View report page

112
The results of these tests were as follows :—
Three samples of the milk contained " acid-fast" bacilli, which
morphologically resembled Bacillus tuberculosis, but which were
proved by the inoculation test to be free from the latter microorganism.
As regards B. tuberculosis, none of the twenty-five samples produced
tubercular infection in the guinea-pig ; all must therefore be
pronounced as free from B. tuberculosis. With regard to the other
types of organisms found, there are only two which require special
mention. Yeasts are commonly found in samples of milk taken for
analysis in the ordinary routine, and their presence in large excess
may be taken as a general indication of staleness of the milk.
Micro-organisms belonging to the group of Streptococci are also
frequently found in milk, and their exact significance, when thus
found in large quantities, is not definitely ascertained. But in a
number of cases milk in which Streptococci, of one species or another,
have been found in predominating numbers, has been suspected of
being a cause of disease in man.
Taken on the whole, the result of the examination of these
twenty-five samples of milk may be said to be satisfactory from the
Public Health point of view, and so far as the question of tubercular
infection is concerned. At the same time, some of the samples
contained an unnecessary amount of foreign dirt.
(Signed) ALEX. G. R. FOULERTON,
f.r.c.s., d.p.h. camb.
Bacteriologist to the Middlesex Hospital; Lecturer oil Public Health
and Bacteriology to the Middlesex Hospital Medical School.
A careful microscopic examination was then made of each coverglass, with a
view to the detection of "acid-fast" bacilli, if present, and at the same time a
note was made of the predominating types of other micro-organisms which were
present in the sediment, and notice was taken of any abnormal quantity of
foreign matter present. Inasmuch as it is impossible to distinguish by microscopic
examination, only between certain harmless " acid-fast" bacilli, which
may be found in milk and Bacillus tuberculosis, and, moreover, since the latter
may be present in milk in such small quantity as to be overlooked in such an
examination, it was necessary to test each sample by inoculation. The
remainder of the sediment left after the microscopic preparations were made
was injected into the ham of a guinea-pig. The several guinea-pigs were killed
by a dose of chloroform on the twenty-first day after inoculation, and the site of
inoculation, and the neighbouring lympathic glands and abdominal organs were
carefully searched for evidence of tubercular infection.—A.G.R.F.