342 



EXPERIMENT STATION RECORD. 



curdles in less than 2 minutes should be rejected, as it is unfit for direct 

 consumption or for cheese-making. 

 Impurities and bacteria in the market milk of Christiania, 



L. SciiMELCK {Ixer.Iniirimt. Falsi/., 7,p]). !>>:'), isi; • ah.s. i)i Chnti. Cextbl., 

 1894, II, JVo. 10, p. 485). — Six hours after milking the milk from 50 

 dairies showed the following impurities in August and November, 1893: 



Dirt and bacteria in market milk of Christiania. 



The dirt consisted principally of cow excrement. The August inilk 

 showed a sour reaction after 2 to 4 hours; the November milk after 24 

 hours. 



Changes during cheese ripening, G. E. Patrick {lon-a 8ta. Bui. 

 24, pp. 90'.l-!Jsj). — The changes in weight and in composition of 1(3 

 cheeses were studied. Analyses are given of the green cheeses each 

 month for 5 months, and the changes in the amounts of ingredients 

 per 100 lbs. of cheese are calculated. A snmmary of the observations 

 is as follows : 



" The loss in weight during ripening for 5 mouths, including mechanical losses 

 caused by leakage aud scraiiiug of the cheeses, ranged from 14 to 24 ])er cent, aver- 

 aging 17.8 ; without including the scrajiings the average was 16.1 per cent. Tlie cor- 

 respoudmg averages for 4 months were 14.7 and 13.5 jier cent, respectively, including 

 and excluding the losses by scraping. 



"The loss of water in ripening for 5 months ranged, per 100 lbs. of cheese, from 

 7.4 to 16.5 lbs., averaging 11.1. For 4 months the average was 9.2 lbs. 



"The entire loss (both mechanical and chemical) of fat in 5 mouths ranged, per 

 100 lbs. of cheese, from 1 to 11 lbs., averaging 4.3 lbs. For 4 months the average 

 was 3.6 lbs. Doubtless a considerable part of this loss was mechanical, from leakage 

 and scrapings, but how much can not be stated. . . . 



"The total loss of nitrogenous matters (all calculated as casein) in 5 months ranged, 

 per 100 lbs. of cheese, from 0.41 lb. to 2.59 lbs., averaging 1.46. For 4 months th6 

 average was 1.26 lbs. These losses are respectively 7.20 and 6.14 per cent of the 

 casein of the green cheeses. What part of these losses, ilany, is chemical andAvhat 

 part mechanical, from leakage aud scrapings, can not be stated. . . . 



•'At the end of 5 months (more exactly, 22 to 27 weeks), an average of about 37 

 per cent of the original casein, or prodiicts derived from it by ripening, were found 

 to be soluble in water — a part in the form of amids aud a small amount as ammo- 

 nium compounds. . . . 



" The acidity apjiears to increase slightly during one or two months, and there- 

 after to gradually diminish. Calculated as lactic acid, it averaged 1.40 per cent of the 

 weight of the green cheeses, increasing to 1.95 per cent during the first 2 months, 

 and thereafter diminishing to 1.44 per cent at the end of the fifth month. . . . 



*' This diminution is supposed to be due, not to destruction, but to neutralization 

 of acids and acid salts, by ammonia resulting from the decomposition of casein." 



