314 TYPHOID FE\T:K IX DISTRICT OP COLVMBLl. 
Table 3. — Results of analyses of the water of the Potomac River hy several investigators. 
Total 
solids. 
Chlo- 
rine. 
Ammonia. 
Ni- 
trites. 
Ni- 
trates. 
Re- 
Investigator. 
Free. 
Albu- 
minoid. 
quire d 
oxygen. 
Not given; Potomac water, 1904-5 o. 
146.1 
5.23 
0. 073 
0.229 
0.0054 
1. 16 
1.72 
Health office, 1897-1900 a 
126.7 
3. 78 
.0008 
.111 
Trace. 
.639 
2.56 
Office of Surgeon-General, 1899 a 
125.0 
4.0 
Trace. 
.150 
Trace. 
1. 10 
2. 10 
R. S. Weston a, 
139.0 
2.60 
.013 
.105 
.002 
.73 
450 
Laboratorv of filtration plant, F. F. Longley . . 
2.0 
.032 
.244 
.0033 
.79 
Hygienic laboratory, division of chemistry 
203.0 
2. 81 
.024 
.161 
.0031 
.61 
41 
Mason, “Water Supplv” (1894) 
165.0 
1.1 
.050 
.127 
Trace. 
.23 
1.021 
a From ‘ The Potomac River Basia” Water-Supply Paijer No. 192, U. S. Geological Survey, hy 
Horatio M. Parker. 
Table 4. — Showing extreme variation in the chemical composition of the water of the 
Potomac. 
Year. 
1889 
1906 
1906 
Source of data. 
Sus- 
pended 
solids. 
Turhid- 
itv. 
Report on typhoid fever in the Dis- 1 
trict of Columbia (1894) | 
Captain Cosby’s report, analyses f 
from Feb. 20 to June 26 ^ i 
Hygienic laboratory (division of 
chemistry) analyses from July 30 
to Sept. 27 * ' 
846 
7 
1,000 
10 
I lO 
16 
Ammonia. 
Ni- 
trites. 
Ni- 
trates. 
Year. 
Source of data. 
Free. 
-Albumi- 
noid. 
1889 
Report on typhoid fever in the Dis- 
trict of Coiumbia (1894) 
;0. 3920 
\ .0000 
0. 6520 
.0600 
Trace. 
0.000 
0.8 
. 50 
1906 
Captain Cosby’s report, analyses 
from Feb. 20 to June 26 
/ .100 
\ .009 
. 556 
.090 
.0070 
Trace. 
1. 10 
.05 
1906 
Hygienic Laboratory (division of 
chemistry) analyses from July 30 
to Sept. ^ 
] .047 
1 .006 
.410 
.066 
.0054 
.0014 
.88 
.40 
i Total solids. 
! Total 
Mineral ' Volatile 
1 residue. 
matter. | matter. 
f 270 
1 76 
1 
430 
i 
382 I 84 
126 
i 
! 
82 18 
1 
Chlo- 
rine. 
5.0 
3- 5 
3.2 
0.8 
3.3 
9 9 
‘ cen^of 
solved con- 
loxygen.; ~ sumed. 
a8o 
I ^ .88 
& 94 I 103. 1 ^ 7. 8 
5. 12 6a 1 I 2. 0 
Table 5. — Chemical analyses of Potomac water, yearly average for five years {1888-1893). 
[Compiled from Report on Typhoid Fever in the District of Columbia, Washington, 1894, Table V, p. 8.] 
Year. 
Total 
solids. 
-Ammonia. 
Nitrites. 
♦ 
Nitrates. 
Oxygen 
con- 
sumed. 
Chlorine. 
Free. 
-Album- 
inoid. 
1888 
Ill 
42 
0. 0170 
0. 1190 
0.000 
0.97 
1.98 
1889 
110 
42 
.0190 
.2140 
.000 
.82 
1.82 
1889-90 
136 
43 
.041 
.295 
.000 
.70 
1.85 
1890-91 
104 
43 
.0043 
.0627 
.000 
.60 
1.97 
1891-92 
113 
43 
Trace. 
.064 
.000 
.60 
1.85 
1892-93 
125 
4.7 
.0200 
.0661 
.000 
.60 
1.64 
According to tliis report (p. 8), “The Potomac water has been subject to vert’- careful 
analyses” and “in general the water may be said to be in excellent condition and to 
compare extremely favorably * * * with that of other cities.” Its chief defect 
is the presence of suspended clay in the winter and after heaxy’ rains in any season. 
