STUDIES OF MARKET MILK. 167 
that “‘ the average number of bacteria per cubic centimeter ex- 
ceeded 9,000,000 in April, 10,000,000 in May, and 18,000,000 
in June. The range in the different samples was from 10,000 
to 74,000,000 per cubic centimeter. Only I.4 per cent. of the 
total number of samples showed less than 50,000 bacteria per 
cubic centimeter. ’’ 
Individual lots of milk frequently run much higher in bac- 
teria than any of the figures given here. ‘The number of bac- 
teria per cubic centimeter is an indication of the care under 
which the milk has been produced and handled. There is, on 
the other hand, considerable milk sold especially in the smaller 
cities which has a much smaller germ content than the figures 
given. 
De Schweinitz* tested thirty-two samples of milk taken from 
fifteen different dairy wagons as delivered in the city of Wash- 
ington, D.C. Of these thirty-two samples one showed only 
about 2,500 bacteria per cubic centimeter, one 4,000, five 
others between 10,000 and 15,000, six between 30,000 and 
50,000, and the remainder more than 50,000 per cubic centi- 
meter, in several instances running above 115,000 bacteria per 
cubic centimeter. 
When we compare these large numbers of bacteria which 
are found in milk at the time it is delivered to the consumers 
with the small numbers existing in the milk as it leaves the 
udder of the healthy cow (from a dozen or two to a few hun- 
- dred per cubic centimeter) the contamination and improper 
treatment which takes place in the production and subsequent 
handling of the milk is apparent. 
Bacterial content of sanitary miulk.—In contrast to the num- 
bers found in ordinary market milk it is interesting to note the 
numbers of bacteria found in the so-called ‘‘ sanitary milk’’ as 
it reaches the consumer. De Schweinitz found that ‘‘sanitary 
milk’’ as delivered in Washington contained a bacterial con- 
tent varying from 200 to 5,000 bacteria per cubic centimeter. 
Out of 135 samples examined only eleven showed a bacterial 
content of over 5,000 per cubic centimeter. Asa result of his 
investigation De Schweinitz makes the following statement: 

* A Report upon Examination of Milk. E. A. De Schweinitz, Annual Report of 
Bureau of Animal Industry, 1899, p. 148. 
