to have somewhat different functions and different powers 

 under the two sets of conditions ; outside the body in the 

 presence of oxygen it appears to develop great " resistant " 

 power and a saprophytic habit, whilst in the anaerobic con- 



