THE CLASSIFICATION OF MARKET MILK. 
By A. D. Melvin, 
Chief of the Bureau of Animal Industry, United States Department of Agri- 
culture. 
In providing for the classification of milk, the primary object is to 
exclude all milk which may be harmful to the consumer and to pro- 
vide for milk that will be Avholesome and nutritious. In doing so the 
restrictions should not be more burdensome than is necessary to ac- 
complish this result, and should not be so severe as to lessen mate- 
rially the quantity and so eliminate milk, on account of increased 
price, as an article of diet for the poor. In view of the danger of 
using raw milk from diseased cows, drawn in improperly constructed 
dairies and under insanitary conditions, and improperly handled, it 
IS imperative that no raw milk be sold to the public except when those 
in authority know that it is safe to be used in that condition. 
Raw milk of the highest standard should be produced for the use 
of infants and invalids and for those w^ho desire to use only such 
milk and who are willing to pay for the greater cost of production. 
A wholesome supply of raw milk which can be furnished without 
involving unreasonable cost should also be provided for others. A 
third class includes undoubtedly the largest proportion of milk which 
is at the present time furnished for consumption and is unsafe for 
consumption in the raw state. To remove immediately from con- 
sumption this latter supply would result in such an increase in the 
cost of all milk as to place milk as an article of diet beyond the reach 
of the poor. It seems necessary, therefore, to provide some means 
of rendering safe all milk of doubtful quality, and this can be done 
under present conditions only by pasteurization under proper super- 
vision. 
The tuberculin test when applied by the Bureau of Animal In- 
dustry during the period from April 1, 1907, to June 30, 1909, to 
2,471 cows supplying milk to the city of Washington showed that 
15.25 per cent of those tested were affected with tuberculosis, and it is 
believed that just as high a proportion of diseased cows will be found 
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