DAIRY FARMING DAIRYING. 687 



from cows well along in the period of lactation. It also shows that butter made 

 from the milk of cows whicli have been in milk for a considerable period of Time is 

 slightly inferior to that made from the milk of cows which are comparatively fresh." 



A few experiments concerning the hardness of butter, H. 



Atwood ( West Virginia Farm Review, 6 (1808), Xo. 11, pp. 355, 356). — 

 Fifty-two and one-half pounds of sweet Cooley cream was divided into 

 2 equal parts, one being wanned gradually to 5G° and churned and 

 the other warmed gradually to 65°, kept at that temperature 2 hours, 

 and then churned. It was found that the butter from the cream 

 churned at 65° came and remained softer than that from the cream 

 churned at 56°. The hardness of the butter was determined by drop- 

 ping a small glass tube filled with mercury upon the butter and observ- 

 ing the penetration. In another experiment both lots of cream were 

 warmed considerably above the proper churning temperature and then 

 cooled quickly. One part was churned at once and the other was 

 allowed to remain at the proper churning temperature for 44 hours and 

 then churned. u The butter from the cream which was churned 

 immediately after being cooled came softer and remained softer than 

 the other." 



Studies on the formation of holes in Emmenthaler cheese, O. 

 Jensen (Gentbl. Bakt. u. Par., 2. Abt., 4 (1898), No. 6, pp. 217-222; 7, 

 pp. 265-275 ; 8, pp. 325-331).— The author reviews the theories in regard 

 to the cause of these holes and reports investigations to test their accu- 

 racy. The conclusions which he reaches are as follows : (1) The normal 

 holes in Emmenthaler cheese are not produced by the same agents as 

 swelling or by yeasts or obligate anaerobic bacteria, but by the agents 

 which cause normal ripening, i. e., lactic-acid producing organisms. 



(2) The gas which is the immediate cause of the holes is not produced 

 at the cost of the milk sugar, but from the nitrogenous substances. 



(3) The lactic-acid organisms of cheese can, under certain conditions, 

 form traces of carbon dioxid from nitrogenous substances, and these 

 traces are the cause of the normal formation of holes in Emmenthaler 

 cheese. 



The cause of the ripening of Emmenthaler cheese, E. von 

 Freudenreich (Landic. Jahrb. Schweiz, 11 (1897), pp. 85-101; and 

 Gentbl. Bakt. u. Par., 2. Abt., 4 (1898), No. 5, pp. 170-171; 6, pp. 223-230; 

 7, pp. 276-284). — Two cheeses were examined bacteriologically with 

 results similar to those found on previous occasions. Numerous lactic 

 acid microorganisms were found, with only a few liquefying organisms. 

 Experiments in inoculating Ducleaux' liquefying organism, tyrothrix, 

 into cheese, showed as formerly that the organism can not increase in 

 cheese but, on the contrary, decrease in numbers. Various experiments 

 are reported with cheese made from pasteurized milk which was inocu- 

 lated with cultures of lactic-acid bacteria, liquefying bacteria, and 

 anaerobic bacilli. These experiments, the author concludes, indicate 

 that the lactic-acid organism plays a principal role in the ripening of 

 cheese, since ripening took place when the lactic-acid organisms were 



