613 
infant feeding in Rochester, N. Y. Ilis methods consisted mainly in 
education in the nursery and on the dairy farm. The clean milk 
obtained thus and distributed through milk depots resulted in lower 
ing the death rate in children under 5 years from 33 per cent from all 
causes to 20 per cent, and now (1907) it is 15 per cent. 
Park and Holt a studied groups of infants in the tenement houses 
and institutions in New York for periods of about three months 
in the summers of two years (1902-3). This work is the most im- 
portant evidence we haA T e on the subject, for it combines careful 
clinical observation with laboratory studies. Although the number 
of cases was comparatively small, the results obtained were almost 
identical during the two summers, and indicate that even fairly 
pure milk, when given raw in hot weather, causes illness in a much 
larger percentage of cases than the same milk gh T en after pasteuriza- 
tion. A considerable percentage of infants, howeAer, did apparently 
as Avell on raw as on pasteurized milk. Park and Holt conclude 
in part : 
Tlie number of bacteria which may accumulate before milk becomes notice- 
ably harmful to the average infant in summer differs with the nature of the 
bacteria present, the age of the milk, and the temperature at which it has 
been kept. When milk is taken raw the fewer bacteria present the better 
are the results. Of tlife usual varieties, over 1,000,000 bacteria per cubic cen- 
timeter are certainly deleterious to the average infant. However, many infants 
take such milk without apparently harmful results. Heat above 170° F. 
(77° C.) not only destroys most of the bacteria present, but apparently some 
of their poisonous products. No harm from the bacteria previously existing 
in recently heated milk was noticed in these observations, unless they had 
amounted to many millions, but in such numbers they were decidedly dele- 
terious. 
When milk of average quality was fed sterilized and raw, those infants 
who received milk previously heated did on the average much better in warm 
weather than those who received it raw. The difference was so quickly mani- 
fest and so marked that there could be no mistaking the meaning of the 
results. 
A few cases of acute indigestion were seen immediately following the use 
of pasteurized milk more than thirty-six hours old. Samples of such milk 
were found to contain more than 100,000,000 bacteria per cubic centimeter, 
mostly spore-bearing varieties. The deleterious effects, though striking, were 
not serious or lasting. 
After the first twelve months of life, infants are less and less affected by the 
bacteria in milk derived from healthy cattle. According to these observations, 
Avhen the milk had been kept cool the bacteria did not appear to injure the 
children over three years of age at any season of the year, unless in A’ery great 
excess. 
a Park, Wm. H., and Holt, L. Emmett : Report upon the results with different 
kinds of pure and impure milk in infant feeding in tenement houses and insti- 
tutions of New York City. A clinical and bacteriological study. Medical 
News, Yol. S3, 1903, p. 1066. 
