145 
rather large percentage of negative results from the examination of 
the control specimens containing typhoid culture which were obtained 
in the early part of the work was discovered to have been due to a 
large extent to the fact that a culture of B. typhosus was used which 
grew poorly and agglutinated feebly. 
The second method of controlhng the laboratory examinations, 
followed the greater part of the time, was as follows: 
The bottles containing the known normal feces plus typhoid 
culture were labeled with a fictitious name to make them appear as 
if they were collected specimens, and placed on the laboratory table 
along with the collected specimens. The amount of broth culture 
added to the 20 to 30 grams of feces was from 1 to 20 drops, and the 
culture was added to the feces from 1 to 72 hours before dehvery for 
examination. The mixture of feces and typhoid culture was kept 
at room temperature from the time of preparation to examination 
unless the culture was exposed to the feces for 48 or 72 hours, in 
which instances the mixture was kept in the cool room at a tempera- 
ture of 20° C. 
This second method had the advantage of being a more exact 
check on the efficiency of the work, but required the greatest possible 
care in the handling and labehng of the series of plates made from 
each specimen to prevent a plate made from a control specimen 
from being confused with one made from a collected specimen. 
By this second method 96 control specimens were examined and 
78, or about 81 per cent, were reported positive. It should be noted 
on the table that the 50 control specimens examined on and subse- 
quent to September 14 were all reported positive. From that date 
a fresh culture from a known vigorous strain of typhoid was used 
invariably, which had not been the case prior to that date. 
Another and more convincing check on the efficiency of the exami- 
nations was the examinations of the feces of ten typhoid-fever patients 
or early convalescents. Positive results were obtained in seven. 
Ten specimens, 9 of feces and 1 of urine, out of the 1,040 examined 
gave a positive result for B. typhosus. Seven of the specimens of 
feces giving positive results were obtained from persons who at the 
time of the examination had typhoid fever clinically. The remain- 
ing two specimens of feces and the one of urine giving positive results 
were obtained from three persons who did not have chnically recog- 
nized typhoid fever. The histories of these three persons were as 
follows : 
1. C. H. J. Male; white; aet. 50 years. Occupation, clerk Post- 
Ofidce Department for the past eight years. Born in New Orleans, 
La., and fived there until about 30 years of age; since then hved in 
Washington and in New England (continuously in Washington for 
the past nine years). For the past three years has lived in an apart- 
179— Bull. 52—09 10 
