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for the collection of samples of milk, and in order to limit the amount 
of clerical work connected with the service, cases are not referred 
daily to the corporation counsel for prosecution, but only at the end 
of each week. The chemist after the close of the week prepares a 
report showing the work done in the chemical laboratory. He re- 
ports from time to time the names and addresses of all persons who 
have sold samples of milk or other foods, which have been found to 
be of an unlawful character. On such reports the chemist recom- 
mends either that a prosecution be instituted or that it be not insti- 
tuted. The minimum amount of butter fat which milk must contain 
in order to permit its lawful sale as whole milk is 3.5 per cent. 
This standard is a reasonable one and should insure the sale of a 
high-grade article. At times, however, even the most careful dealer 
may allow his milk to fall below it. The practice of the department 
requires that wherever a sample of milk is found to contain added 
water or a preservative, or to be colored, or to contain less than 3.25 
per cent butter fat, ]3i’osecution is to be instituted as a matter of 
course. If the butter fat is 3.25 per cent or more, but less than 3.5 
per cent, then prosecution is or is not instituted according as the 
entire recent record of the vendor is good or bad. If his milk has 
been repeatedly below 3.5 per cent, then even though the present 
sample shows more than 3.25 per cent, prosecution is instituted. In 
cases within this class, where the element of judgment enters, the 
inspector submits with his report and recommendations a statement 
showing the recent record of each vendor. A similar practice is in 
force with respect to cream, the legal standard for butter fat being 
20 per cent, and prosecution being instituted as a matter of course 
if the amount contained in a given sample falls below 18 per cent, 
and being instituted or not, according to the entire recent record of 
the vendor, where the amount of butter fat is 18 per cent or more and 
yet less than 20 per cent. 
In the chemical laboratory are analyzed samples of water from 
wells on dairy farms. These samples are collected by inspectors of 
dairy farms, and if from near-by farms are brought to the chemist by 
the inspector. If from outlying farms, as, for instance, those in the 
Frederick district, samples are forwarded by express. 
CONTAGIOUS-DISEASE SERVICE. 
Attention has already been called to the difficult}^ which an in- 
spector of dairy farms incurs in any etfort that he may make to 
detect on the farm cases of communicable diseases, such as typhoid, 
scarlet fever, or diphtheria. For the information of those of the 
readers of this report who are not familiar with technical matters 
relating to milk inspection, it is necessary to add that by no known 
