DAIEY FARMING DAIRYING. 287 



kinds, in health and disease, and fed different rations. In milk from 

 healthy cows there was only one case in which the protein did not bear 

 the normal relation to the fat. The sugar content was found remark- 

 ably constant, fluctuating onl\^ from 4.4 to 5 per cent. 



These regularities in the composition of milk are thought to furnish 

 a reliable means for detecting adulteration. In skim milk the protein, 

 as calculated by the above formula, will be lower than that found by 

 analysis, while the ash and sugar will ])e normal. Water would lower 

 the content of all the constituents without changing their relation to 

 one another, but it would depress both the protein a and protein J, so 

 that the total protein calculated by the formula would be higher than 

 that found by analysis. The sugar content would be another indica- 

 tion of watering. Skimming and watering the same sample is some- 

 what more difficult to detect b}^ this method, but unless both had been 

 practiced to the same degree the disturbance of the relation between 

 the fat and protein would be apparent. 



In a later issue of the same journal (24 (1900), No. 3, p. 16) H. 

 Hoft discusses the above paper and takes exception to some of the 

 conclusions. 



The efficiency of a continuous pasteurizer at different tempera- 

 tures, II. A. Harding and L. A. Rogers {New Yorh State Sta Bid. 

 172^ pp. 507-630., Jigs. 2). — Introductory statements are made concern- 

 ing dairying in Denmark and in the United States. The lack of suc- 

 cess attending the use by Americans of the Danish method of butter 

 making has led the station to undertake a study of the process, the 

 results of which are to be published in a series of bulletins, of which 

 this is the first. The terms pasteurization and sterilization are ex- 

 plained, and the discontinuous or household system of pasteurization 

 for sanitary purposes and the continuous or Danish system adapted to 

 butter making are discussed. 



In the experiments at the station "the objective point was to deter- 

 mine the effect upon the germ life when milk was passed through a 

 continuous pasteurizer at different temperatures." Milk was pasteur- 

 ized at 70, 80, and 85° C. The apparatus used was made in Den- 

 mark, and is figured and described. The method of work is given, and 

 data showing the age, weight, initial temperature, and acidity of the 

 milk, the steam pressure in the l)oiler, the rate of pasteurization, and 

 the germ content of the milk before and after pasteurization are tabu- 

 lated. The milk was usually a mixture of i^ortions 4, 12, 24, and 36 

 hours old and had an acidity requiring from 18.9 to 40 cc. of normal 

 alkali to neutralize 1 liter. The samples averaged 350 lbs. The rate 

 of pasteurization varied greatly. At 80° C. it was about 2,100 lbs. 

 per hour. In the bacteriological tests neutral lactose agar was used as 

 a nutrient medium. The plate cultures were kept at 30° C and the 

 colonies were counted at the end of 48 hours. 



