Schlundt—Radioactivity of Some Spring Waters. 1249 
Table I. 
Name 
Location. 
Date. 
Activity. 
of Source. 
g X 10 _ *U. 
g X 10 _11 Ka. 
E. S. Units. 
Lake Mendota.. 
Aug. 28—’08 
“ 9 
None. 
South Hall Well 
University 
Campus. 
5.6 
21.3 
6.64X10 4 
Waconia Spring 
Lake Mendota 
30 
6.8 
25.8 
8.25 “ 
Merrill Springs. 
“ 
“ 30 
13.8 
52.4 
16.6 “ 
Black Hawk 
“ 
“ 31 ■ 
3.8 
14.4 
4.55 “ 
Spring. 
Parkinson 
• ft «• 
“ 31 
12.2 
45.4 
14.6 “ 
Spring. 
Deep Well. 
Hiram Smith 
Hall, U. W. 
Sept. 1 
10.9 
41.4 
13.1 
Silver Spring... 
Lake Wingra.. 
Sept. 1 
17.7 
67.3 
21.2 “ 
Spring Haven... 
Lake Monona. 
Sept. 3 
14.0 
53.5 
16.8 “ 
City Deep Well 
(Madison). 
Cor. Patterson 
and Main Sts. 
Sept. 3 
6.2 
23.6 
7.6 
That the radioactivity of the different water samples is due 
to the presence of radium emanation was established by the 
curves representing the rise in activity during the first three 
hours, following the introduction of the emanation into the 
electroscope and by the position of maximum activity on the 
decay curves. The sample of water from Merrill Springs was 
evaporated; the residue was tested, but no positive indication of 
activity was obtained. In this case then the activity of the 
water is due almost entirely to radium emanation that has 
diffused into the water in the course of its underground flow. 
The activity is not due to the presence of traces of radium salts. 
This conclusion will probably be found to hold for the other 
springs. Ho attempts were made to test the waters for thorium 
or actinium. 
Although the spring waters show differences in activity still 
the values are of the same order of magnitude. The differences 
in activity are small in comparison with results obtained for 
waters in other areas. The results obtained by Boltwood 1 in 
his tests on the radioactive properties of the waters of Hot 
Springs, Ark., are characterized by marked variations in their 
9 !'! 
1 . J * 3 
i Am. Jour. Sci. 20, 128 (1905). 
