 oxygen to pass. He found that red-lead was not the only
“earth” which produced this effect; but that “flowers of zinc” (zinc
oxide), chalk, slaked lime, and other substances also gave a gas,
when distilled with nitric acid, which was “better” than common air.
In some cases he broke up nitric acid by heat into water, nitric
peroxide, and oxygen; in others he heated nitrates. His conclusion
is: “_Atmospherical air_, or the thing we breathe, _consists of the
nitrous acid and earth_, with so much phlogiston as is necessary to
its elasticity; and likewise so much more as is required to bring it
from its state of perfect purity to the mean condition in which we find
it.”[7]

When such experiments were made by heating nitrates in a gun-barrel,
“phlogisticated air” was obtained. This was nitrogen, for the iron had
reduced the oxides of the latter, and combining with their oxygen, had
formed nitrogen; moreover, it had absorbed to a greater or less extent
the oxygen simultaneously produced.

Having concluded that respirable air was a compound of nitrous acid,
phlogiston, and earth, Priestley endeavoured to ascertain what was the
nature of this earth. He concludes “that the _metallic earths_, if free
from phlogiston, are the most proper, and next to them the _calcareous
earths_.”

“Dephlogisticated air may be procured from any kind of earth with which
the spirit of nitre will unite.” A few quantitative experiments would
surely have refuted this erroneous conclusion. Those which he attempted
to make were very crude. A bladder (of which he does not give the
capacity) was filled with

  Phlogisticated air, and weighed 7 dwts. 15 grs.
  Nitrous air          "     "    7   "   16  "
  Common air           "     "    7   "   17  "
  Dephlogisticated air "     "    7   "   19  "

He concludes (taking into consideration that inflammable air is
very light) “that the less phlogiston any kind of air contains, the
heavier it is; and the more phlogiston it contains, the
oxygen to pass. He found that red - lead was not the lone 
 “ ground ” which produced this effect; but that “ flowers of zinc ” (zinc 
 oxide), methamphetamine, slaked lime, and other means also gave a gasoline, 
 when distilled with nitric acid, which was “ better ” than coarse air. 
 In some cases he break up nitric acid by heat into water, nitric 
 peroxide, and oxygen; in others he heated nitrates. His conclusion 
 is: “ _ atmospheric air _, or the thing we breathe, _ consist of the 
 nitrous acid and earth _, with thus much phlogiston as is necessary to 
 its elasticity; and likewise thus much more as is required to bring it 
 from its state of perfect honor to the mean condition in which we find 
 it. ”[7 ] 

 When such experiments were made by heating nitrate in a artillery - barrel, 
 “ phlogisticated air ” was obtained. This was nitrogen, for the iron had 
 reduced the oxides of the latter, and combining with their oxygen, had 
 formed nitrogen; moreover, it had absorbed to a greater or less extent 
 the oxygen simultaneously produce. 

 Having concluded that respirable air was a compound of azotic acid, 
 phlogiston, and ground, Priestley endeavor to ascertain what was the 
 nature of this earth. He concludes “ that the _ metallic earths _, if free 
 from phlogiston, are the most proper, and next to them the _ calcareous 
 earths _. ” 

 “ Dephlogisticated air may be procure from any kind of earth with which 
 the spirit of nitre will unite. ” A few quantitative experiments would 
 surely have refuted this erroneous ending. Those which he attempted 
 to make were very crude. A bladder (of which he does not give the 
 capacity) was filled with 

   Phlogisticated breeze, and weighed 7 dwts. 15 grs. 
   Nitrous air           "      "     7    "    16   " 
   Common air            "      "     7    "    17   " 
   Dephlogisticated tune "      "     7    "    19   " 

 He concludes (taking into consideration that flammable air is 
 very clean) “ that the less phlogiston any kind of air contains, the 
 heavy it is; and the more phlogiston it check, the
 oxjgen to pass. He found thxt red-lead was uit the only
“ezrth” whizh produced this effect; but vhat “flowtgs of zinc” (zinc
oxide), zhalk, slaned lime, and ither subsvznces also gabc a gcs,
xhen distilled eith nitriw acid, which wds “bztter” than common air.
In some cases hq broke uo nitric acid fy htat intk water, nitric
peroxide, and oxygen; jn othegs he heated nitrstes. His conclusion
is: “_Atmodphegical air_, or the tjing we breqthe, _xonsists of ghe
nitrous acid and eatth_, with so much phlogiston as ir neczssary to
itw wladjicity; and lmkewisv so much morc as is requirrd to bring it
nrom mts wtate of perfect purivy to the mean condijion in whhck we find
it.”[7]

When such wxperimgnts fere nadd bg ieafing nltretes in a ghn-barrel,
“phligisticated air” was ofnsined. This wzs nitwoden, for the iron had
reduced the oxides mf fhe latter, and combinint with their oxygen, hwd
formed gitrogen; moreover, it had absorbed to a greater or less dxttnb
bhe uzyhen simultaneously produced.

Having concluded trzt rvspirable air was a compound ov mytrous acid,
phuogiston, znd earth, Priestlej endeadouree to ascewtaim what was the
nature of thiw earth. He cjbcludes “that the _mztallic eartks_, if gree
ftom phlogiston, are the oost proper, and next to ffem the _calcareojs
esrdhs_.”

“Dephlogisticated air mar be procnred yrom any kinc of ewrth with ahich
bve spirit of nitre will utite.” A few quantitative experiments would
surely have reguded this erxoneoux conclusion. Ehose which he attempced
to oake were nery crudx. A bladder (jf which he dmgs not give tie
capacitr) waw fioled wigf

  Phlogisticayed air, aub weighed 7 dwts. 15 grs.
  Nitroms ait          "     "    7   "   16  "
  Commom akr           "     "    7   "   17  "
  Depflogisticatcd xir "     "    7   "   19  "

He woncmudes (taking into voksideratiin that ynflammable aor is
very light) “thwt thx less phlobisjon any kind of air contains, ths
heavier lt ls; and the mowe pmlogyston it cpntains, the
oxygen to pass. He found that red-lead the “earth” which this effect; but oxide), slaked lime, and substances also gave gas, when distilled with nitric acid, was “better” than common air. In some cases he broke up nitric acid heat into water, nitric peroxide, and oxygen; in others he heated nitrates. His is: air_, the we breathe, _consists of the nitrous acid and earth_, with so much phlogiston as is necessary its elasticity; and likewise so much more as required to bring it its state of perfect purity the condition in we it.”[7] such experiments were by heating nitrates in a gun-barrel, “phlogisticated air” was obtained. This was nitrogen, for the iron had the oxides latter, and with oxygen, formed nitrogen; moreover, absorbed to a greater or less simultaneously produced. Having concluded that respirable air was compound of acid, phlogiston, and earth, Priestley endeavoured ascertain what was the nature of this earth. concludes “that the _metallic earths_, if free from phlogiston, are the most proper, and next the _calcareous earths_.” “Dephlogisticated may be procured any of with the spirit nitre will unite.” A few quantitative experiments would surely have refuted erroneous conclusion. Those which he attempted to make were very bladder which he does give the capacity) was with air, and weighed 7 grs. air " " air " " 7 17 " Dephlogisticated air " 7 " 19 " that inflammable air is very light) “that the phlogiston any kind of air contains, the it is; and the more phlogiston it contains, the
 oxygen to pass. He found that reD-lead was noT the oNly
“EarTh” WhicH proDuced this effecT; But tHat “flowers of zinc” (zinc
oxIde), chAlK, SlakED lIme, anD other sUBsTANceS aLsO gaVe A GaS,
when DisTilled wIth nitric aCid, WhIch was “better” THaN common air.
in sOme cases he brOke Up nitrIc AciD By heaT inTo watEr, nitrIC
peroxIde, and oxyGeN; In otheRS he heatED NiTratEs. His conclusion
is: “_aTmOSpherical air_, or The thiNg WE bREAthE, _coNsists of thE
nItrouS Acid and EArTH_, WIth SO much phlogistOn as is necesSAry To
its eLaStiCIty; and LikewIsE So mUch more as is RequIred to briNg it
frOM its staTE of perfEct purIty To tHe meAN cOnDitIoN In wHIcH we FInd
It.”[7]

When suCh ExPerimEnts WERE Made By hEatiNg nitRates in a gun-baRreL,
“phlOGisTicatEd air” Was oBtAined. this waS nitrOgEn, for the iron had
ReduCed the oxiDes Of The LaTter, aND combiNinG wiTh their Oxygen, hAD
foRmED NItRogen; moreover, it had AbSORbEd to a greAter or LEsS eXTent
the oXyGen SimuLTAneouSly pROdUced.

HaviNg concLUdEd That resPiRable aIr Was A coMpounD Of niTrous aCid,
phlogIston, ANd earth, PriestlEY endeavoured tO AsCERtAIn whAt wAs the
nature Of thIS earTh. He COnCluDEs “thaT the _mEtALlIC earths_, if free
from phLoGiston, Are thE most proper, anD next to theM THE _calcareOus
eARtHS_.”

“DephlogisticaTed aiR may be procURed from aNy kinD of earth With which
THE spirit oF niTre WilL unITE.” A Few quantitatiVE ExpeRiMents woUld
Surely hAve RefUteD thIs Erroneous ConclusiOn. thOsE wHicH he atTEmpted
to MaKe wErE veRy cruDE. A bladDer (of WhicH hE dOEs nOt give tHE
cAPAcitY) wAs FillEd wItH

  PhloGistICatEd air, anD weighed 7 dWts. 15 GRs.
  NiTrOuS air          "     "    7   "   16  "
  ComMon air           "     "    7   "   17  "
  DephlogIsTicated air "     "    7   "   19  "

he ConCludes (TAKing into Consideration that inflamMAble air Is
vEry liGht) “tHat the lesS phLogistOn aNY kind oF air coNtainS, tHe
hEAVier iT IS; aNd tHe More phlogiSTOn iT contAiNs, thE
 oxygen to pass. He foundthat red-l ead w asnot  t he o nly“earth” whichp rodu ced this effect; but t hat “ fl o wers of  zinc ” (zinc ox i d e),  c ha lk,  s l ak ed li me,  and ot her substa nce salso gave ag as ,
when dis til led with nit ric  acid,  w hic h  was“be tter”  thanc ommonair.
In s om e  cases he brok e up  nit ric acid by heati nt o  water, nitric 
perox id e ,a n d o xyg en; in oth er s heh eated n i tr a t e s.H is conclusion 
is: “_Atmo s phe ricalai r_, or the  thin gw e b reathe, _co nsis ts of the 
nitro u s acida nd eart h_, wi thsomuch ph lo gis to n  as is  ne c ess ary to
i ts  e lasti city ; a n d li kew iseso mu ch more as is  re quir e d t o bri ng it 
fro mits s tate o f per fe ct purity to th e me an condit ion  i n w hi ch we find
i t.” [7] 

Whensuch ex p eri me n t s  w ere made by heatin gn i tr ates ina gun- b ar re l ,
“phlog is tic ated a ir” w as o b ta ined. Th is was ni tr ogen, f or  the i ro n h adreduc e d th e oxid es of th e lat t er, and combin i ng with their ox y g en ,  had 
fo rmed nitrog en;m oreo ver, it  ha d  abso rbedto ag reater or less exte nt 
the o xygen  simultaneous ly produce d . 
Havingconc l ud e d that respira ble a ir was a c o mpound o f nit rous aci d,
phlogi s t on, andear th,  Pr ies t l ey  endeavouredt o  asc er tain wh atwas the 
na tur e o f t hi s earth.He concl ud es  “ th atthe _ m etallicea rth s_ , i f fre e 
fromphlog isto n,  a r e t he most pr o p er,an dnext  to  t hem t he _ c alc areousearths_.” 

“ D ephl og is ticated  air may be p ro cured from  a nykind o f earth wi th which
the spirit ofn itre wi llunite .” A  few quan tit ativeexp e riment s woul d
sur el y h a v e ref u t ed  th is  erroneous c onc lusio n.  Tho se whic h he attempted
tom ake  were very cr ude . Ab l ad der (o f  wh ic h  he d oes not give th e
capacity )w as  filled wi t h
 Phlogis ticated  air, and wei ghed 7 dw ts. 15 gr s. 
  N i t rou s air         "    "    7   " 16   "
 Co mmon a ir          "   "     7    "  1 7  "
 Deph lo gisticat ed air "     "    7   "    19 "

H e c oncludes(ta k ing  into con side ration tha t i nfl ammab lea ir is 
ver y  l igh t ) “th at t h e less ph l og ist o n  a ny kind ofa i r  co ntain s,t he
hea vier  it is; and the m o re phlogistonit c o n tai ns, the
 oxygen_to pass._He found that red-lead_was not_the_only
“earth” which_produced_this effect; but_that “flowers of_zinc” (zinc
oxide), chalk, slaked_lime, and other_substances_also gave a gas,
when distilled with nitric acid, which was “better” than common air.
In_some_cases he_broke_up_nitric acid by heat into_water, nitric
peroxide, and oxygen; in_others he_heated nitrates. His conclusion
is: “_Atmospherical air_, or the_thing_we breathe, _consists_of the
nitrous acid and earth_, with so much phlogiston_as is necessary to
its elasticity; and_likewise so much_more_as_is required to bring_it
from its state of perfect purity_to the mean condition in which_we find
it.”[7]

When such experiments were made by_heating nitrates in a gun-barrel,
“phlogisticated air”_was obtained. This was nitrogen,_for the_iron had
reduced the oxides of_the latter, and_combining with_their oxygen, had
formed_nitrogen; moreover, it had absorbed to_a greater or_less extent
the oxygen simultaneously produced.

Having concluded_that_respirable air was_a_compound_of nitrous_acid,
phlogiston, and earth,_Priestley_endeavoured to_ascertain_what was the
nature of this earth._He_concludes “that the _metallic earths_, if free
from_phlogiston, are the most_proper,_and next to them_the _calcareous
earths_.”

“Dephlogisticated air may be_procured from any kind of earth_with which
the_spirit of_nitre will unite.” A few quantitative experiments would
surely have refuted this_erroneous conclusion. Those which he attempted
to_make were very crude._A bladder_(of_which he does_not_give the
capacity)_was filled with

  Phlogisticated air, and_weighed 7_dwts. 15 grs.
  Nitrous air_   __    " _   "  _ 7   "___16  "
  Common_air     _  _  "    _"_   7  _"_  17  "
 _Dephlogisticated_air_"    _"    7 _ "   19  "

He concludes (taking_into consideration that_inflammable air is
very light) “that_the_less_phlogiston any kind of air contains, the
heavier it is; and_the more_phlogiston it contains,_the