BACTERIOLOGY 



ORDINARY MILK. 



If milk is obtained with strict aseptic precautions, it may con- 

 tain only a few hundred organisms per centimetre. If less 

 carefully collected, several thousand are present, and if care- 

 lessly drawn, some 30,000 to 100,000 bacteria per c.c. are found 

 in the freshly-drawn milk, these large numbers being intro- 

 duced into the milk from the skin of the cow, usually con- 

 taminated with faecal excrement, from the hands of the milker, 

 and from dirty water used in cleaning the milking pails and 

 pitchers. Dairy farmers and milkers as well as the middle-men 

 and distributors and the general public must all be educated 

 in these matters. There is at present almost incredible ignor- 

 ance and carelessness, especially among the smaller dealers. 

 For example, the writer recently heard of a dairy farm worker 

 whose duty it was to take the milk cans to and from the local 

 railway station, washing out some of his empty cans with the 

 station lavatory brush ! Cases of undiagnosed diphtheria and 

 scarlet fever and human tuberculosis among those who handle 

 the milk are frequent centres of epidemics of these diseases. 

 Milk is one of the most suitable culture-media for bacteria, 

 and therefore the question of cold storage is one of great im- 

 portance. Bottled milk, if the bottles are really clean, is 

 usually much more cleanly than ordinary dipped milk, and may 

 contain an average of less than half a million organisms per 

 c.c. as against four to eight or ten millions, which are quite 

 common figures in the case of the latter. In some towns, in 

 summer weather, seventy or eighty millions of bacteria may 

 be found ! In America, where the matter of clean milk is re- 

 ceiving more attention than in this country, the Philadelphia 

 Milk Commission fixed the standard of certified clean milk at 

 not more than 10,000 per c.c., New York at 30,000, whilst 

 other towns have a standard varying up to half a million 

 though with proper precautions the more exacting standard 

 can be attained with little difficulty. In this country very 

 radical reform of the milk-supply is urgently required, and, 



