430 BACTERIOLOGY. 
thrown light upon the distribution of the organism in 
the body during life, yet as a regular means of diag- 
nosis it is to be discouraged, on account of the possible 
danger to the patient. The results of the examination 
of the blood and rose-spots of typhoid patients have 
in the main proved unsatisfactory, though the investi- 
gations of some of the later observers have given a 
number of positive results from the blood. The exam- 
ination of the urine and feces of typhoid patients has 
more often given positive results than the blood, 
and these positive results have become more fre- 
quent and satisfactory as the methods for differentiating 
the bacillus typhosus have grown more exact and re- 
fined. . 
There are at present several recently devised media 
employed for the isolation and identification of the 
typhoid bacillus, which are much betier than any of 
those formerly used. These are the Hiss, Capaldi, 
and Elsner media. In the hands of trained bacteri- 
ologists they give satisfactory results. 
THe Hiss Mepia:' Their Composition and Prepa-, 
ration. Two are used: one for the isolation of the 
typhoid bacillus by plate culture, and one for the 
differentiation of the typhoid bacillus from all other 
forms in pure culture in tubes. 
The plating medium is composed of 10 grammes of 
agar, 25 grammes of gelatin, 5 grammes of sodium 
chloride, 5 grammes of Liebig’s beef extract, 10 
grammes of glucose, and 1000 c.c. of water. When 
the agar is thoroughly melted the gelatin is added and 
1 This description is taken from an article by Dr. Philip Hanson Hiss, Jr., 
“On a Method of Isolating and Identifying Bacillus Typhosus and Members 
of the Colon Group in Semi-solid Culture Media,’’ published in the Journal 
of Experimental Medicine, 1897, vol. ii. No. 6. 
