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SEDGWICK AND WINSLOW.- BACILLUS OF TYP,„„n FEVER. 5 
The work which has been done upon the seasonal prevalcnoo of iyuM f.vcr 
within the List ten years has, if anything, only made the suhjocl n.orr ob.ruic 
Magelssen, in his classic brochure (^^'^) on the dependence of discn^.. upon the wontln,' 
in which he showed so clearly the unfavorable influence of oxtreine low Icinpcrafiin- 
upon the general mortality, only alluded to typhoid in parsing, stating that it is n.M 
abundant in the latter months of the year. Korosi, in ISOi^^ mA m clalH.ralo 
comparison of the reported cases of the infectious diseases In Berlin with the rnoisfuro 
and temperature by periods of five days, a week and a month, according to tli.- 
incubation period of the disease. He criticised those observers, especially Il.-.lh r 
died the relation of d 
o 
1 
a comparison can throw no light on the causation of disease as the ph.'numona 
nivolved are too complex. His method consisted in the division of his pcntnds and 
months into five groups, designated as very cold, fairly cold, fairly warm, warm, and 
hot, and the calculation of the relative prevalence of the disease Iji each giuiip of 
periods. He thus eliminated all the effects of the weather preceding the period < 11- 
sidered and obscured the facts. When analyzed into his five temperature group*, two 
le fairly cold months, — and he concludf (] 
'e, on the other hand, appeared to e?rert 
maxima appeared, — one in the hot, one in the 
that no positive relation is shown. Moisture 
an appreciable effect, and he finally concluded that the maximum of morbidity occun^ 1 
in dry weather with medium warmth, while the minimum was reached when a medium 
temperature coincided with an excess of moisture. Fotlor, in 1896,^'^'' declared that 
" the striking dependence on the warmth, and on the season which is so charactt'rlsfic 
of cholera is almost entirely wanting in typhoid fever." In the same year, JesBcn''*' 
published curves which showed the monthly prevalence of measles, croup, and 
diphtheria, typhoid fever, cholera, pneumonia, phthisis, and diarrha^nl di.^ui-"^ of 
children In comparison with variations in wind, temperature, humidity, and rainfall. 
With regard to typhoid fever he concluded that temperature was the only factor 
'Inch affected the disease, and that this was only of slight Importance, as typhoirl fever 
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though occurring principally in the cold months (!), sometimes attained a max 
when the temperature was high. Knoevenagel ^'^^ noted the increased prevalence 
of typhoid fever in Mecklenburg-Schwerin at the end of July and in August and 
September. Berger^^^^ and Ruhemann,^^^) in 1898, emphasized the importance of 
atmospheric conditions In a)tiology, and criticised the exclusive attention paid to the 
l>acteriological factors in .lisease." The former author, after an excellent review • 
hterature on the influence of weather on various diseases (tuberculosis, pneumonin;, 
Piiblished curves of morbidity from diphtheria, scarlet fever, measles, and typhoi 

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