DAIRY FARMING DAIRYING AGROTECHN Y. 783 



Studies of the so-called sterilized market milk, O. Knusel (Studicn iibcr 

 die yo{/rtinnntr StcriUsicrtc Milch dcs flandrls. Inaug. Dixs., Univ. Ziirtch, 

 190S, PI). 7!)). — The literaturo on the subject is reviewed at length and an 

 aeeount is given of the author's study of sterilized milk which he tinds to be 

 a very variable product. 



Of IK) samples of " sterilizcNl " milk 03 contained germs. A perfect steriliza- 

 tion is wellnigh impossible without cooking the milk, for the spores of 

 anaerobic and proteolytic forms are very resistant to heat. The author fol- 

 lows Weber in dividing peptonizing bacteria into two groups, according to 

 the rapidity of protein hydrolysis. A third group, however, is necessary, for 

 a few si)ecies produce neither coagulation nor peptonization. The anaerobic 

 bacteria are not of much impoi'tance in sterilized market milk. 



The peptonizing bacteria produce a rennet ferment, a proteolytic ferment, 

 a reductase, and a superoxydase. Arnold's test with guaiac and Storch's 

 reaction both gave negative results for oxydase. Bacteria rennet is differ- 

 ent from animal rennet. It coagulates sterilized milk and is active at 60° 

 C. as well as at 37°, but ceases to act below 22°. The proteolytic ferment acts 

 at a lower temperature than the rennet, hence milk may become bitter yet 

 not coagulate. When proteolysis takes i)lace at 8° no serum zone is found 

 and the nutrient medium takes on a soapy appearance, which is not noticed 

 when milk is kept in opa(pie receptacles. The superoxydase is united to the 

 fat globules and is destroyed by boiling. To retard peptonization milk must 

 be under 8°. The peptonizing bacteria form nitrates and nitrites on different 

 nutrient media. They also form ammonia and hydrogen sulphid, but do not 

 I>roduce indol to any extent. 



Milk and its relation to infectious diseases, J. W. Tr.\sk (Jour. Anicr. Med. 

 Aftsoc, .')1 ilHOH), Xo. IH, pp. 1 '/fil-l 'i96). — A review of investigations by differ- 

 ent observers concerning milk and butter as carriers of typhoid fever, scarlet 

 fever. dii)htheria. and tuberculosis germs. 



The supervision of the milk supply in towns and cities and the prepara- 

 tion of germ-free milk for children, Bettkndohk and Stier (Ztschr. Flcisch 

 11. Mihlilijiff., 10 (n>OS). So. 2. pp. 6.',-75).—A lecture before the (Jerman So- 

 ciety of Naturalists and Physicians at Cologne, September 20, IDOS. The stiin- 

 gent supervision by physicians of the quality of the milk supply is insisted upon. 

 The methods of detecting adulterants and estimating the bacterial content are 

 reviewed. Directions are given for i>reparing milk for bottle-fed infants. 



Chicago pasteurizing rules (I'ucipc Dairy Rev., 12 {1!K)S), \o. Ji2, pp. 

 It. I.{). — ('hicago is the tiist large American city to make pasteurization com- 

 pulsory. Every pint of milk sold in that city must come from cows that have 

 jiasstHl the tuberculin test or be subjected to pasteurization, and every pound 

 of dairy products must come from such cows or made from i)asteurized milk. 

 The rules are given in full. 



Process and apparatus for keeping milk sound, T. C. Moi.i.incik .md A. 

 i{oMiMKs {IJnglish J'at. 2.')..i;i,t A or. /.). lUOl. ■/our. ,s'oc. ('hem. Indus., 28 

 ' UK)!)), \o. I, p. 3()). — A patented i)rocess Is d«'scribed by which nulk is pasteur- 

 ized iiiid licrnietically sejiied in bottles. 



The judging of milk with the aid of the fermentation test, F. I^ohnis 

 ( l/i7c// y.ti/.. .il (IHOS), So. 1,1. pp. ',S',. /,.S.7).— The author advocates the use of 

 the ferm<'iitation test as an aid in judging the purity of milk. His recent exi)eri- 

 nients indicate that 10 to 12° ('. is the best lempeiature for keeping the milk. 

 Mis methods are described in detail. 



Investigations on the fatty acids of butter, M. Sii:(ikei.ii ( Mihlnr. Zrnthl., S 

 inm\, .\o. 7. pp. 2!<S-2!l(!; ', ( lUOS). .\o. C. pp. 2.')<>-2(i2 ; ('hem. ZUj., 32 {1908), 

 So. ',2, pp. ,'iO.j, ,jOU). — I'-rom an investigation of the piopcrlies of fatty acids the 



