DAIKY FARMING— DAIRYING. I'd. 



lit- reports a Beries of experiments in which quantitative and qualitative compari- 

 sons were made of the bacteria] flora of ra\* and pasteurized milk kept at different 

 temperatures and also discusses the influence of lactic-acid bacteria on the « 1« \ « -1« •} i- 

 uiciit of peptonizing bacteria. No attempl was made to demonstrate the advisability 

 nr inadvisability of pasteurization. 



The experimenta] work is summarized by the author as follows: 



••.Milk was pasteurized under laboratory conditions in a continuous machine al 

 85 < '. (185 1. , the bacteria being reduced from over 10,1 ,000 per cubic centi- 

 meter to less than 500 per cubic centimeter. 



" Milk held at 20 I / [n the unheated milk the lactic bacteria in 



rapidly and the milk became acid in aboul 12 hours. The peptonizing bacteria 

 increased in 6 hours to aboul 5,000,000 per cubic centimeter and then decreased 

 slowly. 



"In tlic heated milk the peptonizing bacteria increased rapidly after 12 hours, 

 and the milk was usually curdled in 48 hours, with a disagreeable taste and odor. 

 Occasionally lactic bacteria survived pasteurization and multiplied rapidly after 24 

 hours, completely inhibiting the peptonizing bacteria. 



"Milk held at 10 C. {50 F.). [n unheated milk the growth of the bacteria and the 

 consequenl curdling of the milk was much retarded. The average milk did qoI con- 

 tain sufficient acid to affect the taste until it was over 18 hours old. The proportion 

 of peptonizing to lactic bacteria was greater than at the higher temperature, and the 

 taste of the milk occasionally showed the influence of the former. 



••In the pasteurized milk the bacteria increased very slowly, and in neatly every 

 case the milk was unchanged in taste and appearance ( .»<; hour.- after pasteurization. 

 In «»nly L' of 14 cases was there a marked increase of peptonizing bacteria. The pre- 

 dominating bacteria were species having little or no effect on milk. 



" The lactic bacteria inhibited the development of the peptonizing bacteria only 



when they had developed sufficient acid to render the milk unlit for use. 



" It seem-- probable that the acid had a distinct inhibitory action on the proteo- 

 lytic en/.yms of the peptonizing bacteria." 



The efficiency of commercial pasteurization and its relation to the milk 

 problem, s. ( '. Pbescott i Technol Quart, 18 {1905), No. 8, pp. U7-256). -Tables 

 show the number of bacteria in milk before and after pasteurization. 



In one series of 32 tests, 97. 1 per cent of the bacteria wen- killed by exposure to a 

 temperature approximating 1(54° F. The average efficiency of another machine in 

 34 tests was 96.1 per cent. In L0 tests where the bacterial content varied from 

 3,250,000 t<» 9,700,000 per cubic centimeter, the average efficiency of commercial 

 pasteurization was 99.1 percent. 



The author believes that all pasteurized milk should he -old as such, and that there 

 should he laws regulating the age, acidity, and bacterial content of milk which i- to 

 he pasteurized and subsequently offered for -ale. 



Raw milk as a food for infants, M. Hohlfeld {Jahrb. Kinderheilk. , <>: 

 No. /./'/'• ■'•' s 4, figs- 4)- — The clinical evidence presented indicate- that raw cows' 

 milk is much better than boiled milk for feeding infants affected with gastric or 

 intestinal catarrh. 



Some creamery problems, E. II. Farrington I Wisconsin .V". Bui. 129, pp. .'>>. 

 figs. 4) ■ — ( 1 ) ( 'are <>/ cream <it tin farm. — It is state. I that the usual causes of defective 

 butter from gathered (Team are keeping the cream in unsuitable place- and holding 

 it too long before delivery at the creamery. Suggestions are given for the proper care 

 of cream at the farm. ( 'a uses of variations in tests of separator cream are stated and 

 direction- are given for sampling and testing cream. 



(2) Overrunfrom milk and cream. — The factors upon which depends the amount of 

 butter that may he made from a given quantity of milk or cream are the te-t of the 

 milk or cream, the los.-es of fat in the >kim milk and buttermilk, the water content 





