View report page

1899] 228
Method:—200 c.c. of each milk sample was centrifugalised for one hour. At
the end of half an hour the centrifugalisation was intermitted, and the cream stirred
in at the top. The centrifugalisation was then completed. This ensures a practical
sedimentation of the tubercle bacilli, and, if scanty in number, greatly increases
the chance of their detection. The sediment was used for inoculation. Of course,
in such a favourable nidus for bacteria as milk a large number of bacterial forms
are present, and are therefore particularly abundant in the sediment obtained.
Amongst these are to be found septicaemic and other organisms, which may produce
quickly fatal results in the test animals. The test for tubercle bacilli requires that
the test animal be kept under observation for at least four weeks.
A number of the inoculated animals succumbed at an earlier period from the
above-mentioned causes, and the test thus became void. We have excluded these
from our results re tubercle. From our experience as regards milk the number of
samples containing tubercle bacilli would have been found to be higher, if it had
been in our power to test all the samples rigorously. In one case the sample was
not used as the milk was sour when received. It will be noted that in a number
of instances where the animal died prematurely, the samples were found to be very
dirty. The following are the results:—
Test void (animals died prematurely) 80 samples.
Samples not used 1 ,,
This leaves 119 samples which were fully tested. Of these, tubercle bacilli
were found in 17 samples, and were not found in 102 samples. The percentage of
samples definitely proved to contain tubercle bacilli was, therefore, about 14 per
cent.
There were, however, 18 cases in which the lesions found suggested tuberculosis,
although no tubercle bacilli were detected. These samples should, therefore,
be regarded as of a suspicious character.
We are, dear Sir,
Yours faithfully,
allan macfadven, m.d.
richard t. hewlett, m.d.
MORTUARY AND CORONER'S COURT.
During the year 712 bodies were received into the Mortuary,
of which 402 were of persons as to the cause of whose death the
Coroner deemed it necessary to hold an inquiry.