experiments on the solubility of fixed air and its density, and
researches by Dr. Brownrigg and Dr. Gahn of Sweden on its occurrence
in mineral waters. He also explains how calcareous petrifactions are
produced by the escape of fixed air from water, which then deposits its
dissolved calcium carbonate, present in solution as bicarbonate. The
deposit of iron from chalybeate waters is ascribed to the same cause,
and the explanation is attributed to Mr. Lane.

“Upon the whole,” these manuscript notes relate, “this sort of air
is quite distinct from common air, though it is commonly mixed with
it in small quantity.” “With regard to its origin, when treating of
inflammable substances and metals I shall consider this more
completely. I shall now only hint that it is a vital air, changed by
some matter, seemingly the principle of inflammability. This appears
from several phenomena when an animal or burning body is enclosed
with a certain quantity of this air, until it is changed as much as
possible.” The air is diminished in volume by the breathing of the
animal or by the burning of the candle. And Dr. Priestley has found
that “growing vegetables had the power of restoring this sort of air
to common or vital air again, which must be by their taking away some
matter which it had received from the burning body or animal.”

Black’s account of fixed air and its properties is the first example we
possess of a clear and well-reasoned series of experimental researches,
where nothing was taken on trust, but everything was made the subject
of careful quantitative measurement. It was not long since Hales had
pronounced air to be a chaotic mixture of effluvia. Black showed that
common air contains a small amount of fixed air, and that fixed air
must be considered as a fluid differing in many of its properties
from common air, especially in its being absorbed by quicklime and by
alkalies. It must be remembered that at that time carbon was not
recognised as an element; and hence, though Black knew that fixed air
was a product of the combustion of charcoal, he did not attribute it
to the union of carbon with oxygen, although the sentence quoted above
closely approaches to the truth.

The discovery of nitrogen was next in the order of time. It was made by

experiments on the solubility of fixed air and its concentration, and 
 research by Dr. Brownrigg and Dr. Gahn of Sweden on its occurrence 
 in mineral waters. He besides explains how calcareous petrifaction are 
 produced by the escape of pay back air from water, which then lodge its 
 dissolved calcium carbonate, present in solution as bicarbonate. The 
 deposit of iron from chalybeate water is ascribed to the same causal agent, 
 and the explanation is impute to Mr. Lane. 

 “ Upon the whole, ” these manuscript notes relate, “ this sort of air 
 is quite distinct from coarse air, though it is commonly mixed with 
 it in little quantity. ” “ With regard to its origin, when treating of 
 flammable substances and alloy I shall consider this more 
 completely. I shall now merely hint that it is a vital air, changed by 
 some matter, seemingly the principle of inflammability. This appears 
 from several phenomena when an animal or burning body is enclosed 
 with a certain quantity of this air, until it is changed equally a lot as 
 possible. ” The air is diminished in bulk by the breathing of the 
 animal or by the burning of the candle. And Dr. Priestley has found 
 that “ growing vegetable had the power of restoring this sort of tune 
 to common or vital air again, which must be by their taking away some 
 matter which it had pick up from the burning body or animal. ” 

 Black ’s account of fixed air and its properties is the inaugural example we 
 possess of a clear and well - reasoned series of experimental research, 
 where nothing was taken on trust, but everything was made the national 
 of careful quantitative measurement. It was not long since Hales had 
 pronounced air to be a chaotic mixture of effluvia. Black show that 
 common atmosphere contains a small sum of fixed breeze, and that fixed breeze 
 must be considered as a fluent differing in many of its properties 
 from common air, specially in its being absorbed by calcium oxide and by 
 alkalies. It must be remembered that at that time carbon paper was not 
 recognised as an element; and hence, though Black knew that fixate breeze 
 was a product of the combustion of charcoal, he did not assign it 
 to the union of carbon with oxygen, although the prison term quoted above 
 closely approaches to the accuracy. 

 The discovery of nitrogen was next in the order of time. It was made by
expfriments on the solubiliuy of fixed air aue its vensity, and
resexrches by Dr. Brownrigg and Dc. Gayn of Sweden on its occurrevce
in minvral watees. Ht also explains how calcavzous lctrifccvions are
producgd by the eswape of fixed dif yrom water, which then deposits its
difsolved cwlcium carbonaje, prtsegt ih solution as bicarbonate. The
deposjt of igon from chalybeaye waters is ascribed to tje swme cause,
and the edplanation us aerributed to Or. Lane.

“Upon the whole,” jhese manuscript notes relate, “thks soxt of air
is qyitf distinct fcom coimon air, thombh it hs commpnly mixed witm
it ii smqll quantity.” “With regerd to its origin, whgn treatinc kf
inflammable subwtqnces and metxos K sgakl consifer this more
dompletely. U shall now only himt nnat it is a bital wiw, changed by
some matter, seemingly the pgincjple of inflammability. Rhis appears
from sevetal phenomqna when an animal or burning body is enclosed
witv a cxrgaiu quangutj of this air, until it is changed as much as
pjasobke.” The air is biminished in vokule fy the breathkng of ths
animal or by the hurning of tye candle. And Dr. Priestley has found
that “growing vegvtaboes had the power lf restoriny this sort of air
to common or vitcl air again, whicj must be cy their taking xwaj soke
matter which it had receyved from the burnine bocy or wnimal.”

Blacn’s acgmunt of fixed air wnd ijs pro[erties is the first example we
possess of a clear and wgll-seavoned sexies on experimental wesearches,
wherg nothing was gaken on tgust, but xverything wws made the sghject
of carehul quantytatuve neasureodnt. It was not long sinbe Halws had
pronounced alr to ge a chaotic miruurt if effluvia. Blsck shjwvd vhat
cjkmon air condainr a xmall amount of nixdd aor, and that fixed ais
musf be considered as a fluid duffering in many of iys properties
from fommoi air, xspecislli in its being absorbed by quicilime and by
wlkalies. It iust be rememberzd that at that time carbon was not
recogiised as an element; and hence, though Black lnew that fmxed ayr
was a psoduct of the combusrion of charcoal, me did not attribute if
to tha uniln of carbon with oxygen, although the sentence quoted above
closely approaxhes to the truth.

Tge doscovvry pf nitwogei xas next in the ogder of time. It was made by

experiments on the solubility of fixed air density, researches by Brownrigg and Dr. occurrence mineral waters. He explains how calcareous are produced by the escape of air from water, which then deposits its dissolved calcium carbonate, present in solution bicarbonate. The deposit of iron from chalybeate waters is ascribed to the same and explanation attributed Mr. Lane. “Upon the whole,” these manuscript notes relate, “this sort of air is quite distinct common air, though it is commonly mixed with in small quantity.” “With to its origin, when treating inflammable and metals shall this completely. I shall only hint that it is a vital air, changed by some matter, seemingly the principle of inflammability. appears from when an or body enclosed with a of this air, until it is as possible.” The air is diminished in volume the breathing the animal or by the burning the candle. And Dr. Priestley has found that vegetables had the power of restoring this sort of air to common or vital air must be by their away some matter it received the body or Black’s account of fixed air and its properties is the first we possess of a clear and well-reasoned series of experimental nothing taken on trust, everything was made the of quantitative measurement. It was since had be chaotic of effluvia. Black showed common air contains a small of fixed air, and considered as a fluid differing in many of properties from common air, especially in its absorbed by quicklime and by alkalies. It must be remembered that at time carbon recognised as an element; and hence, though Black that fixed air was product of the combustion of charcoal, he did not it the union carbon with oxygen, the sentence quoted closely approaches to The discovery nitrogen next of time. It was made by
experiments on the solubilitY of fixed aiR and iTs dEnsItY, and
ReseArches by Dr. BrowNRigg And Dr. Gahn of Sweden on its OccurReNCe
in MInEral wAters. He ALsO EXplAiNs How CaLCaReous PetRifactiOns are
prodUceD bY the escape of FIxEd air from wAteR, which then dePosIts its
DiSsoLVed caLciUm carBonate, PResent In solutioN aS BicarbONate. The
DEPoSit oF iron from chalybeaTE wATers is ascribed To the sAmE CaUSE,
anD thE explanatiOn Is attRIbuted tO mr. lANE.

“UpON the whole,” thesE manuscript NOteS relatE, “tHis SOrt of aIr
is qUiTE diStinct from cOmmoN air, thougH it is cOMmonly mIXed with
It in smAll QuaNtitY.” “wiTh RegArD To iTS oRigIN, whEn treatiNg Of
InflaMmabLE SUBstaNceS and MetalS I shall considEr tHis mORe
cOmpleTely. I ShalL nOw onlY hint tHat it Is A vital air, changeD by
sOme matter, SeeMiNglY tHe priNCiple oF inFlaMmabiliTy. This aPPeaRs
FROM sEveral phenomena wheN aN ANiMal or burNing boDY iS eNClosed
wiTh A ceRtaiN QUantiTy of THiS air, untiL it is cHAnGeD as much As
PossibLe.” the Air Is dimINishEd in voLume by thE breaTHing of the
animaL Or by the burninG Of THE cANdle. and dr. Priestley Has fOUnd
tHat “gROwIng VEgetaBles hAd THe POwer of restoring this SoRt of aiR
to coMmon or vital aiR again, whicH MUSt be by thEir tAKiNG away some
matteR whicH it had receIVed from tHe burNing body Or animal.”

BLACk’s accouNt oF fiXed Air AND iTs properties iS THe fiRsT examplE we
Possess Of a CleAr aNd wElL-reasoned Series of ExPeRiMeNtaL reseARches,
wheRe NotHiNg wAs takEN on truSt, but EverYtHiNG waS made thE SuBJEct
oF cArEful QuaNtItatiVe meASurEment. It Was not lonG siNCe HaLeS hAd
pronoUnced air to be a ChAotic mixtuRe Of eFfluviA. bLack showEd that
common air contains A Small amOunT of fiXed aIr, and that FixEd air
mUst BE consiDered aS a fluId DifFERing iN MAnY of ItS propertieS
FRom CommoN aIr, esPeciallY in its being absorbeD By qUicklime and by
AlkAlieS. iT mUst BE rEMemBeREd tHAT at that time carbOn was not
reCoGNiSed as an eleMEnt; AnD hence, tHough BlAck knEW that fiXed air
was A product oF tHe coMBUstIon of charcOal, he did Not attribUTe it
tO ThE unioN of Carbon WiTh oXygen, AlthouGH thE sentEnce quOtEd abovE
closElY approacHes to the truth.

The discoveRy of niTrogeN waS next in thE orDEr oF time. It waS madE by

experiments on the solubil ity of fix ed ai r a ndit s de nsit y, and
researc h es b y Dr. Brownrigg and Dr . Gah no f Sw e de n onits occ u rr e n cein  m ine ra l  w aters . H e alsoexplains h owca lcareous pet r if actions ar e
p roduced by t heescape  o f f i xed a irfromwater, whichthen depo si t s itsd issolve d ca lciu m carbonate, pres e nt in solution as  bicar bo n at e .  Th e
d eposit ofir on fr o m chaly b ea t e wat e rs is ascribe d to the sa m e c ause,an d t h e expl anati on isattributedto M r. Lane.
“Upon the who l e,” the se man usc rip t no t es  r ela te ,  “t h is  so r t o f air
is  q ui te di stin c t f romcom monair,though it iscom monl y  mi xed w ith
i t in  s mallquanti ty.”“W ith regard to i ts o rigin, wh entr eat in g ofi nflamm abl e s ubstanc es andm eta ls I sh all consider thismo r e 
c ompletel y. I s h al ln ow onlyhi ntthat i t isa vi t al  air, ch angedb yso me matt er , seem in gly  th e pri n cipl e of i nflammab ility .  This appearsf rom several p h en o m en a  whe n a n animal or  bur n ingbody is  en c losed 
with  a ce r tain quantity of th is  air,until  it is change d as mucha s possible .” T h ea ir is diminish ed in  volume by the brea thing  of theanimal or b y the bu rni ngofthe c an dle. And Dr.P r iest le y has f oun d
that“gr owi ngveg et ables had  the pow er  o fre sto ringt his sort  o f a ir 
to  comm o n or v italairag ai n , w hich mu s tb e  byth ei r ta kin gawaysome mat ter whi ch it had  re c eive dfr om theburning bodyor  animal.”
B lac k’s ac c o unt of f ixed air and its proper t ies isthe  firs t ex ample wepos sess o f a clearand we ll-re as one d serie s of  ex pe rimental r e s ear ches, 
w here  nothin g was taken on tru s t,but everythin g w as m a d ethe su b jec to f c a r eful quantitati ve measure me n t.  It was no t  lo ng  sinceHales h ad
pr o nounced  air to b e a chaot ic  mix t u reof effluvi a. Black  showed t h at
co m mo n air  co ntains  a  sm all a mounto f f ixedair, a nd  thatfixed  a ir
mustbe considered as a flui d diff ering  in  many ofits pro perties
f romcommon air , e spe ciall y i n  itsbein g  a bso r bed b y qu i cklime an d  b y
a l k al ies. It mus t b e r ememb ere d  thatat t hat time carbon w a s not
recognis ed a s anele m ent;  a nd hence, thou ghBl a c k knew t ha t fixed air 
was a p ro d uct o f thecombus tion of c ha r coal,he d idnot attri but ei t
to th eun i on ofcarb on  withoxygen ,  alt h o ugh the sentence  quot e d  abov e 
cl osely  a pproach e s to  the truth .

The disc overyof n itrog en wasne xt inthe  o rder of ti m e. It was  made  by

experiments on_the solubility_of fixed air and_its density,_and
researches_by Dr._Brownrigg_and Dr. Gahn_of Sweden on_its occurrence
in mineral waters._He also explains_how_calcareous petrifactions are
produced by the escape of fixed air from water, which then deposits_its
dissolved_calcium carbonate,_present_in_solution as bicarbonate. The
deposit of_iron from chalybeate waters is_ascribed to_the same cause,
and the explanation is attributed to_Mr._Lane.

“Upon the whole,”_these manuscript notes relate, “this sort of air
is quite_distinct from common air, though it_is commonly mixed_with
it_in_small quantity.” “With regard_to its origin, when treating of
inflammable_substances and metals I shall consider_this more
completely. I shall now only hint_that it is a vital air,_changed by
some matter, seemingly the_principle of_inflammability. This appears
from several phenomena_when an animal_or burning_body is enclosed
with_a certain quantity of this air,_until it is_changed as much as
possible.” The air_is_diminished in volume_by_the_breathing of_the
animal or by_the_burning of_the_candle. And Dr. Priestley has found
that_“growing_vegetables had the power of restoring this_sort of air
to common_or_vital air again, which_must be by their taking_away some
matter which it had received_from the_burning body_or animal.”

Black’s account of fixed air and its properties is the_first example we
possess of a clear_and well-reasoned series of_experimental researches,
where_nothing_was taken on_trust,_but everything_was made the subject
of careful quantitative measurement._It was_not long since Hales had
pronounced air_to be a chaotic_mixture_of effluvia. Black showed that
common air_contains a small amount of fixed_air, and that fixed air
must_be_considered_as a fluid differing in_many of its properties
from common air,_especially in its_being absorbed by quicklime and by
alkalies. It_must_be remembered that at that time_carbon_was not
recognised as an element; and_hence,_though_Black knew that fixed air
was_a product of the combustion of_charcoal, he did not attribute it
to the union of_carbon with oxygen,_although the sentence quoted above
closely_approaches_to_the truth.

The discovery of nitrogen was next in the order_of time._It was made_by
