30 THE MILK SITUATION IN THE DISTRICT OF COLUMBIA. 



within 15 days before and 10 days after calving, and contains not less than 8.5 

 per cent of solids not fat and not less than 3.25 per cent of milk fat. 



(2) Blended milk is milk modified in its composition so as to have a definite 

 and stated percentage of one or more of its constituents. 



(3) Skim milk is milk from which a part or all of the cream has been re- 

 moved and contains not less than 9.25 per cent of milk solids. 



(4) Pasteurized milk is milk that has been heated below boiling, but suffi- 

 ciently to kill most of the active organisms present, and immediately cooled to 

 50 F. or lower. 



(5) Sterilized milk is milk that has been heated at the temperature of boiling 

 water or higher for a length of time sufficient to kill all organisms present. 



(6) Condensed milk, evaporated milk, is milk from which a considerable 

 portion of water has been evaporated, and contains not less than 28 per cent of 

 milk solids, of which not less than 27.5 per cent is milk fat. 



(7) Sweetened condensed milk is milk from which a considerable portion of 

 water has been evaporated and to which sugar (sucrose) has been added, and 

 contains not less than 28 per cent of milk solids, of which not less than 27.5 

 per cent is milk fat. 



(8) Condensed skim milk is milk from which a considerable portion of water 

 has been evaporated. 



(9) Buttermilk is the product that remains when butter is removed from 

 milk or cream in the process of churning. 



(10) Goat's milk, ewe's milk, etc., are the fresh, clean, lacteal secretions, free 

 from colostrum, obtained by the complete milking of healthy animals other than 

 cows, properly fed and kept, and conform in name to the species of animal from 

 which they are obtained. 



CREAM. 



(1) Cream is that portion of milk, rich in milk fat, which rises to the surface 

 of milk on standing, or is separated from it by centrifugal force, is fresh and 

 clean, and contains not less than 18 per cent of milk fat. 



(2) Evaporated cream, clotted cream, is cream from which a considerable 

 portion of water has been evaporated. 



CERTIFIED AND INSPECTED MILK. 



The terms " Certified " and " Inspected " have been aptly sug- 

 gested (the former by Dr. Henry L. Coit, whose valuable work in 

 promoting sanitary milk production is referred to elsewhere in this 

 report) to describe grades of milk produced under special require- 

 ments intended to insure the greatest degree of purity and cleanliness. 



Requirements for " Certified " and " Inspected " milk are set forth 

 somewhat at length in a scheme of classification proposed by Dr. 

 A. D. Melvin, Chief of the Bureau of Animal Industry, United States 

 Department of Agriculture, and heartily recommended by the Wash- 

 ington milk conference of 1907. 1 These requirements, especially as 

 to " Certified " milk, have met with general acceptance throughout 

 the United States, with some differentiation, however, as to the maxi- 

 mum number of bacteria 'allowable in various jurisdictions. 



SOURCES OF CONTAMINATION OF MILK. 



It is evident that in nature's scheme for the nourishment of the 

 young milk was never intended to see the light of day, and that if 

 suckled from the normal, healthy gland it is the perfect food for the 

 offspring. In this natural method of nourishment, observes Mr. 

 E. IT. Webster, chief of the dairy division of the Bureau of Animal 

 Indutry, 2 there is little possibility of contamination from outside 



1 See page 27 of this report. 



2 Bulletin No. 56, Hygienic Laboratory, United States Public Health and Mariqe- 

 Hospital Service, March, 1900, 559, 



