78 



DAIRY BACTERIOLOGY 



consumption of ice will be unreasonably large. The accompany- 

 ing illustration shows the arrangement of the cooling apparatus 

 at Fauerholm dairy which supplies Copenhagen with milk. Here 

 the milk is cooled to 3 C. By allowing the milk warm from the 

 cow to flow over a cooler or a special aerating apparatus, some of 

 the unpleasant animal odour is eliminated, but at the same time 

 the milk loses carbon dioxide and takes up oxygen, with the result 

 that the development of the aerobic putrefactive bacteria will be 

 favoured at the expense of the true lactic acid bacteria. As 



FIG. 55. Cooling and Straining of Milk at Fauerholm. In the foreground 

 Ice is being put into the bottom of Busck's Milk Pail. 



aeration will also expose the milk to air infection, it may often 

 do more harm than good on the whole. This will be the case 

 when the cows are in the stable, but here it will be easy to secure 

 rapid and thorough cooling by other means.' It is a different 

 matter when the cows are on pasture where the air will be pure, 

 and more than three hours may elapse before the milk arrives at 

 the farm to be cooled ; in this case immediate cooling on an aerating 

 appliance will do a great deal of good. Weigmann 1 has found that 

 pasture milk contains on an average, when retailed, six times as 

 many bacteria as stable milk obtained under the same conditions 



1 " Centralblatt f. Bakteriologie," 2 Abt., Bd. XLV., p. 105. 



