METHODS OF EXAMINATION 389 



During life, typhoid bacilli may be obtained in culture in the 

 following ways : 



(a) From the Blood. The typhoid bacillus can often be 

 isolated from the blood, especially during the first week, by 

 ordinary methods (see p. 74). A special method has also been 

 used with success. In this 5 c.c. of blood are placed in 10 c.c. 

 of sterilised ox bile. The mixture is incubated for from twenty- 

 four hours to a week, and from time to time the presence of the 

 bacillus is tested for by sub-culturing on such media as those of 

 Conradi or MacConkey. 



(6) From the Spleen. This is the most certain method of 

 obtaining the typhoid bacillus during the continuance of a case. 

 The skin over the spleen is purified, and, a sterile hypodermic 

 syringe being plunged into the organ, there is withdrawn from 

 the splenic pulp a droplet of fluid, from which plates are made. 

 In a large proportion of cases of typhoid the bacillus may be 

 thus obtained, failure only occurring when the needle does not 

 happen to touch a bacillus. Numerous observations have shown 

 that, provided the needle be not too large, the procedure is quite 

 safe. Its use, however, is scarcely called for. 



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

 urine in at least 25 per cent, of cases, especially late in the 

 disease, probably chiefly when there are groups in the kidney 

 substance. For methods of examining suspected urine, see 

 p. 76. 



(d) From the Stools. During the three weeks over which 

 the febrile state usually extends, the bacilli can be isolated from 

 the stools. After that period, though the continued infectiveness 

 of the disease indicates that they are still present, their isola- 

 tion may be more difficult. We have seen that after ulceration 

 is fairly established by the sloughing of the necrosed tissue, 

 the numbers present in the patches are diminished, arid there- 

 fore 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 may cause the typhoid bacilli in a plate to 

 be 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. 

 Cases are recorded where the bacilli have been present in the 

 stools during the incubation period. The microscopic examina- 

 tion of the stools is of course useless as a means of diagnosing 

 the presence of the typhoid bacillus. The cultural procedures 

 recommended by Ledingham are of great value. Two or three 

 loopfuls of the faeces are emulsified in a. tube of bouillon and 



