272 EXPERIMENT STATIOXaRECORD. 



A bacteriological method for determining manurial pollution of milk, 

 J. Weinzirl and M. V. Veldee {Amer. Jour. Pub. Health, 5 (1915), Xo. i), pp. 

 862-866). — It is said that the use of Bacillus sporogenes as an indicator of 

 manurial pollution in milk possesses decided advantages over the B. coli test. 

 Since the organism is a spore producer and goes over into the spore stage under 

 ordinary temperatures, it can not be destroyed by pasteurization, so that this 

 test can be employed on all classes of milks, including pasteurized milks where 

 the B. coli test is worthless, and centrifugalized or clarified milks where the 

 sediment filter test becomes useless. 



The method employed consisted in the use of plain test tubes and milk sam- 

 ples. To secure aerobiosis sufficient sterile paraffin was added to the tube to 

 make a layer one-eighth of an inch or more in thickness. The tube, containing 

 the sample of milk and paraffin, was heated to 80° C. for 10 minutes, cooled, and 

 incubated. If B. sporogenes was present the lactose was digested under the 

 anaerobic conditions and the gas formetl rai.<5ed the paraffin plug some distance 

 up the tube. If B. vulgnris was present, digestion without gas formation ensue<l. 



The relative resistances to infection of raw, pasteurized, and boiled milk, 

 Lucy D. Ckipps and J. E. Purvis {lour. Noij. !<(i)iit. I)hit., 36 (1915), .\o. 9, 

 pp. 391-393). — To raw, pasteurizetl, and boiled milk samples was added 0.05 cc. 

 of a dilute emulsion of Bacillus coli (24 hours' growth), incubated at room tem- 

 perature and at 37° C. for 2, 4, 6, and 24 hours, and the increase in the number 

 of bacteria noted. 



It was found that the organisms increased much more rapidly in the pas- 

 teurizeil and boiled milks than in the raw milk, and in the boiled than in the 

 pasteurized. The increase was strikingly apparent in the 2, 4, and 6 hours' 

 incubations, and it was noticeable that although the relative increase in the pas- 

 teurized and boiled milks was not so prominent in the 24 hours' incubation there 

 was an actual decrease in the raw milk. It is thought that chemical changes 

 take place during the heating process, Avhich make the constituents of milk 

 more suitable for the assimilation by and growth of micro-organisms. Also, 

 " the enzyms of milk undergo definite changes by heat, and, in fact, are de- 

 stroyed when the milk is boiletl. It may be that these enzyms are responsible 

 for the germicidal power of raw milk,, whereas in boiUnl milk they are absent 

 because they have been destroyed ; or, again, it has been suggeste<l that the 

 destruction of the lactic-acid bacillus by pasteurization facilitates the growth 

 of undesirable bacilli ; or, again, where there is a mixture of saprophytic and 

 pathogenic bacteria the condition of the raw milk favors the growth of the 

 saprophytic type rather than of the pathogenic." 



It is concluded from these observations that milk should be pasteurized or 

 boiled immediately before it is consumed. 



Immunized milk in the prophylaxis and treatment of typhoid fever, .J. 

 Rosenberg (Med. lier. [.Y. y.], 88 (1915), No. 17, pp. 695, 6P6).— The author 

 presents evidence tending to show that cows and goats immunized with dead 

 cultures of the typhoid bacillus develop in their milk specific antibodies, agglu- 

 tinins, and precipitins; that feeding this milk to animals or human beings con- 

 veys passive immunity and protection against the typhoid bacillus; and that 

 ingestion of this milk causes the production of specific antibodies in the circu- 

 lation, so that the blood, at first negative, responds to the agglutination tt^t. 

 From these observations it is assumed that " Immunized milk would prtnide 

 protection against typhoid infection, a prophylactic like antityphoid vaccination 

 without its risk and the usual symptoms of discomfort." It is also maintaine*! 

 that immunized milk is a rational remerly for treating typhoid fever, espwMally 

 in the earliest stages, deserving preference to ordinary milk. 



