raction
occurred, and on removing the excess of oxygen, the diminution of
volume was found to amount to 15·4 per cent of the original volume
taken. Making the supposition that the gas of density 19 still
contained nitrogen, and allowing for its influencing the density, it
followed that the pure gas should be twenty times as heavy as hydrogen.

A tube such as is usually employed in examining the spectra of gases
at low pressures was next filled with the gas of density 19. Such a
tube, called a Pflücker’s tube, after its inventor, contains wires of
platinum sealed through at each end, where it is about half an inch
in width; the middle portion of the tube is about 3 inches long, and
its bore is a fine capillary. When the platinum wires are connected
with the secondary terminals of a Ruhmkorff’s coil, and the tube is
partially exhausted, a brilliant glow appears in the capillary portion.
If viewed through a glass prism, different gases show different sets
of  lines crossing the usual gradation of colours of the
spectrum. Thus hydrogen exhibits three striking lines, one bright red,
one peacock blue, and one violet; nitrogen shows a large number of
somewhat hazy bands, red, orange, yellow, and yellow-green in colour,
besides a number of bands of a violet colour; but the new gas, while
exhibiting the bands characteristic of nitrogen, showed in addition
certain groups of red and green lines which did not appear to belong to
the spectrum of any known gas.

[Illustration: FIG. 2.]

While these experiments were in progress, Lord Rayleigh was occupied in
preparing nitrogen from other sources, and in determining its density;
and in every case it was evident that nitrogen from all sources except
the atmosphere weighed somewhat less than atmospheric nitrogen.
He therefore proceeded to repeat Cavendish’s experiment, and like
Cavendish, he obtained a small residue of gas which would not disappear
on sparking with oxygen, in presence of caustic soda. The sparks, as
they passed, could be observed through a spectroscope (which consists
of an arrangement of prisms and lenses so designed as to examine the
components of the light emitted by the sparks), and he, too, was struck
with the unusual character of the spectrum. His experiments proved
raction 
 occurred, and on removing the excess of oxygen, the diminution of 
 bulk was discover to amount to 15·4 per cent of the original volume 
 take. Making the supposition that the natural gas of concentration 19 still 
 contained nitrogen, and allowing for its influencing the density, it 
 keep up that the pure flatulence should be twenty time as heavy as hydrogen. 

 A tube such as is usually employed in analyze the spectra of gases 
 at low imperativeness was next filled with the gas of density 19. Such a 
 tube, call a Pflücker ’s tube, after its inventor, contains wires of 
 platinum sealed through at each end, where it is about half an column inch 
 in width; the middle portion of the tube is about 3 inches long, and 
 its bore is a all right capillary. When the platinum wire are connected 
 with the secondary terminals of a Ruhmkorff ’s coil, and the tube is 
 partially exhausted, a brilliant glow appears in the capillary portion. 
 If see through a glass prism, different gasoline picture different sets 
 of   lines crossing the usual gradation of colours of the 
 spectrum. therefore hydrogen exhibits three striking lines, one bright red, 
 one peacock blue, and one violet; nitrogen shows a large number of 
 somewhat hazy bands, crimson, orange, yellow, and chicken - green in colour, 
 besides a number of bands of a violet semblance; but the new gas, while 
 exhibiting the band characteristic of nitrogen, showed in addition 
 certain groups of crimson and green production line which did not appear to belong to 
 the spectrum of any know gas. 

 [ exemplification: FIG. 2. ] 

 While these experiments were in advancement, Lord Rayleigh was occupied in 
 preparing nitrogen from early sources, and in determining its density; 
 and in every case it was evident that nitrogen from all reservoir except 
 the atmosphere weighed somewhat less than atmospheric nitrogen. 
 He therefore proceeded to repeat Cavendish ’s experiment, and like 
 Cavendish, he obtained a small remainder of gas which would not disappear 
 on trip with oxygen, in presence of caustic soda. The sparks, as 
 they passed, could be observed through a spectroscope (which consists 
 of an musical arrangement of prisms and lenses so designed as to examine the 
 components of the light utter by the spark), and he, too, was struck 
 with the unusual character of the spectrum. His experiments proved
rachion
occurred, and on remoying the excess of oxygxn, the siminutiun of
volume was found to amonnt ro 15·4 ptg cent of the originau volume
twken. Makung uhe supposition tizt the ncs of fensntb 19 still
containgd nitrogen, dnd allowing fmr ics influencing the density, it
followeq that yhf pure gas shoold bt trentg times as heavy as hydrogen.

A tube such av is usually rmployed in examining the dpechra of gases
at low pressures qas gwxt filled wkth the gas of density 19. Such a
tube, called a Pflücker’s gube, cfter its ibvwntlt, contains wmres os
platinum sealed thrmugh at each end, wherc it ms avout half an inch
in wmdth; the middle portyon of tha cube is about 3 inches ling, atd
itv bofw ir a fmne capilparb. When the llatinum wiees are connected
wiuh eye secondary ferminwlf of a Ruhmkorff’s coil, and the tube is
pdrtjally exhausted, a brilluant glow appears in jhe capillwry portion.
If viewed through a glass prism, differant gesds whjd dlfferent sets
of  lines crossing the usual graqztook of colours of bhe
spectrum. Thus hudgobgn exhibits thtee strniihg lines, one brighh red,
ong peacick blue, wnd pne violet; nitrogen shows a large numbeg of
womewhat hazy bandd, red, orangz, yellpw, anc yellow-green in colour,
yesidea a number lf bands kw a violet colouf; blt tve new gas, while
exhibiting the bandw chcracterirtic of nierogen, shoaed ik addition
certain ggoups ox red and hreen lines which did not appeac to belong tp
tve vpectrum of aky known gas.

[Illtstration: FIG. 2.]

Chile thzse exoeriments sere in progress, Ljrd Rayleigh fws occupied mn
preparigg nutroten froo other sources, and in dvttrmining irs density;
and in eyery zzse it was evidzut that nitrogen groo ajl spuwwes except
tha atoosonere deighed somcwhxt lrss than atmospheric nitdogen.
He therefore lrjceeded jo repeat Cavendish’s ecperiment, and like
Favenvish, hx obtaoneq a small residue of gas which would noh dlsappear
on spwrkikg wyth oxygen, in presence of caustic soda. The sparks, as
they passed, coold be observed throuyh a spectrosrope (wrich conshsts
of an arrangemenr of prisms and ltnses so designed as to examite thf
components of the light emitted by the sparks), and he, too, was struck
with rhe unnstal charactsr og the s'eccrum. Hif ex'eciments proved
raction occurred, and on removing the excess the of volume found to amount the volume taken. Making supposition that the of density 19 still contained nitrogen, allowing for its influencing the density, it followed that the pure gas should twenty times as heavy as hydrogen. A tube such as is usually employed examining spectra gases low pressures was next filled with the gas of density 19. Such a tube, called a tube, after its inventor, contains wires of platinum through at each end, it is about half an in the middle of tube about 3 inches and its bore is a fine capillary. When the platinum wires are connected with the secondary terminals a Ruhmkorff’s the tube partially a glow appears in portion. If viewed through a glass show different sets of lines crossing the usual of colours the spectrum. Thus hydrogen exhibits three lines, one bright red, one peacock blue, and violet; nitrogen shows a large number of somewhat hazy bands, red, orange, yellow, and yellow-green besides a number of of a violet but new while the bands of nitrogen, showed in addition certain groups of red and green which did not appear to belong to the spectrum of gas. FIG. 2.] While experiments were in progress, Rayleigh occupied in preparing nitrogen sources, in and every it was evident that from all sources except the weighed somewhat less than to repeat Cavendish’s experiment, and like Cavendish, he a small residue of gas which would disappear on sparking with oxygen, in presence of caustic soda. The sparks, they passed, observed through a spectroscope (which consists of an of prisms and lenses designed as to examine the components of the light by sparks), and too, was struck the unusual character the spectrum. His
raction
occurred, and on removIng the exceSs of oXygEn, tHe DimiNutiOn of
volume was fOUnd tO amount to 15·4 per cent of the oRiginAl VOlumE
TaKen. MaKing the SUpPOSitIoN tHat ThE GaS of deNsiTy 19 still
Contained nItrOgEn, and allowinG FoR its influeNciNg the density, It
fOlloweD tHat THe purE gaS shouLd be twENty timEs as heavy As HYdrogeN.

a tube suCH As Is usUally employed in exAMiNIng the spectra oF gases
At LOw PREssUreS was next fiLlEd witH The gas oF DeNSITy 19. SUCh a
tube, called A Pflücker’s tUBe, aFter itS iNveNTor, conTains WiREs oF
platinum seAled Through at Each enD, Where it IS about hAlf an iNch
In wIdth; THe MiDdlE pORtiON oF thE TubE is about 3 InChEs lonG, and
ITS BOre iS a fIne cApillAry. When the plaTinUm wiREs aRe conNecteD
witH tHe secOndary TermiNaLs of a Ruhmkorff’s Coil, And the tubE is
PaRtiAlLy exhAUsted, a BriLliAnt glow Appears IN thE cAPILlAry portion.
If viewed ThROUgH a glass pRism, diFFeReNT gases shOw DifFereNT Sets
oF  linES cRossing tHe usuaL GrAdAtion of CoLours oF tHe
sPecTrum. THUs hyDrogen Exhibits Three STriking lines, onE Bright red,
one pEAcOCK bLUe, anD onE violet; nitrOgen SHows A larGE nUmbER of
soMewhaT hAZy BAnds, red, orange, yellow, AnD yelloW-greeN in colour,
besiDes a number OF BAnds of a vIoleT CoLOur; but the new gaS, whilE
exhibitinG The bands CharaCteristiC of nitrogEN, Showed in AddItiOn
cErtAIN gRoups of red and GREen lInEs which Did Not appeAr tO beLonG to
ThE spectrum Of any knoWn GaS.

[ILlUstRatioN: fIG. 2.]

While ThEse ExPerImentS Were in ProgrEss, LOrD RAYleIgh was oCCuPIEd in
PrEpArinG niTrOgen fRom oTHer Sources, And in deteRmiNIng iTs DeNsity;
anD in every case iT wAs evident tHaT niTrogen FROm all souRces except
the atmosphere WEighed sOmeWhat lEss tHan atmospHerIc nitrOgeN.
he therEfore pRoceeDeD to REPeat CAVEnDisH’s Experiment, AND liKe
CavEnDish, He obtaiNed a small residue of GAs wHich would not dIsaPpeaR
ON sParKInG WitH oXYgeN, IN presence of causTic soda. The SpARkS, as
they pasSEd, cOuLd be obsErved thRough A SpectroScope (whicH consists
Of An arRANgeMent of prisMs and lenSes so desiGNed as TO eXaminE thE
compoNeNts Of the Light eMIttEd by tHe sparKs), And he, tOo, was StRuck
with The unusual character of thE spectRum. HiS exPeriments ProVEd
raction
occurred, and on r emoving th e exc ess  of  o xyge n, t he diminutiono f
vo lume was found to amou nt to  1 5 ·4 p e rcentof theo ri g i nal  v ol ume 
t a ke n. Ma kin g the s upposition  th at  the gas ofd en sity 19 st ill 
contained n itr ogen,an d a l lowin g f or it s infl u encing  the dens it y , it
f o llowedt h at  the  pure gas shouldb et wenty times as  heavy  a s  h y d rog en. 

A tube s uc h asi s usual l ye m p loy e d in examinin g the spect r a o f gase satl ow pre ssure sw asnext filled  wit h the gas  of de n sity 19 .  Such a 
tube,  ca lle d aP fl üc ker ’s tub e ,aft e r i ts inven to r,  cont ains w i r es o f
p lati num s ealed through  at  eac h  en d, wh ere i t is  a bouthalf a n inc hin width; the m iddl e portion  of  t hetu be is about3 i nch es long , and
i t s b or e i sa fine capillary.Wh e n  t he plati num wi r es  a r e connec te d
w itht h e sec onda r yterminal s of a Ru hm korff’s  c oil, a nd  th e t ube i s 
par tially  exhaust ed, a brilliant glow appears in th e  c a p il l arypor tion.
If vi ewed thro ugha  g las s  pris m, di ff e re n t gases show differ en t sets 
of lines crossin g the usua l g radation  ofc ol o urs of the
spe ctrum . Thus hyd r ogen exh ibits  three s triking l i n es, onebri ght  re d,o n epeacock blue, a nd o ne  violet ; n itrogen  sh ows  alar ge  number o f
somewh at  h az yban ds, r e d, orang e,  ye ll ow,  andy ellow- green  inco lo u r,besides an u mber  o fband s o fa vio letc olo ur; but  the newgas ,  whi le 
e xhibiti ng the bandsch aracterist ic  of  nitro g e n, showe d in addition
certain g r oups of  re d and  gre en lineswhi ch did  no t  appea r to b elong  t o
t h e  spec t r um  of  a ny known g a s .
[Illu st rati on: FIG . 2.]

While these exp eriments were  in  pro g r es s,L or d  Ra yl e igh w as occupied inpreparingni t ro gen from o t her  s ources,  and in  dete r miningits densi ty;
and i never y cas e it was e vident t hat nitro g en fr o mall s our ces ex ce ptthe a tmosph e reweigh ed som ew hat le ss th an  atmosph eric nitrogen.
He there fore p rocee ded  to repea t C a ven dish’s ex peri ment, andlik e
C avend ish ,  he o btai n ed  as mallresi d ue of gas wh ich w ou ld not disa p p e aron sp ark i ng wit h ox ygen, in presence of caustic sod a. T h e  sp ark s , as 
t hey passed, co uld  b e observed  t hrough a sp ectrosco pe (whic h cons ists
o f an ar r a ng e ment o f pr ism s and len ses  s o  design ed  a s  to ex amin ethe
co mponen t s of t he light emitted  by t h e  spar k s),  andhe , too,w as s truck
with  the unusua l char acte r ofthe spe ct rum. H isex perimentsp roved
raction
occurred, and_on removing_the excess of oxygen,_the diminution_of
volume_was found_to_amount to 15·4_per cent of_the original volume
taken. Making_the supposition that_the_gas of density 19 still
contained nitrogen, and allowing for its influencing the density, it
followed_that_the pure_gas_should_be twenty times as heavy_as hydrogen.

A tube such as_is usually_employed in examining the spectra of gases
at low_pressures_was next filled_with the gas of density 19. Such a
tube, called_a Pflücker’s tube, after its inventor,_contains wires of
platinum_sealed_through_at each end, where_it is about half an inch
in_width; the middle portion of the_tube is about 3 inches long, and
its_bore is a fine capillary. When_the platinum wires are connected
with_the secondary_terminals of a Ruhmkorff’s coil,_and the tube_is
partially exhausted,_a brilliant glow_appears in the capillary portion.
If viewed_through a glass_prism, different gases show different sets
of__lines crossing the_usual_gradation_of colours_of the
spectrum. Thus_hydrogen_exhibits three_striking_lines, one bright red,
one peacock blue,_and_one violet; nitrogen shows a large number_of
somewhat hazy bands, red,_orange,_yellow, and yellow-green in_colour,
besides a number of bands_of a violet colour; but the_new gas,_while
exhibiting the_bands characteristic of nitrogen, showed in addition
certain groups of red and_green lines which did not appear_to belong to
the spectrum_of any_known_gas.

[Illustration: FIG. 2.]

While_these_experiments were_in progress, Lord Rayleigh was occupied in
preparing_nitrogen from_other sources, and in determining its_density;
and in every case_it_was evident that nitrogen from all_sources except
the atmosphere weighed somewhat less_than atmospheric nitrogen.
He therefore proceeded_to_repeat_Cavendish’s experiment, and like
Cavendish, he_obtained a small residue of gas_which would not_disappear
on sparking with oxygen, in presence of_caustic_soda. The sparks, as
they passed, could_be_observed through a spectroscope (which consists
of_an_arrangement_of prisms and lenses so_designed as to examine the
components of_the light emitted by the sparks), and he, too,_was struck
with the_unusual character of the spectrum._His_experiments_proved