DAIRY FARMING DAIRYING AGROTECHNY. 681 



and dairy products, and the second part gives directions for bacteriological 

 analj'ses and methods of bacteriological study. 



Acid production by Oidium lactis, W. Rullman (Centbl. Bakt. [etc.], 2. 

 AM., 18 (1907), .Yo. 2-'f-2.j, pp. 7//J-7.)S). — In experiments with sterilized milk 

 inoculated with a pure culture of Oidium laciis, the acid increased decidedly 

 on keeping the milk for considerable periods at room temperature and at 22° C, 

 but at 37° C. it decreased and the organisms eventually died. The results ob- 

 tained in these tests are compared with those of other investigators. 



The effect of moderate heating- upon rennet ferment, M. Siegfeld (Milchic. 

 Zentbl., 3 (1907), No. 10, pp. J,26-.',30).— The author found that heating rennet 

 solution to about 40° C. weakens the strength of the ferment, the destructive 

 effect being increased with continuation of heating. This appeared to be due 

 to hydrolytic action. 



Experiments were also made in which the solutions were diluted not with 

 water but wltli a 10 per cent solution of sodium chlorid, and with a saturated 

 solution. Heating the 10 per cent salt solution containing the rennet ferment 

 to 40° was about half as destructive as heating the water solution to the same 

 temperature, but in the case of the saturated solution the activity of the rennet 

 was reduced only about 10 to 14 per cent. The author suggests that the higher 

 i-esistance of the rennet ferment in the saturated solution may be due to the 

 relatively large quantities of sodium chlorid present. 



The f erm.ents of milk and their relation to pasteurization, R. G. Freeman 

 (Jotir. Amer. Med. Assoc, ^9 (1907), No. 21, pp. 1740-1742, dgm. 1). — The 

 author applies the deductions from the results of recent investigations on the 

 presence and action of ferments in milk to the problem of artificial feeding of 

 infants. He concludes: " (1) Milk for infant feeding should be pasteurized 

 so as not to interfere with its biologic properties or chemical composition, but 

 at a sufficient temperature to destroy the bulk of the bacteria present, includ- 

 ing the tubercle bacilli. (2) A temperature of 140° F. (G0° C.) continued for 

 40 minutes would seem to fulfill this condition." 



The relative rate of growth, of milk bacteria in raw and pasteurized clean 

 milk, E. Q. St. John and M. E. Pennington (Jour. Infect. Diseases, 4 (1907), 

 No. 4, PP' 64'^--656). — Pasteurized milk was rendered bacteriologically com- 

 parable with the original milk by reinfecting it with the residue obtained by 

 centrifuging some of the raw milk and drawing off the supernatant liquid. 



At room or i-efrigerator temperature the reinfected pasteurized milk curdled 

 sooner than the raw milk, and the former showed a marked increase in bac- 

 teriological content over that of the latter. The experiments led the author to 

 conclude that " there is a restraining power for ordinary milk organisms in raw 

 milk, lasting at least to the curding point. This condition is either not present 

 or is reduced in milk which is heated to 79° C, a temperature below that 

 required to destroy its oxidizing action. This restraining power seems to 

 apply to the organisms commonly found in milk in the combinations ordinarily 

 present there." 



Italian soft cheeses, G. Cornalba (Coltivatore, 53 (1907), Nos. 43, pp. 524- 

 527; 45, pp. 581-584; 46, pp. 625-629; 49, pp. 7 /J-7/7).— Different Italian soft 

 cheeses are briefly described and their analyses are reported. 



Investig-ations on goat's milk, E. Ujhelyi (Milchw. ZentU., 3 (1907), No. 

 10, pp. 430-435). — Experiments with 12 goats were made in continuation of 

 similar investigations previously reported. The average milking period for the 

 12 goats was 270 days. The average quantity of milk per goat was li liters 

 per day. The average of the individual fat tests, made monthly according to 

 the Gerber method, was 4.52 per cent. The average composition of the milk 

 for the whole 9 months was, water S5.G2 jier cent, fat 4.77 per cent, protein 



