THE SANITARY FACTORS 109 



sary not only to establish the proper definition of pas- 

 teurization but also to exercise adequate control of the 

 commercial process * and supervision of the product 

 both before and after, and this will require more ex- 

 tensive work than in the case of raw milk supplies. 

 Such is the sum and substance of the opposition, once 

 loud, now dying away, from uncompromising raw-milk 

 advocates. 



Methods of Pasteurization 



Milk may be pasteurized in the home f or commer- 

 cially. The latter way, under adequate supervision, 

 is the more effective and economical. Various types of 

 machinery for commercial pasteurization have been 

 devised, of varying degrees of efficiency. 28 What is 

 called the " flash" method, by which the milk is kept 

 heated for perhaps two minutes and then rapidly 

 cooled, , was formerly most in vogue, but has been super- 

 seded to a large extent by the " holding" method, 

 which is much more reliable. (Plates 8, 10.) In this 



* For specifications as to inspections, temperature records, and bac- 

 teriological tests, see 3d Report of the Commission on Milk Standards. 



t The following practical method of home pasteurization of a one- 

 quart bottle of milk is given in the Health News of the New York State 

 Department of Health for September, 1916. It is stated that this 

 process ensures thorough pasteurization without undesirable changes. 

 (It is well, when possible, to check such methods by use of a ther- 

 mometer.) 



" 1. Boiling 2^/2 quarts of water in a large agate sauce-pan, or better 



"2. Boiling 2 quarts of water in a 10-pound tin lard pail, placing 

 the slightly warmed bottle from ice chest in it, covering with a cloth 

 and setting in a warm place. At the end of one hour the bottle of milk 

 should be removed and chilled promptly. The water must be boiled in 

 the container in which the pasteurization is to be done." 



For a method of home pasteurization in infant's feeding bottles see 

 Plate 5. 



