DAIRY FARMING DAIRYING 591 



the difference was slight." Of the 5 separators used the best results 

 were obtained from the Alpha De Laval Humming Bird Separator, 

 which left only 0.084 per cent of fat in the skim milk as an average of 3 

 tests. No difference was observed in separating the cream immediately 

 after milking or after a period of 12 hours, but better results were 

 obtained by heating the milk to 100° before separating. 



Gravity or dilution separators, H. H. Wing {New York Cornell 

 Sta. Bui. 151, pp. 35-47, fig. 1). — Reference is made to work on cream 

 raising by dilution reported in Bulletin 39 of the station (E. S. R.,4, p. 

 3G1). Descriptions are given of Wheeler's Gravity Cream Separator, 

 Hunt's Improved Ventilated Cream Separator, and the Aquatic Cream 

 Separator, with the claims of the manufacturers. The first two "sepa- 

 rators" are considered similar in all essential features to the Cooley, 

 Moseley, and other cans used in deep setting; the Aquatic differs in 

 being provided with another smaller can intended to be filled with ice 

 and inserted in the large can as a cooler. Fifteen tests were made of 

 the Wheeler and Hunt cans in comparison with Cooley cans, and 5 of 

 the Aquatic. Tests of other cans were also made at various' farms. 

 The data obtained are tabulated and discussed. The following con- 

 clusions were reached: 



"Gravity or dilation separators are merely tin cans in which the separation of 

 cream by gravity process is claimed to he aided by dilution with water. Under 

 ordinary conditions the dilution is of no benefit. It may be of some use when the 

 milk is all from 'stripper' cows, or when the temperature of melting ice can not 

 be secured. These cans are not separators in the universally accepted sense of that 

 term, and can not rank in efficiency with them. They are even less efficient than the 

 best forms of deep-hefting systems, such as the Cooley Creamer. They are no more 

 efficient than the old-fashioned shallow pan, but perhaps require rather less labor. 

 In all probability they would give better results if used without dilution and 

 immersed in as cold water as possible, preferably ice water." 



The relation of certain bacteria to the production of butter, 

 C. H. Eckles {Gentbl. BaU. u. Par., 2. Abt., 4 {18!)8), No. 19, pp. 730- 

 734; 20, pp. 759-763). — Experiments are reported with the use of 4 

 species of bacteria in butter making, viz, Bacillus subtilis, B. vulgatus. 

 No. 13 obtained from milk from the Iowa Agricultural College cream- 

 ery, and B. lactici-acidi. The effects of the first two were bad, produc- 

 ing "butter of no market value. It is a significant fact that these are 

 species closely connected with dirt and filth." The other two, both 

 belonging to the lactic acid group, produced butter of fine quality, with 

 an unusually pleasant aroma. 



"The full effect of B. subtilis and B. mesentericus vulgatus is not 

 reached until from 3 to 5 days after manufacture. This shows that an 

 examination made at once after churning is misleading. No. 13, which 

 produces such a marked and pleasant aroma when grown m milk, gives 

 much less aroma to butter than does No. 8, which has but slight aroma 

 in milk." 



12342— No. 7 



