American citizen. [volume] (Canton, Miss.) 1864-1890, 1880-03-13
USEFUL AND SCIENTIFIC.

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ELECTRIC EXAMINATION OF TIL
BODY.-An improvement in thS appli
cation of electric light TO n speculum
so as to provide means for Il direct il
Illumination and examination of the in
ternal parts or cavities of the body-a:
the urethra, bladder, larynx, esophagus
stomach, uterus, and outer auditory
\ passage-has been brought forward 10y
a Dresden (Saxony) inventor. Thi.
method, and the Instruments construct
ed for carrying it out, afford, it is al
legged, the possibility of introducing the
source of light into the internal parts oil
cavities themselves for examining the
part directly, Or its reflected image
Lenses, or lens systems, for enlarging
the field of viSw may, it is stated, be
employed in combination with the in
struments. The source of light en-
plOyed consists in a platinum wire made
incandescent by an electric current
The white heat of this wire is taken up
and made harmless by means of n cold
water current flowing along the circuit
wire.
TYNDALL's DEFINITION OF THE
BRAIN.-The human brain, according
to Prof. Tyndall's recent definition, is
! the-organized register of infinitely
numerous Experiences received during
the evolution of life, or rather during
the evolution of that series of Organisms
through which the human organism has
been reached; the effects>of the most
uniform and frequent of these expert
ences have been successfully bequeathed,
principal and interest, and have slowly
mounted to that high intelligence which
| lies latent in the brain of the infant.
Thus it happens. says Tyndall, that the
European inherits from twenty to thirty
cubic inches more of brain than the
Papuan-thus it happens that faculties,
as of music, which scarcely exist in some
inferior races, become congenital in
those that are superior-thus, too, it
happens that out of savages unable to
count up to the number of their fingers,
and speaking a language containing
only nouns and verbs, arise at length
Ncwtons and Shakspeares.
RELATION OF THE LIVER TO THE
GENERAL SYsTEM.-Professor LeConte
expresses his belief that the waste tissue
is carried by the blood to the liver, and
is there separated into iver-sugar and
urea, or some substance which rapidly
changes into urea. Experiments made
by Schiff support this theory by proving
that venous blood is soon fatal to ami
mails if the liver is tied, but is not so if
the liver is free to act, the poisoning be-
ing due to decomposed tissues in the
blood. Combustion takes place in the
capillaries of the tissues under the infiu-
ence of venous force, as the blood re-
oivS for in hn
ries of the tissue than in any other Or
gan. The blood acts as a reservoir not
only of oxygen but of food, and, if waste,
the food taken in to-day is not used to
build up tissue to-day, but is taken into
circulation in the blood and the blood
forms tissue and regenerates itself from
the supply of food-so tissue wasted to-
day is carried by the blood to the liver,
there decomposed into sugar and urea,
and so eliminated perhaps the day after,
or even longer.
MOIST AIR UNHEALrHY.-The theory
is now ingeniously maintained by Prof.
Briggs that the summer condition of
temperature, 81 deg to 68 deg, and
relative humidity, so to S5 per cent, is
not de .irable or even attainable at other
seasons in the heating of dwellings. His
argument is that the dry air of America
possesses both curative and preventive
qualities of great value, and that moist
air, which promotes vegetable growth,
is, on sanitary grounds, not desirable
for breathing. He states that the dew
point is far below the freezing point of
water in well warmed and ventilated
rooms, where there is nothing of that
sensation of dryness which is usually
held to accompany the heat of fur
mace, when not supplied with water for
evaporation. Again, new houses, that
are accounted unhealthy in Europe, are
not so in America, and gas burned in
rooms produces much less unpleasant
effects in America than in England;
what is needed is an equality in relative
humidity between the interior and ex-
terror air-thus if the outer temperature
be 0, and relative humidity 40 per cent,
and the interior temperature be 40 deg.
the interior humidity ought to be raised
to 20 deg, by adding little water.
LIFE IN THE SOLAR WORLDs.-Mr.
Proctor holds Mars to be the only planet
old enough to be inhabited. He thinks
the others still incandescent. In lee
ture at Philadelphia he said it was graf
flying to observe the swift growth of
popular interest in astronomy. The
stars are rapidly ceasing to be regarded
as objects of beauty simply, and the
time is approaching when intelligent
people will be ashamed to gaze in indif-
ferent admiration upon the armament
and acknowledge their ignorance IN
a field which the vast strides of modern
science have made accessible to all.
has been largely delivered
from the realms of speculation to the
domain of mathe-
NAUTICAL exactness and, while the scope |
of research and development is bound
less as eternity, enough has been ascer- |
tanned to make the total acquisition inn
possible by any one mind. Draper's
discovery of oxygen in the sun
is the most important fact in
modern astronomical research, because |
it shows that the sun is in part composed |
of elements like the earth's. He thinks |
Saturn's rings will eventually resolve
into moons, and holds that |
the dark places on the moon are not |
or seas, but simply indenta-
lions, and therefore less luminous. The |
black spots visible upon the surface of |
the sun are but holes through the sur
envelope through which only |
the parent mass can be seen.
e it ground, or have it ground in your
wn house, that you may be sure that it |
not half chicory; then measure two