120. [Chairman, Sir Benjamin Hall]--To what points would you desire
to draw the attention of the Committee as regards the sanitary question?
[Dr. Snow]--I have paid a great deal of attention to epidemic
diseases, more particularly to cholera, and in fact to the public health
in general; and I have arrived at the conclusion with regard to what are
called offensive trades, that many of them really do not assist in the
propagation of epidemic diseases, and that in fact they are not injurious
to the public health. I consider that if they were injurious to the
public health they would be extremely so to the workmen engaged in those
trades, and as far as I have been able to learn, that is not the case;
and from the law of the diffusion of gases, it follows, that if they are
not injurious to those actually upon the spot, where the trades are carried
on, it is impossible they should be to persons further removed from the
spot.
121. [Chairman]--Are the Committee to understand, taking the case
of bone-boilers, that no matter how offensive to the sense of smell the
effluvia that comes from bone-boiling establishments may be, yet you consider
that it is not prejudicial in any way to the health of the inhabitants
of the district?
[Dr. Snow]--That is my opinion.
122. [Mr Greene]--Does that extend to all animal substances?
[Dr. Snow]--No. I believe that epidemic diseases are propagated
by special animal poisons coming from diseased persons, and causing the
same diseases to others, and that they are extremely injurious; but that
substances belonging to animals, that is to say, ordinary decomposing animal
matter, will not produce disease in the human subject.
123. [Mr Greene]--Do you apply that, also, to decaying vegetable matter;
do you consider that that will not be productive of disease?
[Dr. Snow]--I do not believe that decaying vegetable matter
would be productive of disease; at least, it is a matter open for discussion
whether certain decomposing vegetable substances, in marshy districts,
may not produce agues; but in London, in any trade I am acquainted with,
I do not believe that any decomposing vegetable or animal matters produce
disease.
124. [Chairman]--Take the case of a bone-boiling establishment, or
a knacker's yard; assuming that there is a large number of horses in a
state of decomposition, from which of course there would be very offensive
effluvia, as far as the sense of smell is concerned, do you apprehend that
that would not be prejudicial to the health of the inhabitants round?
[Dr. Snow]--I believe not.
125. [Mr Adderley]--Have you never known the blood poisoned by inhaling
putrid matter?
[Dr. Snow]--No; but by dissection wounds the blood may be poisoned.
126. [Mr Adderley]--Never by inhaling putrid matter?
[Dr. Snow]--No; gases produced by decomposition, when very concentrated,
will produce sudden death; but where the person is not killed, if the person
recovers, he has no fever or illness.
127. [Mr Egerton]--You mean to say, that the fact of breathing air
which is tainted by decomposing matter, either animal or vegetable, will
not be highly prejudicial to health?
[Dr. Snow]--I am not aware that it is, unless it be in such
quantities as to produce actually fatal effects at the moment; but to produce
those effects it requires that it should be highly concentrated.
128. [Mr Egerton]--Do you not know that the effect of breathing such
tainted air often is to produce violent sickness at the time?
[Dr. Snow]--Yes, when the gases are in a very large quantity,
as in a cesspool.
129. [Mr Egerton]--Do you mean to tell the Committee that when the
effect is to produce violent sickness there is no injury produced to the
constitution or health of the individual?
[Dr. Snow]--No fever or special disease.
130. [Mr Greene]--Are you not aware that persons going into vaults
where there are a number of dead bodies have suffered very severely, and
that sometimes death has been produced by this cause?
[Dr. Snow]--Yes, when those gases are extremely concentrated,
they will actually poison a person and cause death, but not cause disease;
those poisons do not reproduce themselves in the constitution.
131. [Mr Greene]--Are you not aware that, in cases of this kind, illness
has sometimes been produced from which persons have suffered for a considerable
length of time before death ensued?
[Dr. Snow]--I am not satisfied upon that point. If illness
has followed I think it has been a coincident.
132. [Mr Greene]--Are you not aware that, in cases of this kind, illness
has sometimes been produced from which persons have suffered very severely,
and that sometimes death has been produced by this cause?
[Dr. Snow]--Yes, when those gases are extremely concentrated,
they will actually poison a person and cause death, but not cause disease;
those poisons do not reproduce themselves in the constitution.
133. [Mr Egerton]--You say that the effluvia arising from living subjects
are dangerous?
[Dr. Snow]--Or even from certain persons who have died from
disease....
138. [Chairman]--I understand you to say that such effluvia, when
highly concentrated, may produce vomiting, but that they are not injurious
to health. How do you reconcile those two propositions?
[Dr. Snow]--If the vomiting were repeatedly produced, it would
certainly be injurious to health. If a person was constantly exposed
to decomposing matter, so concentrated as to disturb the digestive organs,
it must be admitted that that would be injurious to health; but I am not
aware that, in following any useful trade or manufacture, the effects ever
experienced.
139. [Chairman]--You consider that occasional sickness would be of
no consequence, but that only frequent occurrence of the attacks would
be injurious?
[Dr. Snow]--I am not aware that any occasional sickness is produced
in any useful trade or manufacture.
140. [Mr Egerton]--Do you not know that the effect of a very strong
offensive smell often is to produce vomiting?
[Dr. Snow]--The gases must be very concentrated to do that,
except it be by a kind of sympathy. Persons are often much influenced
by the imagination....
144. [Mr Wilkinson]--Have you turned your attention to the effects
of the late outbreak of cholera in London?"
[Dr. Snow]--Yes, I made special enquiries throughout Lambeth
and Southwark and Newington.
145. [Mr Wilkinson]--Have you satisfied yourself by those inquiries
of any particular results of that outbreak of cholera, so as to state your
opinion of what has been the mode of propagation of the disease?
[Dr. Snow]--I have satisfied myself completely, that the chief
mode of propagation of cholera in the South district of London, throughout
the late outbreak, was by the water of the Southwark and Vauxhall Water
Company containing the sewage of London; and containing consequently whatever
might come from the cholera patients in the crowded habitations of the
poor; and I am satisfied that it spread directly from individual to individual,
sometimes in the same family, but by similar means; that is, by their swallowing
accidentally what came from a previous sick patient.
146. [Mr Wilkinson]--Do you believe that there is evidence to show
that cholera has been propagated almost entirely by the poison being taken
in at the mouth?
[Dr. Snow]--Yes.
147. [Mr Wilkinson]--Absolutely swallowed?
[Dr. Snow]--Yes, it is my belief in every case. |
