HH62/2/LANARK/92

Transcription

[Page] 91

articles, if not dealt with at the public disinfecting station,
should be placed in a solution of mercuric chloride for a
few hours, then soaked in water for some hours before
being sent to wash. These should not be washed with the
clothes of the rest of family.
With the ordinary erections in use in this part of the
country - the majority of which, in our district, are simply
abominations - it is a most dangerous practice to throw
infected materials into the ashpit. They should, if possible,
be burnt or buried.
The poisons of many infectious diseases are undoubtedly
capable of lying dormant for a long time, and then
developing under favourable circumstances. If carried
into the ashpit it is easy to understand how it becomes a
very "magazine of disease," dangerous not only to those in
the immediate vicinity, but to others at a distance. I have
not the slightest doubt but that many epidemics, of which
it was difficult or impossible to trace the origin, have arisen
in this way. Incidentally, I may point out that this is a
most powerful argument why ashpit refuse should not be
deposited in bulk near habitations, and used for levelling
up of old quarries and other surface inequalities. As for
building on such material, the idea is contrary to all
common sense.
I next take up the question of how properly to disinfect
the articles removed to the disinfecting station.

Disinfection by Heat and Chemicals. - Koch and
Parsons, who are among the best authorities on the subject
of disinfection, accept as the true test of a "disinfectant"
that it shall have the power of destroying the most resistant
micro-organisms and their spores. The measure of this
successful destruction consists in the failure or otherwise of
subsequent attempts at cultivation.
The main disinfecting agents are -
1. Heat
2. Chemicals -
(a) In Solution.
(b) In the Form of Vapour.

Heat. - This form of disinfection is the only one of real
value for all articles of clothing, bedding, and carpets which
it is inadvisable to wash in boiling water. It may be applied
in two forms - (a) as Dry Heat, and (b) as Steam.

[Page] 92

(a) Dry Heat. - This is the form in which heat was
generally applied until a few years ago, and there is no
doubt that much good work was done by such disinfecting
stoves, as Ransome's, Scott's, and others. And even
now, for such articles as leather goods, and others which
are injured by steam, dry heat is to be preferred.
As, however, our knowledge regarding the organisms
concerned in the production of infectious disease increased,
and especially after the methods of cultivation enabled
us to determine when these organisms, or germs, were
deprived of their vitality, it became apparent that in
many respects dry heat was an unsatisfactory agent. The
main objection to it is that woollen articles of any thickness
are not penetrated by heat, and that consequently all the
infective particles are not destroyed. This can be simply
illustrated by placing a thermometer in several folds of
blanket, and subjecting to the heat of a disinfecting
machine of this class. A temperature of 200° F. may be
registered on the surface, while that of the thermometer,
even after two hours, may be under 120° F. - a heat in-
sufficient to affect many of the disease germs.
The second objection, and one associated with that
already mentioned, is that it takes a much longer time
to disinfect with dry heat, and that consequently expense
and inconvenience are unnecessarily great.
A third objection is that, if the necessary heat be long
enough maintained, scorching of the articles is apt to occur.
(b) Disinfection by Steam. - Micro-organisms, like all
other living things, die when subjected for a long enough
period to a temperature equal to that of boiling water,
viz., 212° F. The spores, however, show themselves more
refractory. For their destruction a higher temperature
is necessary, or else a much longer exposure to a heat
of 212° F.
Steam disinfectors, therefore, have come now to be
generally used by those sanitary authorities desirous of
carrying out disinfection in a satisfactory manner. Until
a year or two ago Washington Lyon's apparatus, made
by Manlove, Alliott, & Co., of Nottingham, was considered
the most satisfactory, and it still forms the model on which
improvements have been effected by other makers. It
practically consists in its best form of an elliptical
steam jacket surrounding a large central chamber, with a
door at each end. In this chamber the articles to be