Clearfield Republican. [volume] (Clearfield, Pa.) 1851-1937, 1876-11-15
IN l,iND l,I-l'i';;''i,1,E T7,;S; 'Ii,z1,ETar7s.S

IllO ItlNt 10 DE UlNGn n. Ell Slrnn0f
to say, its nature and constitution hav,
only become partially understood with
in the past century. and oven now sci
entifc knowledge could only be re
parded as on the threshold oftbc sub
iect. lnthc yearG4O, b. c., Thales, A pbi
losopher of Miletus, Travelled into Egypt
and having observed the manner in
which the land was fertilized by the
oyerflowinp of the Nile. PROMULGATED
the theory that everything was made
of water. and that ali lie resided in II
Tbales had no aids to forming a cor.
rect theory other than his untutored
senses and Ms far as they led him they
appeared to prove the correctness Of
his vicws. In 548, B. c.. Alcximenas
said Thales was wrong, and that every.
thing Is composed OF air, and that il
was the essence of life. His reason.
ings appear to modern ears utterly
preposlerous, but they were the first
dawnings of philosophy. Five centu-
ries before the Christian era, Diogenes,
Of Appolonia, thought over the same
subject, moro as psychologist than as
a natural philosopher; he considered
air the ANNA mundi OF the world. and
that il was u spirit, unusually benevo-
lent but liable to fits of temper, and
hence storms, mists, fogs. These PHI
losophers were Of disputatious school,
and did not endeavor to test their
IDEAS by experiments, but in 348, b. c.,
Aristotle, who examined things as they
were somewhat more closely, divided
all substances into what he named four
elements-earth, air, fire, and water,
and this nomenclature continued till
little more than century since. Lit
tie further was known about air ill
A. ID. 100, when Saracen, named o.
hansen, found that it had weight, and
that, instead Of extending through all
space, as previously supposed, il ccas.
cd to exist beyond certain distance
from the earth. lie fixed this limit at
So miles--a good guess, as modern OBJ.
servers had asceitained to reach a
height Of about 45i miles from the
earth. In 1890, Galileo investigated
tho action of the common pump. Aris-
totle had said that water rose on draw.
ing off the air, because nature abhor-
red vacuum. Calico found that wa.
ter would only rise in tube 32 feet or
80 feet; did nature then permit of the
vacuum? He soon saw that the wa.
ter rose because of the weight of the
air, and that the limit of pumps &C.
ton was fixed by the weight of water
to be raised. After his time TorricelIi
applied this principle TO mercury. and,
as he anticipated. il would only rise
about thirty inches in pump, as il
was about thirteen times heavier than
water. Thus the first barometers were
made. and the foundation laid of mod.
ern discoveries as TO the subject.
IL was found that mir weighed about
10 lbs. pcr square inch, and that il
varied from day TO day with the
weather. Tho noxt great disoovorcr
was Otto Won Guerickc, Of Madgeburg,
who invented the air-pump. His work
on the subject of air, containing an ac-
count in Latin of bis discoveries, was
still extant, and the lectures had one
OF the two copies now preserved in
this country. Guericke bad several
failures in his attempts TO pump out
air, but at length made what were still
known as the Madgeburg hcmispheres,
two hollow semi-globes, which could
be tightly fitted together and from
which the air could be withdrawn.
The original hemispheres were dis
played upon the table with which, in
1854, Guerickc exhibited 10 the En-.
peror at the Dict of Ratisbon, his no
ted experiment OF Harvesting eight
horses to each of the exhausted hemi-
spheres, when they were unable to
draw the two parts asunder. Guericke
had water.barometer attached to his
house, with figure of o man floating
on tho water and this popularised the
instrument Boyle, the next investi.
gator of the air, was the first to en-.
deavor to ascertain its chemical con.
stituents. Ho got so far as TO prove
that there were "fctitious airs but
never sufficiently distinguished them
from common air. Soon after this,
Hales separated number Of what
were now known TO be constituent
gases of air; he, however. regarded
them as so many impurities, to be got
rid of as much as possible. Black was
the first TO use the plural of the word
air, and to use balance for weighing
air. Before bis time it had been sup.
posed that the diffcrence between mild
lime, or chalk. and causuc lime was
that the principle then called phlogis.
ton was impaired to the latter by the
action of fire. Black argued that if no.
quicklimc ought to be heavier, not
lighter. than chalk; and after some
study and experiments he proved that
lis ligbtncss was due TO the withdrawal
of carbonic acid from il. either by the
action of heat. or of n stronger acid.
and that ouicklimc recovered this from
the atmosphere if exposed 10 its ipflu.
encc. He also showed that this acid
WINS evolved by decavinp Substances.
and passed into the air al every breath
of men and animals. lie also made
important discoveries as TO latent heat
All Blacks discoveries werc made
when he was about "a Years old. and
il was 10 be regretted that tbougb he
lived 10 be so. he mado no further dis.
coyerirs
Cavendish soon afterwards discover.
cd bydrogen the source Of ligbt and
heat and observed thnt Il entered into
the composition Of water. In l772
Ru,berford discovered the great dim. !
Ton, of oir ri,roacn bv nlac;ng micc