THE POLLUTION OF UNDERGROUND WATERS WITH SEW- 
AGE THROUGH FISSURES IN ROCKS. 
BY HENRY ALBERT. 
The possibility of pollution of underground waters through fissures 
in rocks has long been a well established fact. The actual demonstra- 
tion of such as the source of cases or epidemics of disease in Iowa has 
until recently not been proved. It is with the idea of reporting an 
epidemic of typhoid fever due to pollution of this kind and of calling 
attention to the heed of a sanitary water survey in Iowa, that I present 
this paper. 
The more superficial rocks of the state present many joints or fis- 
sures, through which pollution with sewage material may pass. Many 
of the springs of the state which issue from such fissures, have their 
source of water supply from the superficial layers of soil not far away 
which means that such water has not been subject to very much filtra- 
tion or in case the water has entered sink-holes which are especially 
common in the northeastern corner of the state, has probably not been 
filtered at all. 
THE CEDAR FALLS EPIDEMIC OF TYPHOID FEVER. 
During the fall of 1911 there occurred at Cedar Falls, an epidemic 
of typhoid fever during which about 100 persons were affected, and 
about 20 died. The water supply of Cedar Falls previous to the time 
of the epidemic was from a spring in the valley of Dry Run, a small 
intermittent tributary of Cedar river. It comes from a fissure in the 
Devonian lime-stone. That this water was the source of infection was 
shown by both the epidemiological data and laboratory examinations 
indicating contamination of the water with sewage material. That the 
water comes in part at least from surface soil is shown by the fact that 
it becomes turbid after a heavy rain and high river floods. It was at 
first believed that the water issuing from the spring was contaminated, 
and that the contamination had occurred through fissures in rocks. Many 
repeated tests with fluorescein have however all been negative. Prof. 
