18 



pears thinner, and hence people are led to believe that they 

 .get a poorer milk, a less rich cream. 



Drs. Russell and Babcock showed (Wisconsin Report, 1896) 

 -that this lack of "body" in pasteurized milk was due to a 

 change in the condition of the fat globules, a change strik- 

 ingly illustrated in the illustrations of unpasteurized milk 

 (Fig. 6) and pasteurized milk (Fig. 7), and they found by ex- 

 perimenting that the addition of a compound of sugar and lime 

 would restore the viscosity (the "body") and recommended it 

 as it really is as a harmless remedy. 



Fig. 6. Fig. 7. 



They little suspected that they thereby gave unscrupulous 

 milk men a pointer how to increase the "body," that is, the 

 apparent richness of unpasteurized milk and cream. That 

 this has been the result is indicated by a well known supply 

 house advertising: "Viscogen for restoring consistency of pas 

 teurized and separated cream." 



Meanwhile Dr. Theobald Smith in 1898 reopened the ques- 

 tion as to the exact temperature and the time needed to kill 

 the tubercle bacillus and in Wisconsin Report of 1899 Profs. 

 Russell and Farringfton tell us that they have confirmed Dr. 

 Smith's experiments that heating milk to 140 for 15 to 30 

 minutes does not change the "body" of the milk, does not 

 .affect the rising of the cream, as does heating to 150 or above. 



They also found that there was practically no difference 

 in the keeping quality of milk heated to 140 for fifteen min- 

 utes and that heated to 150 for the same time, nor did the 

 bacteriological examination indicate any advantage in using 

 -the higher temperature always provided that milk is agitated 

 while being heated as otherwise as in bottles a film or skin 

 which protects the bacteria, forms on top of the milk, so that 

 even heating it at 140 for one hour will not be satisfactory. 



