The Bolivar bulletin. [volume] (Bolivar, Hardeman County, Tenn.) 1865-1888, 1873-02-21
SCIENCE AND INVENTION.

SCIENCE AND INVENTION.
REsPRAToR FOR F1REarEN. Professor
Tyndall has just perfected a new respi-
rator for fremen, in which the solid
particles of the densest smoke are
arrested by films of cotton wool wetted
with glycerine, and the most pungent
gas by layers of charcoal. By this
simple means firemen can remain with
in burning buildings for upward of an
hour at a time with safety and comfort.
so far as their respiration is concerned.
ABSORBING Power OF THE HUMAN
SKN.-Dr. Thomson, of Edinburgh re-
lates some experiments which he tried
on his own person to ascertain the
truth of the statements made as to the
curative power of mineral water baths,
depending on the absorption by the
skin of certain salts and other sub
stances which they hold in solution
and, therefore, to ascertain whether
certain substances applied in the form
of Ointments, etc, pass through the
skin and reach the blood before they
produce any beneficial effect. His con-
illusions are that not only has absorp-
ton by the skin been greatly exagger-
ated, but in the case of substances in
/ aqueous solution it seems to be the ex-
ception, not the rule, for absorption to
take place; and that, in the case of
Ointments, etc., some of the substances
so applied seem to be absorbed and
others not.
FRENCH THEORY OF EPDENnCs.-
cording to NJ. Alphonse de CandolIe,
when a fatal malady has seriously
effected the younger portion of popu-
latiOn, the succeeding generation, de-
scended from persons who escaped the
| disease or were but little effected by it,
will be found less liable to attack, as an
ordinary effect of the law of descent,
this continuing to be the case from
generation to generation. This, there
| fore constitutes one cause of the weak
ening of epidemics, and may serve to
explain the reason why a disease is
most injurious when it first attacks any
people, and why it subsequently be-
comes rarer or less dangerous, as has
frequently been observed. After the
lapse of several generations, however,
a population moderately affected by
disease approaches the condition of one
which has never had it, and increased
intensity may then ensue.
AMMONIA IN WHooPNG-CO
writer in the British Medical Journal
states that in cases of whooping-cough
in the last stage-that is, after the third
week-he had one ounce Of the strong
est liquid ammonia put into a gallon of
boiling water in an open pan, and the
steam kept up by means of half brick
made red-hOt throughout and put into
the boiling water containing the am
mOnia, the pan being placed in the
middle of a room into which the pa
tients were brought as the ammoniated
steam was passing off. This method,
he says, was used in the evening, Just
before bedtime; and it proved so eff
cacious in abating the spasmodic attack,
and after three or four days terminating
the malady, as to establish, beyond any
doubt, the great value of this mode of
inhaling ammonia as a therapeutic
agent in tranqUilizing the nervous sys-
tenn in whooping-cough.
SOAP-sTONE BUTTONS. -SOap-stOne, OF
steatite, has recently found a new APP
plicatiOn as a raw material for buttons,
dominoes, and other similar objects.
Chips and refuse pieces of mineral are
ground to powder and mixed with sill
cate of soda, water, glass; and, after
repOse of some hours, dried on plate,
and the mixture again pulverized. The
powder thus obtained is then subjected
to powerful pressure in suitable moIds,
and afterwards baked in air-tight cruel
bles. The pressed objects are again
soaked in a cilicate of soda bath, and
again heated out of contact with the
air. The hardness of the product is
said to depend, in a great measure.
upon the number of times the heating
is repeated. The last stage in the pro-
cess of manufacture consists in washing
in water in a rotary tub, drying, and
then agitating III asuitable vessel with
soap-stone powder, this last operation
giving to the surface a bright polish.
A New PROCESS or WoOD-ENGRAvING
is called the "planotype. The design
to be engraved is transferred to a block
of Iime-tree wood, which is then placed
in machine having somewhat the APP
pearance of carving machine, the
shape of which varies considerably ac-
cording to the nature of the work, the
graver being kept red-hOt by a gas-jet
By means of this appliance the design
is gradually burnt into the wood
Figures or letters of reference are i'm
pressed by means of punches. The
whole design having been burnt into
the wood, cast in type-metal is taken
direct from the block; without any
further preparation the cast may be
used for printing from, like an ordinary
stereotype plate. It is said that the
wood does not suffer in the slightest de-
gree from the heat of the molten metal,
and that the finest details are faithfully
reproduced. The processiis carried out
on a large scale. and is found to give
most satisfactory results.
CAUSES OF TYPHOID FEvER.--Ln re-
cent lecture on typhoid fever at Gay s
hospital, Sir William Gull remarked
that $50 years ago one of the kings of
England died of ague, but now by inn
proved agriculture and drainage the
disease had become rare, and certainly