302 MILK AND ITS HYGIENIC RELATIONS 



A well-known dairyman in this country, dealing with the organi- 

 sation of a safe milk supply, says : ' The process of pasteurisation, 

 though apparently so simple, is in grave danger of being discredited 

 by the careless and inefficient methods of some of its exponents. 

 It is a most serious fact that the process, as almost universally 

 conducted in this country, fails to exclude with certainty the germs 

 of tubercle, and thus loses its main raison d'etre. . . . Subsequent 

 dirty methods also render nugatory whatever benefit is conferred 

 by the process. Such sham pasteurisation is a delusion and a snare, 

 against which it behoves the public to be on their guard. Numerous 

 instances are known where such milk contained more germs after 

 the process than before. This is not the fault of the process, but 

 the fault of the operator, his methods, equipment, and the use of 

 originally inferior milk. . . . The ordinary method of pasteurisa- 

 tion is to heat any old milk available, for a single instant, and 

 immediately to cool it by running it over a refrigerator in a thin 

 film, and whereon every drop is exposed afresh to all the impurities 

 of the atmosphere. It is not surprising that milk so treated is 

 often worse rather than the better for it.' 



The inefficacy of careless pasteurisation is brought out by the 

 following facts quoted in a short article in the Medical Officer 

 for October 9, 1915, headed ' Pasteurisation so-called.' The 

 article says : ' In dealing with milks, samples of which have proved 

 to be tuberculous or have been found to contain an undue proportion 

 of organisms associated with excremental pollution, the Medical 

 Officer of Health for Newcastle-upon-Tyne is occasionally met 

 with the statement that the whole of the milk from a supply in 

 question is now pasteurised and cooled at a city dairy before distribu- 

 tion.' Tests made in connection with an inspection at one of the 

 largest and best equipped dairies gave the following results : 

 ' Sample I : Original milk as received from the farm B. Coli 

 present in o-ooooi c.c., the lowest degree to which the test was 

 carried. Sample 2, after " pasteurisation " at 160 R, gave identical 

 results, as also did sample 3, which had been " pasteurised " at 

 180 C. Sample 4 was " pasteurised " at 200 R, and B. Coli was 

 found in quantities down to o-oooi c.c. It is usual to classify as 

 " unsatisfactory " any milk in which B. Coli is detectable in less 

 quantities than o-oi c.c. In the above cases the milk merely 

 passed through the apparatus, and proceeded direct to the cooler, 

 so that the highest temperature reached was probably only main- 

 tained for a matter of moments. The plant in question is an 

 elaborate and costly one, and absolute confidence has been felt 

 by the owners in its efficiency, a confidence which would be entirely 

 justifiable if the operator had known how to use it.' Further 

 comment on the above appears unnecessary. 3 



The general trend of discussions which have taken place in 

 various American cities has been to show that if milk is pasteurised 

 it must be carried out under supervision and must be carefully 



