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28
CONTAMINATED MILK.
With the object of ascertaining how far the milk supplied to the City was
affected by Tuberculosis, a series of samples was taken on arrival at the
various stations, and submitted to Dr. Klein for bacteriological analysis.
It will be remembered that a similar series was taken in 1902, when it
was shown that, although 24 milks were examined, all were found free from
the bacillus.
To make the samples as representative as practicable, two samples were
taken from each county.
It will serve to give some idea of the wide area from which the City milk
supply is derived to mention the counties from which samples examined
were derived, viz. : Bedfordshire, Berkshire, Buckinghamshire, Cambridgeshire,
Derbyshire, Dorsetshire, Essex, Gloucestershire, Hertfordshire, Huntingdon,
Leicestershire. Lincolnshire, Middlesex, Norfolk, Nottinghamshire,
Oxfordshire, Somersetshire, Staffordshire, Suffolk, Warwickshire, Wiltshire
and Worcestershire.
Dr. Klein's report is as follows :—
St. Bartholomew's Hospital, E.C.
1th January, 1905.
The samples of milk submitted to test for Tubercle were collected by your
Inspector in sterile bottles supplied by me, each bottle was stopped with
sterile glass stopper, capped and securely tied.
Of each sample 300 cubic centimetres of the milk were tested; the sediment
being divided in two portions, one was injected intraperitoneally into one, the
other (larger) portion subcutaneously into the groin of a second guineapig.
These guinea-pigs were labelled with the number of the milk sample,
thus: sample 20 was injected into guinea-pig 20 peritoneally, into guineapig
20a subcutaneously.
The animals were kept under suitable conditions, both as to cleanliness of
cages and abundance of good food, for about four weeks, by which time
tubercles, if any, would have developed sufficiently obvious to be detected
both by the unaided eye and by the microscope. Some of the animals died
in the course of the allotted four weeks from causes other than tubercle, and
in the appended tables of results the cause of their death will be stated. This
fact, viz., in experiments of this nature animals injected with the sediment of a
large volume of milk {e.g. each with that of about 150 cubic centimetres)
being liable to succumb to more or less acute disease—abscess, septicaemia and
the like, makes it necessary to use two animals for each sample. The present
series of experiments, as also many other similar previous experiments, show
that by using for each sample two animals, viz., one for intraperitoneal and a
second for subcutaneous injection, the risk of losing the test for a particular
sample qud tubercle, which might happen if only one animal were used for
each sample, is thereby avoided. I have never found that in the case of a
particular sample both the animals succumbed within the four weeks to causes
other than tubercle.