View report page

78
but this is not possible commercially. A sample of Pasteurised Milk which
just passes the allowance of 100,000 bacteria per c.c. must have contained
a very high content of organisms before pasteurisation or is so old that the
spores have been allowed to develop.
There is no bacteriological standard for ordinary milk and ordinary milk
is not examined for bacterial contamination. Fortunately a large percentage
of the ordinary milk sold to the public by the large firms has been pasteurised.
With the present methods of examination it would be impossible to examine
all samples of ordinary milk bacteriologically. Several quicker methods
have been suggested but there is a need for a rapid reliable method of obtaining
an indication of the amount of bacterial contamination present in ordinary
milk.
It is a pity that all milk is not pasteurised as the tubercle bacillus and
other pathogenic organisms are said to be destroyed; it is however necessary
to ensure that the milk before pasteurisation is produced under clean conditions
otherwise contaminated milk may be "camouflaged" by this treatment,
further an age limit for this and other types of milk should be prescribed.
Under the present scheme of graded milks there are a number of types
of milk sold at various prices and complying with different regulations regarding
freedom from disease and contamination while ordinary milk remains an
unknown quantity. Surely the ideal to be aimed at is the supply of uniformly
disease-free and clean milk at one price for all.
Of the 40 samples taken for bacteriological examination, 34 samples
were taken from licensed vendors and 6 samples were taken from Institutions
in the Borough.
The average chemical composition of these samples was:—Fat, 3.52
per cent, and solids-not-fat 8.74 per cent.
Examination for the Tubercle Bacillus.—Six samples of milk were tested
elsewhere for the Tubercle Bacillus by the inoculation method. In one case
a positive result was obtained.
Sterilised Milk.—Bottled sterilised milk is widely sold in the Borough.
This is convenient for retailers who order weekly supplies. The milk is
somewhat browned by the process to which it is subjected. It has the
advantage of being sterile or nearly so, but the vitamins present in raw milk
would no doubt have been affected and it is doubtful whether the milk itself
would be as easily digested as it is difficult to break up chemically. There
is no regulation controlling the production of this article.