DAIRY FARMING DAIRYING. 1081 



country. The milk was iillowcd to .stund in iin ice chest for from 20 

 to 24 hours. This method was found to be as satisfactory for g-etting 

 rid of foreign l)odies as tliat of the centrifuge. Two forms of l)ac- 

 teria were found in the milk samples, one resembling in all respects 

 the tubercle l)acillus and being acid proof, the other form being too 

 short and thick for the ti"ue tubercle bacillus. The latter form of 

 bacillus did not produce tu})erculosis when injected into experimental 

 animals. It was found by experiments^ that the virulence of the 

 tubercle bacillus ma}' l)e considerably increased by repeated culture 

 in milk. Cultures of tubercle bacillus which the author had main- 

 tained upon glycerin agar for 12 years were inoculated in milk, with 

 the result that within a week clumps of developing bacilli were noticed 

 with the characteristic appearance of the tubercle bacillus. Guinea 

 pigs inocidated with this culture developed true cases of tuberculosis. 



Experiments Avith pasteurizing apparatus, 1900, V. Storch, P. 

 V. F. Petekskx, aiid L. C. Nielsen {Ji7. Rpt. KgJ. Vet. LandhoJiiij- 

 shjles LaJj. LandohjH. F'orsog \^Copenhagen\ 1900., ]jjj. 6Jf). — The main 

 part of this report is given up to an account of the working, under 

 ordinary creamery conditions, and tests of the maximum capacity, of 

 3 dift'erent forms of pasteurizing apparatus made by Danish manu- 

 facturers in accordance with suggestions laid down in a previous report 

 of this station (E. S. R., 11, p. 887). 



The results show in general that the apparatus satisfactorily meets 

 the requirements of modern Danish creameries. A table is worked 

 out showing the amount of heating surface required to raise 10,000 

 lbs. of milk per hour 1° C. from to 99°. The trials made show that 

 an apparatus constructed according to the principles explained in the 

 report, which has a heating surface of 15,000 sq. cm., will raise 11,200 

 lbs. (Danish) of milk per hour from 40 to 85° C, which has been esti- 

 mated to be a saving of about 40 per cent in steam consumption over 

 that required })y the older forms of pasteurizing apparatus. 



Destroying foam in centrifugal dclriiintng. — In skinmiing milk by 

 the centrifugal process foam may be formed in three places, in the 

 cream separator, in the skim milk pump, and in the older forms of 

 pasteurizing apparatus. From observations made in the earlier inves- 

 tigations it seemed likely that the improved pasteurization apparatus 

 might act as a foam destroyer, and further trials showed that after 

 certain changes were made in the apparatus it acted satisfactorily in 

 this respect. If the weight of the foamless milk be assumed to equal 

 1, the milk as received from the separators in one series of trials 

 weighed on the average 0.71, and from the skim milk pump 0.65, 

 while milk drawn from different heights of the pasteurizing apparatus 

 (from below upward) weighed 0.90, 0.95, 0.97, 0.98, and at the out- 

 flow of the apparatus, 0.94. In another apparatus tried the following 



