DAIRY FARMING DAIRYING. 1123 



Biological investigations on the pasteurization of milk, A. Hippius (Jahrb. 

 Kinderheilk., 61 (1905), No. .!, pp. 365-384). — A specific precipitin was produced in 

 the blood of rabbits by the repeated injection of raw, pasteurized, and heated cows' 

 milk. This was true even when the milk was heated at 120° ('. for 1 hour. 



Raw cows' milk was found to exert a strong bactericidal influence on Bacillus coli 

 communis and B. prodigiosus. This influence was most marked during the first 3 to 

 4 hours and then gradually decreased, disappearing at the end of 6 to 7 hours. The 

 bactericidal properties were weakened by pasteurization at 65° for \ hour. Pasteur- 

 ization at 85° for 2 minutes likewise reduced the bactericidal power. Boiled milk 

 showed no tract- of bactericidal action. 



The oxidizing ferment in cows' milk was destroyed by heating at 76° for a short 

 period, it was not only uninjured by pasteurization at from 00 to 05°, but showed 

 a stronger reaction when the pasteurization at this temperature was continued for 1 

 hour,. 



The fat-splitting ferment in human milk remained unchanged by heating at 02° 

 for a short period, at 03° it was weakened, and at 04° destroyed. It resisted a tem- 

 perature of 00° for 1 hour. 



The so-called salol-splitting ferment in human milk was weakened by heating at 

 55° for a short period and completely destroyed by temperatures above 65°. 



The proteolytic ferment of cows' milk was found to retain its digestive action in 

 both weak alkaline and acid media by pasteurization at 00° for 1 hour and 05° for 

 2 hour. It was destroyed by heating at 100° for a short period. 



The amylolytic ferment of human milk was not destroyed by pasteurization at 

 00° for 1 hour or 05° for £ hour, but was destroyed by heating above 75°. 



The author therefore recommends pasteurization at 00 to 02° for 1 hour, or 03 to 

 05° for \ hour, which, as well as the customary method of pasteurizing at 85° for 

 1 to 2 minutes, is considered sufficient to destroy all pathogenic bacteria, and not 

 to produce any important changes in the chemical composition of the milk nor to 

 destroy the most important biological properties. Experiments in the feeding of 

 infants with pasteurized milk were not successfully terminated. 



Immunization by means of milk, B. Salge (Jahrb. Kinderheilk., 61 (1905), 

 No. 3, pp. 486-499; abs. in Biochem. Centhl., 3 (1905), No. 22, p. 723).— Milch goats 

 were immunized against diphtheria and typhoid and their milk fed to infants. 

 Blood examinations of such infants failed to show any increase in the content of 

 antibodies. The author does not believe that the passage of antitoxic or bactericidal 

 substances from the milk of animals to infants as the result of feeding has been 

 established. 



Investigation of pasteurized milk, A. A. Bonnema (C'hem. Ztg., 29 (1905), No. 

 14, pp. 182, 183). — The author recommends the pasteurization of milk at 05° C. for 

 15 minutes and describes his method of detecting pasteurized milk. Samples of the 

 milk are incubated at 37° when in case the pasteurization is well done only butyric 

 acid and gas-producing bacteria develop, while in case the pasteurization is not effi- 

 cient lactic-acid bacteria develop and gas production is absent. 



Pasteurization of skim milk, W. W. P. McConnell (Bien. Rpt. Minnesota State 

 Dairy and Food Comr., 10 (1905), pp. 55-57, figs. 2). — Apparatus suitable for pasteur- 

 izing skim milk in creameries is illustrated and described. 



The role of some physical and chemical agents in rendering the phosphates 

 of milk insoluble, P. Biffloth (Abs. in Rev. Gin. Lait, 4 (1905), No. 13, pp. 

 308-310). — A study of the effect of such conditions as may occur in practice upon the 

 solubility of phosphates in the milk is reported. 



For the purpose of this work the phosphates in milk were classed as insoluble cal- 

 cium phosphates, soluble calcium phosphates, and organic phosphorus compounds. 

 The object of the study was to determine the proportion of each of these forms of 

 phosphoric acid and the modifications brought about by conditions met with in thf t 



