504 THE PASTEURIZATION OF MILK 



cool, packed in ice during transportation except in winter, and reach 

 the consumer within thirty hours after being drawn. 



Milk commissions generally employ a veterinarian, a bacteriologist, 

 and a chemist as experts for the control of the animals kept in the 

 dairy and of the milk furnished by them. "The duties of the veter- 

 inarian," as defined by Ward, one of the foremost American experts 

 on milk, "are to determine the general health of the animals, to 

 observe the sanitary conditions, and to scrutinize the technique of 

 milk handling. In general, his duty is to determine if the conditions 

 of the agreement of the dairyman with the commission are being 

 observed. His criticism and suggestions must maintain that degree 

 of alertness on the part of the foreman of milkers and other employees 

 that shall minimize the possibility of contamination of the milk. The 

 control of bovine tuberculosis is a task that demands the utmost 

 vigilance. Without care in regard to this disease the pretentious 

 of a certified dairy are fraudulent. When not vigorously dealt with 

 it constitutes the greatest menace to the financial success of a certified 

 dairy. Tuberculin tests a year apart, with careless supervision of 

 additions to the herd, are useless in a herd that was badly infected 

 at the beginning, for tuberculosis will keep pace with lax efforts 

 directed against it. It is not sufficient to test merely the cows that 

 happen to be in milk at the time of the test. Every dry cow should 

 be included. In an infected herd a test once in six months is regarded 

 as necessary, followed each time by thorough disinfection of the stable. 

 The control of tuberculosis cannot be accomplished by one test, 

 carried out in a perfunctory manner, but the struggle must extend 

 over years. Additions to the herd must be tested with tuberculin, 

 but there is always danger that an animal though not reacting may 

 introduce the disease. On this account it is far better to subject 

 each animal added to the herd to a three months' quarantine with a 

 tuberculin test at the beginning and end of this period. During the 

 period the milk may be used." 



Milk sold as certified under the supervision of a medical milk 

 commission should be examined about once a week by a competent 

 bacteriologist and its bacterial content should not be above 10,000. 

 This expensive milk is almost exclusively used for the feeding of 

 infants, and those paying a high price should have full assurance that 

 they get as excellent an article of food as they have a right to expect. 

 In the State of New Jersey, where the movement creating medical milk 

 commissions originated under the leadership of Henry L. Coit, of 

 Newark, special laws have been enacted to protect the sale of certified 

 milk against any product not coming up to the proper standard. 



THE PASTEURIZATION OF MILK. 



As previously explained, sterilization consists in exposing an object 

 to such (generally thermal) influences that all life in it is destroyed 



