MILK AS A CAKKIKK OF DISKASK 155 



Sundry researches on 1,1m germ-content of COW-dung, :ml on ils <l-|H'ii.l<-nn- 



on the dietary, were carried out by U \Vi TMKICII and I*]. vo\ FBEUDEITBEICH (I.). 



They found up to as many as 375 millions of bacteria per i v/vo// of fresh !; 

 matter, the majority consisting of Bacterium coli coin muni', along with SOUK; 

 3 millions of hay bacilli and others. An equal weight of the hay used for fodder 

 contained about yj millions of germs, of which about one-fourth were hay bacilli. 

 Sour brewers' grains (forty-eight hours old) yielded 375 million colonies. 



The germ-content of freshly drawn milk increases very rapidly during trans- 

 port to the centres of consumption, as also during storage, e.g. in milk-shops. A 

 number of estimations have been made in this connection, a few of which, by 

 FIIEUDENREICH (II.), are subjoined. In these, the influence of the length of 

 storage in conjunction with the prevailing temperature is taken into account. 



Number of Germs per c.c. 



On arrival in (lit; laboratory (two and a half hours after milking), 9300. 



A milk with an initial germ-content of 9300 will be reckoned poor in bacteria 

 when it is known that J. v. GEUNS (I.) found 2.5 million bacteria per c.c. in fresh 

 samples of Amsterdam milk. The reproduction can be moderated, but not 

 arrested, by cold, because, as we have seen in 61, milk contains also sundry 

 species of bacteria capable of 'development at o C. Therefore if it be desired 

 to prevent the decompositions set up by these organisms, it will be absolutely 

 necessary to kill the germs. 



122. The Part Played by Milk as a Carrier of Infectious Diseases. 



The aforesaid requirement is really imperative in view of the fact that diseased 

 cows which the owners often fail (or refuse) to recognise as such yield milk 

 containing pathogenic bacteria. And this applies particularly to tuberculosis, 

 from which complaint (on a moderate computation) one cow out of every five in 

 Germany suffers. As reported by J. OH. BAY (I.), on the authority of a compila- 

 tion made by the Danish pathologist B. Bang (to whom is 'due the honour of 

 clearing up this question), out of 132,294 head of cattle examined in the Copen- 

 hagen slaughter-house between 1891 and 1893, no less than 23,305 (some 17.7 

 per cent.) were recognised as tuberculous by macroscopic examination alone. 

 According to the researches of Dr. Martin, reported by R. CNOPF (I.), one out of 

 every thirteen samples of milk exposed for sale in Paris contains tubercle bacilli, 

 and from the results obtained by Dr. Schroeder in Washington, at least one in 

 every nineteen samples of milk sold in that city contains a sufficient number of 

 tubercle bacilli to produce infection. For the microscopic investigation of the 

 (specifically heavy) tubercle bacilli in milk, the sample, previously prepared by 

 skimming and clarifying, is separated, by centrifugal force, in strong test-tubes, 

 for which purpose special processes have been designed by TFKHIXEH (f.) and 



