90 EXPERIMENT STATION RECORD. 



The author made numerous investigations to find a practicable 

 method by which the casein might be precipitated from milk and pre- 

 pared commercially for food. The plan which he finally worked out 

 consists in curdling the casein with rennet and converting- the casein 

 into a soluble form. It was found that the hitter could be accomplished 

 by adding certain salts to the casein, as trisodium citrate. Experiments 

 showed 2.5 gin. of the citrate per liter of milk to be the best amount. 

 The preparation was partially freed from water by pressing and then 

 dried at a temperature of from 50 to 00° 0., preferably in a vacuum or a 

 well-ventilated oven. The final product is a white powder, nearly free 

 from taste or odor, which dissolves in water, giving a cloudy solution. 

 In order to prevent the solution from curdling on heating, the sodium 

 citrate used in preparation may be made slightly alkaline, or about 10 

 per cent of carbonate of soda may be added to the salt. It was found 

 in further experiments that the casein could be rendered soluble by 

 rubbing the mixed precipitated casein with a mixture of 1.5 gm. of 

 sodium citrate and 1 gm. of trisodium phosphate for each liter of milk 

 originally taken. 



The author believes the method is so simple that it may be employed 

 at creameries without difficulty. An experiment on a large scale is to 

 be undertaken, together with experiments on the use of the prepara- 

 tion of casein for cooking and for food. 



Report of the milk-control station in Christiania, Norway, 1897 (Norsk Land- 

 mansblad, 17 (189S), No. 3, p. 34).— During 1897, 3l2,'_T>!> samples of milk, cream, skim 

 milk, etc., were analyzed for fat content (by the De Laval butyrometer), 27,449 of 

 these being samples of new milk. The average percentage of fat in the new milk 

 was 3.4(17, against 3.44 per cent in 1895 and 3.461 per cent in 1896. The monthly 

 averages in 1897, each of which include analyses of about 2,000 samples, ranged 

 between 3.322 per cent (in April) and 3.745 percent (in October). — F. w, woll. 



Contribution to investigation on the addition of skim milk to whole milk, 

 V. IIoudekt (.'. Congres Internal. Chim. Appl.,1896, IV, pp. 294-JDS). 



A practical method for the preservation of milk samples for analysis — 

 Analysis of curdled milk, P. Dornic (2. Congrfo Internal. Chim. Appl., 1896, II, 

 pp. 7, r >-Sl). — Use of preservatives not recommended. Sample heated to boiling and 

 tightly stoppered. 



The use of acidimetry for testing milk which has soured or is in process of 

 souring, P. Dornic (2. Congres Internat. Chim.Appl., 1896, II. pp. 82-86,dgm. 1). 



Indigo carmin as a means of testing fresh milk, L. VAUDIN (Rev. Internal. 

 Falsi/., 11 {1S9S), Xo. l.pp. 24, 25; abs. in Ztschr. Angew. Chem., 1S9S, No. 14, p. 324). 



On the determination of fat in cream, butter, and cheese, N. Gerber and 

 M. M. Craandi.ik (Milch Ztg., 27(1898), No. 3, p. 35). — Preliminary report of a modi- 

 fication of Gerber's method, by which reliable determinations of the fat in cream, 

 butter, and cheese can be made. — F. W. woll. 



Further remarks on the determination of the fat content of cream, N. (Fer- 

 rer and M. M. Oraandijk (Milch Ztg., 27 (1898), No. 5, pp. 65, 66). — Quotes largely 

 from Farringtou and WolPs book on "Testing Milk and Its Products,'' as to the sources 

 of error in cream testing. — F. W. woll. 



On the accuracy of centrifugal methods of fat determination for the 

 examination of cream, H. Schrott (Milch Ztg., 26 (1S97), No. 52, p. S30).— Dilu- 

 tion of cream with water or Avith skim milk of known fat content previous to the 



