, 1865-12-12

air, water, food, and heat. To one or other of
the relations OF these agents, to our life can we
refer all the varied questions with which wa
have to deal. The lecturer then explained the
operation and the effects of these agents ON the
human system, and continued-T might have
prolonged this sketch of the fundamental nrin.
cipIes and objects of the department. of public
health, but am anxious to dwell a little more
at length on some occurrences which, at fhe
present moment, have assumed a gravity that.
in point Ut interest, throws a shade over all
other Questions. l allude to the presence of
cholera ON the continent of Europe, and to the
extensive prevalence OF the Siberian cattle
plague in England. In anticipation of the one
pla rue, and in the actual presence of the other
there is enough to excite the keenest interest
of the most a~pathetic, and to induce the most
anxious inquiries as to the causes of these
diseases and the best means of arreStinp their
progress. | will not now attempt to settle the
question whether these diseases are CONTAGIOUS
or not whether they arise from a special poi
sou which is prOpdgated in one body and is
conveyed TO another or whether there ara
certain general conditions of external agents
which engender poisonS capable of spontaneous.
" producing them. | need bat thus generally
to refer to the fact of a difference of opinion. to
remind you that amongst our sanitary reform
ers there are two great schools, one of which
maintains that the great mass of zymotic di-
seases are produced by special p%oisons, and are
called cOntaglonlSts, whilst another school do
not believe III the existence of special poisons
but believe mat certain general conditions of
sanitary neglect and dirt are alone necessary to
produce the group of zymotic diseases and thew
are called Acknowledgements. Now, [ believe
that the extreme views of either school ara
Ur0OU and hgVa q varU dam ,,o.o. kl.A
for sanitary measures to be directed by one or
other party III the present state of our know
ledge of the disease would be to plunge liz
into worse evils than quiet submission to their
unresisting Influence. For an officer of health
to suppose that cleansing, and draining. and
Washing would arrest the progress of smallpox
in a house full of unyaccinated persons would
be an utter a~bsurdity whilst the placing a
Gordon around an ill-yentiIated and badlv
warmed house, expecting to keep off broncbitic
and pneumonia, whilst the Temperature is I9
deg. below freezing point would BIZ equally
absurd. But whilst all are agreed that small
pox Is q contagious disease and bronchitis is
not, there is a large Class of diseases ON which
sanitary authorities differ as to their natur. and
the BEST modes OF arresting their development.
1t is on this account that [ now propose briefly
to examine what is really known of the nature
of contagious diseases and their mode of nro.
pagation; and if | succeed in nothing further.
| hope | shall be able to show that it is of the
utmost Importance in all our sanitary onera-
tionS that we should at least consider the issues
of both theories; that whilst believing in CON.
taSion, we should act as if all depended on the
removal of the general external agencies Of
disease or whilst believing in the spontaneous
origin of diseases in dirt, We shall do all tn
avert the possibility of their propagation bv
cOntagion. 1t is of the highest importance at
the same time that We should pursue the inquiry
into the orig Ii and nature of those zymotlc or
pneumatic diseases which carry off annually
upwards of 10000 Of our population. In order
to do this, l think there are three circumstances
that demand our attention. There is, first. the
poison that is supposed TO kindIe the disease
and, secondly, there is this medium that con.
veys it toi thirdly the person predsposed to
take the disease. If we lose sight of any one
of these elements in Investigating zvmotio
diseases we shall most assuredly get wrong
and practically commit great mistakes. Thus,
let me take smallpox as an example. In
order to propagate this disease there must be.
first, the poison matter from a small -pox pus-
tule; and secondly a means of conyeyance.
either the point of a lancet, or an atmosphere.
to convey the poisonous germs and thirdly.
there must be a person predispossd to take it.
If tho 1oiSou - uok %Lo-a