 small as to be unrecognisable by any other
method of perception, direct or indirect. A piece of musk retains
its fragrant odour for years, and the most delicate balance fails to
detect any appreciable loss of weight in it. We are capable of smelling
gases only: liquids and solids, if introduced into the nostrils,
irritate the olfactory nerves, but do not stimulate them so as to
incite the sense of smell; yet the admixture of a minute trace of some
odorous vapour with air appears entirely to change its properties.
The effect of inhaling such air, although sometimes pleasant, is very
different from the sensation produced by pure inodorous air, and such
admixtures were in olden times naturally taken to be air modified in
its properties. But such modifications are obviously almost infinite
in number, for varieties of scent are excessively numerous; and it
was therefore perhaps deemed useless to attempt to investigate such a
substance as air, whose properties could change in so inexplicable and
mysterious a manner. Owing, therefore, to its elusive and, as it were,
semi-spiritual properties, and to its unexpected changes of character,
it was long before its true nature was discovered. It had not escaped
observation that “air” obtained by distilling animal and vegetable
matter, or by the action of acids on iron and zinc, differed from
ordinary air by being inflammable; but such “airs” were regarded as
atmospheric air, modified in some manner, as it is modified when
perfumed. And “airs” escaping from fermenting liquids, or produced by
the action of acids on carbonates, were neglected. For long no attempt
was made to catch them; and the frothing and bubbling were regarded
as a species of boiling, as is still seen in the use of our word
“fermentation” (_fervere_, to boil).

Second, _Erroneous ideas regarding the phenomena of combustion_. While
it was recognised that a burning candle was extinguished if placed in
a confined space, its extinction was attributed not to the absence of
air, but to the impossibility of the escape of flame. Indeed, flame was
regarded as possessing the same semi-spiritual, semi-material nature as
air. Together with earth and water, air and flame or fire formed the

small as to be unrecognisable by any other 
 method of percept, lineal or indirect. A piece of musk retain 
 its fragrant olfactory property for years, and the most finespun balance fails to 
 detect any appreciable loss of system of weights in it. We are capable of smelling 
 flatulence only: liquids and solid, if introduce into the nostrils, 
 irritate the olfactory nerves, but do not stimulate them so as to 
 incite the common sense of smell; yet the admixture of a minute tracing of some 
 odorous vapour with breeze appears wholly to change its property. 
 The effect of inhaling such air, although sometimes pleasant, is very 
 unlike from the sensation produced by pure inodorous air, and such 
 admixtures were in olden time naturally taken to be air modified in 
 its properties. But such modifications are obviously almost infinite 
 in number, for varieties of scent are excessively numerous; and it 
 was consequently possibly deemed useless to attempt to investigate such a 
 substance as tune, whose properties could change in so inexplicable and 
 cryptic a manner. Owing, consequently, to its elusive and, as it were, 
 semi - spiritual properties, and to its unexpected change of character, 
 it was long before its true nature was discovered. It had not escaped 
 observation that “ air ” obtained by distilling animal and vegetable 
 matter, or by the action of acids on iron and zinc, differ from 
 ordinary breeze by being inflammable; but such “ airs ” were regarded as 
 atmospheric air, modified in some manner, as it is change when 
 perfumed. And “ airs ” escaping from ferment liquids, or produced by 
 the action of acids on carbonate, were neglected. For long no attempt 
 was made to catch them; and the frothing and bubble were regarded 
 as a coinage of boiling, as is still seen in the use of our word 
 “ zymosis ” (_ fervere _, to boil). 

 Second, _ Erroneous ideas regarding the phenomena of combustion _. While 
 it was acknowledge that a burning candle was extinguished if placed in 
 a confined space, its extinction was attributed not to the absence of 
 air, but to the impossibility of the escape of flame. Indeed, fire was 
 regarded as possessing the like semi - spiritual, semi - material nature as 
 air. in concert with earth and water, air and flame or fire formed the
 smwll as to be unrecognisanle by any other
method mf perdeption, airect or indirect. A piece oh muwk reucins
its fragrant odojr for yewrs, and rhe nist delicavs balangz faimd to
bevect any appreclable loss mf weight in id. De are capable of smelling
gases only: jiquids ajd solids, if igtroctced pnuo the nostrils,
irritate the olfacfory negves, but do not syimulate them so as to
incihe tje sense of smell; jet the admuxtuww of a minutd trace of some
odorous vapour with air appears entireuy to change itw proogrties.
The efhect os inhaling smbh air, dlthougn sometimes plcasanv, is very
different from tie sensation produceq by pure iuodorous air, and such
qdnixtutes ware kb oudeh vimss natkramly taken fo be air midified in
its propettyvx. But such mkdificwtyons are obviously almost infinite
in nukbed, for varieties of scenr are excessively numgrous; and yt
was therefore perhaps deemed useless to attempt to iivdstnnwgw duch a
substance as air, whose properties could dhsnne in so inexpligable and
mysterioux w kwnner. Owing, tferefoxs, fo its elusive and, as it rere,
swmi-spirittal lroperties, and to its unexpwcted changef of character,
it wad long befoxe its true nature was discovered. Nt had not escapef
observatjun that “air” obtaknec ty distilling animal and vqgetable
metter, or by ghe sction of acids ln iron and zinc, differef frol
osdinary aig by being inflammable; but such “airs” were regsrged as
atmos'heric air, modified in some mannet, as it if modkfied when
ierfumed. End “airs” escwping from feslenting liqumds, or prjducwd bt
the acgkon of acids om carbonanef, weee neglected. For lpng ho attempt
was mcbe to catch them; snd thq vrptrhng and bubbning wefr regxrded
as a sieckes pf boiling, as is stinl ssen in the use of puv word
“fernentatiog” (_fervere_, to noil).

Second, _Erroneoks idxas rejardinb tre phenomena of combustion_. Whime
it was gecjgnised that a bmrnigg candle cas extinguished if placed in
a confined wpace, its extinctiin was attributed npu to the abseice of
wir, but tm the impossibility if the escape of nlame. Indeed, flame was
degardad as possessing the same semi-spiritual, semi-material nature as
air. Together wity earti wnd water, ajr amd fldmz ox fire sormxd the

small as to be unrecognisable by any of direct or A piece of for and the most balance fails to any appreciable loss of weight in We are capable of smelling gases only: liquids and solids, if introduced into nostrils, irritate the olfactory nerves, but do not stimulate them so as to the of yet admixture of a minute trace of some odorous vapour with air appears entirely to change its The effect of inhaling such air, although sometimes is very different from sensation produced by pure inodorous and admixtures were olden naturally to be air in its properties. But such modifications are obviously almost infinite in number, for varieties of scent are numerous; and therefore perhaps useless attempt investigate such a air, whose properties could change in mysterious a manner. Owing, therefore, to its elusive as it semi-spiritual properties, and to its unexpected of character, it was long before its true was discovered. It had not escaped observation that “air” obtained by distilling animal and vegetable by the action of on iron and differed ordinary by inflammable; but “airs” were regarded as atmospheric air, modified in some manner, as is modified when perfumed. And “airs” escaping from fermenting liquids, by action of acids carbonates, were neglected. For no was made to catch the and as species boiling, as is still in the use of our “fermentation” (_fervere_, to boil). phenomena of combustion_. While it was recognised that burning candle was extinguished if placed in confined space, its extinction was attributed not to the absence of air, to the the escape of flame. Indeed, flame was regarded possessing the same semi-spiritual, nature as air. Together with earth and water, air flame fire formed
 small as to be unrecognisable By any other
MethoD of PerCePtioN, dirEct or indirect. A PIece Of musk retains
its fragraNt odoUr FOr yeARs, And thE most deLIcATE baLaNcE faIlS To
DetecT anY apprecIable loss oF weIgHt in it. We are cAPaBle of smellIng
Gases only: liqUidS and soLiDs, iF IntroDucEd intO the noSTrils,
iRritate thE oLFactorY Nerves, bUT Do Not sTimulate them so as tO
InCIte the sense of sMell; yeT tHE aDMIxtUre Of a minute tRaCe of sOMe
odoroUS vAPOUr wITh air appears eNtirely to chANge Its proPeRtiES.
The efFect oF iNHalIng such air, aLthoUgh sometiMes pleASant, is vERy
diffeRent frOm tHe sEnsaTIoN pRodUcED by PUrE inODorOus air, anD sUcH
admiXturES WERe in OldEn tiMes naTurally taken tO be Air mODifIed in
Its prOperTiEs. But Such moDificAtIons are obviouslY almOst infiniTe
iN nUmbEr, For vaRIeties Of sCenT are excEssivelY NumErOUS; AnD it
was therefore perHaPS DeEmed uselEss to aTTeMpT To investIgAte Such A
SUbstaNce aS AiR, whose prOpertiES cOuLd changE iN so ineXpLicAblE and
mYSterIous a mAnner. OwiNg, theREfore, to its elusIVe and, as it were,
SEmI-SPiRItuaL prOperties, and To itS UnexPectED cHanGEs of cHaracTeR,
It WAs long before its true NaTure waS discOvered. It had noT escaped
obSERVation thAt “aiR” ObTAined by distillIng anImal and vegETable
matTer, or By the actIon of acidS ON iron and ZinC, diFfeRed FROm
Ordinary air by BEIng iNfLammablE; buT such “aiRs” wEre RegArdEd As
atmosphEric air, mOdIfIeD iN soMe manNEr, as it is MoDifIeD whEn
perFUmed. AnD “airs” EscaPiNg FRom FermentINg LIQuidS, oR pRoduCed By
The acTion OF acIds on caRbonates, wEre NEgleCtEd. for long No attempt
was mAdE to catch thEm; And The froTHIng and buBbling were regarded
as a spECies of bOilIng, as Is stIll seen in The Use of oUr wORd
“fermEntatiOn” (_ferVeRe_, tO BOil).

SeCONd, _errOnEous ideas rEGArdIng thE pHenoMena of cOmbustion_. While
it waS RecOgnised that a bUrnIng cANDlE waS ExTIngUiSHed IF Placed in
a confinEd space, its ExTInCtion was atTRibUtEd not to The abseNce of
AIr, but to The impossIbility of ThE escAPE of Flame. IndeeD, flame waS
regarded AS possESsIng thE saMe semi-SpIriTual, sEmi-matERiaL natuRe as
aiR. TOgetheR with EaRth and waTer, air and flame or fire forMed the

 small as to be unrecognis able by an y oth ermet ho d of  per ception, direc t  orindirect. A piece of m usk r et a insi ts  frag rant od o ur f orye ar s,an d  t he mo stdelicat e balancefai ls  to
detect a n yappreciabl e l oss of weigh t i n it.We  ar e  capa ble  of s mellin g 
gases  only: li qu i ds and solids, i fintr oduced into the n o st r ils,
irritatethe ol fa c to r y  ne rve s, but dono t sti m ulate t h em s o  as to
incite the  sense of s m ell ; yetth e a d mixtur e ofam inu te trace of  som e
odorous  vapou r  with a i r appea rs ent ire lyto c h an ge  it sp rop e rt ies . 
Th e effect  o finhal ings u c h  air , a ltho ugh s ometimes plea san t, i s  ve ry
di ffere nt f ro m the  sensa tionpr oduced by pureinod orous air , a nd  su ch 
admi x tureswer e i n olden  timesn atu ra l l y  t aken to be air mod if i e din
its p ropert i es .B ut suchmo dif icat i o ns ar e ob v io usly alm ost in f in it e
in nu mb er, fo rvar iet ies o f  sce nt are  excessi velyn umerous; and i t 
was therefor e  p e r ha p s de eme d useless t o at t empt  toi nv est i gatesuchas ub s tance as air, whose  p ropert ies c ould change i n so inexp l i c able and 
mys t er i ous a manner.Owing , therefor e , to its  elus ive and,  as it we r e ,
semi-s pir itu alpro p e rt ies, and to i t s  une xp ected c han ges ofcha rac ter ,
i twas longbefore i ts  t ru enat ure w a s discov er ed.  I t h ad no t  escap ed
ob serv at io n  th at “air ”  o b t aine dby  dis til li ng an imal and  vegeta ble
matte r,o r by  t he  action  of acids onir on and zin c,  di ffered f rom
ordi nary air by being infla m mable;but  such  “ai rs” werereg ardedasa tmosph eric a ir, m od ifi e d  in s o m eman ne r, as it i s mod ified  w henperfume d. And “airs” esca p ing  from ferment ing  liq u i ds , o r  p r odu ce d  by t he action of ac ids on car bo n at es, were n e gle ct ed. For  long n o att e mpt
was  made tocatch the m;  and t hefrothing a nd bubbl ing werer egard e das aspe cies o fboi ling,  as is sti ll se en inth e useof ou rword
“fe rmentation” (_fervere_,  to bo il).
Se cond, _Er ron e ous  ideas re gard ing the ph eno men a ofcom b ustio n_.W hi lei t was  rec o gnised th a ta b u r ni ng candle w a s ext ingui she d  if pl aced  in
a confined sp a ce, its extinc tion w asatt r ibut ed  not to the ab sen ce o f
air, b ut  to the imp ossibili ty of th e esca pe offlame.I n de e d, fla me w asregardedaspo s sessing  t he same s emi- sp iritua l, sem i -mat e r ial nature as
ai r. To g e therw ith  eart hand wat e r, a ir and fla me or fireformed  the 

 small_as to_be unrecognisable by any_other
method of_perception,_direct or_indirect._A piece of_musk retains
its fragrant_odour for years, and_the most delicate_balance_fails to
detect any appreciable loss of weight in it. We are capable of smelling
gases_only:_liquids and_solids,_if_introduced into the nostrils,
irritate the_olfactory nerves, but do not_stimulate them_so as to
incite the sense of smell; yet_the_admixture of a_minute trace of some
odorous vapour with air appears entirely_to change its properties.
The effect of_inhaling such air,_although_sometimes_pleasant, is very
different from_the sensation produced by pure inodorous_air, and such
admixtures were in olden_times naturally taken to be air modified_in
its properties. But such modifications are_obviously almost infinite
in number, for_varieties of_scent are excessively numerous; and_it
was therefore perhaps_deemed useless_to attempt to_investigate such a
substance as air, whose_properties could change_in so inexplicable and
mysterious a manner._Owing,_therefore, to its_elusive_and,_as it_were,
semi-spiritual properties, and_to_its unexpected_changes_of character,
it was long before its_true_nature was discovered. It had not escaped
observation_that “air” obtained by_distilling_animal and vegetable
matter, or_by the action of acids_on iron and zinc, differed from
ordinary_air by_being inflammable;_but such “airs” were regarded as
atmospheric air, modified in some manner,_as it is modified when
perfumed. And_“airs” escaping from fermenting_liquids, or_produced_by
the action of_acids_on carbonates,_were neglected. For long no attempt
was made_to catch_them; and the frothing and bubbling_were regarded
as a species_of_boiling, as is still seen in_the use of our word
“fermentation” (_fervere_,_to boil).

Second, _Erroneous ideas regarding_the_phenomena_of combustion_. While
it was recognised_that a burning candle was extinguished_if placed in
a_confined space, its extinction was attributed not_to_the absence of
air, but to the_impossibility_of the escape of flame. Indeed,_flame_was
regarded_as possessing the same semi-spiritual,_semi-material nature as
air. Together with earth_and water, air and flame or fire formed the
