DAIRY FARMING DAIRYING. 577 



curred. The soluble nitrogen recorded in percentage of the total nitrogen in 

 the butter increased in 428 days from 6.25 per cent and 7.G9 per cent to 6.29 

 per cent and 7.84 per cent for the pasteurized and unpasteurized, respectively. 

 The acidity of the pasteurized butter I'emained constant, while that of the un- 

 pasteurized increased from 25.5 to 33.9° (Fuller's scale). When the growth 

 upon synthetic agar was compared with the growth upon the same agar to 

 which 1 per cent butter fat — freed from impurities by melting and decanting — 

 was added, 9 species of the bacteria showed a more luxuriant growth in the 

 presence of fat, 11 were inhibited and 37 were indifferent, while 20 of the 

 yeasts grew more luxuriant, 5 were inhibited, and 6 indifferent." 



A bactenological study of the milk supply of Washington, D. C, J. J. Kin- 

 youn and L. V. Deiter (p. 231). — The milk was examined to ascertain the 

 actual conditions of the milk supply during a period of 14 months. The average 

 bacterial content for all samples was 9,300.000, and in no instance below 

 1,000,000. Fifty-five per cent contained Bacillus coll and streptococci. The 

 examination of pasteurized milk showed that it was far from satisfactory. 



The bacteriological improvement of a milk supply 6y other than laboratory 

 means, H. A. Harding (p. 232). — Attention is called to the fact that the estab- 

 lishment of a maximum permissible germ content in market milk is undesirable; 

 that bacteriologists must translate the results of their studies in terms of dairy 

 practice, which may well take the form of a score card ; and that any perma- 

 nent improvement in the milk supply must rest on the conditions which make it 

 more profitable to furnish a cleaner milk than to furnish a dirtier one. 



Suggestion of a new method of stating com^posite results of bacterial milk 

 counts, E. C. Levy (p. 233). — The average bacterial count of market milk 

 samples is thought to be of little value Therefore, a new method called the 

 " bacterial index " is suggested, and is explained in detail. 



The control of pasteurized milk by physical and bacterial standards, W. R. 

 Stokes and F. W. Hachtel (pp. 233, 234).— The importance of the control of the 

 pasteurization of milk and the milk after it has been pasteurized is emphasized. 

 The percentage of cases in which colon bacilli were present before and after 

 pasteurization is given. 



" The article then considers the recontamination of pasteurized milk, showing 

 by the work of Koehler and Tonney that while the average count from a large 

 number of freshly pasteurized milks was only 125,000, yet the average count 

 from pasteurized milk 1 day old was 602,0(X) bacteria per cubic centimeter. 

 Some of this milk showed counts varying between 1,000,000 and 4,800,000 per 

 cubic centimeter. These authors think that this recontamination can best be 

 obviated by a strict enforcement of a maximum standard for the temperature 

 of milk of 50° C. 



" The conclusions are that the physical and bacterial standards of Koehler 

 and Tonney are reasonable, and that the question of an additional safeguard 

 establishing a maximum amount in which colon bacilli can be present in 

 pasteurized milk is still open for debate." 



Recent developments in pasteurization of milk for a general market, PI H. 

 Schorer (pp. 234, 235). — A general discussion of the necessity for pasteurizing 

 market milk. " The most efficient method of pasteurization is that under 

 official supervision, controlling the quality of the milk pasteurized, pasteuriza- 

 tion in the sealed bottle at 145° F. for 30 minutes, allowing at least 30 minutes 

 to heat the milk to the pasteurizing tempei''ature, and labeling such milk 

 properly. This will insure suflBcient temperature to destroy pathogenic bacteria, 

 will inactivate the ferments but little, leave a good, cream line, and give a 

 preferred milk." 



