METHODS OF EXAMINATION. 351 



(b) From the Urine. Typhoid bacilli are present in the 

 urine in about twenty-five per cent of cases, especially late 

 in the disease, probably chiefly when there are groups in 

 the kidney substance. For methods of examining sus- 

 pected urine, see p. 78. 



(c) From the Stools. During the first ten days of a case 

 of typhoid fever, the bacilli can be isolated from the stools 

 by the ordinary plate methods preferably in phenolated 

 gelatine. After that period, though the continued in- 

 fectiveness of the disease indicates that they are still 

 present, their isolation is practically hopeless. We have 

 seen that after ulceration is fairly established by the slough- 

 ing of the necrosed tissue, the numbers present in the 

 patches are much diminished and therefore there are fewer 

 cast off into the intestinal lumen, and that in addition 

 there is a correspondingly great increase of the B. coli, 

 which thus causes any typhoid bacilli in a plate to be quite 

 outgrown. From the fact that the ulcers in a case of 

 typhoid may be very few in number, it is evident that there 

 may be at no time very many typhoid bacilli in the 

 intestine. We may add that the microscopic examination 

 of the stools is useless as a means of diagnosing the 

 presence of the typhoid bacillus. 



Isolation from Water Supplies. A great deal of work 

 has been done on this subject. It is evident that if it 

 is difficult to isolate the bacilli from the stools it must 

 a fortiori be much more difficult to do so when the latter 

 are enormously diluted by water. Some have held that 

 the typhoid bacillus has never been isolated from suspected 

 water, and have adduced this as an argument against its 

 etiological relationship to the disease. The considerations 

 just advanced, however, militate against such a view. The 

 B. typhosus has been isolated from water during epidemics. 

 This was done by Klein in the outbreaks in recent years 

 at Worthing and Rotherham. The B. coli is, as might be 

 expected, the organism most commonly isolated in such 

 circumstances. In the case of both bacteria, the whole 

 series of culture reactions must be gone through before 



