oTO SEDGWICK' AND WINSLOW. — BACILLUS OF TYPHOID FEVER. 
The nit'tliof?.s ])y which prosodcmic typLoid mny spreud .-ire almost innumerable. 
The l;i-f link in the chain is, in mo.sL cases, some article of food or drink, and tlie food 
I. .■comes Iiifccte<l, in many instances, from the fingers of a typhoid patient or of his 
unpioffssionul attendants. The transmission of typlioid fever on a large scale by 
water and milk has led sanitarians to minimize unduly this direct personal element in 
itM iutiulogy. In a well-organized, thoroughly sanitary city dwelling the distinction 
hctweon rnntagion and infection is an important one; but In dirty surroundings 
typhoid becomes, for all practical purposes, a contagious disease. This fact, in itself, 
throws some liftle light on its seasonal prevalence. A large number of persons 
who live ordinarily in cities, surroimded by many sanitary safeguards, in vacation 
fiiiie are exposecl in camps and summer resorts to abundant opportunities for filth 
inft'ction. The autumn fever, in small part at least, occurs among those who are 
Attacked on such summer vacations or immediately after their return home. 
Again, several special sources of food contamination have a more potent influence at 
this season of the year. Tliose observers are perhaps correct who consider that ground 
waters arc most dangerous when the wells are at their lowest and liable to receive 
impurities from a wide area. Professor Gualdl would explain the facts by attaching 
great significance to raw vegetables as vehicles for the transmission of typhoid fever; 
and he has traced out a more or less close connection between the consumption of 
these articles and the amount of typhoid in Rome. Most original of all is the sugges- 
tion of Bonne, who seeks to explain the autumnal maximum at Hamburg by the in- 
creased amount of bathing in the Elbe beginning with the July heat. 
Of the three great intermediaries of typhoid transmission, fingers, food, and flies, 
the last is even more significant than the others in relation to seasonal variation. 
Since the emphasis laid on this vehicle of infection by the surgeons who studied the 
conditions of the late Spanish War, our conception of its importance has grown more 
and more considerable. There can be little doubt that many of the so-called " sporadic 
cases of typhoid fever which are so difficult for the sanitarian to exnlain are cond 
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d 1 
y the passage of a fly from an infected vault to an unprotected table or an 
open larder. The relation of this factor to the season is of course close and complete ; 
and a certain amount of 
of fever is undoubtedly traceabl 
presence of large numbers of flies and to the opportunities for their pernicious activity. 
None of the factors noted, however, nor the whole of them taken too-ether, seem 
TA us to account satisfactorily for the observed phenomena. Neither the agency of 
m.sects, nor the exposure of urban subjects to rural unsanitary conditions, though 
both are undoubtedly important, can be held to account for a phenomenon so con- 
