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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Table XVI.— Gives a general summary of the experiments made with S02 exposure 24 hours.

On wood.On cloth.On linen.On paper.
Bacillus typhosus
„ „
,, diphtherise
„ „
„ „
„ pyocyaneus
„ „
Vibrio choleræ
„ „
„ „
Staphylococcus aureus
„ „
Spores of bacillus anthracis+
„ „++
Tubercular sputum++++

B.—Fluid disinfectants.
The microbes were the same as used in former experiments, viz., bacillus typhosus,
bacillus pyocyaneus, vibrio choleræ, staphylococcus aureus and spores of bacillus anthracis. The
bacillus diphtherise was left out because previous experience showed the very feeble resistance
of this microbe. In all further experiments tubercular sputum was substituted for it.
Except the spores of anthrax, the microbes were used as a 24-hour old gelatine
culture incubated at 37° C., and therefore fluid. In this condition the culture was liberally
applied to the surface of the materials; wood, cloth, linen and paper. The spores of anthrax
were distributed in melted gelatine, and this was then applied to the surface of the materials
and treated in the same manner as the other microbes. In cooling the gelatine set solid, and in
this state the materials were placed in a large volume of the disinfectant solution. In this they
were kept for 24 hours, then taken out and the fluid thoroughly sucked up with blotting paper.
The materials charged with the typhoid culture were then placed successively in two lots of
ordinary broth, those charged with the cholera vibrio were placed in peptone salt solution,
and, after superficial washing herein, were transferred to a fresh tube of the peptone salt
solution; both tubes were incubated at 37° C. The same was done in the case of the staphylococcus
aureus and the spores of bacillus anthracis, two tubes of broth being substituted for
peptone salt solution.
The materials charged with the tubercular sputum, after removal from the disinfectant
fluid, were washed in water, then the fluid was mopped up with blotting paper; after this
the sputum was scraped off from the materials and distributed in salt solution and injected
into guinea pigs.
Series I.—Carbolic acid. This was ordinary pure carbolic acid, and was used as a watery
5 per cent solution

Time of exposure, 24 hours.

The result is shown in the following table XVII.—

Nature of microbe.Nature of material.Result of culture and experiment after exposure.
Bacillus typhosusOn wood
On cloth
On linen
On paper
Bacillus pyocyaneusOn wood
On cloth
On linen
On paper
Vibrio choleræOn wood
On cloth
On linen
On paper
Staphylococcus aureusOn wood
On cloth
On linen
On paper
Spores of anthraxOn wood+
On cloth+
On linen+
On paper+
Tubercular sputumOn wood
On cloth
On linen
On paper

It follows then, from these experiments, that 5 per cent. carbolic acid liberally applied
for 24 hours—placing the materials in a large volume of the acid—caused complete disinfection