American citizen. [volume] (Canton, Miss.) 1864-1890, 1880-03-20
USEFUL AND SCIENTIFIC.

BEST ARTIFICIAL LIGHT FOR TIE
most essential conditions of
n good artificial light, as proved by
various and prolonged series of expert
ments, are as follows: 1t should under
all circumstances be steady, and neither
dull nor very intense; pickering lights
are always very injurious; the Argand
burner is the best; if n shade is used it
should guard the eye from the direct
rays, while permitting a fair amount of
light in the room; the eye should not be
kept in darkness by too much shading;
a lightly tinted paper is better than pure
white for reading or writing; yellow
glasses have been found superior to 9th
ers in some cases of weak eyes; in
reading, the light should if possible
come from behind the person, and the
eyes should be allowed to rest n little
every few minutes, even when they do
not seem to require it.
SALT IN WELL-WATER.-A serious
epidemic of typhoid fever in Rochester
has led to an examination of well-water
by Professor baltimore, and in his report
he lays special stress on the significance
of common salt in well-water in general.
No single indication, he holds, is of so
great sanitary Importance in judging of
the purity or impurity, and, conse-
quently, of the safety or danger of any
water. He proceeds then to show that
though, from the universal diffusion of
this substance in the air and in the soil,
we should expect to find it in all waters,
whether from rain, springs, OF wells,
because of its extreme solubility, never
theless, he argues, the quantity of salt
that should be found normally from the
causes named in well-water is extremely
small, ard, therefore, whenever "i
rises above very few grains per gallon,
it becomes certain that it comes from
some other source than the soil;" and
he concludes with the logical inference
that, as nearly all the salt used for do
nestle purposes escapes by the way of
two channels, the water-clOset and the
house-drain, we should therefore expect,
"what is always found on examination
to be true, that, whatever sewage may
or may not contain, it always contains
salt" 1t may be interesting to know
that the addition of little nitrate of
silver to water is an easy method of
roughly ascertaining both the amount of
salt and of organic matter. The water
to be tested should be placed in a clean
glass and set in the sun, with the adj
dition of about ten grains of nitrate of
silver to each pint of water. Ii the
water is perfectly pure (Which is never
the case) no change will occur, while if
the water contain either salt or organic
matter, it will blacken after standing a
little, and the amount of sediment which
settles to the bottom of the glass is
fair measure of the impurity. Christian
Union.
PURIFYING THE HOUsE.-Tbe SIM
plest disinfectant, and one which can be
used at the lowest cost, is to dissolve the
common sulphate of iron of commerce
in water, pound to bucket of water,
and use in all those parts of the house
where water is turned on. The action
of the sulphate of iron is purely chem
zeal one without antisceptic properties.
All it does is to deoxidize the decom-
posing substances. Nitrate of lead,
more expensive, is also q very safe dis
infectant. The permanganate of pot
ash acts even more rapidly than the
salts of iron or lead. OF late years the
use of carbolic acid as disinfectant
has not been so much in vogue. Its in
fluence seems to be more local, acting
rather on the atmosphere than the
source from which the decomposition
arises. 1t may be taken as good rule
that, in attempting to purify a house, it
is of little use to attack the atmosphere.
The vitiated air, though breathed and
containing the poison and the germs of
the disease, renews itself over and over
again, faster, perhaps, than it can be
corrected. A saucer of chloride of lime
in a room may destroy the poisonous
gases. But it is the source itself which
must be sought and corrected. Strike
at that, purify that by destroying the
cause, and the effects must pass away in
time. The use of iodides and bromides
in house is accompanied by SO many
drawbacks as not to be recommended
Some old methods, as used on board
OF ships, are excellent. A room in which
fever patient has been confined may
be rendered salubrious, and the germs
of all disease killed, by burning sulphur
in the room, At first having, Of course,
removed all the furniture, otherwise it
would become rotten and bleached
There ought not to be, even with de-
fective sink, bad atmosphere in the
house, providing the source of such dis
turbance be properly watched. Two or
three dollars worth of sulphate of iron,
or twice that amount if expended in nj
trate of lead, used little every day DUR
ing the summer, must tend to kill the
germs of the disease. The ventilation
of a house from the cellar is thought BY
some who have carefully studied the
subject to be unwholesome. The argu-
ment is that since the cellar is nearer to
the dangerous ground, we take this vi
tiated air and allow it to permeate the
house. 1t would be impossible in ninety
cases in the hundred to isolate the cellar
from the rest OF the house, though it is
attempted in some cases. The only true
method is to keep the cellar perfectly
clean in summer, and to watch carefully
all pipes and drains leading into it. 1t
is there mostly that the hygiene of the
house is to be attended to, for no amount
Of precaution above will prevent the
danger which exists below.