The Dorset County Express and Agricultural Gazette.
Dorchester, Dorset, England, 1862-02-18 00:00:00

Correspanbence.

THE SEWERAGE QErESTION.

To the Editor if the Doreet County Express and

gricultural Gazette.

Sra,—l observe in the Telegram of the 6th February,
• letter from Dr. Penton, health officer of Dorchester,
on the subject of the application of charcoal air filters
to the ventilatidi Of sewers. Dr. Penton regrets that,
while I mention how the noxious gases containing
carbon and hydrogen emanating from the sewers are
disposed of, I do net take any notice of the very
noxious gas—snlpheretted hydrogen.
The reason why I did not state, in my short letter to
/dr. Jewett, that sulphuretted hydrogen was also de-
composed by contact with charcoal and atmospherical
air (water being formed, and the whole of the sulphur
being deposited within the pores of the charcoal) was,
simply, that this fact has long been generally well
known, and had, been fully stated at page 11 of a lecture
on the economical applications of charcoal to sanitary
purposes, delivered by me at the Royal Institution, on
2nd of March, 1855, and subsequently published by
Churchill. In fact, there is no sewer gas so easily and
rapidly decomposed by charcoal as sulphuretted hy-
drogen. In confirmation of this statement, I beg to
qm.te from the valuable report recently addressed to
the Commissioners of Sewers for the City of London,
by Dr. Letheby, Medical Officer of Health, and W.
Haywood, Eeq., Engineer and Surveyor, so recently as
the 21st of rimUary last, on the results of applying
charcoal to sewer' VentilatiOn. At page 20 of this report,
when referring to the fatal accident in the sewer at
Fleet-lane, about a year ago, by which, owing to
the evolution of -aulphuretted hydrogen • gas, four men
were killed, these gentlemen make the following state-
ment :—" The experience of our present investigations,
as well as the results of laboratory experiments, point
to the advantage' which may be derived from the use of
an apparatus in the form- of • 'respirator, containing
charcoal. Dr. Stenhonee hes already contrived such an
apparatus; and we believe it might be resorted to by
the men in times of danger, as, when there is an odour
of foul gas; and would afford them an opportunity of
quitting the dangermuslocality, and _teaching • place of
safety. It is very .probable that under the worst cir-
cumstances, when the air is charged with a large pro-
portion of milphuretted hydrogen, there is still enough
oxygen to Maintain 'the functions of respiration; the
danger, indeed, is nottrom the shames of atmosphericoir
gen, but from the presence of salphuretted hydrogen, and
this the chart/MI.OI the respirator would destroy. It is
desirable, therefore, that each of the sewer men be pro-
vided with, a respirator of this construction, and be
advised to use it when the air of the sewer is expected
to be unusually offensive, and when they are disturbing
large deposfla of mud."
So much, then, for the matter of anlphuretted hydro-
gen. I trust I shall be excused for again referring to
the report of Dr. Letheby and Mr. Haywood, as to the
general efficiency of charcoal air filters in destroying
noxious emanation& from sewers, At page 14, after dis-
cussing the nature Of these poisonous mmainate, which
are the invariable products of putrefaction, they state,
—" Let thein, however, be what they may, either physi-
cally suspended organic molecules, or oomplex volatile
alkalies, and be the morbitic agent either the one or the
other, there is In Mfaecoal-a perfect means of arresting
and oxidishig all' the noxious compounds coetained in
these tiese4 nista dernonstrated not merely by their
absence in the sewer air which has passed the charcoal,
but also by the presence of the alkalies, and the changed
molecules in the charcoal limit." At page 25, the fol-
lowing passage also occurs,—" Our general conclusions
from these experiments, and from the coneideration of
collateral evidence are--that dry Charcoal, in the presence
of atmospheric alr, Is &powerful means of destroying the
mephitic gases and vapours of seCers and house drains.
That the chitties/110ms may be used with efficacy in
the (nurse 'of the tee Channels from the drains and
closets of haulm, Meilensa in the ventilation of the
public sewers-; thatilst vpfying. the charcoal, those
contrivammeeharld'llted ddaVhich offer th- least resist-
.
situation of the
itected from wet
; that from the
troying the dan-
system may be
: and that, from
re practical en-
of the system
that indicated by

ivaneei th,
ance to the paimage of tho r • at e
filters is bed, when the•charts;al is protected
and from dirt, and is easily accessible •
asoertained efficacy of charcoal in destr;
gerons emanations from sewers, the
generally applied with great advantage •• r
the experiedee derived !torn this extenihre
quiry, we are satibeed that the expense -
might be coalidershly reduced below the coat of the experiment."
I trust, therefore, that the .
will now be 'convinced that the ,
air Alters to the destruction of sewer
hypothesis, iStst • weltescertsined r
Weal truth -* they will •
their able c.

authorities

of Dorchester
,n of charcoal
Is not a mere

ppUC%ton

glees