484 EXPERIMENT STATION RECORD. 



G-alactase, K. v^on Frf.udenreich {Laixlir. Jahrh. Schweiz^ llf. 

 {1900), Xo. 2, pp. J^-n5; Ann. Af/r. Su!.s.^c, 1 {1000), Xo. S,pp. 77-81^).— 

 Experiments were conducted in duplication of some of the work 

 reported by Babcock and Russell (E. S. R., 10, p. 785). Skim milk to 

 which 10 to 20 per cent of ether had been added was kept at room 

 temperatures and also at 35 C. The soluble nitrogen in the milk at 

 different periods from 1 to 8 months was determined in one series of 

 experiments by the method employed bj^ Babcock and Russell (heating 

 with acetic acid) and in another series by the use of the Chamberland 

 filter. In each series the nitrogen was determined in the filtrate by 

 the Kjeldahl method. The results of the experiments confirm the 

 work referred to. 



Bacterial growth of Tyrothrix tenuis in skim milk and also in bouil- 

 lon cultures was prevented b}^ the addition of 10 to 12 per cent of 

 ether. The addition of 20 per cent of ether to the milk as compared 

 with 10 per cent increased the swelling of the casein which was precip- 

 itated in a flaky gelatinous form, but did not increase the soluble 

 nitrogen. Milk heated to destroy the galactase and treated with ether 

 showed no increase in soluble nitrogen. The presence of O.B to 0.5 per 

 cent of lactic acid decreased markedly the action of the enz3mi. For- 

 malin lessened the action of galactase and to a less extent that of jjep- 

 sin and pancreatin, which had been added to sterilized skim milk. 

 Dilution of the milk did not lessen the action of galactase. Heating 

 to 85° destroyed it. Sterilized skim milk to which 20 per cent of 

 ether had been added was inoculated with a few drops of an emulsion 

 of spores of Tyrothrix tenuis and incubated at 35° C. Another sample 

 was similarly treated, except that the bacterial culture was previously 

 heated to 100° C. to destroy the enzyms present. There was an increase 

 in the soluble nitrogen in the first case and none in the second, which 

 was considered as showing that bacteria and their spores may contain 

 proteolytic enzvms. Galactase would not pass through a porcelain 

 filter. 



The author does not believe that galactase plays the principal r61e 

 in the ripening of cheese, especially Emmenthaler, but thinks that in 

 rendering the casein soluble it possil)ly prepares for and facilitates the 

 work of the bacteria which cause the ripening and produce the flavor. 



Dairy development in the United States, H. E. Alvord ( U. S. Dept. Agr. 

 YearJxjok 1899, j>jt. oSl-'/OJ, ph. 8, Jigx. /;.-'). — This is an account of the development 

 and present status of dairying in the United States. The progress made in the dif- 

 ferent periods of the nineteenth century is described. The establishment, features, 

 and management of cheese and butter factories are considered. Notes are given on 

 the introduction of dairy cattle and efforts at herd improvement. The centrifugal 

 cream separator and the Babcock milk tester are described. The article closes with 

 statistical information on the number of cows and quantity and value of dairy 

 products. 



Feeding dairy cows, T. L. li.vECKKK [Mimienula /^tu. Bal. 67, pp. 517-549). — This 



