London's Pulse: Medical Officer of Health reports 1848-1972

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London County Council 1900

[Report of the Medical Officer of Health for London County Council]

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The following table V. shows the summary of the experiment—

Nature of the emulsion.Nature of materials.Result of culture after exposure.
Broth emulsionOn wood
,, ,,On cloth
,, ,,On linen
,, ,,On paper

G.—Spores of bacillus anthracis.
As mentioned above, virulent spores of an agar culture of bacillus anthracis were used
for the experiment; they were distributed in separated milk, and in this form were liberally
applied to wood, cloth, linen and paper, and after drying were exposed to the formalin in the
way above described.
After exposure the materials were placed in broth, and whether or not after incubation
at 24 hours at 37° C., growth appeared, a small amount of the broth was injected subcutaneously
into a guinea pig, and the result watched. Where growth appeared in the broth, subculture
was made on agar or on gelatine, and the resulting growth studied for identification of bacillus
anthracis. The positive or negative result indicated in the following table YI. refers, it
will be understood, both to the cultural test as also to experiment in the animal.

Nature of emulsion.Nature of material.Result of culture and experiment.
In separated milkOn wood+
,,On cloth+
,,On linen-
,,On paper+

It follows then that anthrax spores applied to linen were killed by the formalin, while
those on wood, cloth and paper yielded growth of bacillus anthracis and killed a guinea pig
with typical anthrax.
7.—Tubercular sputum.
In this, as also in all other cases of disinfection with fluids, the sputum was derived
from human tubercular lung, and on microscopic examination showed a fair number of tubercle
bacilli. The sputum was applied on the surface of the materials and allowed to dry. This
took generally 24-48 hours; but in order to insure that by this process the tubercle bacilli of
the sputum remained uninjured, a control was at the same time made by allowing the sputum
to dry on paper for 48 hours, and then using this directly without exposure to the disinfectant
for injection of a control guinea pig. As might have been expected, this control
guinea pig developed typical general tuberculosis in due course of time. The materials were
exposed to the formalin in the manner already described. Next day the surface of the materials
was scraped and the scraping distributed in a little salt solution, and guinea pigs were
injected subcutaneously into the groin. After four weeks the animals were killed
and a careful post-mortem examination was made on them. In this, as also in other
experiments with the sputum to be described later, a positive result means local tuberculosis
of the inguinal glands of the injected side, with typical tubercle bacilli in the caseous purulent
gland, and tuberculosis of the viscera; either spleen alone, or spleen, and liver and lung; and
the tubercles containing the typical tubercle bacilli. A negative result means negative locally
and viscerallv.

The following table shows the result after exposure to formalin as in the previous experiments—

Table VII.— Disinfection with formalin of tubercular sputum.

Nature of the sputum.Nature of the material.Result of experiment.
The sputum contains crowds of tubercle bacilliOn wood+
,, ,,On cloth+
,, ,,On linen
,, ,,On paper

We have here the same distinction as was found in the first experiment with typhoid
bacillus, viz., owing to the thickness of the wood and cloth the microbe that had been able to