barber: diphtheria ix Kansas. 31 



A of the Census Report, including the New England states, New- 

 York, New Jersey and Pennsylvania, the mortality from diphtheria 

 and croup was 4.9 per cent of the deaths from all causes. In 

 Grand Division B, including Delaware, the District of Columbia, 

 Florida, Georgia, Maryland, the Carolinas and Virginia, the nior- 

 talit)^ was 3.0 per cent of all deaths. In Grand Division C, in- 

 cluding Alabama, Arkansas, Kentucky, Louisiana, Mississippi, 

 Tennessee and Texas, the deaths from diphtheria and croup were 

 only 2.g per cent of all. In Grand Division D, including all the 

 remaining states, exclusive of the Pacific states, the mortality was 

 6.2 per cent. In the Pacific states. Grand Division E, the mortal- 

 ity was 3.8 per cent. It is seen from these figures that the 

 mortality from diphtheria is comparatively high in the northeas- 

 tern, the middle, and the northwestern states, lower in the milder 

 Pacific region and lowest of all in the southern states. Averaging 

 the states Colorado, North Dakota, South Dakota, Idaho, Montana 

 and Wyoming, where the rainfall is not great, the elevation high 

 and the climate relatively cool, the proportion of deaths from diph- 

 theria is rather high, averaging 5.3 per cent. If we average the 

 south Atlantic and Gulf states. North Carolina, South Carolina, 

 Georgia, Florida, Alabama, Mississippi, Louisiana and Texas, we 

 find the proportion only 0.77 per cent. If we can trust these 

 figures the conclusion seems to follow that a cool climate favors 

 the prevalence of diphtheria more than a warmer, and the degree 

 of humidity is probably a factor of less importance than the tem- 

 perature. The hygienic conditions of the northwestern states 

 mentioned is probably as good, or better, than that of the Atlantic 

 and Gulf group, and the population is certainly more dense in the 

 latter. 



Taking into consideration this collateral evidence, we may say 

 that the presumption is strong that diphtheria is more prevalent in 

 the northern part of Kansas than in the southern, and that this is 

 due, partly, at least, to the difference in temperature. For the 

 partial immunity enjoyed by the western part of the state, sparsity 

 of population, dryness, better drainage and greater elevation are 

 possible explanations; but whether all of these are concerned in 

 the problem or not, and what the relative weight of each factor is, 

 the evidence is hardly sufficient to decide. 



As to the influence of sanitation on diphtheria there are some letters 

 in the State Reports, one of which I will mention, that of Dr. P. W. 

 Barbe, of Oswego, Kansas, given in the 1892 report. In answer to my 

 letter of inquiry, Dr. Barbe kindly wrote me further information and 



