DAIRY FARMING DAIRYING. 575 



lug as conipared with the evening milking, it has little effect on the total weight 

 of fat given at each milking. 



On the law relating' milk flow to age in dairy cattle, R. Pearl (Proc. Soc. 

 Expt. Biol, and Med., 12 (191/,), No. 1, pp. 18, 19).— The author finds that, 

 contrary to the general assumption, the relation between the two variables milk 

 flow and age is a strictly linear one. " The amount of milk protluced by a cow 

 in a given unit of time (7 days, 1 year, etc.) is a logarithmic function of the 

 age of the cow." The law may be stated in the following way : 



" Milk flow increases with increasing age but at a constantly diminishing rate 

 (the increase in any given time being inversely proportional to the total amount 

 of flow already attained) until a maximum flow is reached. After the age of 

 maximum flow is passed the flow diminishes with advancing age and at an 

 increasing rate. The rate of decrease after the maximum is, on the whole, 

 much slower than the rate of increase preceding the maximum." In general 

 the law applies to the absolute amount of fat produced in a given time as well 

 as to the amount of milk. 



General rules and reg'ulations regarding the conduct of advanced registry 

 tests in New Jersey, A. S. Cook (Xcw Jersey Stas. Circ. 38, pp. 3-7). — This 

 gives general directions to breeders and supervisors regarding the conduct of 

 advanced registrj- tests in New Jersey. 



The production and care of milk and cream ( U. S. Dept. Agr., Office Sec. 

 Spec. [Circ.], 1914, Dec. 31, pp. 4). — A ix)pular discussion. 



Handling milk in pint bottles, E. Kelly {Hoard's Dairyman, 48 (1915), 

 No. 25, p. 145). — In surveys made by the U. S. Department of Agriculture of 

 the relative number of milk bottles handled by milk dealers in five cities, it was 

 found that a surj^risingly large number of pint bottles are used. With 74 deal- 

 ers an average of 1.39 pints was handled for each quart, and these constituted 

 41 per cent of the entire bottled milk. It is believed that because of the small 

 profit made in some cases on milk handled in pints, it would be well for dealers 

 to encourage the quart trade in every jiossible way. 



The pasteurization of milk in the final package, B. W. Hammer and A. J. 

 Hattser {Imva Sta. Bui. 154 (1914), pp. 321-356, figs. 6).— In the work reported 

 an effort was made to determine the most favorable vat temperature and time 

 of exposure for final package pasteurization. The points considered in the 

 determination were bacterial efficiency, creaming ability, and the heated flavor 

 produced. 



It was found that " the method of final package pasteurization must be 

 regarded as a modified holding method because of the slowness with which the 

 bottle<l milk can be heated or cooled. 



" High pasteurization temperatures are unsatisfactory for the methotl of final 

 package pasteurization because of the decreased creaming ability and pro- 

 nounced heated flavor of milk so treated. 



"An exposure of HO minutes in water at 145° P. gave an average bacterial 

 eflSciency of 99.56 (13 experiments) and an average creaming ability of 94.68 (20 

 experiments). The heated flavor developed was so slight that only 8 persons 

 out of 61 detected that the milk had been pasteurized. 



" Milk pasteurized in the bottles with an exposure of 50 minutes in water at 

 145° was very satisfactory from the viewpoint of the consumer. Out of a total 

 of 61 i)ersons, 11 preferred the raw milk, 36 preferred the pasteurized, and 14 

 saw no difference. 



" The intensity of the heated flavor in milk depended to a certain extent on the 

 amount of fat present, inasmuch as the larger quantities of fat tende<l to mask 

 the heated flavor. Because of the influence of various factors, such as the fat 

 content, and also on account of the variations in the ability of different persons 



