CARRIAGE OF DISEASE 
139 
plumbing ordinances often loom large as the chief 
weapons of combating disease. Too often attention is 
diverted from really significant and tangible dangers 
to health by the cry that the garbage dump or the sew¬ 
age manhole is emitting vile odors. It is of course 
well known to physicians that there is no evidence that 
disease can be spread by odors, although foul air may 
possibly impair health and render the body less re¬ 
sistant to disease. 
“Many sanitarians are beginning to fear that a sim¬ 
ilar misapplication or misunderstanding of the relation 
of the house fly to typhoid fever is coming about. No 
one questions that the house fly is an unmitigated nui¬ 
sance. Neither is there any doubt that under certain 
conditions, such as prevail in military or mining camps 
or on many a country farm, or even in cities that allow 
the crude type of privy, the house fly is an exceedingly 
important agent in the transmission of infection. This 
has been abundantly proved. There is observable, how¬ 
ever, a tendency to assume a connection much wider 
than this and to attribute to fly infection a portion, 
sometimes the major portion, of the typhoid fever oc¬ 
curring in large and well-sewered cities. 
“Several instances of this misguided enthusiasm have 
come to notice within the last few months. It need 
hardly be pointed out that the house fly, no matter how 
disgusting its origin or habits, cannot convey the spe¬ 
cific germ of typhoid fever to any food substance un¬ 
less it has access both to food substances and to typhoid 
germ. Those amateur investigators who assume that 
