University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
History of Science and Technology

Page View

Chambers, Ephraim, 1680 (ca.)-1740 / Cyclopædia, or, An universal dictionary of arts and sciences : containing the definitions of the terms, and accounts of the things signify'd thereby, in the several arts, both liberal and mechanical, and the several sciences, human and divine : the figures, kinds, properties, productions, preparations, and uses, of things natural and artificial : the rise, progress, and state of things ecclesiastical, civil, military, and commercial : with the several systems, sects, opinions, &c : among philosophers, divines, mathematicians, physicians, antiquaries, criticks, &c : the whole intended as a course of antient and modern learning

Accursed - aerometry,   pp. 21-40 PDF (18.1 MB)

Page 23

Af ' t  a
. AA _
C(21, )
from the Allies, does not crytlallize, but frill greedily im-
bibes the Acid Spirits.
Hence it may be probably concluded, that the Lixivious,
or fix'd Alcaly Salt, is no other than the Earth of the
Plant, which, notwith{'+anding the Violence of the Fire,
has retain'd a little Portion of its acid Salt, fufficient to
diffolve it in Warer; {Till referving a fufficient Number of
ioculi or Pores, to lodge the firfl i4cid that fhall offer it felf,
in lieu of that driven out of it by the Fire.-And as the
Name Alcal) is only given to a Salt, in refpea of its im-
bibing and retaining an Acid prefented to it, in order to the
producing a cryflalliz'd Salt ; the Lixivious Salts of Plants
may be fiid to be more or lefs Alcaline, as they abforb
more or lefs of the Acid; or, which amounts to the fame,
as they contain more or fewerVacuities to be fill'd with Acids.
An Alcaly, after it has been fully fatiated with one fort
of Acid, will yet fometimes admit and retain part of ano-
ther Acid: This is chiefly obferved where a Vegetable A-
cid has been received firff, and a Foflil one is offer'd after.
And it feems owing to this, That the Vegetable Acid hav-
ing undergone a greater degree of Fermentation in the Body
of the Plant, is become rare and pervious, in refpet of the
more folid and weighty Particles of the Mineral Acid;
which therefore force a way in.
The fame is always the Cafe, where an Acid appears an
Alcaly with refpea to another Acid; that is, where, of two
Acid Spirits, one whereof has a Mixture of fome Alcaly;
the rarer of the two having poffifs'd the Pores of the Al-
kaly, is comprpefs'd by the other denfer Acid.-Thus, a
Pin-cuflhion, tho ever fo full of Cotton, will admit a good
Number of Pins.
Now, urinous Salts are Alkalies as well as the Lixivious
Kind, i. e. they greedily imbibe Acids, retain 'em, and to-
gether with 'em compofe Salts which cryilallize.-But their
Volatility feems to make it plain, that they are not, like
the former, a Compofirion of a mere earthy Matter, with
a little Acid; in regard a mere Earth can never become Vo-
latile by fuch Admixtute. Yet is there a great deal of Rea-
fon to imagine, that their Compofition is no other than a
Part of the fame Matter, which would have produced the
Lixivious Salt, intimately mix'd with a deal of the fetid
Oil of the Plant ; and that the Oil is the fole Caufe of the
Volatility of thefe Salts.
M. Homberg, in his, Efai du Sel Principe, makes three
Claffes of Acid Salts, correfponding to the three Species of
Sulphurs wherewith the primitive Acids may be combined.
The firfl Clafs confifis of fuch as contain an Animal, or
a Vegetable Sulphur, which amount nearly to the fame.-
To this Clafs be ong all the diffill'd Acids of Plants, Fruits,
Woods, Uec. which mufl neceffarily retain part of the Oil
of the Plant, which is their Sulphur. To this Clafs alfo be-
longs Spirit of Nitre; as being a 6ubftance procur'd from
the Excrements of Animals, E&c.
The fecond Clafs is of thofe which contain a bituminous
Sulphur.-Such are Vitriol, common Sulphur, and Alumn;
which are all ufually procur'd from a Mineral Stone, where-
in Bitumen is the prevailing Ingredient.
The third is of fuch as contain a more fix'd Mineral Sul-
phur, approaching the Nature of a metalline one.-Such
are the Acids drawn from Sea Salts and Sal Gemma's ; the
latter of which is chiefly found in Places near Mines of
Metals, and the former probably arifes from Rocks, or Veins
of Sal Gemmx running into the Sea, and there diflolved.
From the peculiar Nature and Properties of the Sulphur
thus accompanying the feveral Kinds of Acid Salts, their
different Phxnomena and Effedfs are to be accounted for.-
See the Article SALT.
The Acids of Animals are doubtlefs chiefly derived from
Plants, in the ordinary way of Food, and Nutrition; and
thofe of Plants, again, from thofe of Minerals. So that
there lhould feem to be but one Spring of Acidity: The
Diverfities arife from what happens to 'em  in pafling thro'
the organiz'd Bodies of Plants and Animals. Hence it is,
that Plants and Animals efpecially, yield a very volatile Al-
kaly Salt ; whereas, the Salts of Minerals are found altoge-
ther acid, and much more fix'd and concrete ; tho 'tis the
fame Matter in both Cafes, under different affumed Forms.
Thus, the younger Lemery argues, that as Animals feed
on Plants, and reciprocally, in the Inf'ance of Salt-petre,
C c. Plants feed on Animals; inafmuch as their Vegetation
is excited by Manure; it happens, that what was real
Salt-petre in Plants, becomes only a nitrous Sal Ammoniac
in Animals, and vice vercfa.-The fame Author accounts for
this double Metamorphofis, by fuppofing that the nitrous
Principle remains the fame in both Cafes, and in both Cafes
is attach'd to the fame Matrix, with this only diflerence, that
the Matrix becomes more earthy in Plants, and by that
means, fix'd ; and in Animals, lofes its earthy Parts, and
affumes other oily ones, which render it volatile. Mean. de
1'Acad. An. 1717.
As to the Alanner wherein Acids ai  on Alcalies, the great
Nuzber of little Bubblg es prodcd during their Adiion, and
the Heat arittng tereupof . Lig, . Hemberg explains It
thus.-The Matter of Light, which he fuppofes to be the
chymical Principle, Sulphur, and to poffefs the whole Extent
of the Univerfe; is kept in a perpetual Motion by the con-
tioual Impulfes which the Sun and Fix'd Stars give it : But
this Motion, happening on fome Occafions to be flacken'd,
may be retriev'd again, and augmented by the near Approach
of Flame, which that Author fuppofes the only Matter capa-
ble of giving Motion to Light.-This Motion of Light can-
not proceed, without continually firiking againfi the folid
Bodies, and even pailing thro' all the porous ones, it meets
in its way. See SULPHUR, and FIRE.
Suppofe, now, Acids to be little, folid, pointed Bodies,
fwimming at liberty in an aqueous Fluid, and kept in con-
tinual Motion, by the repeated Impulfes of the Matter of
Light; and Alcalies, to be fpongious Bodies, whofe Pores
have formerly been fill'd with the Points of Acids, and
which fill retain the Dents or Impreffions thereof, and are
ready to receive the like Points when driven within 'em.
'Tis eafy to conceive, that if fome of thofe porous Alcalies
float in the fame Liquor wherein the folid Acids float; thefe
latter, being impell'd by the Matter of Light, will enter the
Cavities of the former, which are framed as it were on pur-
pofe for their Reception; and that they will do it the more
readily, if the Motion of the Matter of Light, wherewith
they are impell'd, have been accelerated by external Heat.
This Introduaion of Acids into the Body of Alcalies, is,
in all appearance, effeded with a great Velocity and a deal
of Fridion; inafmuch as it produces fo confiderable a de-
gree of Heat: And as the Pores of the Alcalies were before
flll'd with an aerial Matter, which is now expell'd by the
Points of the Acids; that Air is put in Motion, and produces
the Bubbles, which are fo much the more fenfible, as the
Heat accompanying the Affion is the greater. See AIR,
and HEAT.
Sir I. Newton accounts for the Effecs of Acids in a dife-
rent manner, viz. from the great Principle of Attrafion.
I The Particles of Acids, he obferves, are of a fize
' grofler than thofe of Water, and therefore lefs volatile;
' but much fmaller than thofe of Earth, and therefore much
' lefs fix'd than they.-They are endu'd with a very great
C attraffive Force, wherein their Adfivity confides; it being
' by this that they affet and Simulate the Organ of Taile;
' and by this alfo, that they get about the Particles of Bo-
' dies, either of a metalline or frony Nature, and adhere
' clofely to 'em on all fides; fo as fcarce to be feparable
' from them by Diflillation or Sublimation: and when thus
' gather'd about the Particles of Bodies, by the fame Power
'they raife, disjoin, and fhake them one from another;
' that is, dilfolve 'em.' See DISSOLUTION.
' By their attraffive Force, alfo, wherewith they rufh to-
' wards the Particles of Bodies, they move fluid ones, and
'excite Heat; Shaking afunder fome Particles, fo as to turn
' them into Air, and generate Bubbles: and hence all vio-
' lent Fermentation ; there being in all Fermentation a la-
' tent -Acid, which coagulates ill Precipitation.' See FER-
' Acids, alfo, by attraffing Water as much as they do the
' Particles of other Bodies, occafion the diffolv'd Particles
' readily to mingle with Water, or fwim or float in it; after
' the manner of Salts: And as this Globe of Earth, by the
' Force of Gravity, attrading Water more firongly than it
does lighter Bodies, caufes thofe Bodies to afcend in Wa-
ter, and go upwards from the Earth ; fo, the Particles of
Salts, by attraaling the Water, mutually avoid and recede
' from one another as far as they can; and are thus diffus'd
' throughout the whole Water.
I    The Particles of Alcalies confifi of earthy and acid
' Parts united together; but thefe Acids have fo great an
attradive Force, that they can't be feparated therefrom  by
' Fire ; and that they even precipitate the Particles of dif-
folv'd Metals, by attraffing from them the acid Particles,
* which before had diflolv'd, and kept them in Solution.' See
' If thefe acid Particles be join'd with earthy ones, in a
'finall Quantity ; they are fo clofely retain'd by the latter, as
I to be quite fupprefs'd and lolk as it were, in them5 fo that
they neither Simulate the Organ of Senfe, norattra& Wa-
C ter; but compofe Bodies which are not acid, i. e. fatty and
fweet Bodies; as Mercurius Dulcis, Brimflone, Luna Cor-
' nea, Wc.-From the fame attrative Force in thefe acid
' Particles thus fupprefs'd, arifes that Property of fat Bodies,
" that they fick or adhere to almoft all Bodies, and are ea-
' fily inflammable.-Thus, the Acid that lies fupprefs'd in
:   fulphureous Bodies,by more firongly attraffing the Particles
e of other Bodies (earthy ones for infiance) than its own;
promotes a gentle Fermentation, produces and cherifhes
natural Heat, and carries it on fo far fometimes as to the
Putrefaacion of the Compound; Purrefaffion arifing hence,
' that the acid Particles which have long kept up the Fer-
- mentation, at length infinuate into the little Interilices that
' lie

Go up to Top of Page