262
THE NEW ZEALAND GAZETTE.
into streams, springs, or wells, from which the supply
of water is drawn, or into the sub-soil in which the
wells are situate; a danger which may exist on a small
scale, as at the pump or dip-well of a private house,
or on a large scale as in the sources of supply of
public water-works.

And secondly, there is the
danger of breathing air which is made foul with
effluvia from the same sorts of impurity. Information
as to the high degree in which those two dangers
affect the public health in ordinary times, and as to
the extreme degree of importance which attaches to
them at times when any diarrheal disease is epidemic,
has now for so many years been set before the public,
by this department and otherwise that the larger
works of drainage and water-supply by which the
dangers are permanently obviated for large popula-
tions, and also the minor structural improvements by
which separate households are secured against the
dangers, ought long ago to have come into universal
use. It is to be feared that on a very large scale
this wiser course has not been adopted, and that
even yet, in very many instances, temporary security
has to be found in measures of a palliative kind. So
far as such is the case, attention is most earnestly
called to those parts of the General Memorandum
which relate to the matters in hand. All chief
sources of the one danger may be held in check, as
follows:-By immediate thorough removal of every
sort of house-refuse and other filth which is now
accumulated; by preventing future accumulations of
the same sort; by attention to all defects of house-
drains and sinks through which offensive smells are
let into houses; by thorough washing and lime-
whiting of uncleanly premises, especially of such as
are densely occupied; and by disinfection, very freely
and very frequently employed, in and round about
houses, wherever there are receptacles or conduits
of filth, wherever there is filth-sodden porous earth,
wherever anything else, in, or under, or about the
house, tends to make the atmosphere foul.

As
provision against the other danger, it is essential
that immediate and searching examination of sources
of water-supply should be made in all cases where
the source is in any degree open to the suspicion of
impurity; examination both of private and of public
supplies; and that where pollution is discovered,
everything practicable should be done to prevent the
pollution from continuing, or if this object cannot be
attained, to prevent the water from being drunk.
The examination of sources of water-supply should
of course extend to all receptacles of water storage,
such as the tanks and reservoirs of public supply, and
the butts and cisterns of private houses.*

• If unfortunately the only water which for a time can be got
  should be open to suspicion of dangerous organic impurity, it
  ought at least to be boiled before it is used for drinking, but
  then not to be drunk later than twenty-four hours after it has
  been boiled. Or, under medical or other skilled direction, water,
  in quantities sufficient for one day's drinking in the house, may
  be disinfected by a very careful use of Condy's red disinfectant
  fluid. This should be added to the water (with stirring or
  shaking) in such number of drops that the water, an hour after-
  wards, shall have the faintest pink colour which the eye can
  distinctly perceive. Filtering of the ordinary kind cannot by
  itself be trusted to purify water, but it is a good addition to
  either of the above processes. It cannot be too distinctly
  understood, that dangerous qualities of water are not obviated
  by the addition of wine or spirits.

5. That such precautions as the above (never
   uuimportant where human health is to be preserved)
   are supremely important when the spread of cholera
   is to be prevented, is a truth which will best be under-
   stood when the manner in which cholera spreads is
   considered. Happily for mankind, cholera is so little
   contagious, in the sense in which smallpox and
   typhus are commonly called contagious, that, if proper
   precautions are taken where it is present, there is
   scarcely any risk that the disease will spread to
   the sick. But cholera has a certain peculiar con-
   tagiousness of its own, now to be explained; which,
   where sanitary circumstances are bad, can operate
   with terrible force, and at considerable distances from
   the sick. It appears to be characteristic of cholera
   —not only of the disease in its developed and alarm-
   ing form, but equally of the slightest diarrhea which
   the epidemic influence can produce, that all matters
   which the patient discharges from his stomach and
   bowels are infective; that the patient's power of
   infecting other persons is represented almost or quite
   exclusively by those discharges; that they, however,
   are comparatively non-effective at the moment when
   they are discharged, but afterwards, while undergoing
   decomposition, acquire their maximum of infective
   power; that, if they be cast away without previous
   disinfection, they impart their own infective quality
   to the excremental matters with which they mingle,
   in filth-sodden earth or in depositaries and conduits
   of filth, and to the effluvia which those excremental
   matters evolve; that, if the infective material, by
   leakage or soakage from drains or cesspools, or other-
   wise, gets access, even in the smallest quantity,
   directly or through porous soil, to wells or other
   sources of drinking water, it can infect in the most
   dangerous manner, very large volumes of the water;
   that the infective influence of choleraic discharges
   attaches to whatever bedding, clothing, towels, and
   like things, have been imbued with them, and renders
   these things, if not disinfected, capable (as the cholera
   patient himself would be capable, under the same
   conditions) of spreading the disease in places whither
   they are sent for washing or other purposes; that, in
   the above described ways, even a single case of
   disease, perhaps of the slightest degree, and perhaps
   quite unsuspected in its neighbourhood, may, if local
   circumstances co-operate, exert a terribly infective
   power on considerable masses of population. "If
   local circumstances co-operate, however, is the stated
   condition for that possibility; and it will be observed
   that the essence of the sanitary precautions, which
   have been recommended to nuisance authorities and
   others, is to annihilate those "local circumstances."
   The choleraic infection does not seem able largely to
   injure any population unless a filthy state of things
   be pre-supposed. It is pre-supposed that the
   atmosphere or the drinking water of the population
   is impure with the most loathsome of impurities,
   that the infective material has had opportunities of
   action which decent cleanliness would not have
   afforded it, that, in inefficient drains or cesspools or
   other like depositaries, it has had time to develop its
   own infective power, and to render other stagnating
   filth equally infective with itself, and that, from such
   foci of infection, the disgusting leaven of the disease
   has spread, in air or water, to be breathed or swallowed
   by the population. In this view of the case, it will
   be understood that works of sewerage, house-drainage
   and water supply, properly executed and properly
   used, give to town populations an almost absolute
   security that cholera, if introduced among them, can
   have no means of spreading its infection. And
   equally it will be understood that, in the absence of
   those permanent safeguards, no approach to such
   security can be got without incessant cleansings and
   disinfections, or without extreme vigilance against
   every possible contamination of drinking water.

6. It is highly important that the public should not
   be under any misapprehension as to the course by
   which the above-defined sanitary objects (so far as the
   law provides for them) may be attained. The admin-
   istration of the Nuisances Removal Acts is a matter
   of exclusively local jurisdiction. Over the various
   nuisance authorities, in whose hands it is vested,
   neither the Privy Council, nor any other department