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109
obtained for purposes of examination. It was collected in sterilized
bottles and examined at the Town Hall within a few minutes of
being purchased.|| The results obtained are set out in the following
table:—
District of London.
Standard of
Shop.
Average No.
of Bacteria
per c.c.
No. of
Liquefying
Colonies
per c.c. *
City of London Good class 4,800,000 120,000
City of Westminster Good class 1,600,000 125,000
Borough of Holborn Good class 4,800,000 145,000
Borough of Islington Good class 1,600,000 10,000
Borough of Finsbury A Good class 2,300,000 6,000
Borough of Finsbury B Good class 1,280,000 30,000
Borough of Finsbury C Poor class 3,200,000 45,000
Borough of Finsbury D Poor class 2,700,000 †
Borough of Finsbury E Poor class 340,000‡ 0
* These numbers are included in the total average number of bacteria
per c.c.
† These plates liquefied too rapidly for correct enumeration to be
made of liquefying colonies.
‡ This milk probably contained a considerable quantity of preservative.
The samples above recorded were obtained in a haphazard manner,
and do not necessarily represent the usual quality of the milk in
these several districts. It would be absurd to conclude from these
|| It should be stated that the examination was made on ordinary Petri plates,
and the culture medium used was best French gelatine. The milk was diluted
immediately after receipt with sterilized water to a dilution of ; 1 c.c. of milk
was added to 9 c.c. of sterilized water in small Hasks, and thoroughly mixed ;
1 c.c. of this 1/10 dilution was then added to 49 c.c. of sterilized water and again
thoroughlv mixed. This gave a dilution of which was found necessary in
order to examine the milk. Two plates of each sample were made, and the
resulting colonies of bacteria were counted on the second and third days after
incubation at 22-c. The figures were checked by three counters.