147 
3. J. K. Male; white; age 9 years; school boy. Born in Balti- 
more, Md., where he lived until about 6 years old. Since then has 
lived in Washington, at 933 Twenty-fifth street NW. Eight in 
family — father, mother, and six children. None ever had typhoid 
fever. No sickness in family vdtliin past six months. Rooms 
occupied b}^ family to rear and on floor above a small grocery store 
owned and run by boy’s father and mother. 
Laborator}^ examinations; Urine, on September 21, gave positive 
result for B. typhosus. Examinations of urine obtained September 
25, October 8, and October 24, all were negative for B. typhosus. 
Examinations of feces on September 25, October 8, and October 24 
were negative for B. typhosus. 
As the plates made from the specimens of urine examined on Sep- 
tember 21 showed, beside the typhoid colonies, a large number of 
colonies like those of B. coli and other bacteria it is probable that the 
urine was caught in a soiled vessel before being placed in the clean 
specimen bottle. 
The possibility of the typhoid bacilli found in this specimen of 
urine having come from the excreta of some other members of the 
family was considered; but repeated examinations (altogether 32) of 
specimens of feces and urine from other members of the family were 
negative for the typhoid bacillus. 
The organisms isolated from the specimens of excreta of C. E. and 
of J. K. were carried through the various culture media. Their 
cultural characteristics and their serum reactions were those of the 
typhoid bacillus. 
In work of this kind the possibihty of experimental error must be 
conceded, particularly when 30 or more specimens of feces are 
examined in one day. However, the hkehhood of such error occur- 
ring by the misplacing or mislabeling of plates should have been 
reduced to practically nothing by the exercise of the utmost care. 
Considering each of the three positive results with a view to possi- 
bihty of error, we have the following; 
1. Specimen of feces of C. H. J. ; On the day that this specimen was 
examined only two other specimens were examined, so there was 
no need for hurry in doing the work. No control specimens con- 
taming typhoid bacilli were presented for examination that day; so 
the possibility of a control plate having been mistaken for one of 
the C. H. J. plates can be eliminated. The only apparent reasons 
for doubting this positive finding seems to be that the organism was 
not tested on all the culture media which may be used to identify 
the typhoid organism and only one serum was used to determine 
its agglutinability. However, the typical appearance of the colonies 
on Endo’s medium, the failure of the organism to ferment lactose 
broth to gas formation, its typical growth in this medium, and its 
