502 EXPERIMENT STATION RECORD. 



The role of lactic-acid bacteria in cheese ripening, H. Weigmann 

 (Gentbl. Baht. u. Par.. 2. Abt., 4 (1898), No. 15-16, pp. 593-607; 17-18, 

 pp. 669-67 I; and Milch Ztg., 27 (1898), No. 42, pp. 660-663; i3, pp. 673- 

 075; 15, pp. 706, 707). — This is an extended discussion of the part played 

 by lactic-acid bacteria in cheese ripening, with special reference to von 

 Freudenreich's work. The author concludes from his review of the 

 subject and from his own work that — 



(1) The specific lactic-acid bacteria are not cheese-ripening bacteria, 

 the form used by von Freudenreich in his experiments being only facul 

 tative or more probably degenerate lactic acid bacteria. 



(2) Lactic-acid bacteria have an important role in cheese ripening, 

 not in actually taking part in the ripening, but by directing the process 

 in the right direction. 



(3) This function consists in eliminating certain forms of bacteria 

 and fungi by the lactic acid formed, and providing an acid nutrient 

 medium upon which only such bacteria and fungi can thrive as can 

 withstand the acid or consume it. The micro-organisms which consume 

 the acid prevent its accumulation in too strong a degree, take part in 

 the peptonizing and flavor-producing processes, and enable other bac- 

 teria or fungi whose activity was weakened by the acid to continue 

 their work. 



(4) The specific character of a particular kind of cheese depends 

 upon the predominating form of micro-organism which the manner of 

 preparation and the handling of the cheese have brought about. 



Preliminary report of tests of the Thistle milking machine, B. Maktixy (Mitt. 

 Deut. Lanrtw. Gesell.', 13 (1898), No. IS, pp. 281-285; and Milch Ztg., 27 (1898), No. 42, 

 pp. 657-660). — Two tests of 77 and 40 days, respectively, were made on a private 

 estate, 10 of the heaviest milkers being selected from a herd of 120 Dutch cows. 

 In each test the cows were milked in alternate periods by hand and with the 

 machine. The results as to yield and fat content of the milk are fully tabulated 

 for the individual cows. The machine -was found satisfactory and did not cause any 

 disturbance or shrinkage of the cows. There is believed to be greater difficulty in 

 keeping impurities out of the milk, especially micro-organisms, than with hand 

 milking, and it is recommended to pasteurize machine-drawn milk immediately 

 after milking. It is questioned whether in the case of young cows machine milking 

 will make as good milkers as hand milking. As the machine is complicated and 

 requires to be carefully looked after, the author doubts whether it simplifies or 

 lightens the management of a dairy farm, provided good hand milkers can be 

 procured. 



Passburg's dry milk (Trockenmilch), G. Baumert (Ztschr. Angew. Chem., 189S, 

 Xo. 13, pp. ~97, $98). — Analyses are given of this product made by evaporating milk 

 at a low temperature without the addition of any foreign material, and of tablets 

 made from it by mixing with it a little cocoa, sugar, etc. The product is said to keep 

 well. 



Preparation of casein from skim milk (Chem. Ztg., 22 (189S), No. 87, p. 930). — 

 Three patents have been granted in England to' H. Higgius for the preparation of 

 casein from skim milk by means of hydrochloric acid, in the proportion of 5 lbs. of 

 acid to 100 gal. of hot skim milk (130 to 140° F.); and the manufacture of several 

 dried food products from it, either alone or mixed with Hour, rice, tapioca, sugar, 

 aromatic substances, etc. 



