604 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 
Back of the whole situation is the existence in the public mind of 
wrong or antiquated conceptions of disease and the causes of disease. 
It was unfortunate in many respects for the cause of public health 
that much of the popular interest in health matters was evoked before 
the germ theory of disease and its corollaries became fully developed. 
As the result of premature generalization the public has warmly 
espoused a number of wrong conceptions of disease and of ways of 
preventing disease. ‘To be specific, twoinstances of this confusion are 
found in the demand for garbage disposal and plumbing inspection. 
Sanitarians do not admit that even a grossly improper method of 
garbage disposal can have much to do with the spread of disease in a 
sewered city or that diphtheria or typhoid fever, or any other disease, 
is properly attributable to the entrance of sewer air into dwelling 
houses. So firmly embedded in public belief, however, is the connec- 
tion of piles of decaying garbage with outbreaks of infectious disease 
and of defective plumbing with all sorts of maladies that to the aver- 
age citizen garbage disposal and plumbing inspection bulk large as the 
chief if not the only activities of a municipal health department. 
In the light of our present knowledge we may well ask what are the 
actual dangers to health from these two sources? It is now well 
known to bacteriologists that disease germs do not breed in garbage 
heaps, but that, on the contrary, if added from outside, they speedily 
die off. The offensive odors of decomposition may be unpleasant 
and undesirable; there is no evidence that they produce disease or 
dispose to disease. On the other hand, it may be argued that the 
existence of heaps of decomposing organic matter tends to maintain 
or create general habits of uncleanliness, which themselves are detri- 
mental in a roundabout way to the health of a community. And 
again it is known that the house fly may breed in garbage piles, par- 
ticularly if horse manure is present, and that under certain conditions. 
this noxious insect may become the bearer of disease germs to food. 
But when the worst is said it must be admitted that the known danger 
to health from garbage piles and dumps is relatively insignificant 
compared with the danger from other well-known but less popularly 
feared sources. Disease does not originate in garbage piles, however 
offensive they may be. The house fly, however disgusting and annoy- 
ing its habits, suffers from no disease transmissible to man, and does 
not convey disease unless it has access to material in which disease 
germs are present. The truth is that garbage disposal in large cities 
is more a matter of municipal housekeeping than of public health. 
Proper methods of garbage collection and destruction must be urged 
rather from economic and esthetic considerations than on hygienic 
grounds. There are of course certain features in the handling of 
~ refuse and waste that need hygienic control just as there are in street 
