1916] DAIRY FARMING DAIRYING. 175 



value of roots of different percentages of solids was disclosed by the experi- 

 ments, when these were used in conformity with their content of solids. 



Nutritive value and digestibility of Juncus effusus and Scirpus lacustris 

 used as litter, N. von EirrzuoRFF-KuPFi-EU {Landw. Jahrb., 48 (1915), No. 3, pp. 

 J/29-487). — In digestion experiments with rabbits it was found that ./. cfju-ms 

 when freed from fat was readily eaten by the animals but was not well digested. 



Feeding experiments with milch cows showed that a daily ration of 13 lbs. of 

 S. lacustris hay had no bad effect upon their healtli but that the milk yield was 

 decreased even if as lov>^ as 4.5 lbs. per head were fed. The percentages of the 

 fat and total solids of the milk were not altered but the absolute quantity of 

 these constituents was decreased. Feeding S. lacustris hay did not change 

 the consistency, flavor, taste, or color of the butter but the Reichert-IMeissl 

 number was decreased and the iodin value increased. 



The author considers these two plants to be of considerable value as litter. 



Cooling milk, H. E. Ross and T. J. McInerney {Cornell Reading Courses, 5 

 {1915), No. 102, pp. 55-71, figs. 6). — Tiiis pamphlet treats of methods of cooling 

 milk and types of coolers. 



The results of experiments indicate tliat the bacteria content of milk held 

 at a temperature of 50° F. increases slowly, while that of milk held at 90° 

 increases i^ipidly whether the milk had either a small or a laige number of 

 bacteria in it originally. 



Cooling milk by placing the cans in a tank of ice water is deemed a practical 

 method for use on farm dairies. To cool the milk rapidly it must be stirred at 

 fx'equent intervals, but stirring every 5 minutes caused a sufficiently rapid drop 

 in temperature and the difference from stirring at intervals of 10 minutes was 

 very slight. When suflxcient quantities of ice were used stirring the water in 

 the cooling tank had little effect on the rapidity of cooling. 



In order to obtain the highest efficiency from the conical type of cooler it is 

 absolutely necessary to stir the water inside the cooler. Lower temperatures 

 can be obtained by using brine and ice than with ice water alone. 



Artificial refrigeration {Milk Dealer, 5 {1916), No. 8, pp. 26, 30).— From milk 

 plant surveys made by the Dairy Division of the U. S. Department of Agri- 

 culture, data were obtained on the cost of ice in plants where no refrigerating 

 machines were used, and on the cost of operating the machines in plants where 

 they were used. These figures were obtained from some of the smaller-sized 

 plants in the east North Central States, and in all cases electric power was used 

 for operating the compressor, so that very reliable costs could be obtained on 

 this item. The power also included, in many cases, the amount used in operat- 

 ing the pasteurizer, bottle washer, etc. Some of the plants bought a small 

 amount of ice for the delivery wagons. The overhead expense on the machine 

 was figured at 16 per cent on the cost, 6 per cent interest on the money invested, 

 and 10 per cent depreciation. 



The average cost per year per gallon of daily capacity of plant in thirteen 

 plants using artificial refrigeration was $1.44. Tlie average cost in nine plants 

 using ice was $2.25. It is pointed out, however, that these figures do not neces- 

 .sarily indicate that it is more economical for all plants to use artificial re- 

 frigeration, as the size of the plant and individual conditions must be deter- 

 mined by each dealer for himself. 



A new method for the destruction of bacteria in large volumes of milk by- 

 means of electricity, F. C. Lewis {Jour. Bd. Agr. [London'^, 22 {1916), No. 12, 

 pp. 1229-1238, i)ls. 2, fig. 1). — A method of destroying baetei-ia in milk by means 

 of electricity is descril)ed. The essential feature of the method consists in 

 passing a suitable current of electricity through the milk during its passage 



