36 



KANSAS UNIVERSITY QUARTERLY. 



District of Columbia alone a much smaller difference is shown. 

 During a fourteen years' period, ending in 1897, ^^^*^ deaths from 

 diphtheria and croup averaged annually o 57 per 1,000 among the 

 white people, and o 52 among the colored people. 



As regards the incidence of diphtheria on the different months of 

 the year only three of our reports give any definite information, 

 and this is summarized in table I, given below. 



Table I. 



It is seen from this table that the month of highest mortality is 

 October, and the lowest July; and the months from September to 

 January, inclusive, show a much higher death rate than the rest of 

 the year. One cannot safel}^ generalize on so little evidence, but it 

 may be noted that the results agree substantially with those of other 

 localities in this latitude. The Health Reports of Kansas Cit\', 

 Mo., for 1898, so far as they have been received, agree in the main 

 with the above table; and the stati.^'tics of the city of Denver dur- 

 ing the years 1897 and 1898 show the highest mortalities during the 

 months of October, November, December, January and April, and 

 during an eleven year period, ending in i8g6, the highest rates are 

 in January, February, March, May, October, November and De- 

 cember. It may be of interest to compare reports from localitii r- 

 having a very different climate. The Pacific coast states during 

 the census year 1890 show the highest diphtheria mortality in the 

 months of January, September, November and December. Ac- 

 cording to the Health Reports of the state of Florida there was a 

 total of fifteen deaths from diphtheria during the three years 1891, 

 1893 and 1894; these are distributed by months as follows: Janu- 

 ary, three; March, three; October, two; November, four; Decem- 

 ber, two; all other months none. Massachusetts and England and 

 Wales agree with the above localities in showing the greatest mor- 

 tality during the first and fourth quarters of the year. It will be 

 noted that these localities all agree in having their coldest weather 

 in the first and fourth quarters, and that there is not much else 

 common to all that could have an influence of diphtheria. In some 

 the season of greatest rainfall comes in the winter, in others in the 

 spring and early summer months; while the periods of vacation 



