1920] DAIRY FARMING — DAIRYING. 779 



Tlie trend of the dairy industry in Canada, J. A. Ruddick et al. {Agr. Guz. 

 Canada, 7 (1<J20), No. 4, pp. 311-313, 318-325).— These pages contain a series of 

 brief statistical articles dealins \\ith the manufacture of dairy products in l'.)l'.) 

 and preceding years in the Doniini(jn as a whole, and in Prince Edward Island, 

 Nova Scoda, New Brunswick, Ontario, Manitoba, Saskatchewan, and Alberta. 



The milk industry, [It.] S. Williams {Jour. Farmers' Club [Loudon'], I'Jli), 

 May, pp 59-'iJ). — Some account is given of the policies, woric. and handicaps of 

 the Ilesearch Institute of Dairying established in 1913 at University College, 

 Reading, and al.so notes on the activities of the Associated Milk Producers' 

 Council, an organization of dairy farmers whose main purpose appears to be 

 self-instruction in the sanitary aspects of milk production. The paper is fol- 

 lowed by a general discussion. 



Dairy farming in Switzerland in 1 919, J. Loxg {Jour. Brit. Dairy Farmers' 

 Assoc.. 32 {1920), pp. 30--'i2). — Observations made in Switzerland in 1919 and 

 previous years are recorded. 



" Dairy farming in Switzerland is successful chiefly on account of the abun- 

 dance of grass which the cultivated lands provide for stall feeding in summer 

 and for the production of hay for use in winter." The excellence of the soiling 

 crops is attributed mainly to the system of seed control which the author has 

 discussed elsewhere (E. S. R., 29, p. 337). 



The butter industry, O. F. Hunzikeb {LaGrange, III.: Author, 1920, pp. 

 611, figs. 115). — One of the purposes of this volume is to acquaint investigators 

 with "the real problems of the butter industry." The topics discussed include 

 the history of the butter industry, creamery organization, the buying of milk 

 and cream, cream separators, and the grading, sampling, neutralization, pas- 

 teurization, and ripening of cream ; churning, washing, salting, working, pack- 

 ing, marketing, storing, and scoring the butter; the overrun, butter defects, 

 whey butter, and renovated butter ; the chemical, physical, and biological prop- 

 erties of butter and butter standards and definitions. 



Mottles in butter — their causes and prevention, O. P. Hunzikee and 

 D. F. HosMAN {Jour. Dairy Sci., 3 {1920), No. 2, pp. 11-106, figs. 19).— The 

 authors report gross and microscopic observations on butters made in a series 

 of experimental churnings. 



Mottles appeared only in salted butter that was improperly worked. The 

 deep yellow patches in mottled butter contained relatively large and relatively 

 few water droplets, whereas the white dapples contained a multitude of minute 

 droplets. It is concluded that the presence of salt disturbs the water-in-fat 

 emulsion and that uniformity in the emulsion is restored by the process of 

 working. 



" In order to prevent mottles, butter must be worked sufficiently to accomplish 

 this fusion and reemulsification of water and brine. This point is usually 

 reached when the butter has been reduced, by working, to a plastic, tough, and 

 waxy body. The working must be uniform throughout the churn; overloaded 

 workers and workers improperly set, loose, or slipping, will not work butter 

 evenly and are prone to produce mottled and wavy butter." 



The cause and control of " buttons " in sweetened condensed milk, L. A. 

 Rogers, A. O. Dahlbkrg, and A. C. Evans {Jour. Dairy Sci., 3 {1920), No. 2, 

 pp. 122-135, figs. 6). — Tlie authors report observations, made in the laboratories 

 of the Dairy Division of the U. S. Department of Agriculture, indicating that 

 the hard reddish-brown lumps of curd occurring on sweetened condensed milk 

 and known as buttons are caused by the enzyms produced by Aspergillus repens 

 and possibly other molds. Contamination probably occurs after the milk leaves 

 the condensing pans. Sealing the cans under a 20-in. vacuum was found to be 

 an effective means of control, as the molds require oxygen for growth. 



