DAIRY FARMING DAIRYING. 171 



Milk| its analysis and utilization, A. Monvoisin (Le Lait, son Analyse, 

 son Utilisation. Paris, 1911, pp. X-\-286, figs. 40). — The various chapters of this 

 book deal with the chemistry of the milk constituents, the composition of milk 

 from various animals, the changes in the composition of milk due to infection 

 or adulteration, physical and chemical methods for preserving milk, and some 

 special chapters dealing with unsweetened and sweetened condensed milk, 

 powdered milk, milk for infant feeding, etc. The official French analytical 

 methods are included. 



[Analyses of milk and its products], A. Devarda {Ztschr. Landw. Ver- 

 sucJisw. Osterr., 1/f {1911), No. //, pp. 363-373). — ^Analyses are reported of milk, 

 cream, butter, cheese, kefir, kumiss, skim milk, diabetic milk, whey, condensed 

 milk, powdered milk, and casein. 



Investigations on the surface tension in railk and the nature of the mem- 

 branes surrounding the fat globules, H. Bauee (Biockem. Ztschr., 32 {1911), 

 No. 5-6, pp. 362-379). — Surface tension was found to be largely dependent on 

 the percentage of fat. The depression by cooling was due to the congealing of 

 the fat, as previously reported by Burri and Xussbaumer (E. S. R., 22, p. 413). 

 The tension was nearly restored by heating for three-quarters of an hour at 50° 

 C It can be readily ascertained whether or not milk has been previously cooled 

 by comparing the surface tension as measured by a stalagmometer before cooling 

 and after cooling the milk for 1 hour at 10° G. 



The fat globules were thought to vary somewhat in chemical composition and 

 to be surrounded by a membrane the resistance of which to thermal and 

 mechanical influences is weakened when the milk is acidified or becomes abnor- 

 mal from any cause. 



The composition of East Hungarian sour cream, J. Adorjan {Ztschr. 

 Vntersuch. Nahr. u. Genussmtl., 22 {1911), No. 5, pp. 297-300 ) .—Thirty-five 

 samples of such sour cream from cow's milk and 1 from sheep's milk were 

 analyzed. 



Experiments in the production of sanitary milk, H. Atwood and N. J. 

 GiDDiNGS {West Virginia Sta. Bui. 134, PP- 81-105, pis. 4)- — A. study of the 

 sources of contamination of milk in the udder and during the process of cooling. 



The germ content of milk was much gi-eater after passing over the milk cooler. 

 A steam tight compartment to enclose the cooler and bottling machine was 

 then constructed in the form of a box divided with doors convenient to operate. 

 After turning live steam into the enclosure for 15 minutes the cooler ceased 

 to be a source of contamination. To further test the efficiency of this treat- 

 ment sterile water instead of milk was allowed to flow over the cooler and was 

 found to contain on the average 2 bacteria per cubic centimeter, but when 

 ■ the cooler was left open and merely washed and scalded the average number 

 was 11,400 per cubic centimeter. 



From these experiments it is concluded that the ordinary milk cooling de- 

 vices are not nearly so efficient as they should be for keeping down the bac^ 

 terial count of milk, but that by properly closing such apparatus and subject- 

 ing it to live steam, as described above, it ceases to be a source of contamina- 

 tion and the beneficial effects of cooling are much greater. 



Bacterial counts were made of the first milk, middle milk, and strippings, and 

 although the first milk and strippings contained far more bacteria than the 

 middle portions it should not be assumed that the strippings should be left. 

 The bacterial counts of the milk from the different quarters showed pronounced 

 differences both in the amount of milk and bacteria, but the order of differences 

 exhibited in one animal may be reversed in another. Where the number of 

 bacteria was high the amount of milk is usually small, and where the number 

 of bacteria is small the amount of milk is large. This test demonstrated the 

 22214°— No. 2—12 6 



