608 
in the dairy herds supplying many other cities. These cows should 
be replaced by healthy ones. The work of testing with tuberculin all 
cows supplying milk to a city of considerable size is an immense 
undertaking and must necessarily consume much time. Much time 
is required also in providing suitable cow stables, milk houses, and a 
pure water supply in all instances where such essential features are 
lacking. Facilities must also be provided for delivering milk at a 
reasonable temperature. 
It has been demonstrated that cows showing no physical evidences 
of tuberculosis may be affected with tuberculosis and secrete milk 
containing germs of that disease; also that the feces of such cattle 
are contaminated with that bacillus, and particles of such feces can 
readily gain entrance into milk. It seems important, therefore, in 
any classification of milk for city use, to require pasteurization of all 
doubtful milk for some time, or until all doubt as to the wholesome- 
ness of the milk is removed. 
It is therefore recommended that milk be graded in three classes, 
(1) certified milk, (2) inspected milk, and (3) pasteurized milk, in 
accordance with the specifications following, and that this classifica- 
tion be embodied in laws and regulations and enforced by public 
health authorities. 
CLASS 1.— CERTIFIED MILK. 
The use of this term should be limited to milk produced at dairies 
subjected to periodic inspection and the products of which are sub- 
jected to frequent analyses. The cows producing such milk must be 
properly fed and watered, free from tuberculosis, as shown by the 
tuberculin test and physical examination by a qualified veterinarian, 
and from all other communicable diseases, and from all diseases and 
conditions whatsoever likely to deteriorate the milk. They must be 
housed in clean, properly ventilated stables of sanitary construction, 
and must be kept clean. All persons who come in contact with the 
milk must exercise scrupulous cleanliness and must not harbor the 
germs of typhoid fever, tuberculosis, diphtheria, or other infections 
liable to be conveyed by the milk. Milk must be drawn under all 
precautions necessary to avoid infection, and be immediately strained 
and cooled, packed in sterilized bottles, and kept at a temperature not 
exceeding 50° F. until delivered to the consumer. Pure water, as 
determined by chemical and bacteriological examination, is to be 
provided for use throughout the dairy farm and dairy. Certified 
milk should not contain more than 10.000 bacteria per cubic centi- 
meter, and should not be more than twelve hours old when delivered. 
Such milk should be certified by, public health officers or by some other 
properly constituted authority. 
