INTRODUCTION. 
By request of the Commissioners of the District of Columbia the 
undersigned were appointed a board b}^ the Surgeon-General of 
the Public Health and Marine-Hospital Service on July 2, 1906, 
for the purpose of making an investigation of the origin and preva- 
lence of t}"phoid fever in the District of Columbia Since that date 
this investigation has been continuous, and this bulletin gives the 
results of our studies on typhoid fever in the District of Columbia 
during the season of 1908. Our first report on the subject, for the 
5 ^ear 1906, is contained in Hygienic Laboratory Bulletin No. 35, and 
our second report, that for 1907, in Hygienic Laboratory Bulletin 
No. 44. 
This 5 ^ear our studies included a continuation of the epidemio- 
logical investigations of the disease during the t}q)hoid-fever season. 
This makes the third consecutive j^ear of these studies. The data 
for the epidemiological part of the work were collected by one of us 
(Lumsden) . Special mention is made of this fact for the reason that 
we believe that differences between the results for any two of the 
three years may be attributed to differences in conditions, as the 
factors of personal equation have not varied. 
In addition to the epidemiological data collected from personal 
visits to every case reported during the t 3 rpho:d season (May 1 to 
November 1) we made during that season bacteriological examina- 
tions of the raw and filtered Potomac River waiter, also numerous 
examinations of the tap water, the applied water, etc. 
At the suggestion of Professor Sedgwick, made at the meeting of 
the advisory board of the Hygienic Laboratory, we made an intensive 
stud}^ of the problem in a selected district comprising 32 city blocks 
and containing 5,300 persons. This stud}^ was made by Passed 
Assistant Surgeon Norman Roberts. We found no cases of clinical 
typhoid fever among these people which had not been diagnosed as ' 
such and reported to the health officer. A special search was also 
made for bacillus carriers in this area. Specimens of feces were col- 
lected from about 1,000 healthy persons and examined for the pres- 
ence of t}qfiioid bacilli. Most of these examinations were made by 
Assistant Surgeon W. W. Miller, assisted by Dr. Walter D. Cannon. 
Three of the specimens — one of urine and two of feces — were found 
( 5 ) 
