250 
TYPHOID FEVER IFT DISTRICT OF COLUMBIA. 
from typhoid in five counties of Maryland, which, with the exception 
of a small part of Garrett and Montgomery, are included in the water- 
shed : 
County. 
Jan. 
Feb. 
Mar. 
Apr. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Allegany 
1 
3 
3 
2 
1 
2 
1 
2 
3 
8 
10 
3 
Frederick 
3 
2 
0 
0 
1 
1 
2 
3 
0 
1 
0 
1 
Garrett 
0 
0 
2 
2 
0 
2 
0 
0 
0 
1 
0 
1 
Montgomery 
0 
1 
0 
0 
0 
1 
1 
4 
2 
6 
1 
0 
Washington 
1 
0 
0 
0 
0 
0 
0 
1 
4 
1 
2 
0 
Total 
5 
6 
5 
4 
2 
6 
4 
10 
9 
20 
13 
5 
Mean (ratio 100) 
5.6 
6.5 
5.6 
4.5 
2.2 
6.5 
4.5 
11.2 
10.1 
22.4 
14.6 
5.6 
In the area included in the above table there were recorded a some- 
what greater number of deaths during the period January 1 to July 1, 
1906,® than in the corresponding period last year, as may be seen by 
comparing the following with the preceding table: 
County. 
Jan. 
Feb. 
Mar. - 
Apr. 
May. 
June. 
Allegany 
3 
2 
5 
0 
1 
2 
Frederick 
0 
1 
1 
1 
0 
2 
Garrett 
0 
0 
0 
1 
0 
0 
Montgomery 
0 
1 
2 
1 
0 
0 
Washington 
0 
0 
2 
1 
9 
0 
Total 
3 
4 
10 
4 
10 
4 
SEWERAGE. 
In the description of the sources of pollution mention has been 
made of the presence or absence of sewerage systems in the several 
communities considered. It will have been noted that few are 
sewered, even partially; cesspools and privies, some of which, how- 
ever, overhang convenient streams, are in very general use. 
Of the total population of the watershed it is estimated that not 
more than 45,000 (9 per cent) contributes direct sewage pollution 
(see Table No. 5). About 78 per cent of this sewage pollution is at 
points more than 175 miles from Great Falls, about 17 per cent at 
points between 50 and 175 miles, and the remaining 5 per cent at 
points between 19 and 50 miles from Great Falls. 
The volume of direct sewage pollution at points within 19 miles of 
the intake of Great Falls is, in relation to the total, practically nil; 
but inasmuch as this portion of the watershed is inhabited, pollution 
of a dangerous character may occasionally find its way into the river 
from some point or points within this distance of the intake. 
a Obtained in correspondence fronr Dr. John S. Fulton, secretary State board of 
health of Maryland. 
