818 EXPERIMENT STATION RECORD. 



certain period following milking the bacteria in the milk decrease in numbers. This 

 is more clearly shown in milk poor in bacteria than in milk containing large num- 

 bers. The bactericidal substances are more active at 37° C. than at lower tempera- 

 tures and are destroyed by cooking. Certain species of bacteria and molds are 

 destroyed by the toxic substances. Colostrum possesses a vigorous toxic influence 

 upon the coli bacillus. The bacterial flora of market milk furnishes an indication of 

 its freshness. The individuality of the cow has an influence upon the richness of the 

 milk in germicidal substances. 



The second part of this article is a discussion of the changes taking place in the 

 germ content of milk during the process of decomposition. 



The influence of formalin on milk and rennet, E. Lowexstein (Ztschr. Hyg. u. 

 Tnfectionshrank., 48 {1904), No. 2, pp. 239-246).— -The results of the experimental 

 work reported show, according to the author, that formaldehyde acts upon milk 

 lessening its coagulability with rennet, the extent of the change produced depend- 

 ing, in the first place, upon the length of time during which the formaldehyde acts 

 upon the milk and, in the second place, upon the amount of the preservative present. 



This effect is brought about even by the small amounts of formaldehyde ordinarily 

 used as a disinfectant. While formaldehyde in the gaseous state destroys the power 

 of dry rennet extracts, solutions of formaldehyde do not act to such an extent upon 

 rennet in solution. 



Pathologically altered milk, C. Schnoep {Schweiz. Arch. Tkrh., 4$ {1004), No. 6, 

 pp. 249-281). — A study was made of the physical and chemical changes which milk 

 undergoes as a result of certain pathological conditions, such as nymphomania, 

 estrum, ovariotomy, tuberculosis, inflammation of the udder, diabetes, emaciation, 

 and other diseases. The milk obtained from cows thus affected was tested by means 

 of the refractometer, cryoscopic and electrical apparatus. 



It is concluded from this study that the preservation of milk in glass flasks for 48 

 hours at a temperature of 15° C. had no effect upon its electrical conductivity. The 

 same may be said for the process of coagulation until this process has reached an 

 advanced stage. The conductive power of the milk for electricity remains quite 

 constant at different periods during health, hut differs somewhat in different animals. 

 Estrum was found to have no influence upon the electrical conductivity of milk but 

 lowered the freezing point. The refraction index of milk from cattle suffering from 

 different diseases appeared to be unaltered. The freezing point, however, was some- 

 what elevated. 



The care and handling of milk, C. E. Marshall, W. R. Wright, and J. 

 Michels (Michigan Sin. Bui. ..'21, pp. 53-74, figs. 12). — This is a popular bulletin 

 made up of 2 parts, the first by Marshall and Wright, dealing with the transmission 

 of diseases by means of milk, influence of food upon milk production, contamina- 

 tions of milk, aerating, cooling, and straining milk, sanitation in the stable and dairy, 

 and other topics; and the second part, by Michels, dealing with practical conditions 

 for the production of milk, including a discussion of dairy utensils, stables, barn- 

 yards, etc. 



Clean milk, W. J. Fraskk (Illinois >Stu. Qirc. 78, pp. 14, figs. 7). — Brief popular 

 notes are given on this subject and on standard milk. 



Discussion on the control of the milk supply, (I. Newman et al. (British 

 Mill. Jour., 1904, No. 2278, pp. 421-429). — The prevention of milk-borne diseases and 

 the improvement of milk supplies are treated in a comprehensive manner by Dr. 

 Newman in this address which was delivered before the section of State medicine of 

 the British Medical Association at its seventy-second annual meeting in July, 1904. 



Considerable information is presented on the production, conveyance, and sale of 

 milk in England, the quality of the milk, and on the control exercised over milk 

 supplies; the best working dairy farm known to the author in that country is briefly 

 described; the supplying of modified milk for infants is discussed; and suggestions 

 are made for the improvement of existing conditions. 



