anatomists have begun to use sulphate of
soda tor the same purpose, with success,
especially when mixed with kreosote. Alkaline
salts are rather antiseptic than
disinfectant; metallic salts are disinfectant. Lead,
arsinic, mercury (as corrosive sublimate), are
singularly useful. Sulphate of iron, too, has
wonderful disinfecting properties, "as wonderful
as it used to have when it figured in the
world as the powder of sympathy."
Gay-Lussac aud Mr. Young recommend the
chloride of manganese, "the waste product
of the manufacture of chlorine;"  but Dr.
Smith shows that this is a harmful and
dangerous application, substituting chloride
of zinc as one of the best disinfecting salts
known. But, we must give a word to his
own discovery—the disinfecting agent known
as McDougall's Disinfecting Powder.

Finding that magnesia was the best base
to use in the disinfection of manures, as
the only one which gave an insoluble
ammoniacal salt, and preserved the ammonia
at the same time; finding, also, that of all acids
sulphur was the best, equal at least in power
to chlorine, without the destructive property
of chlorine—namely, the decomposing of
ammonia—Dr. Smith combined magnesia and
sulphurous acid, and found the effect as a
disinfecting and deodorising agent as efficient
as he could desire, save in one particular—a
slight remaining smell. He therefore added
to the sulphite about five per cent. of phenic
acid (got from coal-tar), and with these
combinations obtained a perfect disinfecting
powder. It has been tried at the Manchester
cavalry barracks, sprinkled on the floor of
the stable, with the bedding laid over it; it
was used on board the transport-ships
carrying troop horses to the Crimea; and it has
been found specially valuable in certain large
stables of private owners.

In consequence of powdering the floor with it
almost daily, the manure becomes thoroughly mixed
with the disinfectant. The results are remarkable.
The manure does not heat or ferment, as in other
cases, so that there is no fear of loss by ammoniacal
gas, or by putrid vapours. The liquid which flows
from it is without smell. From the arrest of decay,
flies do not come around it in numbers, and the horses
also are preserved from flies, a state which has a very
favourable effect upon them. Mr. Murray, who has
always four or five dozen of the most valuable horses
on hand, says that headache has disappeared from his
stables; and of lung disease, which was formerly
common, he has not had an instance. The horses are
healthier and in better spirits, whilst a good deal of
straw is saved. They breathe air without either
ammonia, which hurts the eyes of those who enter, or
of putrid matter;  the whiteness of the powder makes
the stable appear as if constantly newly whitewashed.
A curious circumstance is said by most of those who
use it to occur. The stable is cooler, not only to the
feeling, as we might suppose, by removing animal
matter, but to the thermometer. I have not made
the observations myself, but they are to be relied on,
and to the feeling the change is distinct. The removal
of heat I ascribe to the fact that the animal matter has
ceased to oxidise. The slow combustion or
putrefaction produces heat in the manure, probably also
in the atmosphere itself, where the vapours are mixed
with the oxygen. The oxidation and putrefaction are
simultaneously arrested. It might be said that since
decomposition is arrested, the manure is made unfit
for plants; besides, it is known that liquids from tar
put a stop to vegetable life as they do to animal. But
Mr. Murray found that after having sold his manure
of one year with the powder in it, he was offered
double for it next year. It is therefore established
that a just medium has been attained, the preservation
of the manure on one side, and the health of the plant
on the other.

The great object to be attained is the
disinfection of town sewage.  Last year the
little town of Leek was attacked by an
epidemic.  A council of medical men decided
on trying this McDougall's disinfecting
powder. It was tried, and the following are
the results communicated by Mr. Dale, town
surveyor.

Its use was most efficient in staying the plague;
never was the intimate connection between foul
cesspools, &c , and disease more strikingly demonstrated.
The fever and putrid sore throats prevailed most in
the neighbourhoods nearest to the open sewers and
cesspools. On using the disinfecting powder, the
offensive smells were perfectly removed, and the
abatement of the disease immediately followed.
There were no new cases, and those under treatment
at the time assumed a much milder form. We
exhausted a small stock of disinfecting powder on the
third of January. In the course of a few weeks, when
the cesspools began again to give off offensive smells,
the disease broke out a second time, when the
authorities ordered a further supply, and upon using it as
before, the disease again assumed a milder form and
eventually disappeared.

THE DISMAL POOL.

   IT lies in deepest forest gloom,
       Where huge trees push the sun away,
   And tall weeds catch each struggling beam
       That through the branches peers its way

  It sleeps in bed of flinty rocks
        Whose shatter' d foreheads shrink from light,
    And scowl from out their dusky home
       With frown that makes a blacker night

  It dwells encinctured from the view,
       And stamp' d as with a brand of doom,
    As hated as a spot accursed
       And shunn'd as is a plague-fill'd tomb.

  It seems a haunt where Horror sits,
        And fixes deep her ebon rule;
    And men have named it, passing by
        With bated breath, The Dismal Pool.

  A wondrous sorrow seems to rest
        Upon the almost stirless trees;
    And listless as the eye of death
        The livid lake looks up to these

   And never at the morning's birth
        The sweet lark soars this lake above;.
    Nor children come with matin glee
        To read their mirror'd smiles of love.