1160 EXPERIMENT STATION RECORD. 



The composition of milk, 11. D. Richmond {Analyst, 32 (1907), No. 37.J, 

 ..,/>. l.'i 1-1 ',.',). — The average eompositiou of 13.513 samples of milk received from 

 farms and examined during 19()6 was as follows: Specific gravity 1.0322, total 

 solids 12.(;4 per cent, and fat 3.71 per cent. The average fat content of the 

 morning's milk was 3.55 per cent and of the evening's milk 3.88 per cent. 



Contribution to the knowledge of milk, E. Fynn (Centm. Bait, [etc.], 2. 

 AM., IS il'JOl), .\o. i.J-J.J. pp. Ji2S-Jili9, pis. 2). — Samples of whole milk and milk 

 diluted to different degrees with water were sterilized by heating at 105° C. 

 on 3 consecutive days. The author observed after 1 week certain microscopic 

 changes in the samples which were attributed to peptonization, and which were 

 more marked the greater the dilution. The samples were studied microscopically 

 in hanging-drop preparations made by diluting a drop of the milk with water 

 and staining by the addition of borax-methylene blue. The many changes ob- 

 served in the fat globules are described in detail and fully illustrated. 



The author also describes the cellular elements observed in both human and 

 cow's milk and the changes taking place in them when mixed with sterile 

 bouillon and kept in the incubator for several days. In sterile bouillon to 

 which a few drops of blood were added similar transformed cellular elements 

 were observed. The observations, however, are insufficient to warrant definite 

 conclusions as to whether or not certain cellular elements in milk are derived 

 from the blood. Sterile milk when added to bouillon seemed to exert a slight 

 ixictericidal action toward the typhoid bacilli. 



Nature and value of goat's milk, A. Burr {Milch Zt{/., .36 {1907), Xos. 19, 

 pp. 219. 220; 20. pp. 229. 230; 21. pp. 2.'il. 2-'i2). — This is a compilation of infor- 

 mation relating to the comiKisition and utilization of goat's milk. 



The acid coagulation of milk, C. Revis and A. Payne {Jour. Hipj. [Cam- 

 bridffe], 7 {1907), ^o. 2, pp. 216-231). — Experiments were undertaken to secure 

 information on the increase in acidity of milk in relation to the development of 

 lactic-acid bacteria. The results failed to throw light on the cause of the delay 

 in acid formation in comparison with the increase in bacteria, but are considered 

 by the authors as elucidating some of the chemical changes which take place 

 progressively as milk sours. They suggest, however, as highly probable that 

 the bacteria develop the power of producing acid only after a certain period of 

 growth. 



The experiments show that the lactic acid first produced is not neutralized by 

 some of the constituents of the milk. The amount of lactic acid combined with 

 the casein as well as the amount of calcium triphosphate combined with the 

 casein were found to be directly jn-oportional to the total lactic acid present. 

 The authors conclude that the compounds of calcium salts and of lactic acid with 

 casein as they are formed in milk do not possess the definite compositions of 

 the covuix)unds formed by calcium and lactic acid with casein after its separa- 

 tion from milk as described by Soldner and by Van Slyke and Hart. 



The presence of a kinase in cow's milk, A. Hougardy {Acad. Roy. Bch/.. 

 Bui. CI. Sci., 1906, .To. 12. pp. 8SS-900) .—The digestion of milk by the pancre- 

 atic juice is retarded by heating the milk for 20 minutes at 75° C. or above and 

 hastened by the addition of enterokinase. The author found that a cube of 

 coagulated egg albumen was more readily digested by the pancreatic juice when 

 jtreviously macerated in milk. This increased digestibility was, however, mini- 

 fied by heating the sensitized cube for a half hour at 73°. 



The conclusion is therefore drawn that there is present in milk a substance 

 capable of increasing the activity of the pancreatic juice in the same manner 

 as the enterokinase of Pawlow. The name lactokinase is proposed for this 

 hitherto undescribed substance. 



