SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 11 
they realize that the ordinances in regard to standards, clean- 
liness, ete., are for their own interests. It is gratifying to 
see them come to the office for advice and counsel. 
With the close of this year the first systematic bacteriological 
work has been done on ‘the milk supphed, 39 dairies have been 
visited by the City Bacteriologist, and three sets of tests made 
from each dairy. 
At the various city depots 12 different visits have been made 
and 49 different dairies tested as the milk was brought in to 
the depot. Tests have been made also of the milk as delivered 
to the consumer—46 specimens from restaurants and hotels 
were examined. 
In July of this year the Board of Health established a bae- 
terial standard for milk of 500,000 colonies to 1 ¢. ¢., after a 
eareful study of the tests made. This has been conformed to by 
the better conducted dairies and the work has proved a stimulus 
to the majority of the dairymen. The lone years of education 
by Dr. Powers, and the activity of the present Board of Health 
in visiting the dairy ranches have resulted in the use of more 
whitewash on the dirty corrals, more screens and cleaner milk 
houses and in some cases even in the washing of the milker’s 
hands and cleaning of the udders of the cows than in several 
years. 
There is perhaps no medium outside of blood serum which 
forms such an ideal culture material for bacteria as milk. It 
is estimated that milk 24 hours old contains more bacteria than 
sewage. 
These are derived from the body of the cow, the hands of 
the milker, his pails and utensils, the water with which the 
cans are rinsed, the air and the flies. The temperature of milk 
results in a rapid increase of the number of germs and even 
under ordinarily clean surroundings the number of organisms 
in a given sample is necessarily large. 
The udder of a cow is practically free from bacteria, but the 
lactiferous ducts are more or less crowded with various forms. 
Prof. Russell, of the University of Wisconsin, gives the 
following interesting figures. Foremilk, 26,000 to 48,000; Milk 
after removal of foremilk, 1,000 to 4,000 colonies in le. e. In 
many of the large eities this fact is taken advantage of and 
certain dairies are under the immediate supervision of phy- 
sicians and health boards. The cows are cleaned, milk utensils 
are scalded and milkers wear clean white clothing, the fore- 
milk is disearded and the high grade product is known as 
““eertified milk.’’ So far Los Angeles has no econeern which 
furnishes this class of milk, but it is believed by those who 
have studied the question that there is a fortune in the dairy 
business alone this line. 
