996 EXPERIMENT STATION RECORD. 



A sample of German Caniembert cheese was mixed with water and 

 injected into a guinea pig. The pig died within 24 hoars of peritonitis. 

 Fifteen samples of cottage cheese were tested, with the result that many 

 of the animals died of peritonitis in 1 or 2 days; and 3 samples were 

 found to be infected with true tubercle bacilli. 



The rancidity of butter and the effect of pasteurizing cream 

 on the keeping quality of butter, H. Schmidt {Ztschr. Hyg. u. Infec- 

 tionsleranh., 28 {1898), No. 2, pp. 163-188).— Different lots of butter from 

 the same source were kept under a variety of conditions in light and 

 darkness, and observations made on the germ content, the production 

 of acid, the rancidity, taste, odor, etc. Salted and unsalted butter 

 from unpasteurized cream and from cream pasteurized at 70 to 75° 

 and 90 to 95° C. was used. It was fouud that the acidity and the 

 germ content were appreciably lower in the salted and the pasteurized 

 butter in proportion to the height of temperature employed in pasteur- 

 izing. Both the acidity and germ content were greater in butte^ kept 

 in the dark than in the light at similar temperatures; but both were 

 reduced by keeping in a refrigerator and increased by keeping in a 

 breeding oven at 23° C. In sunlight with free access of air there was 

 no increase in germ content and the germs were gradually destroyed. 

 There was a slight increase in acidity, which is believed to be due to 

 chemical action. 



Under exclusion of air, both in darkness and diffused light, the 

 acidity of butter from cream pasteurized at 90 to 95° exceeded that of 

 butter from cream pasteurized at 70 to 75°. This was true of both 

 salted and unsalted samples. The cause of this is not explained. 



In general, butter with a high acidity was more or less rancid in taste 

 and odor, but there were some exceptions to this rule, notably in butter 

 kept in sunlight with free access of air. Such butter soon became rancid 

 and greasy, lost its color, and was wholly inedible, although the acidity 

 did not indicate it to be rancid, or only slightly so. Butter became 

 rancid most rapidly in sunlight and next to that in the breeding oven 

 (in darkness). Keeping in a refrigerator was the best protection 

 against rancidity. Butter from ordinary cream became rancid more 

 rapidly and to a greater degree than that from pasteurized cream, and 

 the keeping quality of butter was increased by pasteurizing the cream 

 at the higher temperature. Salted butter did not become rancid as 

 soon or to so great a degree as unsalted. 



The best conditions for keeping obtained in salted butter from pas- 

 teurized cream kept in a refrigerator. Such butter was normal after 

 15 days, only slightly rancid after 30 days, and was still edible when 

 70 days old. 



Pure cultures for Cheddar cheese making, J. R. Campbell 

 ( Trans. Highland and Agr. Soc. Scotland, 5. ser., 10 {1898), pp. 181-224).— 

 A preliminary experiment in the use of a pure culture of lactic-acid 

 bacteria proviug satisfactory, experiments were made on a practical 

 scale at Craigley during June, July, and August, the results of which 



