HEALTHFULNESS OF BUTTER 565 



sufficient to destroy the virus of scarlet fever, streptococci and 

 other pathogenic organisms. He therefore concludes that milk 

 heated to 60 C. and maintained at that temperature for twenty 

 minutes may be considered safe so far as conveying disease with 

 the micro-organisms tested is concerned. Schroeder 1 states that 

 the minimum effective temperature of pasteurization that will 

 destroy the non-spore bearing disease germs is 60 C. for twenty 

 minutes. Mohler, Washburn and Rogers 2 recommend heating 

 the cream to 60 C. for twenty minutes or to 80 C. momen- 

 tarily, as a reliable means to effectually destroy all the tubercle 

 bacilli that may have found lodgement in it. Marshall 3 holds 

 that milk should be heated to 85 C. (185 F.) momentarily in 

 order to insure freedom from tubercle bacilli. Ayres 4 reports 

 that such disease producing bacteria as Bacillus tuberculosis, 

 Bacillus typhosus, Bacillus diphtheria and the dysentery bacillus 

 are destroyed when heated to 140 F. for twenty minutes and 

 that the same process safeguards the public against the virus of 

 scarlet fever. Dr. H. D. Pease, 5 Director of the Lederle Labora- 

 tories, New York City, who conducted an extensive investigation 

 on the efficiency of the holding process of pasteurization to de- 

 stroy the germs of tuberculosis, typhoid fever and diphtheria in 

 milk, found that the use of temperatures from 142 to 147 F. for 

 a fraction of a minute and the additional holding of the heated 

 milk for thirty minutes, at temperatures ranging from 143 to 

 145 F. is sufficient to insure the total destruction of these 

 germs, even when present in milk in large numbers. His experi- 

 ments were made with commercial equipment, under strictly 

 commercial conditions and with milk heavily inoculated with 

 these disease germs. 



In Denmark the pasteurization of cream for buttermaking 

 at 82 C. to 85 C. (180 F. to 185 F.) is compulsory. 



These citations may suffifce to conclusively show that, since 

 the milk and cream from which butter is made, may be and 

 frequently are contaminated with germs of infectious disease, 



1 Schroeder, The Relation of the Tuberculous Cow to Public Health, 

 U. S. Dept. Agr. B. A. I. Circular 153, 1910 



2 Mohler, Washburn and Rog-ers, The Viability of Tubercle Bacilli In 

 Butter, U. S. Dept. Agr. Twenty-sixth Annual Report. B. A. I., 1909. 



3 Marshall, Tuberculosis and Its Management, Mich. Bull. 184, 1900. 



* Ayres, The Pasteurization of Milk, U. S. Dept. Agr. B. A. I. Circular 

 184, 1912. 



5 Pease, Pasteurization Experiments, Lederle Laboratories, N. Y. City, 

 1915. Results not published. 



