406 PATHOGENIC MICROORGANISMS 



Of 224 cases during first week, 89 per cent were positive. 

 Of 484 cases during second week, 73 per cent were positive. 

 Of 268 cases during third week, 60 per cent were positive. 

 Of 103 cases during fourth week, 38 per cent were positive. 

 Of 58 cases after fourth week, 26 per cent were positive. 



The technique recommended by Coleman and Buxton for obtaining 

 blood cultures is that recommended by Conradi, 1 slightly modified. The 

 blood is taken into flasks each containing about 20 c.c. of the following 

 mixture: 



Ox-bile 900 c.c. 



Glycerin 100 c.c. 



Pepton 20 grams. 



About 3 c.c. of blood are put into each flask. The ox-bile, besides 

 preventing coagulation, may possibly neutralize the bactericidal sub- 

 stances present in the drawn blood. The flasks are incubated for eigh- 

 teen to twenty-four hours, at the end of which time streaks are made 

 upon plates of lactose-litmus-agar and the organisms identified by 

 agglutination or by cultural tests. 



European workers have generally preferred to make high dilution of 

 the blood in flasks of bouillon, small quantities of blood, 1 to 2 c.c., being 

 mixed with 100 to 150 c.c. of nutrient broth. 



Epstein 2 has reported excellent results from mixing the blood in 

 considerable concentration with two-per-cent glucose agar and pouring 

 plates. 



The writers in hospital work have had equally good results with the 

 bile medium and with broth in flasks, rather less uniform but still satis- 

 factory results with the plating method. In general it may be said that 

 any one of these methods carried out with reasonable accuracy may be 

 satisfactorily employed. 



Typhoid Bacilli in the Stools. The examination of the stools for 

 typhoid bacillus is performed for diagnostic purposes chiefly in obscure 

 cases. It may, furthermore, furnish information of great hygienic 

 importance. Thus Drigalski 3 and Conradi have succeeded in isolat- 

 ing typhoid bacilli from the stools of ambulant cases so mild that 

 they were not clinically suspected. It la oy means of such examina- 

 tions that the so-called typhoid-carriers are detected, cases which, 



1 Conradi, Deut. med. Woch., xxxii, 1906. 



2 Epstein, Proc. N. Y. Path. Soc., N. S., vi, 1906. 



3 Drigalski and Conradi, Zeit. f . Hyg., xxxix, 1902. 



