TYPHOID FEVEK IN DISTRICT OF COLUMBIA. 
117 
In the following summary the information regarding the relation 
of privies to the various wells was obtained from the spot map pre- 
pared by the health department of the District of Columbia through 
the courtesy of Dr. Wm. C. Woodward, health officer. 
Bacteriologically . — Well waters containing less than 100 bacteria 
per cubic centimeter and no fermenting organisms are classed as 
good; those containing more than 100 bacteria per cubic centimeter 
and no fermenting organisms are classed as fair; those containing 
fermenting organisms but no colon bacilli are classed as indicating 
surface contamination; and those containing the colon bacillus are 
classed as indicating sewage pollution. For bacteriological methods 
see page 261. 
Chemically . — Well waters high in chlorin and nitrates are regarded 
as indicating remote pollution and those high in free and albuminoid 
ammonia and nitrites are classified as polluted. 
Epidemiologically . — The number of cases of t}^hoid among per- 
sons using the water of each particular well refers to the cases occur- 
ring in the District and reported between June 1 and November 1, 
1906. 
DEEP WELLS — NORTHWEST SECTION. 
No. 3. 
Location. — First and G streets NW., Gales School (New Jersey and Massachusetts 
avenues) . 
Kind. — Iron. 
Condition. — Fair; old; pipe drain to sewer. 
Depth. — Deep; below surface, 141 feet; water, 137 feet. 
Sewer. — Depth, 10 feet; distance from well, 20 feet. 
Privies. — Nearest, two blocks. 
Bacteriologically. — Good. 
Chemically . — Unpolluted . 
The following 2 cases of typhoid fever drank the water of this well; 
Case 
No. 
Onset of 
disease. 
During the 30 days preceding onset of disease used the well water — 
Probable source of 
infection. 
177 
May 26 
July 4 
Frequently 
? 
251 
Occasionally 
Contact. 
No. 17. 
Location. — Twelfth and M streets NW. (southwest corner). 
Kind. — Iron. 
Condition. — Out of order. 
Depth. — Below surface, 149 feet; water, 38 feet; deep. 
Sewer. — Depth, 10 feet; distance from well, 8 feet(?). 
Bacteriologically . — Good . 
Chemically. — ^Unpolluted. 
