83 
microbes to be liberated and distributed by the melting snows of the spring. There 
is here a resemblance to a water-borne disease, and until Widal’s serum test (see 
below, p. 66) is tried there will be cause for skepticism and a diversity of opinion as 
to the true nature of the malady.” 
Montana . — McCullough (1902) says that “spotted fever” occurs in the spring, more 
likely in April and May than at other times, yet it has occurred as early as January 
and as late as July. According to Gwinn (1902) time bears a causal relation, as is 
shown by the fact that the disease does not occur during the latter half of the year; 
nearly all cases occur in the months of April, May, and June, May being the worst 
month. Wilson and Chowning (1902a, p. 132; 1903a, pp. 42, 68; 1904a, pp. 35, 43) 
state that the disease occurs only in the spring. The earliest recorded case began 
March 17, and the latest about July 20, though most cases occur between May 15 
and June 15. There are no records of any cases occurring between August 1 and 
jMarch 17, though there are rumors of some cases having occurred as early as 
February. Anderson (1903c, p. 8) agrees essentially Avith Wilson and Chowning. 
Wilson and Chowning (1903a, p. 43) print a table of the cases, distributed by 
months; they later insert (1904a, p. 35) the cases of 1903. In the folloAving table I 
add to their cases the Bitter Root Valley cases I have collected. 
Month. 
Reported 
by Wilson 
and Chow- 
ning, 1904a, 
page 35. 
Additional 
cases. 
Total. 
Remarks. 
January 
(?) 
(?) 
(?) 
See McCullough, 1902; uncertain case, see Cobb, 
1902, page 1868. 
Rumors, see Wilson and Chowning, 1902a, page 
132; a few cases when March Ayas mild, see 
Cobb, 1902, page 1868. 
February 
(?) 
March 
6 
6 
April 
24 
9 
26 
53 
The 2 additional cases (1, 2) in 1904. 
The 7 additional cases (3, 4. 5, 6, 7. 8, 9) in 1904 
The 2 additional cases (10, 11) in 1904. 
May 
46 
7 
June 
35 
2 
37 
July 
5 
5 
August 
Cases in 1903, see page 30. 
September 
I - 
2 
“Spring” 
10 
10 
Total 
126 
13 
139 
Of the 17 cases reported by Gates for another locality, 4 occurred 
in April, 6 in May, and 7 in June. 
It is a more or less popular belief among some of the inhabitants of 
the Bitter Root Valley that cases of ‘ * spotted fever ” are more likel v 
to occur during the time that the streams are rising than while they 
are falling. This would indicate that it occurred either during or fol- 
lowing a rise in temperature, such as would melt the snow on the 
mountains, or during or following a rainfall. 
Through the kindness of Prof. Willis Moore, Chief of the United 
States Weather Bureau, I have been able to obtain the daily tempera- 
tures and rainfall for Missoula for the months of Februar^^-September, 
inclusive, 1899-1901, inclusive, so far as these have been recorded b}" 
volunteer observers (Prof. M. J. Elrod), and I have attempted to plot 
the cases of “spotted fever” which are reported for the Bitter Root 
Valley for the corresponding da}^s. While this study was interesting, 
it is not entireh" satisfactory for several reasons; in the first place, 
23339— Vo. 20—05 3 
