282 
TYPHOID FEVEK IX DISTKICT OF COLUMBIA. 
INTERPRETATION OF THE RESULTS OF THE SANITARY ANALYSES 
OF THE WATER SUPPLIES OF THE DISTRICT OF COLUMBIA. 
Since the celebrated Broad street well investigation (London), in 
1854, which, according to Kinnicutt® was the first to attract gen- 
eral attention to the fact that there might be a connection between 
the use of polluted water and disease, various attempts have , been 
made, especiall}^ by English chemists, to devise chemical methods 
and standards whereby the sewage pollution of a given water could 
be accurately measured. The earlier investigations on this subject 
were made by Frankland^ (member of the Kivers Pollution Com- 
mission, London), Wanklyn, Chapman, and Smith,*" and by Tidy. 
It is interesting to note that these investigators were by no means 
agreed as to the methods and standards best suited for measuring 
the pollution of natural waters. As a matter of fact their labors, in 
this field immediately gave rise to one of the most prolonged contro- 
versies on this subject, a controversy which, in one form or another, 
has been carried on more or less vigorously from that time dovm to the 
present. The result has been that no sooner has one standard been 
agreed upon by one chemist and his immediate followers than its 
value has been called in question by others, and other methods and 
standards substituted in its place. That this matter is still the sub- 
ject of much discussion and much difference of opinion ma}^ be seen 
from the titles of three very interesting communications on this sub- 
ject, of recent date, by three American chemists, all of whom have 
had a wide experience in this particular field of chemical investiga- 
tion, and a very good idea of the present condition of sanitary water 
analysis may be gained from a stud}^ of these three communications, 
viz: ^^The sanitary value of a water anal 3 ^sis,’’ b}^ Leonard P. Kin- 
nicutt (Science, N. S., Vol. XXIII, 1906, No. 576, pp. 56-66); “Inter- 
pretation of a water examination,^ b}" W. P. Mason (Science, N. S., 
Vol. XXI, No. 539, pp. 648-653), and “The futility of a sanitar}^ 
water analj'sis as a test of potability,’^ by Marshall O. Leighton (in 
Biological Studies by the Pupils of William Thompson Sedgwick, 
Boston, 1906, pp. 36-53). 
Without entering more fully into the merits of this ^evj vexed 
question, concerning which doubtless much remains to be said on 
both sides, it may be stated briefly that it is the general concensus of 
opinion of those most competent to deal with the subject of water 
pollution, that no one is au}^ longer justified in passing judgment on 
a Science, N. S., XXIII, p. 57. 
&Joiir. Lend. Chem. Soc., XXI (1868, pp. 77-108, and ibid., Vol. XXIX (1876), 
pp. 825-851, also Reports of Rivers Pollution Commission (London), (1866-1874). 
cibid., Vol. XX (1867), pp. 445-454, and Vol. XXI (1868), pp. 152-172, and also 
“Water analysis, ” by Wanklyn and Chapman, London, 1868. 
^?Ibid., Vol. XXXI (1879), pp. 46-106. 
