582 EXPERIMENT STATION RECORD. 



from Copenhagen in which 30,000 liters of milk can be handled daily. 

 From one-fourth to one-third of the whole amount of milk is frozen 

 artificially in cakes of about 12 kg. in weight and placed in large cans 

 of about 500 liters capacity. The following morning the cans are 

 filled with fresh milk and are then closed air-tight and sent to Copen- 

 hagen. They can be kept in this way for several weeks, being opened 

 for consumption at will. When it is desired to use the milk it is thawed 

 by placing the contents of the cans in vessels surrounded by hot- water 

 coils. The gradual thawing creates currents in the milk which prevent 

 any of the constituents separating out. A can which had been put up 

 June 17 was opened in Paris June 25. The milk had all the character- 

 istics and taste of pure, fresh milk. The composition was the same as 

 that of pure milk, but the keeping quality of butter made from it was, 

 for some reason, unsatisfactory. 



Frozen milk {Apoth. Ztg.; dbs.in Milch Ztg., 20 {1*97), Xo. 40, p. 

 638). — In experiments at the Hamburg Hygienic Institute about 30 

 liters of skim milk was completely frozen by placing in cold storage 

 for 72 hours and was then gradually thawed out without mixing the 

 contents of the can. Samples were taken from the top and bottom of 

 the can, and the whole quantity was then thoroughly mixed and 

 sampled. The analyses of these samples are given as follows: 



Analysts of frozen milk. 



Specific 

 Specific ! T . , gravity of 



gravityat *H»J Fat. milk 



15° C. 80UO8. seJ . um , |t 



15° C. 



Sample from top of can. 

 Sample from bottom of can . 



Percent. Percent. 

 1.0001 1.70 Trace. 



1.0375 0.84 0.20 



Mixed frozen milk 1.0 9.40 .15 



1. 0045 

 1. 0J85 

 1.1274 



As the milk melted, the ice collected on the surface and its contents 

 after thawing did not mix with the rest of the milk. 



Conditions affecting the consistency of milk, S. M. Babcock 

 and H. L. Russell ( Wisconsin Sta. Bpt. 1896^ pp. 73-80, pis. 2, fig. 1). — 

 It is mentioned that milk and cream are rendered thinner by heating, 

 but unlike most viscous substances the original consistency is not 

 restored wiieu they are cooled. This is a serious objection to the use 

 of pasteurized milk and cream. The authors made microscopic exam- 

 inations with a view to determining the cause of this. Some of the 

 results of these examinations are figured. 



"A microscopic examination of pasteurized milk or diluted pasteurized cream pre- 

 sents a very different picture from that of normal ruiik or cream. In the case of the 

 normal milk the fat globules in place of heing homogeneously distributed throughout 

 the microscopic field are grouped in part in irregular, but well-defined masses. All 

 of the fat globules are not included in these fat aggregations. Some of the globules 

 remain isolated and distinct. . . . 



"The microscopic appearance of milk or cream that has been heated above 65° C. 

 (149° V.) is totally different. Not only is this true with pasteurized milk, but steril- 



