;the fleam is , : ÿ h e /piflon
is forced1 up -; ft earn is d'eJlr;©|B„e|l by pro-
| eâin^T^afef1 in which tlie ^iftoTi works,
/ht pifton flefcend^By the weight o f the atmofpEerp.
preffmg upon it. A n d fo alternately, as long > as the
.engine works. '
* ' domniol^ p ^ jÿ k e r k a i air is an e|||a§:
fluid,, A c -
«carding lllp tè pre^eiatSteg^^; o f c h€miÿ^ÿ|^|sÿ®m:
cipMÿ’èomppfed of" -Ai,, vital
air, and phlogj^ieotedax. ^^^^pïes- .'tbefe,' the èÿmp
anon air I fp ll.• B e H i T i J g ' f r o m
/fermentation, !;p^i;e;^^nl^oeG.^ % i ^varions/other ! fàb-
dïaù'c'es. ^^I^pmogfmcafôd^îft^was djfçdverech by Dr.
P R1 Esî^^^^ffip^’tÇe^pp|ë.Jart .of^^l^^dfpaere^ or
that part which is fit for refpiration. Phlc^ifticaied air
is iinaY,eai04yein it.
•minium, J&xr.^with, lomM_ôf «nière. .%|(|:E.y
diftillation he proEu'ê^dt^‘0 air; -and- lie confiders this
air, which he calls dephlogifticated air, as one of, t h e B g l'
ftituent j>ag$fef the atmofpiere ; and that the ptlfdr cpnr
flituent parts] are earth and a^^D-yLohjihlogi/lon as is necef-
fary to' its e a ^ ^ ^ y ,fa ^ as it
is ufualW ^M ^ M. X avoisI éM1!^ ^ ^* . th a t a tÉlÉi,
ture -of f z ; parts _of phlogifticà^tgdi and 2V8 parts of-
a fluid like. ’£o/f|ir atrnof-
pherical air ; and he concluded that ‘ thé * âtmofphere was
a mixture o f thefe two airs : for b y applying §|p|§
flances wKioh^have an affinity to vital air, fh e portion o f
this flpid|^p^®^ mrthe atmofpherical air, i&aBfomed,
and the refidihm is phlogifticated_air,- jO the^effemifts
fupppfe that it is not a meré^rMfcure^ b h |S.xh® ü c#
hompotlhd • for as th&vital air is o f greate^fneciflc
gravity than, thé jflilqgifticated, they Aught. tg feparate,
i f “it; Was Only a mîx t urê^ the y^ah^^ Temaih fng^o éloy^
beingsô f the grêa t^ Mo^m: gravity^^^^^fa^dfjier- af-
cending? ' The
Frçnçb chémfft^jConf^r; ?âeph^gülicated "air as ccumfl^
M o f a bafis called oxygéné, or the acidifying principle,
jè tÿm n id with fire. T h a t âhacid isjcô^ameâ the
air, is probable from the change o f colour induced on the
tinfeture o f turnfole by t&e d è ^ î c Igark palling. th rough
air in' cdntaél W itK^mï hq'uor. A n d this.. auo.lhoy^:
that thef'fll^fcricfpark flecorhpofes the.air, and. difen-
gages the âcid. Çq^îrfdh' air i l alfov *fô,und to diflolve
ifeveralearthy and ni etalic mblfà nces^ indicgtmgjlieçeby
-rah acidity.
v- 433'. Vital air iè'Jû'eàlled, Becaufe it is peculiarly ne-
ÿHIary for refpiratipn,; ^ ranimais will live-much, lo.nger
in this air than im theÿjpmmon air. A l l perfons who
havg i'clpirea*vital air/ agree,, that it communicates^!
gentle vivifying^ heat to the lungs, which infenfiBly ex-
Undi/l'o all parts o f the body. A n d ânimals will live
J oftp^ fiV e times as long in^Jms ^air, as/in common air.
But p attimafi |ffe( în'bBtÿgiÆicafÿwi:*] Vital air is
alhrneceflary fo r^ p fb u ^ ^ ^ fp ^ w h ^ k bodies biÿrn in
-common air, it is the vifal/partjkhfell affifis combuftion ;
/or there is" ho this' air. "If/y©.u
'$fehgf.; 41 ight ed can dlëj ||#p a veffe'1 filled with this air,
the flame becomes more ardent; arid] bright,' and the com-
^ffiion is four times more <iajpid.,, Bhlo,gifticatcd air is
unfit 'fon^^buflion.^ That air jtherllçre which is ne-
ceflary for the fupport .offlifejisI^|||ifeeilary fow £ ê
itr’e ; | and tha|r
former, .is^alfo unfit for the latter. . ,
434* A i r is neceflaiy
plants. ( For plants will ; ;a0tf gro>v m/y%ciio; Dr ,
P ries tiay that, plants ^will not.pnly g^ovn, in
confine^ aii% but a-lfo in aii vitî«uc%by burniijigÇà-ffl^i re'-
fpirâit^É^^S 'that fuch air waSj.^I^p^l^d^iy,.’Vegeta-
vegetation was employ--'
jeab^àâ^Bé^^m^mean. >^^,pprifying the air, which
mu ft be continugll y corrupted by refp irati on, putrefaction
, and combuftion. M. I ngenhous^ has~'p.urfaed:
this. fubjedt by a courfe o f experiments, and eftablifhed
^^Ool}^4ng+^6ts.;,^./1
435. .AIt plaütsrpoïïefs a;, i^^&r^Q^ ^ m e ^ n^fduI.yàir
unfit for^ÿÿaration but'this'happvens;ö^ly in clear day
IJgh t, 0 r iMfh e fu n - Hi ine. ..
4f'^|l|^ll--P’l^ I s yield a certain quantity o f dephlq-
gifticated air in the day time, "when growing in the open
ajFj anflrreeTrqm.flia^e.
437. Plants evaporate bad air by night, and fouls
-.the common air which furrounds them ; biat^this is far
over-balanced b y 1 their ib&eficiai operation in tE^jd^y.i, i
438. Hence he concludes, that the - faeiilfey which
planfsjhap^^ ^ ^ B i^ y ^Mlogiift^tèÉ-^Éii^^oriKë^itti^-
air, improving ordinary , air,, isj not owing
to^vegefation, as fuch : for if lTwcre, plants wqutd «exert
at.ÿ^timcs^ g^ ^ |^ a lj^|g è s, w i g i f
lation go/s on ; which is not the cafe. A plant may thrive
well in darknefs, and fpread-round its deleteriious exhala^-
tions, andmaye^no^pqwer* to c^-rreft the badnefs o f the
air. ^^m%^feration qf. cp-rfe^ing-- bad, air, he -impurs
to tEei B^i^^^tbegfuînîj^qn/tji&»plaaU
H e Ihows, however, that the light o l t f e ^m,by itfelf,
but L that
ting it, and ^Ouriuguut^||e^ita l
takes^ place only in ■ the day. ' H e alfo eftablifeed
- 439. That flowers ooze out an i^nwholefome ^ir by
day and by-nighty and fpoil'a confiderable body o f air
44Q. That all fruits exhale a deleterious air by day
and by* night,, and fpread
the 'fürE|undingair. ’
441. That the
ground, yield, in general,-ba'd airy a^muoilyommon air
at all times, fpnie few excepted:
. I 442. That depldogi(licated air from -the leaves- of
plants,/(3oes not ex'ilb in that^fthie'in the p la n t e d : that
the air within the If^ve^Jft ^urifledy, and>thefpüre part
efcapes.
/ 443- It'appears pró cable,,that or}« of^he great la,bp-
rat^rie^ pfg^ture £qjf jpprifying.the air, is .placed in.; the
. leaves
leaves o f trees and[ vegetables', and put in aâLiohuby’l i e
influence óf the light ; and that-the air thus pffiriiéii-’is;'
is
.prin'S^Siy by the excretory d'udts, placed, for.the;^m^
part, on t& u fld ë f itôel of the leaves ; and this^ânftÿi'n’p;' '
«heavier
air in which wre bieathe. But moil foul airs are lighter ■
than Æommèn. air, and ^therefore they afeend, and efcape
us. Thefe are ftriking in fiances o f the wildom!. an(d b e nevolence
>'0/ Providence. T h e iniiuertêG',©;/-^he'vege- :
-^flglq^ fcrea|rqn/e|aïêsà indent er |©|| is. amply
^^ppenfa'ted' by the d^nfilmlitio.n of the gened-al*pfe o^J
r': p a0h||^gr|a|fêp|©
iS r a fe l i&jt]
, *.,444. > D r. P riest
bettg.r^n£fb^a| than in vital air ; and by t-heir having the
power to corifecÿ^dusaitr, and give out again fhë'pure
part, it follows, that the vegetable kingdom is fub£6f-
vient to the animal ; and that air rendered noxious by
animal îcfpiiation, fermes to plants as a kind o f nouiifh-
'tó e iit,.
445. The air which we if^laith^ji® rendered unfit for
refpiratiod,-;by recei\Mng-"a'p©rff§^^^*ed air, which is-
generated in ^S|)©dy. We conftme, b y each infp'ira-
tion, about 30 cubic inches of air.
^446/‘ B y th/e,'Vèxperiméri€s 'of Dr . H ailes, we kh'ow-
1 quîè|i(t.ÿ '©flair îa g
p j o n f p j f f i ^ f a i f ïshendered el^fti’cj^àimIsxy
pelled frô-ÉrîÆhe body, b y heat. H e /o.und/that-fFÓ% a
cji'k’c inclicof heart o f oak, was genWefted 216 cubic
whieh was / o f flffiswêiglït
^f^he :oak. . A;'-eubic.$i|J 'of Mewp;a#e coal gave -©u#
3.,6o|fef§c inches-of aii, which is nearly y o f the weight
o f A s air therefore -couflitutes 'd’pnfiderahl'è
I a pa.rt,©f'fome bodies,- it feems that the ftatein w hiëlik
exif^|ng^0^f®, may be tMp bf% Iblid^ aiïld may|f||||^
Is a c'ohefi5©m for the other parts. ^There Teems, to' be
nothing in this fuppofition incon/iftent with e?tiher properties
o f air, as we know ? that, the mixtures’’^ two airs
wilhproduee' water. That the air in the - body .Wilfj
havte been in a non-elaflic flate, is manifeft from hericè',
that, in -the air which iyaé^ë.V^klwS'
into ,an‘ velaftic. fluid o f .atleaft I fp d / üm è sO i^ '^ ^ i® 1
Bulk, Hiould he'comp 1 eüëd again1 into its original bulkjV
its elafticity ^oh ld:b e increafed 360 times, in whiclï-
fl-ate',/ifsCorcp'VÇQhlf; be fufficient fo rend aistady, in^
which it migit/be confined,, to atoms. W i tÖ S t e 1 original
d.enÿfpN therefdre, it m u i have exifled in® ^ ^® f'
non^kâicity. - ,
v 447 • The ’^ fs jttó s ^proteée^rptórBpdies by* difiilla-
JaoR,Fermentation, &ci.baye'different.'properties acéoÿdr?
Eig to the, diflierenti-Bo^s’l! ' There is.,what is !(faÈe|f|^l^
air, arifing-from, vegetables / caîcarëous air, or'air
from calcareous earths';/this is ealled'^<?J air; vitriolic
acid air, arifing .from a mixture o f vitriolic acid anfl S i
flannnable fuhÓlInÊpSs/ inflammable, .air,- arifing ham a'
mixture o f water, vitriolic acid, .and zinc, '%0<ns &c.
A.nd airs are formëê ’frffi*n^Mfe^®F'COï^6ïnal5ó 'M
of fubftances, from which, the airs - take their name..
: .8.
'■ The' inflammable air. is that' with which Balloons are
filled. A mixture o f /h'is ah’d 'common air will take
fire. I t is t-fiftes lighter than! the common air. ‘ All-
T O t p a l fdBitiovs airs*- are no%i-
; but moft o f them being lighter 'than common air,
they : a'fe^d:/ i-n'Vthe atmolphere as. fobri I as* ’their are
fo rmed:^
‘I ?448. V eg e t a t ron. M r " H ales, in his vegetable
IftltiN/ 'kafcfm^M;e‘^gi^&'j^nb'er o f eMj^timents in order
M eftab-lifii the principles o f vegetationwe ^ |il therefore
-here give the refult of his enquiries ; with fp,tnc further
and the j^afpgy, between fheiii*
and the m®^M/eReaCi;0n. ]
449/3|Eqre. fubftan'c'evo’f Vegetables o f ful-
V'\phlflr, volatile fall, watci, eai th / jftlf air.
450. - Wat^^^d air enter by tlie-i;p©ts^p® afeend in.
r;fhe refpcftive' MbeS:, thp water forming the fap; and na--
^ w^fh a; very fiife.
thick.ftrSiner, that nothing can "be admitted into them
what'cau-readily be canied- ,
' oiftm^ging the^s
>Tedre!m'eh't‘. • ,
. 451. The elaftic aereal fluids d'iflveVd ’each dihSile' part-,,
and b y eiflivening and invigorating f i e Tap, 'and 'mixing
with thb o|her principles,' the;^^p|;ll^V' and motion,,
aflimulate into theMouriflimcnt of the refpefhive parts'.
'W hile i§f|Ms nutritive flatc,'hy|sthe gfadual cohefion o f
the'-e’O'iaflituent particles, they are at length1formed into
.a fifm ly^ d b^ ^ ^ ^ l^ d y .. M
452. "The fap r-'i^e|^all winter, but in ■ a^fm.ajllei1 degree-
than in the fumrner. ^ h p the perfpiring matter of'trees
is rather a&ua'te’d'by jvarsnth, an-d fo exlialed, ;mampfc^-'
i 453. The air enters intbl'^e-' vegetable, not u.tly by-
the 'ibots]ifMutplroM^™E^rui^^m e^recMlly at
flight-;' '‘when' they are-1 G'hang’edp^ii^^M expii-mg^i an.
arifes Jaffp);,fr0^^the leaves plentifully •: imbibing.' dews
p a u l ' ^ i p f & c \ :0|| qeit^.
imjife^fl'ated with thefe fubfiances,
v 454. Leaves are 'a lia Ibfllumental in drawin^<n'burifli--
^m^ht from the-i oots, a n d *> p ‘fhing4the youq^ ’'fiiooLS'-
' with nut riment. . T hey alfo-i con tain the main excretory
du6fs, - and feparat’e aim oan-y ^oJ' thB.Ee'^U-ndan t >y/at e.ry ■
i fluid, which by being l&n.g detained,‘would turn rancid,
Wd^utSjrdJiidicial to tKe plain'; 'thus leaMh^ t|rk more
: nutritive parts to cpalefce. }" *
455. The ufe,of kavesy-fwllTeh are placed juft 'where
- thcx he tree, is to bring nourifliment to the
! we find "that the leaves, next adjoinjyi&
s^are-, in the-fprihg, very much expanded,|
> whOnf^lre^o|her leaves on barren'fiioots; are but b'eghP
ning to : S’p prOviden-t,'-is nature in making timely
Npfo^fipfif for nouriflung th^( ,e^’B,i*yq».ff^^ T h e
. peMst§*f l^nf-flalks are alfo placed whei e noui i Ihmcrffl
' is wan.feed',tQ ^.fodircfe leavesy fhoo-ts, and fi n it; a-nd^bm'e^
fuch thin leafy exparifion is lo .nee'eflary for this p f lra jfly f
t^a^'iratu're provides fmall'thin expanfions, -which may*,
be. cafled pnmaiy'ieayes^th^t Terve to pTbte^t and draw
flouriftiment:.