the milk-inspection service of any community is measured. It may 
be claimed, however, and with some show of propriety, that many 
factors other than improvement in the milk supply have been at work 
to reduce the number of infantile deaths ; or that a diminishing birth 
rate may account for the lessening of the infantile death rate, com- 
puted as that death rate perforce is, upon the total population and 
not upon the basis of the infantile population alone. To eliminate 
as nearly as possible error from these causes, no effort has been made 
to gauge the results of milk inspection by the general infantile 
mortality, but consideration has been limited to one single class of 
diseases, the intimate relation between which and the milk supply 
is almost universally conceded; that is, to diarrhea and enteritis 
occurring among children under 2 years of age. 
When a sudden drop in the death rate from any particular cause 
is practically coincident with the inauguration of measures intended 
to bring about that very result, when there is no other discoverable 
cause for such drop, and when the lower death rate persists with the 
5 continuance of such measures and continues to fall in proportion, 
more or less, to their efficiency, it is reasonable to suppose that the 
relation of cause and effect exists. And such are the circumstances 
• wnth respect to the improvement in the milk supply of the District 
of Columbia and the diminution in the mortality from diarrheal 
diseases among persons less than 2 years old. The beginning of a 
persistent fall in the general death rate appears when we compare 
' the figures for 1892 with those for 1893. A fall in the death rate 
of infants under 1 year of age appears at the same time. But no 
permanent lowering appears in the death rate from diarrhea and 
[ enteritis among children under 2 years of age until the second j^ear 
after the enactment of the milk law. This law was enacted March 2, 
1895, and a certain period elapsed before it could be put into effective 
■ operation. The death rate from diarrhea and enteritis among infants 
during the fiscal year following its enactment was 168 per 100,000. 
I The next year it had fallen to 151, the third year to 136, and the 
fourth year to 110. There have, of course, been slight fluctuations. 
In the calendar year 1900 the death rate rose to 132 per 100,000, but 
the annual average for the five-year period, 1900-1901, was only 109, 
and during 1903 it fell to 91. In 1905 the rate was 101, and in 1906 
I it was 97. In 1907 it was 98, and during 1908 it remained at the 
I same figure. The death rate from diarrhea and enteritis among chil- 
» dren under 2 years old during the five-year period preceding the 
enactment of the milk law, in 1895, was 175 per 100,000. If the 
same rate had continued during the thirteen years that elapsed after 
* its enactment and prior to December 31, 1908, the number of deaths 
from these causes would have been approximately 6,919, or 2,386 
. more than actually occurred. And if the number of fatal cases of 
