The Sun.
London, England, 1848-01-17 00:00:00

MON D A Br N 1 NG, JANUARY 17, 184 q.

CHEMICAL HISTORY OF 1)IS-

INFECTANTS.
On Saturday Dr. John Ryan gave an admirable
lecture on the above-named subject at the Polytechnic
Institution. He said, one of the great objects of an
institution like the Polytechnic is to bring before the
world, by means of apt illustrations, the various dis-
coveries and applications of scientific research. lie
then entered into the chemical history and character-
istics of the various materials which have been
brought before the world under the name of " dis-
infectants," and entered at some length into the
subject of decomposition of animal and vegetable
matter, and of the ill effects arising from it in
crowded districts. The learned doctor then stated—
I shall therefore call your attention, first, to the
principal poisonous and fetid products of animal and
vegetable decomposition ; and, secondly, to the
remedial means proposed fur their removal. The
offensive compounds given off during animal
and vegetable decomposition consist of combina-
tions of hydrogen with sulphur, forming sulphuretted
hydrogen; of carbon with nitroxcn to form cyanogen,
and again, of cyanogen and sulphur to form sulpho-
cyanogeu ; and carbon with oxygen to form carrmic
oxyde and carbonic acid. Dr. Leeson, of St. Thomas's
Hospital, has classified the products of putrescence
in the following manner :—Dangerous but inodo-
rous—Remittant miasmata, typhoid miasmata, car-
bonic oxyde, carbonic acid. He gives " remittent
miasmata" as the product of vegetable decomposition,
and "typhoid miasmata" as the result of animal
putresoence. Odorous, but slightly offensive—Am-
monia carburetted hydrogen, cyanogen, sulpha-
cyanogen. Most offensive--Sulphuretted hydrogen,
phosphuretted hydrogen, hydro-sulphate of ammonia.
The compounds w.hich more especially demand our
attention on this occasion are those headed
" most offensive," inasmuch es they are not only
the most poisonous, but also are those which
appeal the most readily to our senses. Sulphuretted
hydrogen, or hydro-sulphuric acid, is a compound of
sulphur and of hydrogen, and is a common product of
animal decomposition. It is also given off during the
destruction of certain vegetables—sulphur existing
largely in some families, for example in the liliscee
(as in garlic), in cincirferd (as in mustard), in urn-
belliferd (as in assafastida). He then proceeded to
consider the various remedial agents proposed to coun-
teract those noxious compounds. These he classed
under three heads, referring, first, to perfumes, which
he condemned as useless, if not dangerous ; secondly,
to mechanical remedies, such as drainage, ventilation,
&c.; thirdly, to chemical agents. The principal ones
referred to were chlorine, and the chlorides of lime
and soda ; chloride of zinc, Sir 'William Burnett's
disinfecting finid,^. perucitate of iron ; Mr. Eller-
man's liquid sulphates of manganese and soda, the
refuse of chlorine works, patented by Mr. Young ;
nitric acid vapour, for which Dr. C. Smyth received
from Parliament 5,0001.; nitrate of lead ; M. Ledoyen's
fluid. The doctor here mentioned a melancholy cir-
cumstance connected with the history of the last-
named disinfectant, as it is erroneously called. Col.
Calvert, who was associated with M. Ledoyen in the
matter, and whose correspondence with Government
was not only voluminous but most decided in its tone,
relating to the power of the compounds over infectious
miasmata, has just fallen a victim to fever in Canada,
to which place he and M. Ledoyen were sent officially
to test the virtues of the liquid : the inventor himself
is returning home with shattered health. Lastly,
after explaining the mocha operandi of all these
agents in removing odours—a process dependent on
the removal of hydrogen from its bases, sulphur, and
phosphurus, the professor emphatically urged his
audience not to trust to these chemical agents, but to
the more simple operations of ventilation, light, drain-
age, and cleanliness.

THE NAVY.
TO THE EDITOR OF THE SUN.

Six,—lf we intend, as a nation, to be independent,
we must look to our navy ; that has not had justice
done to its (Amts. I mean those who have got you
through your difficulties ; for after thirty years of
peace, you hay, commenced to superannuate upon
loss than you gave to the ether services, which must
appear unjust, for they have served their country
upwards of fifty years, and would be glad, for the few
years they have to live to be relieved from the toils
of the sea.

They want nothing but justice, and look to tha
press to point out their grievances.
.1 am, Sir, ONE OF THEM.
London, Jan. 15, 1848.