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37
Summary of Report on Milk Samples.
Forty-nine samples were examined.
The Dirt was estimated by the eye, from the sediment formed in a conical glass
after standing 24 hoars.
The samples, as a whole, were in this respect good.
I class 97.9 per cent. as Clean.
2.1 „ „ Unclean.
No specimen deserved to be called a really dirty milk.
Tubercle.—Each sample was allowed to stand 24 hours, and a guinea-pig was then
inoculated subcutaneously with about lcc. of the mixed sediment and cream.
The great majority of the animals developed local abscesses, but these mostly healed
and disappeared in 4 or 5 weeks.
In two instances the animals died prematurely.
One died of gangrene 8 days after inoculation. I found acid-fast bacilli in the
cheesy remains of the cream, but I cannot class this as a positive result. A second sample
from the same source yielded a negative result.
One died of wasting 20 days after inoculation. No tubercle was present, and this
deserved to rank as a negative result.
Five out of the 49 Figs (10.2 per cent.) became tuberculous, i.e., roughly one
milk sample in 10 contained living tubercle bacilli.
(Signed) F. W. ANDREWES, M.D.
So far as cleanliness is concerned these results show a marked improvement on the
record of previous years, and the fact that only 2.1 per cent. of the samples Avere found
to be unclean is eminently satisfactory. It is of course desirable that no sample should
be so classed, but having regard to the difficulties associated with the production and
delivery of milk, and to the fact that no specimen could be regarded as a really dirty
milk, the result of the examination of this particular series in this respect is gratifying.
The results as regards the presence of the tubercle bacillus cannot, however, be
regarded with the same satisfaction.
The fact that 10.2 per cent. of the samples are shown to harbour living
tubercle bacilli would appear to indicate that past efforts to eradicate this source of
tuberculosis have not met with the desired success.
Certainly it is difficult to base a firm opinion on the result of the examination of
an isolated and small group of samples, but one must not forget that the last
examination in the City conducted in 1913 on similar lines yielded a percentage of
10.4 tuberculous samples. At the present day one expects that a series of milk samples