156 THE PRESERVATION OF MILK 



ILKEWITSCH (I.). K. OBERMULLER (I.) examined Berlin market milk in this way, 

 and recognised it as infected with tubercle bacilli in a high degree. In this 

 connection it should be remarked that, according to determinations made in 1896 

 by A. BULLING (I.), goats are also liable to this disease, and therefore cannot be 

 considered as immune. 



The extent of the danger attendant on the consumption of unboiled milk is 

 not sufficiently illustrated by the foregoing particulars, which are only concerned 

 with the possibility of infection by such bacteria as are pathogenic for men and 

 animals, i.e. tuberculosis, anthrax, and so on. Milk is, however, also a frequent 

 carrier of typhus bacilli, which fission fungi (almost exclusively pathogenic for the 

 human subject alone) find their way into the milk, either directly from diseased 

 milkers or milk-dealers, or from the milk vessels being swilled out with water 

 containing these microbes. Farmyard wells are frequently very close to dung- 

 hills, cesspools, and closets, and if typhus breaks out on such farms, then the 

 well-water very soon becomes impregnated with typhus bacilli by means of fsecal 

 matter. Proofs of this exist by the dozen. The first reliable observation on this 

 subject was made by Ballard in 1870, when an epidemic of typhus broke out in 

 Islington, 67 houses and 167 patients being infected. A careful investigation of 

 all the cases led to its being traced to a farm-house from whence the milk supplied 

 to the infected families was derived, and there the closet cesspool was found to com- 

 municate (through rat-holes) with the well, the water from which was also used 

 for cleansing the milk-pails. To this first instance two others of recent date may 

 be added. One of them was investigated by PAUL SCHMIDT (I.), and arouses 

 interest because it treats of the inmates of a prison, where communication with 

 the outer world is much easier to trace. In two prisons in Strassburg (Alsace), 

 where typhus had not recurred since the Franco-German War, it broke out again 

 in 1890, and that, too, among a section of the inmates who had partaken of milk 

 derived from a neighbouring village where the disease was rife. The epidemic 

 died out when the supply of milk from this source was prohibited. A second 

 equally convincing instance was observed by REICH (I.) in 1892. ROWLAND (I.) 

 found living typhus bacilli in an Indian milk-comestible (known as " Dahi "). 

 The so-called explosive occurrence of this rapidly extending pestilence in a healthy 

 neighbourhood is thus explained by the fact of its germs gaining access to the 

 system with the food. Finally, milk is also a carrier of certain diseases that are 

 recognised as infectious, but whose exciting agent has not yet been discovered, 

 e.g. scarlet fever a case of which is recorded by W. H. POWER (I.) and foot- 

 and-mouth disease. 



123. Boiling 1 Milk. 



The particulars given sufficiently evidence the necessity for killing the germs 

 present in milk. Experience teaches that a short boiling suffices to destroy the 

 pathogenic organisms, the tubercle bacilli being according to the researches of 

 J. FORSTER and C. DE MAN (I.), and of BONHOFF (I.) killed by the action of a 

 temperature of 



55 C. in 4 hours. 

 60 C. i hour. 

 65 C. 15 minutes. 

 70 C. 10 



80 C. in 5 minutes. 

 90 C. 2 

 95 C. I minute. 



The cholera bacteria and typhus bacilli are, as proved by GEUNS (II.), capable 

 of still less resistance, and are therefore killed much more quickly than the 

 tubercle bacilli by a treatment expressed by the above figures. Only a single 

 pathogenic species can withstand the short boiling to which milk is ordinarily 

 subjected in domestic management, and this is the anthrax bacillus (spores). 



