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A         t                  t s.
t^  ,ret, exprefies the eight at which the barometer, muft
tands where the Air would be as heavy as Gold, an2 the
Number 14w- Lines, the Thicknefs to which ou't Q-
Iumn of 36 Fathoms of Air, would be reduced in the Tame
place.
Now, we know, that 409640 Inches, 6r 43 528 FathotbI,
is only the 74th Part of the Semidiameter of the Earth:
and when you are paff that, whatever Matters there be,
They muft be heavier than Gold: 'Tis not improbable,
therefore, that the remaining Sphere of 645 J 5 38 Fathoms
Diameter, may be full of denie Air, heavier, by many
degrees, than the heavieft Bodies among us.-Hence, again,
as it is proved, that the more Air is compreffed, the more
does the fame degree of Fire increafe the Force of its
Spring, and render it capable of fo much the greater Efe&l;
and that, for inflance, the Heat of boiling Water increafes
the Spring of our Air, beyond what it ordinarily is, by a
asnity equal to one third of the Weight wherewith it
is preffed: We may infer, that a degree of Heat, which in
our Orb can only produce a moderate E1flta, may have a
very violent one in fuch lower Orb; and that as there  Hay
be many degrees of heat in Nature, beyond that of boiling
Water, tis probable there may be fome, whofe Violence,
thus affifled by weight of the Air, may be fufficient to
tear funder the folid Globe.  Mum. de I'Acad. An. I703-
This elaffick Power of the Air, is the fecond great Source
of the Effbas of this important Fluid.-In virtue hereof, it
infinuates into the Pores of Bodies, carrying with it this pro-
digious Faculty of expanding, and that I0 eafy to be excited:
whence it muff neceifarily put the Particles of the Bodies
it is mixsd withal, into perpetual Ofcillations. In efta&, the
Degree, of Heat, and the Air's Gravity and Denfity, and
confequently its Elaf icity and Expanfion, never remaining
the fame for two Minutes together; there mufi be an in-
ceffant Vibration, or Dilatation and Contraftion, in all Bo-
dies. See VxBRarioN.
This Reciprocation we obferve in feveral Inflances, par-
ticularly Plants, the Trachex or Air-Vetfels whereof, do
the Office of Lungs: For the contained Air alternately ex-
panding and contrasing, as the Heat increases or diminifhes,
by turns preffes the ViSels, and eafes 'em again; and thus
promotes a Circulation of their Juices. See VaGETAULZ,
CIRCULAmotI, WC.
Hence, we find, that no Vegetation or Gernination will
proceed in Vacuo.-Indeed, Beans have been obferved to
prow a little tumid therein ; which has led fome to attri-
bute that to Vegetation, which was really owing to no other
than the Dilatation of the Air within 'em. See VEG4TA-
,rioN, GEaIMINATION, UeC.
From the fame Caufe it is, that the Air contain'd in the
Bubbles in Ice, by its continual Action, burfis the Ice:
And thus Glatfes and other Veflels frequently crack, when
their contained Liquors are frozen. Thus, alfo, entire Co-
lumns of Marble Sometimes cleave in the Winter time, from
fome little Bubble of included Air's acquiring an increafed
Elafficity.
From the fame Principle arifes all Putrefaaion and Fer-
mentation; neither of which will proceed, even in the bedt
difpofed Subjects, in Vacuo. SeeFP!uTrXFcTloN, and FER-
lvi ENTATION.
In this we have a fingular Inflance of the wonderful Ef-
ficacy of Air, that it can change the two Kingdoms, and
convert Vegetable Subftances into Animal, and Animal into
Vegetable. See ANIMAL, &C.
In effecT, alltnatural Corruption and Alteration feems to
depend on Air; and Metals, particularly Gold, only feem to
to be durable and incorruptible, in Virtue of their not being
pervious to Air.-Accordingly, Names flightly wrote in the
Sand, or Duff, on the Tops of high Mountains, have been
known to remain 40 Years, without being in the le4ft al-
teerd or effaced. See CoRRPu10oN, ALTxA^mot, SC.
Effeffs of the peculiar Ingredientsof the AiR.
Air not only aas-by its common Properties of Gravity,
and Elafficity, but there ate numerous other Elf&as, ari-
fing from the peculiar Ingredients whereof it confifds.
hus, 10, it not only difolves and attenuates Bodies by
its Prefture and Attrition; but as a Chaos, containing all
Kinds of Menflruums, and consequently having wherewithal
to diffolve all Kinds of Bodies. See DISSOLUTION.
'Tis known, that Iron and Copper readily diffiolve, and
become rufty in Air, unlefs well defended with Oil.-Boer-
haave affures us, he has feen Pillars of Iron fo reduced by
Air, that one might crumble 'em to Dull between the
Fingers; and for Copper, it is converted by the Air into a
Subliance much like the Verdegreafe produced by Vinegar.
See ILON, COPPER, VEI)OREASE, FC.
IMr. .Boyle relates, that in the Southern Englijb Colonies,
the great Guns rut1 fo fahl, that after a few Years lying in
the Air, large Cakes of Crocus Martis may be eafily beat
off'em.-Acofta adds, that in Peru the Ar diflolves Lead,
A J
and confiderably incteafes its wveight.-Yet Gold
rally effeem'd indifioluble by Air; 'beig never I
contract Ruff, thu expofed ever fo long. The Reaf
of is, that Sea Salt, which is the only Menfiruuni
of aaing on Gold, being very diffic4lt to volatilize;
but a fmall Proportion of it in the Atmofphere.
Chymifls Laboratories, where Aqua Regia is prepari
Air becoming impregnated with an unufual O a
this Salt; Gold contrats a Ruft like other Bdi
GOLD, &C.
Stones alro undergo the common Fate of Met
rV L. n...^ /:Dv'or .Crrnals-re ..1- C"1;,bL-,rAv -th-
is obferved gradually to become fofter, and moulder
in the ASt; and the like Mr. Payle relates of .lack,
Stone. See STONE.-He adds, that Air may have
table Oneration on Vitriol. even when a Prong Fire
aa no further on it.  The fame Author has-even I
the Fumes of a Sharp Liquor to work more fuddenly
manifesfly on a certain Metal, when fuftained in the
than the Menfiruum it felf did which emitted thofe Fu
On thofe Parts of the Metals it cover'd.
10, Air volatilizes fix'd Bodies.-Thus Sea Salt being
calcined, then fufed by the Fire, and when fufed expo,
the Air to liquify, when liquified fet to dry again, thei
taQ ag^; 5 _UU  L11o        +*. t          "AII wl
grees be almofi wholly evaporated; nothing remaining but a
little Earth behind. See VOLATILITY, VOL4TILIZATION,
Wc.
Ifelmont mentions it as a mighty Arcanum in Chymifiry,
to render fixed Salt of Tartar volatile: but the thing is
eafily efefted by Air alone; for if fome of this Salt be
expofed to the Air in a Place replete with acid Vapours, the
Salt draws the Acid to it felf, and when Saturated therewith,
is volatile. See TAILTAIL, U3C.
3t, Air alfo fxes volatile Bodies.-Thus, tho Nitre or
Aquafortis readily evaporate by the Fire; yet, if there be
any putrified Urine near the Place, the volatile Spirit will
be fixTd, and fall down in form  of Aqua fecunda. Sex
FIXITY.
40, Add, that Air brings many quiefcent Bodies into Ac-
tion, i. e. excites their latent Powers.-Thus, if an acid Va-
pour be diffifed thro'the A4ir, all the Bodies whereof that is,
a proper Menfiruum, being diffilved thereby, are brought in-
to a State proper for Adion. See SALT, UC.
In Chymiflry, not only the Prefence or' Abfence of the
Air, but even its being barely open, or inclofed, is of great
confequence.-Thus, Camphire fired in a clofe Veffel, runs
wholly into Salts; whereas, if during the Procefs, the'Covet
be removed, and a Candle applied, the whole flies ofT in
Fume. So to make Sulphur inflammable, it requires a free
Air: in a clofe Cucurbit, it may be fublimed a thoufand
times without kindling. Sulphur being put under a glafs
Bell, and a Fire applied, rifes into Spirit of Sulphur per
Campanam : But if there be the lea{} Chink whereby the
included Air communicates with the Atmofphere, it im.
mediately kindles. So an Ounce of Charcoal, inclol'ed in a
Crucible well luted, will remain without lofs for fourteen
Days in the intenfefd Heat of a melting Furnace ; rho the
thousandth Part of the Fire in open Air, will prefently turn
it into Alhes.-JfelAnont adds, that the Charcoal remains alt
that while without any Alteration of its black Colour ; but
that if the minute 4ir is let in, it falls instantly into white
Afhes. The fame holds of the Parts of all Animals and
Vegetables; which can only be calcined in open Air: In
clofe Veffels they never become any other -than black Coals.
See CALCINATION, COAL, ES)C.
The Air is liable to abundance of Alterations, not only
in refpe&t of its 'Mechanical Properties, Gravity, Denfity,
Ec. but alfo in refpecq of the Ingredients it confills of.-
Thus, in Places abounding with Marcafites, a fretting vitrio-
lick Salt is obferved to predrominate in the Air, which rots
the Hangings, and is often feen lying on the Ground in a
whitilh Efflorefcence.-At FaJhizin in Sweden, noted for
Copper Mines, the mineral Exhalations afR-a the Air fo
fenfibly, that their Silver Coin is frequently difcoloured ii
their Purfes; and the fame Erfluvia change the Colour of
Br_-r :oyl ws atue          by a Linima       i
Brats.-Mr. JBoyle was aflured by a Uentlemnan wrh
fefs'd fome Ground wherein there were feveral Vt
Metals, and other Minerals, that he had frequentl
Pillars of Fumes afeending thence ; fome having no
fome an ill one, and fome few a good one.-In Ca
Campania, &c. where there are Mines of Sulphur, ri
at times becomes very unwholefomr  whence frequei
demick Difeafes, U$c.-'Tis added, that the Mines n0
Cape of Good Hope, emit fuch horrible Fumes froi
Arfenic that abounds there, that no Animal can liv
them ; fo that fuch as have at any time been o
were obliged to be immediately clofed again.
The Effluvia of Animals alfo have their Effe& in
the Airr; as is evident in contagious Difeafes, Plagues
rains, and other Mortalities which are fbread by rh
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