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6000366120 




M W 




xi 


I. 




• 


^md Nitrous 


Gas, 




10U9 Oxide. 







071 ihe comfofition 
r co7tthinatton$ ivltl) 

I 

i.j Acid • - 3 

G 

.i of Nitrous Acid - 11 

17 
; ition of Nitrous Gas with 

17 
23 
29 

the difference between 

30 
rent Nitrous Acids - 3(5 
\cid with Water - 38 

42 
i with thofc of Cavcndifh 

4!: 



RESEARCHES, 



CHEMICAL AND PHILOSOPHICAL J 



CHIEFLY CfONCERNING 



NITROUS OXIDE, 



OR 



DEPHLOGISTICATED NITROUS AIR, 



AND ITS 



RESPIRATION. 



By HUMPHRY DAVY, 

SUPERINTENDENT OF THE MEDICAL PNEUMATIC 

INSTITUTION. 



LONDON: 

:fRINTED FOR J. JOHNSON, ST. PAUL's CHURCH-YARD, 
BY BIGGS AND COTTLE, BRISTOL* 

1800. 



CONTENTS. 



Introduction, ----- ad. 

RESEARCH I. 

Into the analji/ii of NiTRio Acid and NiTROt's Gas, 
and the prodtu^hn ^Nitrous Oxidk. 

DIVISION I. 

£xPBRiMEttTS and OrserVations on the c^mfofitktn 
of Nitric Acid, cmd on" its combinations tvitb 
Water and Nitrous Gas. 

1. Preliminaries - - - - - 1 

2. Produdion of aeriform Nitrous Acid - - 3 

3. Specific gravity of Gafes - - . 5 

4. Experiment on the formation of Nitrous Acid - 11 

5. Conclufions - - - - - 17 

6. Experiments on the combination of Nitrous Gas with 

Nitric Acid - - - - 17 

7. Additional Experiments - - - 23^ 

8. Conclufions - - * - 29 

9. Mr. Thomson's Hieory of the d>fierence between 

Nitric and Nitrous Acid - - - 30 

10. Compofition of the different Nitrous Acids - 36 

11. Combination of Nitric Acid with Wat^r - 38 

12. Of Nitrous Vapor . . - - 43 

13. ComparKbn of the refults with thofe of Cayendiih 

add Lavoifier - - - - 49 



( iv. ) 

DIVISION H. 

Experiments and Observations on the compofitidn 
of Ammoniac and on its combinations with Water; 
and Nitric Acid. 

1 . Anglyiis of Ammoniac - - - 5(> 

2. Specific gravity of Ammoniac - - 62 

3. Of the quantities of true Ammoniac in AmmoniacaJ 

Solutions - r * - - 65 

4. Compofition of Nitrate of Ammoniac - 7i 

5. DecompofitionofCarbonateof Ammoniac, by Nitrous 

Acid - - ^ ^ - - 75 

5. DeCompofition of Sulphate of Ammoniac by Nitre /y 

6. Non-exiftence of Ammoniacal Nitrites - "^Q 

7. Sources of error in Analyfis - - 80 

8. Lois in Solutions of Nitrate of Ammoniac during 

evaporation * - / - . 83 

DlVISrON III. 

Decomposition* of Nitrate of Ammoniac — Prepara- 
ration of respirable Nitrous Oxide. 

1. Of the heat required for the decompofition of Nitrate 

of Ammoniac - - - - 84 

2. Decompofition of Nitrate of Ammoniac — Produ6tion 

of refpiraUe Nitious Oxide — its properties - 86 

3. Of the Gas remaining after the abforption of Nitrous 

Oxide by Water - - _ - gC) 

4. Specific Gravity of Nitrous Oxide - - Q4 

5. Analyfis of Nitrous Oxide - - - 95 

6. Minute examination of the decompofition of Nitrate 

of Ammoniac - - - - jqi 

7. Of the heat produced during the decompofition of 

Nitrate of Ammoniac ... lOS 



f V. ) 

^. Df compofition of Nitrate of Ammoniac at high tem- 
peratures - - - . - iqg 

g. Speculations on the decompofitions of Nitrate of 
Ammoniac - - - » ^ 113 

iO. Of the preparation of Nitrous Oxide for experiments 

on refpiration - - - - 117 

DIVISION IV. 

Experiments and Observations on tlic compofition of 

Nitrous Gas^ and on it# abforption by different bodies., 
3. Preliminaries - - - - 122 

2. Analylis of Nitrous Gas by Charcoal - 126 

3. Analyfis of Nitrous Gas by Pyrophorus - 132 

A, Additional obfervations on the compofitiou of Nitrous 

Gas ---,-- 134 

5. Abforption of Nitrous Gas by Water - 14P 

6. Abforption of Nitrous Qas by Waterof different kinds 14/ 

7. Abforption of Nitrous Gas by folution of pale green 

Sulphate of Iron - - - 15^ 

8. Abforption of Nitrous Gas by folution of green mu- 

riate of Iron - - - - 179 

9. By Solution of Nitrate of Iron - - I87 

10. By other metallic Solutions 

1 1 Aftion of fulphurated Hydrogene on folution of green 

fulpliate of iron impregnated with Nitrous Gas. IQl 
12. Additional Obfervations - - - 193 

DIVISION V. 

Experiments and Observations on the produfSlion of 
Nitrous Oxips from Nitrous Gas and Nitric 
Acid in different modes. 
J. Preliminaries - - - - I97 

IJ. Converiioh of Nitrous Gas into Nitrous Oxide by 
alkaliae fulphitei - - - - 199 



( vi. ) 

3. By MmiaHc ofRo - - - . ^ WH 

4. By Sulphurated Hydrpgene ... 203 
^. Decompo^on of Nitrous Gas by Nafcept Hydro- 

geae - - - - - - 206 

6. Mifcellanequs Obfcrvations - - - - 209 

7. Recapitulation - - - --211 

8. PrOdudion of Niti-ous Oxide from Metal% Solutions 213 

9. Additional Obfervatipns relating to thp produ6tion of 

Nitrous Oxide - - - - 21 9 

H) Decompofition of Aqu^ regia'by platina, and evolu- 
tion of a gas analogous to oxygenated muriatic acld^ 
andnitrogene - - - - 222 

11, Adion of the eledric fpark on a mixture of Nitro- 

gene and Nitrous gas ^ - . 229 

12. General remarks on theprodudion of Nitrous O^dde 23 X 

RESEARCH II. 

JntOi the comhinations 0/" Nitrous Oxide, and Its decern- ' 
• fofition, 

DIVISION I. 

ExPERiMEKTs and Observations cm the combinations 

of Nitrous Oxide^ 

1. Combinatiop of Water with Nitrous Oxide - 235 

2. __— . of Nitrous Oxide with fluid inflamma- 
ble bodies. - - - , - 240 

3. Adion of fluid Acids 00 Nitrous Qxide - 244 
A^ ■ of Saline' Solutions - - 245 

5. • of Gafes* - ^ • - 248 

6. Adion of aeriform Nitrous Oxide on the alkalies— 
Hifl:ory of the difcovery of the combinations pf 
Nitrous Oxide, with the alkalies ;<• 254 

7. Combination of Nitrous Oxide tvith Potaih - 262 



( vii. ) 

8. Combmation of Nitrous Oxide with Soda ^ 26B 
g. ■ ' ' — with Ammoxuac U6q 

10. Ptobability of forming compounds of Nitrous Oxide 

and the alkaline earths - - 273 

11 Additional Obfervations - - 2/4 

\2 The properties of Nitrous oxide refemblethofeof Add0276 

DIVISION II. 

J)ecompofition of Nitrous Oxide by combufliUe 

BocUes. 

1 Preliminaries - - - - 2/8 

2 Converfion of Nitrous Oxide into Nitrous Acid and 

a gas analogous to Atmo^heric Air by ignition 279 

3 Decompoiition of Nitrous Oxide by Hydrogene ^ 2S6 
4, m ' ■ ' ' byPhofphorus 293 

5 ■ ■ by Phc^phorated Hydrogene 300 

6 by Sulphur - 303 

7 ■ ' ' by Sulphurated Hydrogene 306 

8 — - by Charcoal - 311 

Q by Hydrocarbonate - 313 

10 Combuition of Iron in Nitrous Oxide - 3l6 

11 of Pyrophorus - - 318 

12 of the Taper ♦ - 319 

13 of different Compound Bodies - }21 

14 General Concluiions relating to the decompoiition 

of Nitrous Oxide, an^ to its analyfis - 322 

li Obfervations on the combinations of Oxygene and , 
Nitrogcne - - - - 325 

RESEARCH III. 

Belatingto the RianRATioN 0/ Nitrous Oxide dnd 
• OTHEE Gases. . 



- ( -viai. ) 



DIVISION I. 

ExPEEiMENTS and OfiSERVATxoNs OQ the effeds pro'* 
duced upon Animals by the refpiration of Nitrous 
.• .Oxide. 

.1 Prelirainaiies - - - - ^ 333 

2 On the refpiration of Nitroi^s Oxide by warm-blooded 
Animals - - - - - 336 

3. Effe6ts of the refpiration of .Nitpus Oxide upon 

Animals, as compared ^th thofe produced by their 
immerlion in Ilydrogene and Water - 343 

4. Of the changes effected in the prganifation of warm^ 

blooded Animals, by Jtl^e refpiration of Nitrous. 
Oxide . -. - - - 347 

5. Of the refpiration of mixtures of Nitrous Oxide and 

other Gafes, by warm-blooded Animals - 358 

6. Recapitulation of fa6ks relating to the refpiration of 

Nitrous Oxide, by warm-blooded Animals - 360 

7. Of the refpiration of Nitrous Oxide, by amphibious , 

Animals - - - - 36:? 

8. EfFeds of Solution of Nitrous Oxide on Fifhes - 366 

9. EfFe*^ of Nitrous Oxide on Infeds - - 3/0 

^ DIVISION II. 

Oi the changes efFefted in Nitrous Oxide and other 
Gafes, by the Refpiration of Animals. 

1. Preliminaries - - - - 373 

X Abfurption of Nitrous Oxide by Venous Blood 374 

3. Of the changes effeded in Nitrous Oxide by Refpi- 

ration .... 388 

4. Refpiration of Hydrogene - - 400 

5. Additional Obfervations and Experiments on t}ie 

Refpiration of JMitrous Oxide - - 411 



.( ix. ) 

43. Of the Refpiratioft of Atmofphcric Air - '420 

■7. Rel'piration of Oxygene - - - 439 

8. Obfervations on the changes efFe«5ted In the blood by 

Atmofpheric Air and Oxygene - - 446 

g. Obfervations on the Refpiration of Nitrous Oxije 440 

RESEARCH IV. 

Belai'tng to the Effects produced by /i&tf Respiration of 
Nitrous Oxide upon different Individuals. 

DIVISION I. 

History of the Difcovery. — Effects produced by the 

Refpiration of different Gases. 

1. Rcfpirability of Nitrous Oxide - - 456 

2. Efteas of Nitrous Oxide - - - 453 

3. General Elleas of Nitrous Oxide on the Health 464 

4. Refpiration of Hydrogene - - - '466 

5. ofNitrogene - - - 457 

6. EfFeas of Hydrocarbonate - - 46S 

7. — of Carbonic Acid - - 47I 

8. — of Oxygene - - _ 473 

9. — of Nitrous Gas - - - 475 

10. Mofl exteniive aaion of Nitrous Oxide produces 

no debility - - - - 495 

DIVISION II. 

Details of tlie Effeas produced by the Refpiration of • 
Nitrous Oxide uuon diftx^rent Individual?, fumifhed 
by Thcmfelvcs. 

1 DetailofMr. J. W. Tobln - - 497 

2 — of Mr. \V. Clayfield - - 602 

3 Letter from Dr. Kinglake - - 50a 

4 Detail of Mr. Southey - . . 507 



* 



3 Letter from Dr. Roget ... qqq 

6 Letter from Mr. James Thom(oB - - 512 

7 Detail of Mr. Coleridge - - - 5l6 

8 — of Mr. Wedgwood - « . 518 

9 — of Mr. G. Burnet - . . 520 

10 — of Mr. T. Pople - - -521 

11 — ofMr. Hammick - . , 522 

12 — of Dr. Blake - - . '• • 524 

13 — ofMr. Wanfey - - - 525 

14 — of Mr. Rickman - - - 526 

15 — of Mr. Lovdl Edgworth - - 527 

16 — of Mr. G. Bedford - - - 52fi 

17 — ofMilsRyland - - - 530 

18 Letter from Mr. M. M. Coates - - 530 

DIVISION III. 

Abftra6b fiom additional Details — Obfervations on the efFe6ts 
of Nitrous Oxidp, by Dr. Beddoes — Conclulion. 

1 Abf^adb firom additional details - - 533 

2 Of the efFeds of Nitrous Oxide on delicate females 537 
3' Obfervations on the efFedts of Nitrous Oxide by Dr. 

Beddoes, - ... - 54X 

4 Conclufion - - - - • 548 

APPENDIX. 

No. I. Of the eiFe6ts of Nitrous Oxide on Vegetables 56l 
No. 11. Table of the Weight and Corapofition of the 

combinations of Nitrogene . - . ^QQ 

No. III. Additional Obfervations - - - qQ'^ 

No. IV. Dcfcription of a Mercurial Airholder, and 

Breathing Machino, by Mr. W. ClaYfield. 
No. V. Propofals for the Prefervation of Accidental 

Obfervations in Mc<licine. By Dr. Beddoes. 



•v. 



n 






INTRODUCTION. 



TSS 



JLN confequence of the difcovery of the ref- 
pirability and extraordinary efFcils of nitrous 
oxide, or the dephlogifticated nitrous gas of 
Dr. Prieflley, made in April 1799, ^^ ^ manner 
to be particularly defcribed hereafter, * I was 
induced to carry on the following inveftigalion 
concerning its compofition, properties, combi- 
nations, and mode of operation on living beings. 

In thecourfe of this inveftigation, I have met 
with many difficulties ; fome arifing from the 
novel and obfcure nature of the fubjedl, and 



^ A fhort account of this difcoveiy has been given in Di; 
3eddoes's Notice of fome Obfervations made at the Pneu- 
matic Inftitution, and in Mr. Niciiolftn's Phil. Journal for 
'jAzy aod December 1739. 



( 2i"- ) 

others from a want of coincidence in the obfer- 
vations of different experimentalifts on the 
properties ajid mode of produ^iion of the gas. 
By extending roy refearches to the different 
fubflances connected with nitrous oxide; nitrous 
acid, nitrous gas and ammoniac ; and by mul- 
tiplying the comparifons of fadts, I have fuc- 
ceeded in removing the greater number of 
thofe difficulties, and have been enabled to give 
a tolerably clear hiftory of the combinations of 
' oxygene and nitrogene. 

By employing both analyfis and fynthefis 
whenever thefe methods were equally applica- 
ble, and comparing expcrin>ents made under 
different circumftances, I have endeavoured to 
. guard againft fources of error; but I cannot 
flatter myfelf. that I have altogether avoided 
them. The phyfical fciences are almoft 
wholly dependant on the minute obfervation 
and comparifon of properties of things not im- 
mediately obvious to the fenfes ; and from the 
difficulty of difcovering every poffible mode of 
examination, and from the modification of per- 



( xiii. ) 

ceptions by the flale of feeling, it appears nearly* 
impoffible that all the relations of a feries of 
phaenomena can be difcovered by a fingleinvefti- 
gation, particularly when thefe relations are 
complicated, an^ many of the agents unknown. 
Fortunately for the a<£iive and progreffive. na- 
ture of the human mind, even experimental 
refearch is only a method of approximation to 
truth. 

In the arrangement of fa6ls, I have been 
guided as much as poflible by obvious and 
fimple analogies only. Hence I have feldom 
entered into theoretical difcuffi^ns, particularly 
concerning lights heat, and other agents, which 
are known only by ifolated cfFedls. 

Early experience has taught me the folly 
of hafty gcneralifation. We are ignorant of the^ 
laws of corpufcular motion ; and an immenfe 
mafs of minute obfervattons concerning themorc 
eomplicated chemical changes muft be collelfted, 
probably^ before wq fhali be able to afcertain 
even whether we are capable of difcovcringthem. 
Chemiftry in its prefent ftate, is (imply a partial 



( xiir. ) 

liiftory of phaBnomena, confifting of many 
feries more 6r lefs extenfive of accurately con-^ 
nefled fa&s. 

With the moft important of thefe ferieSj thtf 
arrangement of the combinations of oxygene of 
the anfiphlogiftic theory difcovered by Lavoi- 
fier, the chemical details in this work arc 
capable of bcirig connefled. 

In the prefent ftate of fcience, it will be 
unnecefiary to enter into difcuflions concern- 
ing the importance of invefligations relating 
to the properties of phyfiological agents, and 
the changes cfFi|(fled in them during their ope- 
ration. By means of fuch invefligations, we 
arrive nearer towards that point from which we 
(hall be able to view what is within the reafch 
of difcovery, and what muft for ever remain 
unknown to us, in the pha^nomena of organic 
life. They are of immediate utility, by enabling 
us to extend our analogies fo as to inveftigate 
the properties erf untried fubftances, with greater 
accuracy and probability of fuccefs. 



■\ 



( xir. ) 

The firO: Refearch in this work chiefly relates 
to the produdlion of nitrous oxide and the aaa^ 
lyila ofnitraus gaa and nitrous acid. In thi9 
there is little that can be properly called mine ;. 
and if by repeating the experinients of othejf 
chemiiis, I have (bmelimes been able to tnake 
more minute obfervations concerning phaeno- 
mena, and to draw different conclulioDS, it is 
wholly owing to the ufe I have made of the 
iodruments of inveftigation difcovered by the 
illufirious fathers of chemical philoibphy,* and 
fo fuccefsfally applied by them to the difcovery 
of truth. 

In the fecond Refearch the combinations and 
compofitioQ of nitrous oxide are inveftigated, 
and an account given of its decompofition by 
rooft of the combuftible bodies. 

The third Refearch contains obfervations on 
t^ adlioh of nitrous oxide upon animals^ and 



* Cavendiih, Prieftley, Black, Lavoi^r, Scb«cle, Kir- 
irran, Gayton> JBertbollet^ &c« 



. ( xvi. ) 

an invefiigation of the changes efFe<^ed in it 
by refpiration, 

' In the fourth Refearch .the hiftory of the 
refpirability and extraordinary effects of nitrous 
oxide is given, with details of Qicperiments 
on itf powers made by different individuals. 

I cannot clofe this introduction, without 
acknowledging my obligations to Dr. Beddoes. 
In the conception of many of the following 
experiments, I have been aided by his conver- 
iation and advice. They were executed in an 
Inflitution which owes its e^iftedce to his 
benevolent and philofophic exertions. 

Thwry-Square, Hotwe/Is, BriftoL 
June2^h, 1800. 



■M. ' 

4* 



RESEARCH I. 

CONCERNING THE ANALYSIS 

OP 

NITRIC ACID AND NITROUS GAS. 

AND 
THE PRODUCTION OF 

NITROUS OXIDE. 



^sissstEBbsssBBmmEBmasaaeitBtssmm 



RESEARCH I. 

INTO THE PRODUCTION AND ANALYSIS 



OF 



NITROUS OXIDE, 

AND . ^ . 

THE AERIFORM FLUIDS RELATED TO IT* 



DIVISION L 

EXPERIMENTS and OBSERVATIONS on the com* 
fosiiion 0/ NITRIC ACilD, and on its combinatigm 
with Water ahd NitROus Gas. 



HP + 
L X HOuGH fince the commenccmeiit 

of Pneumatic Chemiilry, no fubftance has bef^n 
more the fubjedt iDf experiment than Nitrous 
Acid ; yet Aill the greateft uncertainty exifU 
with regard to the quantities of the principles 
entering into its compolition* 

In comparing the experiments of the illus- 
trious Cavendifh on the fynthefis of ^ nitrous 
zcid, with thofe of Lavoifier on the decdmpo- 
pofition of nitre by charcoal^ we find a much 
greater difference in the refults than can be 



( 2 ) 

laccdunted for by fuppofing the acid formed^ 
and that dccompofed, of different degrees of 
Oxygenation. 

In the moil.aeeiirate^fperinient of Cavendifh^ 
when the nitrous acid appeared to be in a ilate 
of deoxygenation, 1 of nitrogene combined with 

4 

about 2,346 of oxygcne.* In an earlier experi- 
ment, when the acid was probably fully 
oxygenated, the nitrogene employed was to 
the oxygene nearly as 1 to 2,92."f' 

Lavoiiier, from his experiments on the de- 
compolition of nitre, and combination of ni- 
trous ^as end tixygene, ^^nclBdes, that tha 
peifeif^ly^xygehMted, or Whalt he dalis ^liitrtc 
aetd, is compofed of inearly l tiitPogMe, with 
8i9t)f oxygene; and the acid ra the laft flate 
cf ^eoxygenatioH, ornititHss ^d, ofa^ut-8 
oxygcne with 1 irftrogette.;J: 



* PhU. Ttanf. ▼• 7«,.p. 270. t Phil- Tw«f- ▼• ?^> J?- 3tW- 

tiHem. Jl^tTfs Tranf. page 76, and 216, andHicm. a«f 
'flat. StnBig«« torn, t^, yage 629. 



( 3 ) 

Great as the diiFerence is between the e&U 
mations of tbefe pbilofopbers, we find difier*- 
ences ftiU greater.io the accouotsof tbe quaDtities 
of nitrous gas Decef&ry to (at urate, a given quan-- 
tity of osygeae, as laid down by very accurato 
^perimentalifts. On the one band^ Prieilley 
found } of oxygene condenfed by 2 of jiitroua 
gaa, ai»d Lavoifier l^ 1 ^. On itbe other^ 
Ingenbouz, Schevei-^ and De U, Metberici^ 
fiate the quantity neceilary to be iirom 3 to &«* 
Httmbolty who b^ lately iovefligated Eudn 
ocnetfy wi& great ingen^ity^ eoniidera theineaa 
qAumtity of nitrous g/^ neceflary to ikturate ) 
o£ ea;;ygene9 aft about- 2^5.^ 

II. To reconcile tbefe difierent refulta U 
kBpQ0ibl«| apd the immediate ooaoei^n of 
tbe fubje£): with tbe produ£lioa <^ lutrous 
oxide, as well as its general importance, dbliged 
m6 to fearcb for means of accurately deter-* 



^Itigenbooarrar les Vegetaox, pttg. 905w De l» Metboriis. 
Sflai fat diSex€Di Airs^ pag. 252. 

t Jbmalcs de Ckimie, tooib 2&y p< l$B, 



( 4 ) 

tnining^ the ib6ibp6{ition of nitrous acid in itd 
different degrees of oxygenation. 

The firft defideratum was to afcertain the 
nature and compofition of a fluid acid^ which 
by being deprived of, or combined with nitrous 
gas, might become a ftandard of comparifon 
ibr all other acids. ' 

' To obtain this ac^dl fhould have preferred 
the immediate combination of oxygene and 
hitrogene over water by *he cledric fpark, had 
it been pofiible to obtain in this way by a com- 
mon apparatus fuffiGient for extenfive examina- 
tion; but oh carefully perufing the laborious 
experiments of Cavendifb, I gave up all thoughts 
of Attempting it. 

' My firft experiments were made on the 
decompofition of nitre, fortned from a known 
quantity of pale nitrous acid of known fpecific 
gravity, by phofphorus, tin» and charcoal : but 
in thofe procefles, unafcertainable quantities of 
nitrous acid, with excefs of nitrous gas, always 
efcaped undecompounded^ and from the non- 
coincidence of refults^ where different quanti- 



( 5 ) 

ties of combuJfiibte fubftances were fftDfl6ftd, 
I had reafons for believing that water was 
generally decompofed. 
Before thefe experiments were attempted/I had 
analiz^ nitrous gas and nitrous oxide, in a man- 
ner to be particularly defcribed hereafter ; ib 
that a knowledge of the quantities of nitrous 
gas and oxygene entering into the compofition 
of any acid, enabled roe to determine the pro* 
portions of nitrogene and oxygene it contained.' 
In confequence of which I attempted to coiU- 
bine together oxygene and nitrous gas. In fuch: 
a manner as to abforb the nitrous acid fottned 
by wiater, in an apparatus by which the quanti- 
ties of the gafes employed, and the increafe of 
weight of the water, might be afcertatned ; but 
this process likewife failed. It was impoflible 
tQ procure the gafes perfedlly free from nitrp- 
gdne, and during their combination, this nitro- 
gene made t6 pafs into a pneumatic apparatus 
communicating with a veflel containing the 
water carried over with It, much nitrous acid 
vapor, of different compofition from the acid 
abforbed. 



( 6 ) 

A^er xnany unfuccdsful trials^ Dr. priefiley'f 
exf^Twa^Qts OIL aitrouB yapor * Hi4iK^ me 
to fuppofe that oxygene and oitraus ga^9 tirade 
iD oombioc out of the conta6i of bodies having 
affioity for oxygene^ would reoMiin perma^ 
gently aeriform^ and on tbrowiog them fepa- 
rately into an exbaufted glafs balloon^ I found 
ti)at tbis was a^iially the cafe ; increafe pf teob- 
pef«tare was produced* and orfinge colwed 
nitrqua acid gas ibrmed, which aftt^ re* 
inaining for many days in the globe, at a tem* 
perature below ^6% did not in the (ligbtcft 
degree condense. 

This fa<5l afforded me the means not only o( 
fcHrming a flandard acid, but likcwife of a(cer- 
taiqing the fpc^ific gravity of nitrous acid in 

r 

its ai^riform fiate. 

IIL Previous to the experiment, for the pur^ 

9 

pofe of correcting incidental errors, I was in- 
duced to afcertain the fpecific gravity of the 



* Experiments and Obfervation^, Vol. iii. hft edition^ 
]Mige 106, &c* 



(?) 

g9^6Si employee^ particularly 9s I, waa unto-* 
qUfinted with . any . prooef^ by wjiifih th? 
weight of nitrous g4a hnd. b^ accurateljf 
determined. Mr. Kkwan^s ^m*Uc«i, which 
i$ ge;perally ddoptod, beung fouoidfid , upon th(? 
wipparifon of tt^e loGj of weight of a fol^tioa 

of copper in dilute nitrous acid| with the ^WX^ 
tity of gas. produced,* - 

The iaftrurnent9 that I made vife qf for eon- 
taming and meafuring my gafe«, were two mer* 
curial airholders graduated to the cubic inch of 
£verardj 3pd furnished with flop cocks.^ 



* When copper is diflblved in dilute nitrous acid, certain 
qoantities of sitrogcHM tre genertiUy prodiicad^ Ukevifttho 

pitKQu^ gas carrlef off in (o\vtfi(m fome Aitroai 9cid« 

f This airhokier^ eoolidered as a pncutsatk InilruHieBl^ 
U Qf greati^r impooiftance^ and capable of a v^QVC e^^teofive 
application than any other. It was invented by Mr. W. 
CLATFitLD, and in its form is analogous to Mr. Watv^ 
bydrauUc bdlows, coofifting of a glaft beU fWvug under 
the prefTure of the atmofphere, in a fpace between two cy- 
linders filled with mercury. A particular account of it will 
be given in the appendix. 



\ 



( d ) 

They were weighed in a glafs globe, of the 
capacity of 108 cubic inbhes^ which with the 
fmall glafs ftop-cock affixed to it, was equal, 
when £Iled with atmofpheric air, to 1755 
grains. The bafance that I employed, when 
loaded with a pound, turned with lefs than one 
eighth of a grain. 

t Into a mercurial airholder, of the capacity 
of 200 cubic inches, l6o cubic inches, of ni* 
trous gas were thrown from a (blution of mer« 
cury in nitrous acid. 

70 meafures of this were agitated for fbme 
minutes in a folution of fulphate of iron,* till 
the diminution was complete. The nitrogene 
remaining hardly filled a meafure; and if we 
fuppofe with Humbolt ^ that a very fmall por- 
tion of it was abforbed with the nitrous gas, the 
whole quantity it contained may be eftimated 
at 0,0X42, or ^^. 

75 cubic inches received from the airholder 

* This abforption will be hereafter particularly treated of. 
t Annalea de Chimie. Tome xviii. page 139. 



( <J ) 

]f)ta m exbaufted balloon^ incteafed hin weight 
25,5 grains ; thermometer being: 5j6^, ahdr 
barometer 3a,9. And allowing for ; the. imall 
quantity . of nitrogene in the gas^ 100 cubio 
inches of it will weigh 34.3 grain& 

One hundred and thirty cubig inches oi 
oxygene were procured from oxide of man|;an«^. 
efe and fulphuric acid, ^by heat, and received in 
another mercurial airholder.. 

10 meafures of it, mingled, with 26 of the 
nitrous gas, gave, after the refiduum was £x- 
pofed to fblution^ of fulphate of iron, ' rather 
more than one meafure.* Hence we ^ may con- 
elude that it contained about 0, 1 nitrogene. 

6o cubic inches of it weighed. 20, 7 5 grains ; 
and accounting for the nitrogene contained in 
thefe, 100 grains of pure oxygene will weigh 
35,09 grain§. 

Atmofpherical air was decompofed by nitrpus 
gas in excefs; and the refiduum waihed with 
folution of fulphate of iron till the Kitrogene 
remained pure ; 8/ cubic inches of it weighed 
26,5 grains, thermometer being 48% barometer 
30,1 ; 100 will confequently weigh 30,45. 



( w ) 

' ffit cubic inobw of the atf of: tbe labomtoiy 
ikot^ deprived of its carbocrici acid, weighed' 
1J3^75 grains ; (beimbaeter 53, barometer 30 i 
100 cubic inches will confeqaontly weigh 3 IsQ.^ 
l6 meafures of this mt, with ]& nitrous gas^^ 
6f known compofition, diminiihed to IQ. 
Hence it contained abbut fi& oxygene.^ 

In comparing my refulis with thpfe of Lavoifier 
and Kirwan, the eftimation of the weights of ni^ 
trc^ene And oxygene is very little different, the 
corredions for temperature and preflure being 
made, from that of thofe celebrated philo(bphers« 
The firft makes oxygene to weigh ^ 34,^1, and 
nitrog^n^ 30>o64 per cent ; and the laft, oacy-* 
gene 34, X ^"^ nitrogene 30,5. ' 



* A table of the fpedfic gravities of thefe gafes^ and 
other gafes^ hereafter to be mentioned^ reduced to a 
barometrical and thermometrical fiandard^ will be given 
Itt the appendix. 

( 40 meafares, expofed to foiution of potafh^ gave aa 
abforption of not quite a quarter of a meafure : hence it 
contained an inconltderable quantity of carbonic add. 

f Traite £lementaire. 
X Eflai fur le phlogifiique^ page 30. 



< 11 ) 

The fpecific ^vitj of nitrous gas, according 
to Kirwan> is to that of common air as 1 194 to 
1000* Hence it (boold weigh about 37 grains per 
cent. This difference from my eflimation is not 
nearly fo great as I expe<9ed to have found it.^ 

IV,* The thermometer in the laboratory 
flanding at 55^ and the barometer at 30^ 1^ I now 
proceeded to my experiment. The oxygene that 
I employed was of the fame compofition as that 
which I had previoofly weighed. The nitrous 
gas contained ^166 nitrogene. 

For the purpofe of combining the gafes^ a 
glaft ballooa was procured, of the capacity of 
148 cubic inches, with a glafs ftop-cock 
adapted to it^ having its upper orifice tubulated 
and graduated for the purpofe of containing 
and o^eafuring a fluid. The whole weight of 
this globe and its appendages, when filled with 
common air, was 2o60,5 grains. 

§ The dimioutioo of the fpecific gravity of the gas ftom 
the quantity of nitrogene evolved in his experiment, proba- 
bly deftroyed, in feme meafure, the fource of error from 
t}i€ nitrous acid carried ovcJm 

« 

* Experiment I. 



( 14 ) 

It was partially exhaufted by the aiir-pump, 
and loft in weight juft 32 grains. From whencd 
we may conclude that about 1 5 grains of air 
remained in it. 

In this ftate of exhauftion it was immediately 
cemented to the ftop-cock of the mercurial 

t i 

airbolder^ and the communication being made 
with great caution^ 82 cubic inches of nitrous 
gas ruQied into the globe, on the outfide of 
which a flight increafe of temperature was per- 
ceived^ while the gafcs on the inlide appeared 
of a deep orange. 

Before the common temperature was reftored, 
the communication was flopped^ and the globe 
removed. The increafe of weight was 29,25 
grains; whence it appeared that 1,14 grains of 
common air, part of which had been contained 
in the flop-cocks, had entered with the nitrous gas. 

Whilft it was cooling, from the accidental 
loofening of the ftopper of the cock, 3 grains 
more of common air entered.* 

* That no greater coDtra6tion took place depended on 
die folution of the nitrous acid formed in the nitrous gas 3 
a phenomenon to be explained hereafter. 



(13 ) 

The communication was now made between 
the globe and the mercurial airholder con- 
tainrhg oxygene. 64 cubic inches were flowly 
prefled in, when the outlide of the globe 
became warmer, and the color on the infide 
changed to a very dark orange. As it 
cooled, 6 cubic inches more flowly entered ; 
but no new increafe of temperature, or change 
of color took place. 

The globe being now completely cold, was 
flopped, removed, and weighed ; it bad gained 
24,5 grains, from whence it appears that 0,4 
grains of common air contained in the flop- 
cocks, had entered with the oxygene.* 

To abforb the nitrous acid gas, 4 1 grains of 
water were introduced by the tube of the flop- 
cock, which though clofed as rapidly as poffi- 
ble, muft have fufFered nearly ,5 grains of air to 



* t judged it expedient alwajs to afcertain the quantity 
of air in the ilop-cocks by weight, as it was impoffible to 
join them fo as to have always an equal capacity. The 
upper tabes of the two flop-cocks not joined, contained 
xieariy an inch and half. 



( 14 ) 

enter at the fame time, as the increafe of weight 
was 41)5 grains* The dark orange of 
the globe diipiniibed rapidly ; it became warm 
at the bottom, and moid on the fides. After a 
iew minutes the color bad almoft wholly difap* 
peared. 

To afcertain the quantity of aeriform fluid 
abforbed^ the globe was again attached to the 
mercurial air apparatus, containing 140 cubic 
inches of common air. When the *a)mmuni- 
cation was made, 5 1 cubic inches rufbed in> 
and it gained in weight l€,5 grains* 

A quantity of fluid equal to 54 grains was 
*iiow taken put of the globe. On examination 

* 

it proved to be flightly tinged with green, and 
occupied a fpace equal to that filled by 41,5 
grains of water. Its fpecific gravity was con-* 
fequeatly 1,301. 

To afcertain if any unabforbed aeriform ni- 
trous acid remained in the globe, 13 grains of 
iblution of ammonia were introduced in the 
fame manner as the water, and after fome mi- 
nutes, when the white vapor tiad condenfcd. 



( 15 ) 

the cbmoMinicaticm was ^gaifi made with the 
inerjcuriafl ^irbolxldr coataiQing common ^^ir. 
A minute quantity entered, which could ^ot 
be efthnated at daore than three fourths of an 
incbj and the globe waa increafed in weight 
about 13^35 :grain6.* 

Common air waa now tbrowu into the ^obe 
till the refidual gafoa of the eijperiment werje 
judged to be difpJaced; it weighed 2106,5 
grsuna, that n, 40 grains more than, it had 
weighed when 611c4 wjylh cooaiaon air befone 
"the .experiiaent.i)* 

r 

«irhat if^ hy tfaeiohitioD of amniomi asd 9ir« 

•f The fbllowing is tn aecouat of the incwafe and ificpi- 
oution of weight of the globe^ as it wa3 noted in the jour- 
nal. 

Glohe filled with common air - gr. 2€66,5 
After exhaniHon - - - 2034,5 

After introdudton of nitrous gas, 82 

cubic inches - - 20^;2il 

Ajfter the.accidental adnnffion of com- 
mon air - - - 20<l7,25 
Alter the adiaiffioo of pKygese * ^tOQl^JS 

•-— . 41 grains of water 2133,25 

■ — — • 51 cubic inches of air 2l4§tfS 
Taken out 54 grains of folution - 2095,7s 
Iptroduoed 13 grains of ammoniacal 

folution -. - - . 2109,25 

Aiffeer iB&odQiftioo of-eommim ik ^ %10S,^ 



(16.) 

And if iffbm thofe 40 grakis we tiikc 1 3 for 
tbe folutibn of ammonia inffoddced^ ihe re-^ 
mainder^ 27, will be the quantity of folution 
of nitrous acid in water remaining in the globc)^ 
'which added to 54, equals 81. grains, the whole 
quantity formed ; but if from this be taken 41 
grains, the ' quantity of water, the remainder 
40 grains, Will be the qi^antity of nitrous acid 
^^ abfdrbed in the folution. 

To find the abfolute quantity of nitrous acid 
ibrmed, we touft find the fpecific gravity of 
that abforbed ; but as during, and after its 
abforption, 17 graihsof air, equal to 53,i cubic 
inches entered, it evidently filled fuch a 
ipace. 53,2 cubic inches of it confe- 
quently weigh 40 grains, and 100 cubic 
inches 75,17. grains. THien ,75 cubic inches 
weigh ,56 grains, and this added to 40, makes 
40,56 grains, equal to 53,95 cubic inches, the 
whole quantity of aeriform nitrous acid pro- 
duced. 

But the quantity of nitrous gas entering into 
this^ allowing for the .nitrogene it contained^ is 



( 17 ) 

27,6 grains, equal to about 80,5 cubic inbhes j 
and the oxygene is 40,56 — 27,6 = to 12,96 
grains, or 36,9 cubic inches. 

V. There could exift in this experiment 
no circumftance connedled with inaccu- 
racy, except the impoffibility of very liiU 
nutely determining the quantities of com- 
mon air which entered with the gafes from 
the ftop-cocks. But if errors have arifen from 
this fource, they muft be very inconfiderable ; 
as will appear from a calculation of the fpecific 
gravity of the nitrous acid gas, founded on 
the volume of the gafes that entered the 
globe. 
The air that remained in the globe 

after exhauftion was 15 grains = 47*cub. in. 
The nitrous gas introduced was 82 
Common air - - - 13 

Oxygene - - - - 70 
Common air • - - 1 



* Decimals ar&jomitted, becaufe the excefs of the two 
firft numbers is exa6tly corre^ed by the deficiency of th« 
laft. 



( IS ) 

Whole quantity of air thrown into 

the globe 213^ 

From which fubtrafl its capacity 148 

The remainder is 65 

And this remainder taken from 80,5 nitron* 
gas -}- 36,9 oxygene, leaves 52,4 cubic inches, 
which is the fpaoe occupied by the nitrous acid 
gas, and which differs from 53,95 only by 1,55 
cubic inches. 

I ought to have obferved, that before this 
conclufive experiment, two iimilar ones had 
been made. In comparing the refults of one 
of them, performed with the affiftance of my 
friend, Mr. Joseph Pkiestley, Dr. Priest- 
ley's eldeft fon, and chiefly detailed by him 
in the journal, I find a coincidence greater than 
could be evett well expedled, where the pro- 
cefles are fp complex. According to that 
experiment, 41,5 grains of nitrous acid gas 
fill a fpace equal to 53 cubic inches, and 
are compofed of nearly 2Q nitrous gas, and 
12,5 oxygene. 






( 10-) 

We may then conclude, Firft, that 100 
cubic inches of nitrous acid^ fuch as exifts in 
the '^ aeriform ftate faturated with oxygene, at 
temperature 55% and atmofpheric prcflure 30,1 
weigh 75,17 grains. 

Secondly, that 100 grains of it are compofcd 
of 68,06 nitrous gas, and 31,94 oxygene. Or 
afluming what will be hereafter proved, that 
100 parts of nitrous gafe confift of 5^95 oxy- 
gene, and 44,05 nitrogene, of 29,9 nitrogene, 
and 70,1 oxygene; or taking away decimals, 
of 30 of the one to 70 of the other. 

Thirdly, that 100 grains of pale grceij 
folution of nitrous acid in water, of fpecific 
gravity 1,301, is compofed of 50,62 water, 
and 49,38 acid of the above compofition. 

VI. Having thus afcertained the compofition 
of a ftandard acid, my next obje<St was to ob- 
tain it in a more condenfed ftate, as it was 
otherwife impoflible to faturate it to its full 



^ As is evident from the fuperabundaot quantity of 
•xygene thrown into the giobe* 



f ■ 



( 20 ) 

extent with nitrous gas. But this I could efFe<S¥ 
in no other way tlian by comparing mixtures 
of known quantities of water, and acids of dif- 
ferent fpecific gravities and colors, with the 
acid of 1,301. 

For the purpofe of combining my acids with 
water, I made ufe of a cylinder about 8 inches 
long, and ,3 inches in diameter, accurately 
graduated to grain meafurfes, and furniflied with 
a very tight ftoppcr. 

The concentrated acid was iirft flowly poured 
into it, and the water gradually added till the 
required fpecific gravity was produced;* the 
cylinder being clofed and agitated after each 
addition, fo as to produce combination without 
any liberation of elaftic fluid. 

After making a number of experiments nvith 



* The weight of the acid poured into the cylinder being 
known, its fpecific gravity was known from the fpace it 
occupied in the phial. The weight of water being likcwifc 
known, the fpecific gravity of the folution, when the com- 
mon temperature was produced^ was given by the con- 
denfation. 



( 21 ) 

acids of difFerent -colors in this advantageous 
way, I at length found that QO grains of a deep 
yellow acid, of Ipecific gravity 1,5, became, 
when mingled at 40° with 77,5 grains of water, 
of fpecific gravity 1,302, and of a light greed 
tinge, as nearly as poffible reiembling that of 
the flandard acid. 

Suppofing, then, that thefe acids contaia 
nearly the fame relative proportions of oxygcne 
and nitrogepe, 100 grains of the deep yellow 
acid of 1,5, are compofed of .91^9 grains true 
nitrous acid,'f' and .8,1 grains of water. 

To afcertaln the difference between the com- 
pofition of this acid, and that of the pale, or nitric 
acid, of the fame fpecific gravity, I infcrted 150 . 
grains of it into a fmall cylindrical mattrafs of the 
capacity of ,5 cubic inches, accurately graduated 
to^grain meafures, and conne<5led by a curved 



f That is, fuch as It exifts in the aeriform ftate at 55o. 
From the ilrong affinity of nitrous acid for water, we may 
fuppofe that this acid gas contains a larger proportion of it 
than the other gafes. 



( 22 ) 

tube with the water apparatus. After heat had 
been applied to the bottom of the. mattrais for 
a few minutes^ the color of the fluid gradually 
-changed to a deep red, whilft the globules of gas 
formed at the bottom of the acid, were al mod 
wholly abforbed in paifing through it. In a 
fhort time deep red vapour began to fill the 
tube, and being condenfed by the water in the 
apparatus^ was converted into a bright green 
fluid, at the fame time that minute globules of 
gas were given out. As the heat applied be- 
came more intenfe, a very fingular pheenomenon 
prefentcd itfelf ; the condenfed vapor, increafcd 
iti quantity, at length filled the curvature of the 
tube, and when expelled, formed itfelf into 
dark, green fpberules, which funk to the bottom 
of the water, refted for a moment, and then 
relblved themfelvcs into nitrous gas.* 

When the acid was become completely pale, 
it was fufFered to cool, and weighed. It had 
lofl near 1 5 grains, and was of fpecific gravity 



^ This appearance will be explained hereafter. 



(23 ) 

1,491* ^ cubic inches and <|uarter of nitrou« 
gas only were colle6itd. 

From this experiment evidently no conclu- 
sions could be dravvn, as the nitrous gas bad 
carried over ^ith it much nitfou8'acid*(in the 
form of what Dr. Prieftley calls nitrous vapor) 
and was partially diflblved with it id the water.-j^ 

To afcertain, then, the difference betweea 
the pale and yellow acids, I was obliged to 
make ufe of fynthefis, compared with analyfid, 
earned on in a driierent mode^ by means of thp 
following apparatus. 

VIL To theftop*coct of the upper cylinder of 
the mercurial airholder, a capillary tube was 
adapted, bent ib as to be capable of introdudlion 
into an orifice in the ftopper of agradiaated phial 
fimilar to that employed for mingling acids 
with water, and fufficiently long to reach the 
bottom. With another orifice in the fiopper 
of the phial was conne61ed a fimilar tube cur- 



t This phaeAomenon will be particularly explained 
iiereafter. 



( 24 ) 

ved, for the purpofe of containing a fluid, and 
of increafed diameter at the extremity.* 

50 cubic inches of pure nitrous gas ^ were 
thrown into the merdurial apparatus. The 
graduated phial, containing QO grains of 
nitric acid, of fpecific gravity 1,5, was 
placed on the top of the airholding cylinder, 
and made to communicate with it by means of 
the ftop-cock and firft tube. Into the fecond 
tube a fmall quantity of folution of potafh was 
placed. When all the junctures were carefully 
cemented, by prefling on the air-tbolder, the ni- 
trous gas was flowly pafled into the phial, and 
abforbed by the nitrous acid it contained ; whilft 
the fmall quantities of nitrogene evolved, flowly 
drove forward the folution in the curved tube ^ 
from the height of which, as compared with that 
of the mercury in the conducting tube, the 
prcfllire on the air in the cylinder was known. 

* The putllne only of this apparatus is given here, as far 
as was neceflary to make the experiment intelligible ; a 
detailed account of it, and of its general application, will 
be given in the appendix. 

f That is, from nitrous acid and mercury. 



( 25 ) 

In proportion as the nitrous gas was abforbed, 
the phial became warm, and the acid changed 
color; it firft became ftraw-colored, then 
pale yellow, and when about 7^ cubic inche? 
had been combined with it, bright yellow. It 
had gained in weight nearly 3 grains, and was 
become of fpecific gravity 1 ,496. 

This experiment afforded me an approxima- 
tion to the real difference between nitric and 
yellow nitrous acid ; and learning from it that 
nitric acid was diminifhed in fpecific gravity 
by combination with nitrous gas, I procured a 
pale acid of fpecific gravity 1,504.* After this 
acid had been combined in the fame manner 
as before, with about 8 cubic inches of nitrous 
gas,^ it becanie nearly of fpecific gravity 1,5, 
and had gained in weight about 3 grains. 

* A pale acid of 1.52, by being converted into yellow 
"Veld, became nearly of fpecific gravity 15,1. 

§ It is impoffible to afcertain the quantity of gas abforbed 
to more than a quarter of a cubic inch, as the firft portions 
of nitrous gas thrown into the graduated cylincl^r are com- 
bined with the oxygene of the common air in it, to form 
nitrous acid^ and hence the flight excefs of weigUt. 



' ( 26 ) 

'' Aflbming the accuracy of this experiment as 
a foundation for calculation, I endea^^oured in 
the fame manner* to afcertain the differences in 
the compofition of the orange-cdored acids, 
and the acids Containing ftill larger proportions 
of nitrous gas. 

93 grains of the bright yellow acid of 1,5 
became, when 6 cubic inches of gas had been 
paflcd through it, orange colored and fuming, 
whilft the undiflblved gas increafed in quantity 
fo much as to render it impoffible to confine it 
by the folution of potafh. When g cubic 
inches had pafled through^ it became dart ' 
orange. It had gained in weight 2,75 grains, 
and was become of fpecific gravity 1,48 nearly. 
JHence it was evident that much nitrous gas had 
pafled through it undiflblved. 25 cubic inches 
more of nitrous gas were nowflowly fent through 
it : it firfl: became of a light olive, then of a . 
dark oHvc, then of a muddy green, then of a 
bright green, and laftly of a blue green. After 
its aflTumption of this color, the gas appeared to 
pafs through it unaltered, and large globulus 



( 27 ) 

of fluid) of a darker green than the reft, 
remained at the bottom of the cylinder, and 
when agitated, did not combine with it. The 
increale of weight was only 1 grain, and the 
acid wa8 of fpecific gravity 1,474 nearly. 

In this experiment it was evident that the 
unabforbed nitrous gas had carried over with it 
a coofiderable quantity of nitrous acid. I en- 
. deavoured to correal the errors refulting from 
tbis circumftancc, by connefling the curved 
tube firft with a fmall water apparatus, and 
aiflerwards with a mercurial apparatus ; but 
when the water apparatus was ufed, the greater 
part of the unabforbed gas was diflblved with 
the nitrous acid it held in folution, by the water; 
and when mercury was employed, the nitrous 
aqid that came over was decompofed, and the 
quantity of nitrous gas evolved, in cOnfequence 
increafed. 

As it was poffible that a fmall deficiency of 
weight might arife from the red vapor given 
oat during the procefles of weighing and 
exaniining the acid in the laft experiment, 



< ^« ) 

35 cubic inches of nitrous gas were very 
flowly palled through 90 grains of pale nitrous 
acid, of fpecific gravity 1,5 : it became of fimi- 
lar appearance tothat juft defcribed, had gained 
in weight 6,75 grains, and was beconae of fpe- 
cific gravity 1,4/5. 

Thefe experiments did not afford approxima* 
tions fufBcientJy accurate towards the compofi- 
tion of deoxygenated acids, containing more 
nitrous gas than the dark orange colored. To 
obtain them, a folution confifling of 94,25 
grains of blue green, ox perfectly nitrated acid, 
(if we may be allowed to employ the, term), of 
specific gravity 1,475, was infertcd into a 
graduated phial, and connedled by a curved 
tube, with the mercurial airholder ; in the 
condu»flor of which a fmall quantity of 
water was infertcd to abfbrb the nitrous acid 
which might be carried over by the gas. Heat 
was flowly applied to the phial, and nitrous 
gas given out with great rapidity; When 4 
cubic inches were colledled, the acid became 
dark olive, when .9 dark red, when 13 bright 



( 2g ) 

orange, and when 18 pale. It had loft 3 r 
grains, and when completely cool, was of fpeci- 
fic gravity 1,502' nearly. The water in the 
apparatus was tinged of a light blue ; from 
whence wc may conclude that fome of the 
nifrous gas was abforbed by it with the nitrous 
acid : but it will be hereafter proved that the 
orange colored acid is the moft nitrated 
acid capable of combining undecompounded 
with water, and that the color it commu- 
nicates to a large quantity of water, is light 
blue. If then we take 6,1 grains, the quantity 
of gas collef!led, from 3 1 the lofs, the remainder 
is 24,9, which reafoning from the fynthetical ex- 
periment, may be fappofed to contain nearly 
3 cubic inches of nitrouu gas. Confequently, 
94,25 grains of dark green acid, of fpecific 
gravitj 1,475, are compofed of nearly 21 cubic 
inches, or 7,2 grains of nitrous gas, and 87,05' 
grains of pale nitrous acid, of 1,504. 

VIII. Comparing the different fynthetical and 
analytical eixperiments, we may conclude with 
tolerable accuracy, that 92,75 grains of bright 



( 30 ) 

yellow^ or ftandard acid of 1,5, are compofed 
of 2,75 grains of nitrous gas, and QO grains of 
nitric acid of 1,504; but 92,75 grains of ftandard 
acid contain 85,23 grains of nitrous acid^ com- 
pofed of about 27,23 of oxygene, and 58, 
nitrous gas : now from 58, take 2,75, and the 
remainder 55,25, is the quantity of nitrous gas 
contained in QO grains of nitric acid of 
1,504 ; confequently, 100 grains of it are 
compofed of 8,45 water, and 91,55 true acid^ 
containing 61,32 nitrous gas, and 30,23 oxy- 
gene ; or 27,01 nitrogene, and 64,54 oxy gene : 
and the nitrogene in nitric acid, is to the oxy- 
gene as l to 2,389. 

IX. My ingenious friend, Mr. James 
Thomson, has communicated to me fome 
obfervations relating to the compofition of 
nitrous acid (that is, the orange-colored acid), 
from which he draws a conclufion which is, in 
my opinion, countenanced by all the fads we 
are in pofleffion of, namely, " that it ought 
*' not to be confidered as a diftindl and left 



i 3r y 

^* oxygerrated flafte of acid, butMS'tripIy lis nifritf 
^ or pale acid, hbldrng iti f61ut?on, that isf, 
^* looffely combined with, nrtVdus g^fe."* 
7t is impoffibleto csfll any fitbflance a fitnpl^acS'd! 
that IS incapable of entering undecompouHded 
into combination with the alkalies, fee ; bdt it 
will appear hereafter that the falts called in the 

* In a letter to tne, dated 06t. 28, 1799, ^^ter giving an 
account of fome experiments on the phlogidication of 
nitric acid by heat and light, he fays, '* It was from an 
*' attentive examination of the manner in which the nitric 
" acid was phlogiiHcated in thefe experittte^ts, that I was 
'^ confirmed in the fufpidon I had long before entertdned, 
'' of the real difference between the nitrous and nitric adds. 
*' It is not enough to (hew that in the mtrotis acid, (that is, 
the nitric holding nitrous gas in folution), the propottioii 
of oxygene in the whole compound is lefs than^faat enter- 
ing into the compofition of the nitric acid, and that it is 
therefore lefs oxygenated. By the fame mode of reafonlng 
we might prove that ^ater, by abfbrbing carbonic atid 
'* gas, became lefs oxygenated, which is abfurd. Shouli 
any one attempt to prove {which will be ridceflary to fub- 
'* dantiate the generally received do^rine) that the oxygene 
of the nitrous gas cotnbines with the oxygene of the acid, 
" and thcnitrogene, ifllike manner, fo that the reful ting acid, 
*' when nitrous gas is abforbed by nitric add, is a binary 
'' combination of oxygene and cfilrogene, he "would fiadit 
^ foniewhat more difikitlt than he at fifit itbagiued : it ap- 
<* pears to me impoffible. It is ttidt^hihot^ coiifoaaot with 



€€ 
t( 

et 

€t 

ec 
<t 

€< 



( 32 ) 

Dew nomenclature nitrites, cannot be dire<91y 
formed. If^ indeed^ it could be ' proved, 
that the beat produced by the combina- 
tion of nitrous acid with falifiable bafes^ was 
the only caufe of the partial decompofition of 
it^ and that when this procefs was efFefted in 
fuch a way as to prevent increafe of temperature, 
no nitrous gas was liberated, the common 






experiment to fuppofe that nitrous acid is nothing more 
than nitric acid holding nitrous gas in folution^ which 
might in conformity to the principles of the French 
'^ nomenclature, becalled nitrate of nitrogene. ThedifHculty, 
*^ and in fome cafes the impoflihility, of forming nitrites, 
'^ arifes from the weak affinity which nitrous gas has for 
*' nitric acid, compared with that of other fubftances ; and 
** the decompofition of nitrous acid) that is, nitrate of 
** nilrogene) by an alkaline or metallic fubflance, is perfedly 
" analogous to the decompofition of any other nitrate, the 
** nitrous gas beiog difplaced by the fuperior afifinity of the 
'' alkali for the acid. 

Agreeable to this theory, the falts denominated 
mtriiei are in fad triple falts, or ternary combioations of 
nitric acid, nitrous gas, and falifiable bafes.** 

ThiB theory is perfedly new to me. Other Ghemifis 
to whom I brave mentioned it, have likewife confidered it 
as new. Yet in a fubfequent letter Mr. Thomfon mentions 
that he had been told of the belief of a fimilar opinion 
among the French Cbemifii. 



u 



( 33 ) 

theory might have iboae foundation ; but though 
dilute phlogifticated nitrous acid conibines 
* with alkaline folutions without deconopofition, 
yet no excefs of nitrous gas is found in the 
folid fait : it is either difengaged in proportion 
as the water is evaporated, or it abforbs oxy- 
gene from the atmofphere, and becomes nitric 
acid. 

In proportion as the nitrous acids con« 
tain more nitrous gas, fo in proportion do they 
more readily give it out. From , the blue 
green dcid it is liberated flowly at the tempera* 
ture of 50^ and from the green likewile on 
agitation. The orange-coloured apd yellow, 
acids do not require a heat above %QO^ to free 
them of their nitrous gas ; and all the 

-* In fome experitnc!hts made on the nitrites of potafh^ 
and of ammoniac^ before I Was well acquainted with 
the. oompofition of nitric acid, I found tiiat a; light olive- 
colored acid of 1 ,28, was capable of being faturated by 
weak folutions *of potafh and ammoniac^ without lofing 
any nitrous gas \ but after the evaporation of the neutralifed 
folution,. at very Ic^. ten^raturesy the faltsin all tbdr 
properties refecnbled nitrates. 



oilcrfirf Mdk; wfcerf exptrfedf io the ^tmblphere, 
afcf6t%f ^xyg^nei infd become by degrees pferfe; 

« 

If fhei rifttoti^ vapotefr, i. e. fcrcb as? is 
cfifeingageci Airing the dehitf-afion of tfce 
cbidrkd ticids, Was capable 6f combining with 
the alkalies, it mJght be fupipoled a diftiri<*lf 
icid, dtid called nitrods aictd ; arid the acidi 
of different colors might be confidered finiply 
ad comf^oundd of this acid with nitric acid ; 
but it appears to be nothing more than a folu* 
tiotl of nitric acid in nitrous gas, incapable of 
co^detifation, undecbnfipoanded, and when 
deconifpdunded and condehfed, conftitCiting 
the dark green ^t\A, which 1^ immifcible with 
Water^-f khd uncoflibinable with the alkalies.:|: 

it feems therefore reafonable, till we are in 
pofleilion of new lights on the fubje<ft, to con- 
fider^ with Mr. Thomfon, the deoxygenated or 
nitrous acids iimply as folutious of nitrous gas 



t As is eiddent from the curious appearance of the dark 
gfeen fpheroles^ repulfive both to wd'ter, and light greed 
add. 

:|: That is, undecompounded. 



( 35 ) 

in nitric acid, and as analogous to the (blutions 
of nitrous gas in the fulphuric and marine 
acids, &c. apd the falts called nitrites, ternary 
combinations, fimilar to the triple compounds 
compofed of fulphuric acid, metallic oxides^ 
and nitrous gas.* 

• Suppofing the truth of thefe principles ac* 
corditig to the logic of the French nomencla- 
ture, there is no acid to which the term nitrous 
acid ought to be applied ; but as it has been 
ufed to iignify the acids holding in folution 
nitrous gas, it is perhaps better ftill to apply it 
to thofe fubftances, than to invent for them 
niew names. A nomenclature, accurately ex- 
prcffing their conftituent parts, would be too 
cohiplet, and like all other nomenclatures 
fonnded upon theory, liable to perpetual alter-? 
ations« Their compolition is known from their 
fpecifio gravity and their colors ; hence it is 
better to denote it by thofe phyfical proper- 
ties: thus orange nitrous acid, of fpccific 
gravity 1,480, will fignify a folution of nitrous 

* The cxiftencc of thefe b«dies will be hereafter proved. 



( 36 ) 

gas in nitric acid, in which the nitric acid is to 
the nitrous gas, nearly as 87 to 5, and to the 
water as 1 1 to 1. 

X. The eftimation of the compoHtion of thcr 
yellow and orange colored nitrous acids given 
in the following table, may be confidered ar 
tolerably accurate, being deduced from the 
iynthetical experiments in the (ixth {tfkiotif 
compared with the analytical ones. But as in 
the fynthetical experiment, when the acid be-i^ : 
came green, it was impoiiible to ascertain the 
quantity of nitrous gas that pailed through it . 
unabibrbed, and as in the analyfis the quantity 
of nitrous gas diflblved by the Vat er at different 
periods of the experiment could not be afcer-, 
tained, the accounts of the compofition of the 
green acids mnft be confidered only as very 
imperfedl approximations to truth. 



( 37 ) 



TABLE I. 

Containing Approximations to the quantities of NITRIC 
ACID, NITROUS GAS, and WATER in NITROUS 
AC IDS f of different colors and specific gravities. 



100 Parts 



861. Nitric Acid 
'YdlowNitrouft 
Bright Yellow 
Dark Orailge 
Light Olive % 
Dark Olive % 

Bright Green t 
Blue Green* 



of 



Specific gra. 



1,504 

l^50S 

1,480 

1,479 
i;4f8 

1,475 



NitricAcid 


Water 


91,55 


8,45 


90,5 


®>3 


8«,04 


8,10 


86,84 


Ifi 


80,00 


7,55 


85,4 


^,* 


84,8 


7,44 


84,6 


7,4 



Nitrous gas. 



* The blue green acid is not komogeneal in its compofition, it is 
compofed of the blue green fpherules and the bright green acid. 
the blue green fpherules are of greater Specific gravity than the dark 
sn acid, probably becaufe they contain little ox no water. 



X The compoAtion of the acids thus marked, is given from cal- 
^ulatipns. 



( 38 ) 



• TABLE II. 

Bhiary PrpportioKS of OXYGENE and NITBOQMNE 
in NITRIC and NITROUS ACIDS* 



100 Facts. 



Nitric Acid 
Brightj^UowNitrous 
Orange coloured 
Da]^ Green 



gene 



Nitro- 
gene 



70^0 
70,10 
^,63 
69,0s 



29,50 
29,90 

3iQt>3i7 
30,9^ 



5 



«> 

e 

2 



Nitio- 
gene 



'6 



F 

G 
O 



1 
1 
1 

o 

1^ . 



gene 



2,389 
2^344 
2,29^ 
2,2301 




XL I have before mentioned that dilute nitric' 
acids are incapable of diflblving fo niuph nitrous 
gas in proportion to their quantities of true 
Bcid, as concentrated ones. During their 
abforption of it, they go through fimilaf changes 
of color; 330 grains of nitric acid, of fpecific 
gravity 1,36, after 50 cubic inches ofgaa^bad 
been pafied through it, became blue green, an*H 



^ Nitrous gas contains 44,05 Nitrogcne, and 55,95 
Ox)rg^e, as bas been faid before. 



( 39 ) 

of fpecific gravity 1,351. It had gained in 
weight but 3 grains ; and when the nitrous 'gas 
was driven from it by heat into a water appa- 
ratus, but 7 cubic inches were colledled.* 

From the diminution of fpecific gravity of 
nitric acid by combination with nitrous gas, 
and from the fmaller attraction of nitric 
acid for nitrbus gas, in proportion as it is 
diluted, it is probable that the nitrated acids, in 
their combinations with water, do not contradl 
fo much as ^ nitric acids of the fame fpecific 
gravities. The affinities refulting froirt the 
fmall attra<9ion of nitrpa$ gas for water, and 
its gi^er attraflion for nitric acid, mufl be 
f\i6h as to lefleh thie affinity of nftric acid and 
Vkter for each othSf. 

Hence it would require an infinite number 
of experiments to afcertain the real quantities of 

acid, nitrous gas, and water, contained in the 

... 

* 4- great portion of it, of courfe, diffolved in the water 
with the nitrous acid carried over. 

t Their changes of volume^ correfponding to changes 
of temperature^ mofl probably^ are Hkewife difierent. 



( 40 ) 

different diluted nitrous acids ; and after thefe 
quantities were determined^ they would proba* 
bly have no important conne<3ion with the 
chemical arrangement. As yet, our inftru-- 
ments of experiment are not fufficiently exadi 
to afford us the means of afcertainiDg the 
ratio in which the attradlioa of nitric acid* 
for water diminifhes in its progrefs toward^ 
Saturation. 

The eftimations in the following table^ of the 
real (][uantities of nitric acid in iolutions of dif- 
ferent fpeciiic gravities^ were deduced frpm 
experiments m^de in the manner defgribed in 
fedlion VI, except that th^ phial employed was 
longer^ narrower, and graduated to half grains. 
The temperature^ at the time of combination, 
was from 4(y to 46°, 



* Probably in the ratio of the fqaare of the quantity o( 
wfiter united to it. 



r 



( 41 ) 



TABL?: III. 



<■...!!■ : 



Of the Quantities qf J!rut NITRIC ACID in soititian 
,. ofdiferent SPECIFIC GRAVITIES. 



• » 



:'< I-;:/-,: 



100 Parts Nitncl 
Acid of fpecfic 
gravity 



I 



1,5040 
1,4475 
1,4285 
1,390a 
1,3551 
1,3186 
1,3042 
1,2831 
1,2090 



True Acid* 






.9 



Water 



\ . ' 



9l>55 


8,45 


80,39 


19>fil 


71.65 


i28,35 


63,96 


2(7,04 


56,88 ' 


43,12 


52,03 • 


47,97 


49,04 


50,96 


46,03 


53,97 


45,27 


54,73 






; . 



* The quantities of Oxjrgene and Nitrogejie in any folu- 

tion, may be thus fbund — Let A = the true acid, 

K the bxygcne, and Y the nitrogene, 

Then 238 A A 

X = and y = 

33^ l^Q 



» 



^ 



( 42 ) 

XII. The blue green fpberules mentioned in 
fedlion V. produced by the condenfation of 
attroQs va^r, add by the combination of mfric 
acid witl) nitrous gas, may be confidered as 
faturated folutions of nitrous gas in nitric acid. 
The combinations of nitric acid and nibrous 
gas containing a larger ptoportion of nitrous 
gas, are incapable of exifting in the fluid flate 
at common temperatures ; and^ as appears 
from the firft experiment, an increafe of voltime 
take place during their formation. They cdnfe- 
quently ought to be looked upon as (blutions ' 
of nitric acid iii nitrous gais, identical with the 
nitrous vapor of Prieftley. 

From the refearches of thife great difcovcrer, 
we learn that nitrous vapor is decompolable, both 
by water and mercury^ Hence it is almoft im- 

poffible accurately to afcertain its compofition, 

• ... 

In one of his experiments,^; when more than 
1 30 grains of ftrong nitrous acid were expofed 



:( Experiments and Obfervations } lad edition^ vol. 1, 
page 384. 



( *8 ) 

fqji: tyio days to a^vly 247 ciibic incbes of 
lutrpqs g^k^i Qver water: about balf of tfa^ 

acid wa^ dUlpliifC^ .^^ depofited with the g^s 
in, the water,^ 

XIll, I() ^mpaHH^g the rafults of my fun* 
daGOjental experiaient on the qompoiitioi:i:. of 
nitrous acidy^ witbtthofeof CavendiOi^ the great 
coiqcideqce between them gave roe very high 
ii^is(a<Slionv as affording additional proofs of 
accuracy* If the acid formed in the lali expe. 
riment of this ill^iiricKis pbilofopb^r be fuppofed 
analogous to the light green ac^id formed in mjr 
firfi; experimenifj; qw e(limatiQi)$ will be atmoft 
identical* 

Lavoifier's acpoi^nit of the compofition of the 
^itric and nitrous acids^' has been generalljf^ 
adopted. According to his eitimation, thcie 
fubflaQceiS: contain a much larger quantity of 
o:^ygene than J have aifigaed to them. 

§ Nitrous gas> holding in folution nitrous acid, is more 
readily abforbed by water than when in its pure form, 
from being prefented to it in a more condenfed ilate in the 
green acid^ formcfl by the contaS of water and nitrous 
vapor. 



( 44 ) 

The fundamental experiments of tliis great pbt-» 
loifbpher were made at an earljr^ period of phetx-^ 
maitic chemiflry,* on thte deoitopdfition of nitre 
by charcoal ; and he coniidered the mtrogene 
evolved^ and tbe^oscygehe. d( the earbonic acid 
produced in this procefs^ as the component 
patrts of the nitric acid contairied in the nitre.' - 

I h^ve before ttientidtied the liberation of 
nitrous acid^ in the decbmipofitibn of nitre by 
combuilible bodies ; and I had reafons for Cnf^ 
pe6ting that thisi circomfiance was not the only 
foqrce of inaccuracy. 

That my fafpicions were well founded^ will 
appear from the following experiments : 

EXPERIMJENT a. I introduced into a 
ftrong glafs tube, 3 inches long, and nearly ^3 
wide, a mixture of 10 grains of pulverifed, 
welt burnt charcoal, and 6o grains of nitre. It 
was fired by means of touch-paper, and the 
tube inftantly plunged under a jar filled with 



* Mem, des Savani Etrangers^ v. xi. 220. Vide Kirw3ii 
fur le phlogiftique pag. 110. 



( 45 ) 

I 

tify mfcfctlry. A quantity of gits, clouded with 
denfe white vapor was colledled* When thi^ 
vApor was precipitated, fb that the furface of 
the mercury could be feen^ it appeared white, 
as if aAed on by nitrous acid. On introducing*^ 
a little oxygene into the jar, copious red fumes 
appeared. 

EXP. b. A fimilar mixture was fired* 
under the jar, the top of the mercury being 
covered with a fmall quantity of red cabbage 
juice, rendered 'green by an alkali. This juice, 
examined when the vapor was precipitated, was 
become red, and on introducing to it a little 
carbonate of potaih, a flight efFervefcence took 
place. 

EXP. c. Five grains of charcoal, and 20 
of nitre, were now fired in the fame manner as 
before, the mercury being covered with a ftratum 
ofwat^r. After the precipitation of the vapor 



» In this experiment, as well as in the laft, fome of the 
tnixture was thrown into the jar undccompounded. 



( 46 ) 

CKOt the intreduiSion of oxygene, no red fumes 
were perceived. 

EXP. d. 30 grains of nitre^ 5 of charcoat, 
and five of (ilicipus earth,* were now mingled 
and fired. The ga? rece:ived under mercury 
was ^om poled of 18 carbonic acid, and nearly 
12 nitrogene.-f* A little muriatic acid was 
poured on the refiduum in the tube; a flight 
efiervefcence took place. 

EXP. e. The top of the mercury in the jar 
was now covered with a little diluted muriatic 
acid, and a fmall glafs tube filled with a mixture 
of 3 grains of charcoal, and 20 nitre. After 
the deflagration, the tube itfelf with the refi- 
duum it contained, were thrown into the jan 
The carbonic acid was quickly detached from 
them by the muriatic acid, and the whole quan- 



* To detach the potaih from the carbonic add. 

f This nitrogene contained a little nitrous gas^ as it gare 
red fumes when expofed to the air. The free nitrous acid 
was decompofed by the mercury^ as it was not covered 
with water. 



(47 ). 

tity of gas generated in the procefs, obtained ;- 
it meafured 15 cubic inches. 

4 cubic inches of it expofed to folution of. 
potafti, diminifhed to i y^; 7 of the remainder,, 
with 8 of oxygene, gave only 12* 

EXP, /. 6o grains of nitre, and g of char-, 
coal were fired, the top of the mercury in the 
jar being covered with water. After the defta- 
gration, the tube that had contained them wast 
intr^uced, and the carbonic acid contained by, r 
the carbonate of potafti, difengaged by muriatic^ 
acid, 30 meafures. of the g^fes evolved were 
expofed to cauftic potafti; 20 exadly werCr. 
abforbfed, the 10 remaining, with. 10 of oxy* 
gene, diminiftied to 17.. 

EXP. g. A niixturc of nitre and charcoal .■ 
.were deflagrated over a little water in th^e noer- 
curialjar: after the precipitation of the vapor, 
the water was abforbed by filtrating paper. 
This filtrating paper, heated in a folution o( 
potafti, gave a faint fmell of ammoniac, 

EXP. ,i&. Water impregnated with the 
vapor produced in the deflagration, was, heated 



( 48 ) 

tvith quicklime, and prefeiited feparately td 
V pcrrjr^s accuffomed to chemical odor». 
Two of them inftantly recognifcd the ammo- 
niacal fmell, the other could not afcertain it. 
Paper reddened with cabbage juice was quickly 
turned green by the vapor. 

Thefeexj- ..imcntsarcfufficienttofhewthatthe 
decompofition of nitre by charcoal i&a very com- 
plex procefs, and that the intenfc degree o( heat 
produced may efFeift changes in the fubflances 
employed, which wq are unable to efiimatc. 

The products, inftead of being fimply car- 
bonic acid, and nitrogene^ are carbonic acid, 
nitrogene, nitrous acid, probably ammonia, 
and fometimes nitrous gas. The nitrous acid 
is difengaged from the bafe by the intenfe heat. 
Concerning the formation of the ammonia, it 
IS ufelefs to reafon till we have obtained un- 
equivocal teftimonics of its exiftence ; it may 
be produced either by the decompofition of 
the water contained in the nitre, by the com- 
bination of its oxygene with the charcoal, and 
of its nafcent hydrogene with the nitrogene of 



( 49 ) 

the ohric aoid ; or from fome unkdo^n, decani^ 
pofition of the potafh. 

As neither Lavoifier nor Berthollet found 
nitrous gas produced in the decompofition of, 
nitre by cbarcoa]^; when a water apparatus was 
employed ; and as it was not uniformJjf Qvolyed 
in ray experirnents^ the moft probable. fuppoi> 
fition iS| that it'arifes from the decompofition 
of a portion of the free nitrous acid intenfely 
hea^ed^ by the mercury^ 

. In none of my experiments was the whole of 
the.nitre;and,cbarco4i; decomppfed, (ba)epf it 
was uniformly thrown with thegafes iqto tthe 
mercurial apparatus. The nitrogeqie evolved, 
as %;aal could afcertmn by the cpn^moa telPts, 
was mingled with no inflammable ^as. 

If we coniider experiment / as accurate, with 
regard to the relative quantities q( carbonic acid 
and iiitrogede prodqcifd^ they are to each other 
nearly as 20 to a ;. that i^, allowing 2 for the 
nitr:ouS: gas, and confequently, reafoning in the 
fame manner as LavoKier, concerning the com- 
polition of nitric acid, it (hpuld h6 compofed 



'*, 



the quantity of oxygerr&in t&ts''6ftittriltldtl is 
t^filiort brHiittgivbti it fals. yet ftUI if is' too 
ittuth. ''fVMtt'What«vfcf ftmtw tlie erfbr* isrife, 
t^hethcf ftom tl^c cvdltition of phlogifticated 
itftttms ddid, dttht desctfrnpofittett of Wa«^, or 
th* jHtMkrftiortf of mtroas gas, they all tend to 
itocHwrfc the proportion of the'carbonie acid to 
the tiitrogterte. 

I am unacquainted with any expistiment from 
whibh idtcctifate opinions concemin^g the ^^er^ 
tnt relative pfopdftions ofoxygewcandnitrdgene 
ih\bt nitric and nitrous adds could be deduted. 
tiStvoifier^s calculation is founded on his fundir* 
intht^l experiment, and oti the combination of 
nitrous gli&isihd oxygene. 
' Dr. Pricftley''8 cxpetilment inentionfed in 
fciflidh 12, on the abfbrptibn of nitrous gas by 
tiitfous acid, from which Kirwan* deduces the 
' Compbfit»ra of the differently colored nftrdus 

• » 

acidd, was made over watef^^ by whieb, as i« 



* Eflajr 00 phlogifton. 



( •! ) 

/ 

\ 

/ 

evimt)t^ torn 8 minute exambatioD of the fiitSfai^ 
the greater portloii of the nitrous giuKcmpIojred 
was ai>(brbed. ^ : ' 

•XIV. The opiokmi heretofore adufied 
f^pe^ittg the 'Entitles 0f real or true acid 
in lbiution» of* nitrons aeid of dtfifareotfpepifiKr 
gravities^ bave>. been founded onieafieriinetitr 
made on the nitro^neutral -ftlts^ the moft aeoti^i 



'-*■':■.. • V . ;M>f "'(^ 



' t Dr. Prieftlcy fayti ** Halving fiBecl a jAi* cohtaMb^ 
^ /Qvudijr tbp qpamitj of |9W Efonaf HHtigi^l^ of waif fjf i^i^ 
'' ftroQg, pale, yellow f^irtt of nitre, with its mouth qyite 
^ clofc to the top or a lar^e receilveV l^itdiag m yirzt^, 'f 
** tarcfoUj dnwifiur aliDoft dft tb^ eommoii; wr, apct l|if(ir 
*' fille4.it with mtrpus air j and a^.this was abforbed^ I J^ept 
*^ putHng in more and more, till itr lefs than two day^ it 
** had completely abforbed 130 ooiice meafeifcs. ^tdiktly 
'7 lifter ttiyu pooeft began; the fuiffce of .|he acid afluipcd 
*' a deep orange color, and when 20 or 30 ounce meamrcA 
** of air were abfotbed, it b«^aifne greea at the tt^ t M^ 
green dplcend^ lowisr and lower^ tiU it reachfd;^ 
bottom of the phial. Towards the end of the procefti 
the eTaporatiQii' was'^^perceived-lo^be very great> and' wkok 
I took it out, the quantity was found to have dimini(hed 
*^ to one half. Alfo it had become, by means of this pro* 
'' ceA, and the eti^mttoii together, exceeding weal^ and 
•' was rather blue than green," 

Efeferimenti ^nd OifirtfOtkmi ^(A. f, p. 3S4. Lail edition. 



U 



( 52 ) 

r^ojd£)ii#hbkciaier.fhoreof Kir!9»my' fiftrgoBitiy- 
diodrcWeiiM^: ?r>^Rhfi gre^t diScrepec 4n . th6; 
refults of thefe celebrated metf, . pf^ovi^; tbo 
difficulty of 4lie:im*tftt|^aliim|i)an$|!tbe eliftKpce 
df ibuffces -of iciroi^wt Kirwiiiii :,drdu0$s (be^ 
GBuhpofitloDidf tlie(^fbIutiQ(is.of:t nitrons j^akt^ifi' 
wHter^: fieaincBQL exjpcHiiicDt onxthdi i^mation.of 
RitMtedfiidaj^ jIi;^ this .'experimeoU! 96,05 gmim 
of (bda were iaturated by 145 grains of nitrous 
apift of fpcdfiq ^ayity, 1,27.54.. -3y: a, 49ft 
e^^i^feriment^ be found tbe quantity of fait formed' 
to be %^AA% smx^h^ JE][eince he conclude^ 
that loo parts of nitrckcM acid, of ipeotfic gravity 
Ifi^A^^ contain 73,54 of tbe ftforigeft,^ br^ 
nlc^ concentratediacid« 

Suppofing bis eftimatidn perfedHy* true, lOb' 
pafcts of tbe aeriform acid of 55^ r would be ^cooi-^ 
pbfed of 74,54 of his teal acid,' * and 25,45 
wafer. In examining, however, one of bis later 



. • • 



I : ' 



'■■ * See Mr. Keiir's excdknt obferyatiQBt on thif fabje^ 
Chem. Di^. Art. Acid. 

f Irifli Tr^D&dions, vol. 4^ p. 34. 



t 53 ) 

eSi(^, thtft thewcia itf {titrated fodii dintndt ttth- 
iiih^dbfa lefs Sleatcf'ttiiab the wintbrh add; A.^ 
folu^dtr of caihOnkiiA' fo6&, cohfkidlii^ l^ 
Ijrahw of rcarklkalii Vas fatuAted''^ '366,2' 
y^iiis aenitTbiii^'ac%'hffyet^Sbi^4itj 1,416, 
Ifhe evHporatioa Was cattted on hi -a-tetiaperattire' 
not exceeding 120*, and the refidaum eirixxM 
foVliieat '6f 4Dii''fbr''firi6utt; ittbieendof 
#bicV' tioieit < viiieigfabd^ graks:' "Ni^'kc:. 
<dr<Ki^g-ib Wy'^Siti^mal 3od grait» 'btilitriti 
add;. df'i,4l«',''A6illd^feootaitf 'tis ti-ite acid"^ 
ifid vft'-^mAlfta^^^fc, Ut^d dtiHng the 
evaporation and confequeht 'l<&g ekpofdi^'TO 
Heii!,"foaie'x>f the ^itrstcid fodtf wiS 1o^ With 
tti^^trte-- '''^ •■■•■■ • " ""■■ <:<'^'-' ■■ ' 
fiirgchin eftitriate^'tlie quantity- 6f Watar'Ift 
thiif nit at 25, and the acid at 43^'cen¥i(' 6iit 
his real aiid -vfiii'iii^ 1^ xiOncksiiirkti as Kit- 
xv'dh%7 coriftqu^Htiy '-«ie' hlfrii? afeid in nitra- 
ted ifdda- •fliddld ^^i^lntee-water -tliah-m^ 
^ue acid. 

• Addi't. Obf. pag. 74.. 



•f. 

Wenz^ from an expetimcat on the compo* 
fition of nitrated (bda, concludes that it coar 
tains 37^48 of alkali^* and 62^52 of nitrous acid ; 
aad IQOO 9f this aqid^ fro?i Kirwan's Qi^lcola* 

tion» contain B\%fi of his real acid; confer 

«."■■••■• ■ ■ ' " ■ 

9Uj»at|y^. IpQ pa^s of my triform aqid fluHild 
cpntaiu 93y2B of Wen;^'s acid^ and 6j[2 of 
waten 

I fatunited with.fOta(h. 54 fWns of fphiti«a 
of nitri&acidy qf^ecificgravity ljr901« Erapo* 

i«ted at about 212% it produoed 66 grains of 

» 

nitre* This nitre expofed to a higher tempera-^ 
tfire, and kept in fufion for fome titpe^ wfia 

reduc^ to 6q grains. 

Noiif from the taUe» 54 of 1)301^ ihould 
contain 2Q,5 of true acid. But accgrdii^g to 
KLim^an's eil^matioD^ lOO parts of dry nitre 
contain 44* of his real acid^ wkb 4 wM&r ; 
confequently 6o ibould cofitain 2694. 

Again, QP grains of acid^ pf fpeciiic grayity 
1^504^ iaturated with potaft^ and treated iix 

« Additional Qbfeiyatipns. page yd 



( 55 ) 

the fame manner, gave 173 grains of dry nitre* 
Confequently, 100 parts of it fhould eontaio 
47,3 grains of true acid. 

Now Lavoifier-f- allows about 51 of dry 
acid to 100 grains of nitre, atid Wenzel 52. 

From Bertbollet's:}; experiments, 100 grains 
of nitre, in their decompofition by heat, give 
out nearly 4g grains of ga^.§ 

Hence it appeaurs that the aeriform acid, that 
is, the true acid of my table, contains rather 
lefs water than the acid fuppofed to^xift'ia 
nitre. 



t Elements, pag. 103, Kerr's Tranflatioo. 



X Mem. Acad. 1787. 



§ As well as oxyg*ne and nitrogene, Mr, WatfsexpQtii 
meats prove that much phlogiAicated nitrous add il pro- 
duced. 



DIVISION IL 

EXPERIMENTS mid OBSERVATIONS on the com- 
fniihm of AMMONIAC and on its combinations with 
WATER and NITRIC ACW. 



JL Analysis of AMMONIAC er VOLATILE ALKALI. 

X H£ ibnnfition and decompofition of volatile 
alkali in many procefles, was obferved by Prieft- 
ley, Scbeele^ Bergman^ Kirwan^ and Higgins ; 
but to Berthollet we owe the difcovery of its 
confiituent parts, and their proportions to each 
other. Thefe proportions this excellent philo- 
ibpher deduced from an experiment on the 
decompofition of aeriform ammoniac by the 
elediric fpark :* a procefs in which no apparent 
iburce of error exifls. 



* Jeurnal de Phyfique, 1786. Tom. 2, pag. 17ft 



( 5M 

Sihce, UdWeYih^^ iris' eitoatk>i)[s titiVcl beee 

0ade^ tbe proJfbrtibns olf oxygttirl'Jirtd hydWM 

gcn^ in Witd: KaVe becw iribW^acctihrtely de^ 

terarincd. This chrcuhfifiaiitie^ as'well as tbe 

conviction of the impoiiibility dfKto minutely 

fcrutiniiring fa<9s^ iftrndamdital fd^ j^eat mafs 

of itafoning; induoec} me ti> ' itaal^ Yh6 follo^ 

■ t 1 

ipg cKpcrtincnts.^ ' 

A porcelain tube was provided^ open at both 

ends, and weQ glazed infide atiidomflde, its 

< ^ • ■ 

^ametet being abo&t ,5 iricfaHes'. To otie end 
oFthis^ a glafs tube Vas affixed; - ciiiVed for^bg 
purpofe'of oomtnunieatiiig v^tth th6 witter appa* 
ratus. With tbeothier end a glais ^ retort wias 
accurately /connect^ contiEiimng a niixture of 
perfectly caufttc iOiaclted lime/ and tntiriiate of 
enraioniac. •' ' * ■•• 

The water iii the apparatus for rebelving • the 
gafes bad been previoufly boiled^ to expel the 
air it might contain^^ and during the experiment 
^as yet warm.. 

When the tube had beea.redd^ned in a fur-^ 
f)ace adapted to the purpofe^ tbe flame of a 



( w ) 

fpirit lamp was^^pf^ied to the J^ttom of^be 
retort. 4 ff^ quantity of ^. y(^ colIe(6U4 
hi the water appai;atu;i ; o^tJ'jA? tbi?:^!^^ porljaq^ 
were rejedled, afu), tN la^ tranfifmred: tp,t|b^e 
mercurial tg^qgh.,^ 

/ . A fiqaU ,;quantity exaaiine^. . did xiot at ^1 
dimioi(h witjh oitrous gasj m^l t>uri^ wlt|i ^ 
lambent wbite flame, in contact witb.cooijiKMI 

t 2| of titM3ig?8j eqoal to );io gc^in meafoce^ 
fifere fire4fwith 2^ equal to.8py.of otfyesnq, jip 
a detonatfog tube^ by th& clei^ic (p^k» T^bfj^ 
were reduced jto 2^, or 9Q^ , . Oo JI^rud^9f p^ 
to the rei9aii)ider a folutio9;of jftroiMimi^ it b(^ 
came fligblly . plpuded qn it^ top^ and an 
pbibrption cff ipme grain gyeafpreB took place. 

It was evident^ then^ that in this experiment^ 
charcoal f had been £)mehow ^clent in the 



* Though ihC' tube had never beca ufed, and wis tppa- 
rtnilj clean and dry on the infide, it mofi have contained 
fomething in the form of duft, capable of fomiihing eithtr 
fajrdro^carbonatjB, otcharcoaL 



( «9 ) 

tube ; which being ^iilblved . by the nafcent 
hydrogene, had rendered it flightly carbonated^ 
and in confequence made the refults incon- 
clufive. 

A tube of thick green glafs carefully made 
clean, was now employed, irfclofed in the por- 
celain tube. Every other precaution was taken 
to prevent the exiftenceof fources of error^ and 
the experiment conduced as before. 

140 grain meafures of the gas produced, 
fired with l!2(> of oxygcne, left, in two experi- 
ments, nearly llO. Solutiort'offtrontian placed 
in contact with the refiduum, did not become 
clouded, and n6 aWbrption was perceived. 

Now 1 5o meafures of gas were deftroyed, 
and if we take Lavoifier's arid Meufnier's efti- 
matioti of the compofition of water, and fuppofe 
the weight of oxygene to be 35 grains, and that 
of hydrogene 2,6 the hundred cubic inches; the 
oxygene employed will be to the hydrogene ai 
243 to 576. Put X for the oxygene, and j^ for 
the hydrogene. 



( ^ ) 

Xhen «-f^ i= 150 

X : y :: 243 : 57^ 
343 > 



JP 



576 

S19>^=F864Q0 , 

j^=10§ ^=45 
And 140 — 105 = 35 

Confequently^ the nitrogene in ammoniac i$ 
fothP liydrogene as 35 : )05 in volume : and 
13^3 grains pf ammoniac are compofed qF 10^^ 
nitrogene^ (fuppofing that 100 cubic inche$ 
iveigh 3p^45 grains) and 2,7*hydrogene. 

According, to Berthollet, the weight of the 
jnitrogene in ammoniac is to that of the hydro- 
gene as 121 to 29** The difference between 
this eftimation ^n4 mine is fb fmall 2|s to be 
almoft unworthy of notice, and ^rifes moft pro- 
bably from the flight difference between the 
accounts of Lavoifier and Monge, of the comr 
pofition of water, and the dilflferent weights 
affigned to the gafes employed. 

* Journal de Phyfique, 1786, t. 2, 177. 



t 61 ) 

We may then conclqde^ tbiit 100 grains ol 
jBOimoniac are compoied of about 80 nitrpgen^ 
^nd 2Q hydrogepe. 

The decompofition of aromooiac by heat, tmi 
well as by t]he eledric fpark, was firft difcoveredl 
by Prieftley, In an experinjent-f' M^hen aeriforinj 
ammoniac Was fent through a heatec} tube fvottti 

a caudic folutipn of ammoniac in water^^ thU 

<■ . < - . 

great difcoverer obferved that an iqflammabla[ 
gas was produced^ though in no great quaiH 
tity, and that a fluid blackened by matter, prcH 
fjably carbonaceous, likewifc came over. 

In my experiments the whole of the ammOr 
niac apj/eared to be decompofed ; the quantity, 
of gas generated was immenfe^ and not clouded^* 
as is ufually the cafe with gafes generated at 
high temperatures. It is poffible, that the larger 
quantity of water carried over in his experi- 
ment,* by its ftrong attraction for ammoniac in 
the aeriform ftate, might have, in fpme me*- 
fure, retarded the decompofition. It is how- 



* Phil. Traaf. vol. 79, page 294. 



( 62 ) 

%V€T, more probable to fuppofe, that a fi^re 
^xifted in the earthen tube he emplo]^^ 
through which a certain quantity of gas efcaped[, 

^nd Goaly matter entered* 

]. 

Prieftley found that the metallic oxides 

when firongly heated^ decompofed ammoniac^ 

the metal being revivified and water and nitro- 

gene produced.* The eftimations of the com- 

poiition of ammoniac that may be deduced from 

his experiments on the oxide of lead, differ very 

little from thofe already detailed. 

. , 11. Specific gravity of Ammoniac 

From the great folubility of ammoniac in 
-water, it is difficult to afcertain its fpecific 
gravity in the fame manner as that of a gas 
combinable to no great extent with that fluid. 
It is impoflible to prevent the exiflence of a 



Vol. 2, page 39&. 



< «s ) 

fmall qtuftftity 6ir4l)t«it!oii ofaMnoffiav itf^lM 
DMtPCttriiA ai^h^fr,-f^ or apparaitvis eontain^^ 

ft 

the gab ; ^%i}d dfSfiing thje dhnifiution of ^ 
{^rdTui^ of the dtibof^here on this tb)ution^^<A 
^lertain C(llir<it4ty (^g&sis Hbetatc^ from ity ^md 
hence a (bttrce ot*^rror. 

To afcertpin, tben^ the v/i^g^btorammoniac, 
I employed an apparatus limilar to that ufed 
for the abforptfon of nitrous gas by i^'kric 
acid, i 

50 cubic itic^hes of gas wdpe ^iecfted in thf 
ttiercflfrial aii^oldel*^ from t^ decompofitbn of 
muriate of ammoniac by lime ; thermometer 
birffigSBS and barometer 29,6. 

100 grains of diluted ililphuri^ acid wert 
introduqi^d into the ihiail graduated cylincterp 
which after being earefbltyiveighed, was made 



r 



^ t ^mmon&c getitoted ^ a tetnpicrattire vbow that of 
iheatow^b^f^^ alw«iy84Qpofiit8^fyiqtnp{H9CaU<datioi!i ^firisg 

its redudioa.to the common temperature. 

f • I, ■ . I . ■ ■ -• t 

t By the introdufUon of aeriform ammoniaG iata the 
tnchaoiled globe. 



( «* > 

40 3eo(nmimiMAe.Mlth tb^.ajtrhc^der/ ih« cutved 
tube contamiiig a fmall qtidatity of water« 
!JH)e gas was. ilpwly pailed iat6 th^ floid^ and 
th(. globules wholly abforbed - before they 
miched the. t6p ; mnebincreafeof temperaturai 
being confequent. When the abibrption was 
compleat, :.the pftiial. was increafed in weight 

; iTbis experiment was repeiated three time6< 
The difFerence of weight, which was probably 
conaec^ed with alterations of temperature and 
preifiire, never 9U)0unted to more thiao one 
fixlh of a grain.. 

We may then conclude^ that at temperature 
68% and atmofpheric preilure 1^^6> 100 cubio 
incbes of ammoniac; weigh 18t grains. .>r 

According to KirWan^ 100 cubi^ incbes of 
alkaline air * weigh 18,1 6 grains; barometer 
dOo, thermometer 6l. The difference between 
4hefe eftimations^ the corredWons for tempera* 
ture and prcflure being made, is trifling. 



r • 



Additional ObfervationS; page 107- 



( ^5 ) 

lit. Of ^e qUantitiis df true Ammoma^ h 
A^eotis Ammoniacal SoJutionSy of difftrerJ fpe^ * 
cific gravities. 

To afcerfain the quantities pf ammoniac, luch 
as cxifts in the aeriform fiate, faturated with 
moifture, in folut ions of different fpecific gra- 
vitieSj I employed the apparatus for abfbrption 
fo often mentioned. Thermometer being 52% 
the mercurial airholder was filled with ammo- 
niacal gas, and the graduated phial, containing 
50 grains of pure water, connedled with it. 
During the abforption of the gas, the phial 
became warm. When about 30 cubic inches ' 
had been paflcd ' through, it was fuffered to 
coolj and weighed : it had gained 5,25 grains^ 
and the fluid filled a fpace equal to that occupied 
by 57* grains of water. 

* It is neceifary in thelc eitperiments^ that the greatefl 

care be obferved in tho introdadion and extra6tion of the 

capillary tube. If it is introduced dry> there will be/ a 

fource of error from the moiflure adhering to it when 

taken out. 1 therefore always wetted it before its intro- 

dudion^ and took care that no more fluid adhered to i6 

after the experiment^ than before. 

E 



(.66 ) 

Confequenlly^ 100 grains of folution of am- 
moniac in water of Ijpecific gravity ,9684 con- 
tain 9,502 grains of ammoniac. 

The apparatus being adj lifted as before, ^ 
grains of pure water were now perfecSlly fatu- 
rated with ammoniac. They gained in weight 
17 grains, and when perfectly cool, filled a 
ipace equal to 74 of water Confequently 100 
grains of aqueous ammonial folution of fpecific 
gravity ,9054 contain 25,37 grains of ammo- 
niac. 

The two folutions were mingled together ; 
but no alteration of temperature took place. 
Confequently the refulting fpecific gravity 
might have been found by calculation. 

On mingling a large quantity Of cauftic folu- 
tion of ammoniac with ^ of its weight of water, of 
exactly the fame temperature, no alteration of it 
w^ perceptible by a fenfible thermometer.-— 
Hence the two experiments* being aifumed as 

^ Previous to tkofe experiments, I had made a nmnber 
cyf others on the combination of ammoniac with water.-.-* 
My defign was^ to afcertaia the diminution of fpecific 



( 67 ) 

data^ the intermediate eilimations in the fol- 
lowing table^ were found by^calculation. 



gravity for every three grains of ammoniac abforbed ; but 
this I found impoffible. The capillary tube, when taken 
out 6f the phial; always carried with it a rointite portion 
of the folution, which partially evaporated before it could 
be again introduced; and thus the fources of error increnfed 
in proportion to the number of examinations. 



( 68 ) 

TABLE IV. 

Of approximations to the quantities of AMMONIAC, 
sucb as exists in tbe aeriform statCy saturated with 
water at 5 20, in AQUEOUS AMMONIACAL SOLU- 
TIONS of different specific gravities. 



100 

specific gra. 




Ammoniac 


Water. 


90M 


25,37 


74,63 


piee 




22,07 


77,93 


9255 




19,54 


80,46 


932(5 




17.52 


82,48 


9385 




5,88 


84,12 


9435 


c 


14,53 


85,47 


9476 


G 


13,46 


86,54 


9513 


8 


12,40 


87,60 


9545 




11,56 


88,44 


9573 




10,82 


89>18 


9^97 




10,17 


89,83 


9619 




9>60 


90,40 


9684 




9,50 


90,5 


9^39 




9,09 


90,91 


9713 * 7*17 ' 


92,83 



* As yet no mode has been difcovered for obtaining gafes 
in a flate of abfolate drynefs ^ confequently we are igno- 
rant of the different quantities of water they bold in fola-«, 
tion at different temperatures. As far as we are acquaintod 
with the combinations of ammoniac, there is no ffate Uh 
which it exifls fo free from moiffure^ as when aeriforyn, 
at low temperatures. 



( 69 ) 

' That no confiderable fource of error exifted 

In the two experiments, is evident from the 

trifling difterence between the ellimations of 

the quantities of real ammoniac, in the folu- 

lion of ,q684, as found in the iirft experiment, 

and as given by calculation from the lad. 

The quantity of ammoniac in a folution of 

fpecific gravity not in the table, may be thus 

determined — Find the difference between the 

two fpecific gravities nearbft to it in the tablie; 

dy and the difference between their quantities 

of alkali, I ; likewife the difference between 

thegiven fpecific gravity and that neareft to it, c. 

b c 
then d \ h \\ c \ x and x == — — 

d 

Whicji, added to the quantity of the lower 

fpecific gravity, is the alkali fought. 

The differences in fpecific gravity of the 

folutions of ammoniac at temperatures between 

40° and 65^ * are fo trifling as to be hardly 

* The expanfion from increafe of temperature is proba- 
bly great in proportion to the quantity of ammoniac in 
the folution. 



■i 



( 70 ) 

fticertainable, by our iroperfci^ inftruments, and 
confequently are unworthy of notice. 

It is poilible at very low temperatures to ob* 
tain ammoniacal (blutions of lefs fpccific gravity 
than ,Q, but they are incapable of being kept for 
any length of time under the common prefTure 
of the atmofpbere. 

, IV. Combinations of Ammoniac with Nifrif 
Acid. Compojition of Nitrate of Ammoniac^ £gf^, 

^200 grains of ammoniacal fblution^ of fpeci«- 
fie gravity ,9056, were faturated by 385,$ 
grains of nitric acid, of fpccific gravity 1,306, 
The combination was efFedled in a long phial, 
. the nitrous acid added very flowly, and the 
phial clofed after every addition, to prevent any 
evaporation in confequence of the great increafo 
of temperature.-f- The fpccific gravity of the 
folution, when reduced to the common tem- 
perature, was 1,15. Evaporated at a heat of 

f From the combination. 



( 71 ) 

312^:|: it gave 254 gmn^ of felt of fibi^us 
cryftalization. This fait was diflblved in 331 
grains of water ; the fpeciiic gravity of the 
iblution was iJ48 nearly. 

Hence it Was evident that fomc of the fafU 
bad been loft during the evaporation. 

To find the quantity loft, fibrous nitrate 6( 
afttmoniac was diflblved in fmall quantities in 
the folution, the fpecific gravity of which was 
examined after every addition of 3 grains. 
When 1 6 grains had been added to it, it became 
of 1,15. 

Cbnfequently, the foto^tion cottipofed of ^XSO 
grains of ammorriacal, and of 385,5 of nitric 
acid folut ion, contained 262 grains of felt of 
fibrous cryftalization, and of this faft ff grains 
were loft during the evaporation. 

But the alkali in 200 grains of ammohiacal 
folution of ,9056 = 50,5 grains. And the 
true nitric acid in 385,5 grains of folution of 
1,306'=^ igo grains. 

i r 

J i had before proved that at this teqopcrature the fait 
flSSther decompofed Bor feblimed. 



( n ) 

Then 262 — 240,5 ==21,5, the quantity of 
water. 

And 262 grains of fibrous cryftalized nitrate 
of ammoniac, contain 190 grains true acid, 
50^5 ammoniac, and 2I55 water. And 100 
parts contain 72,5 acid, 19,3 ammoniac, and 
8,2 water. 

In proportion as the temperature employed 
for the evaporation of nitro-ammoniacal folu^ 
tions, is above or below 212*', fo in proportioa 
does the fait produced contain more or left 
water than the fibrous nitrate. But whatever 
may have been the temperature of evaporation, 
the acid and alkali appear always to be in thp 
fame proportions to each other, 
- Of the falts containing diiFerent quantities of 
water, two varieties mud be particularly noticed* 
The prifmatic nitrate of ammoniac^ produced at 
the common temperatures of the atmofphere, and 
containing its full quantity of water of cryfiali-r 

# 

fation ; and the compadl nitrate of ammoniac^ 
either amorphous, or compofed of delicately 
pecdied cryflals, formed at 300% and containing 



( 75 ) 

hut little more water than exiils in nitric acid 
ahd ammoniac. 

To difcover the compoiition of the prifmatic 
nitrate of ammoniac, 200 grains of fibroiis fait 
were diflblved' in the fmalleft poffible quantity 
of water, and evaporated in a temperature not 
exceeding. 70^; The greater part of the fait 
was compofed of perfcflly formed tetraha^ral 
pi^tfms, terminated by tetrahaedral pyramids. 
Jt.had gained in weight about 8,5 grains. 

Confcquently 100 grains of prifmatic nitrate 
of ammoniac -may be foppofcd to contain 69,5 
0cid, 18,4 ammoniac, and 1^,1 water. 

To afcertain the ccnnpofition of the compa6l: 
nitrate of ammoniac, I expofed in a deep por- 
celain cup, .400 grains of the fibrous fait, in a 
temperature below 300*^. It quickly became 
fluid, and flowly gave out its water without any 
ebullition, or liberation of gas. When it was 
be&Qtue perfedlly dry, it had loft 33 grains. 
Ifufpe6led,.that in this experiment fome of the 
ialt had been carried off with the water; to 
4iB^termine this, I introduced into a fmall gjafs 



\ 



/ 



i 74 ) 

retort^ 46o grains of fibrous fait ; it was kept 
at a heat below 32QP, incomrminicatioEi with 
a mercurial apparatus^ in a regulated air-fur- 
nace, till it was pcrfe^aiy dry : it ^ad Ibft 
1^3 grains. No gas^ except the common air c( 
the retort came over, and the fluid collefied 
had but a faint tafte of nitrate of ammoniac. 

Though in this experiment I bad removed 
all the fluid retained in the neck of ike 
retort, flill a few drops remained in the bead, 
and on the fides, which I could not obtain*- ' It 
was of importance tc^ me to be accurately ae« 
quainted with the compofition of the compadl 
fait, and for that reaibn I compared theie ana- 
lytical experiments with a fynthetical one. 

I faturated 200 grains of folution of amm&A 
niac, of ,9056 with acid, afcertained the fpe- 
cific gravity of the folution, evaporated it at 
212<>, and fufed and dried it at about SOO** — 
260^. It gave 246 grains of fait, and ^ folu- 
tion made of the fame fpecific gravity a^ that 
evaporated, indicated a lofs of 9 grains. Con- 
fequently, 255 grains of this fait contain 50.A 



( 75 ) 

grains aUcali^ 190 grains acid^ and 14^5 grains 
water. 

We may then concludej that lOp parts of 
compadl nitrate of ammoniac contain 7^9^ Kid, 
Xg^^ alkali^ and 5,7 water. 

■ ■ . ■ ■■-•■»■ . ' 

V. tkcQif^pqfitifln. of Carhwat^_ of jimmomaf 









In my firft cxperio^ents on Ijhe proda<Slion of 
nitrate of ammoniac^ I endeavoured to afcertaiu 
its' Gpmpofition ;by . d^cop) pounding carbon- 
ate of ammoniac by nitrio acid ; and in making 
for this purpofe; the analyfis of carbonate of 
' ammoniac, I difcovered that there exifted many 
varieties of tfajis fait, containing very difFerent 
proportions of carbonic acid, alkaliy and water ; 
tbe carbonic acid and water being fuperabun- 
dant ia it, in proportion as tbfe temperature of 
its formation was low, and the alkali in pro- 
portion as it was high : and not only that a 
different fait was formed af every difFerent.tem* 
perature, but likewife that the difference in 



( 76 ) 

them was (b great, that the carbonate of amnio* 
niac formed at 300^ contained more than 50 
per cent alkali, whilft that produced at 6(y> con« 
tained only 20.* 

I found 210 grains of carbonate of ampaa- 
niac, which from comparifon with other falts 
previoufly analifed, I fufpe<fted to contain about 
20 or 21 per cent alkali, faturated by 200 
grains of nitric acid of 1,504. But though 
the carbonate was diilblved in much water^ 
ftill, frt)m the fmell of (he carbonic acid gcne« 
rated, I fufpe£l that a fmall portion of the 
nitric acid was diflblved, and carried off by 
it. The folution, evaporated at about 200*^, 
and afterwards expofed to a temperature below 
300°, gave 232 grains of compa<Sl fait. But 
reafoning from the quantity of acid * in 200 
grains of nitric acid of 1,504, it ought to have 
given 245. Confequcntly 13 were loft by 



* A particular account of the experiments from which 
chefe fads were deduced^ was printed in September^ and 
Fill appear in the fird volume of the Beftarcbes, 



{77 ) 

evaporation ; and thU lofs agrees with that in 
Ae other experiments. 

V. Deicompofihon of Sulphate of Ammoniac hv 
Nitre. . •• 

• • ' • 

A3 a cheap mode of obtaining nitrate of am- 
mpniac^ Dr. Bedpoes propoied to decompofe 
nitre by fujphate of ammoniac, which is a well 
||:nown article of commerce. From ()'nthefis 
9frulpbate of ammoniac, compared with analy- 
fis made in Auguft 1799^"^ I concluded that 
100 grains of prifmatic fait were compofed of 
about 18 grains ammoniac, 44 acid, and 38 
water ; and fuppofing 100 grains of nitre to 
contain 50 acid, 100 grains, of fulphate of 
ammoniac will require for their decompofitioa 
134 grains of nitre, and form 90,9 grains of 

■ p ■ • 

com pad nitrate of ammoniac. 



- * And which will be publiflied, with an acww* of lit 
per£cd decomposition at a high tex)[iperatare> in the 
JReJtdrchei, 



( 78 ) 

To afcertain if the fulphate ofpotafh audi 
nitrate of ammoniac could be eafily feparated, I 
added to a heated faturated folution of fulphate 

of ammoniac^ pulverifed nitre^ till the decom- 

■ 

poiition was complete. After this decompofi* 
tion, the folution contained a flight excels of 
fulphuric acid^ which was combined with lime, 
and the whole fet to evaporate at a temperature 
below 25(y>. As fbon as the fulphate of potafh 
began to cryftalife^ the folution was fuffered to 
C00I9 and then poured off from the cryftalifed 
falt^ which appeared to contain no nitrate of 
ammoniac. Afler aYecond evaporation and 
cryftalifation, almoft the whole of the fulphate 
appeared to be depofited, and the folution of 
nitrate of ammoniac was obtained nearly pure : 
it was evaporated at 212% and gave fibrous 
cryflals. 

VI. Non-exiftence of Ammoniacal Nitrites. 

I attempted in different modes to combine 
nitrous acids with ammoniac, fb as to form the 
falts which have been fuppofed to eidft^ and 



\ 
« 



( 79 ) 

called mffiUs of atninontac ; but without fuc^ 
cefs. 

I fiHi: decompofed a iblution of carbonate of 
ammaniao by dilute olive colored acid ; but in 
this procefSy though no heat was generated, 
yet all the nitrous gas appeared to be liberatejJ 
with the carbonic acid.* I then combined a 
fmdl quantity of Ditrous gas, with a folutron 
of nitrate of ammoniac. But after evaporating 
this folution at 70^ — 8<y, I could not dctc6l 
the e:^iftence of nitrous gas in the fdid (alt; 
it was given out during the evaporation and 
cryftalifation, and formed into nitrous acid by 
the oxygene of the atmofphere. I likewife 
heated nitrate of ammoniac to different degrees, 
and partially decompofed it, to afcertain if in 
any cafe the acid was phlogiflicafed by heat : 
but in no experiment could I detcA theexiftence 



* When nitrous gas exifts in ncutro-falin« folutions^ 
they are always colored more or lefs intenfely, from yellow 
tp olive; in proportion to the quantity combined With 
them« % 



( 80 ) 

of nitrous acid in the heated fait, when it luid 
been previoufly perfe<31y neutralifed. 

When nitrate of ammoniaCi indeed^, with 
excefs of nitric acid, is expofed to beat, the 
faperabundant nitric acid becomes phlogifii« 
cated, and is then liberated from the fait, which 
remains nejatral.* 

We may therefore conclude that nitrous gaa 
has little or no affinity for folid nitrate of am*- 
moniac, and that no fubftance exifts to which 
the name nitrite of ammoniac can with propriety- 
be applied. 

VII. Of tie four ces of error in Analyfis. 

To compare my (ynthefis of nitrate of ammo?- 

niac with analyfis, I endeavoured to feparate 

the ammgniac^and nitric acid from each other^ 

' without decompofition. But in going through 

the analytical procefs, I foon difcovered that 



* Hence a nitrate of ammoniac 'with excefs of acid^ 
when expofed to heat^ firfi becomes yellow^ and then 
white. 






( 81 ) 

it Was impoffible to make it accurate^ without 
many collateral laborious experiments on the 
quantities of ammoniac foluble in water at 
different temperatures. 

At a temperature above 212^ I decompofed^ 
by caullic flacked lime, 50 grains of compa<St ni« 
trate of ammoniac in a retort communicating 
with the mercurial airbolder^ the moiflure in 
which had been previoufly faturated with ammo- 
niac. 22 cubic inches of gas were colle<^ed at 
38o, and from the lofs of weight of the retort, it 
appeared that 13 grains of folution of ammo- 
niac in water^ had been depofited by the gas. 

Now evidently, this folution mufl have con- 
tained much more alkali in proportion to.its 
water than that of 55^, otherwife the quantity 
of ammoniac in 50 grains of fait would hardly 
equal 8 grains.* # 



* The aiccoants given by different chemifls of the com- 
poiition of nitrate of ammoniac, are extremely difcordant ^ 
they ha?e been chiefly deduced from decompositions of car- 
bonate of ammoniac (the varieties of which have been 



( 82 ) 

Vllt. Of the lofs of Solutions of Nttrale of 
Ammoniac during e^uiporaiion. 

The moft concentrated folution of nitrate of 
ammoniac capable of exifling at 60**, is of fpcci- 
iic gravity 1 ,304, and contains 33 water, and 
67 fibrous fait, per cent. When this folution 
is evaporated at temperatures between 60© and 
100, the fait IS increafed in weight by the 
addition of water of cryflalifation, and no por- 
tion of it is loft. 

During the evaporation of folutions of fpecific 
gravity 1,146 and 1,15, at temperatures below 
120°, I have never dcteded any lofs of fait. 
When the temperature of evaporation is 212% 
the lofs is generally from 3 to 4 grains per 
cent ; and when from 230° to the ftandard of 
their ebullition, from 4 to 6 grains. 



•• 



heretofore unknown) by nitrous acids of unknown degrees 
of nitration. Hence they are particularly erroneous with 
regard to the alkaline part. Wenzel fuppofes it to be 3Z 
per cent, and Kirwan 24, Addit, Ohferv, pag. 120, 



( S3 ) 

I» propmliofi as folutions are more dilute^, 
tl^eir lofs in evaporation at equal temperature^ 
is greater. 



I- 

I- 



DIVISION m. 

Decomposition o/NJTRATE of AMMONIAC : prepa- 
ration of RES PIRAB IE NITitOllS OXIDE t iti 
ANALYSIS. 



5222 



I. Of ibe beat required for tbe decompasUion ^ 
NITRATE of AMMONIAC. 

■ 

± HE dccompofition of nitrate , of ammoniac 
has been fuppofed by Cornette* to take, place 
at temperatures below 212^^ and its fublimatira 
at 234°. 

Kirwan, from the non-coincidence in t1 
accounts of its compo(ition« has imagined tl 
it is partially decompofable^ even by a heat 

'f o afcertain the changes efFeded by idcre 
of temperature in this falt^ a glafs retort vras 
vidcd, tubulated for the purpofe of introdudi 

* Mem. Par. 1783. See Irifli Tranf. voj. 4. 
t Addit. Obf. pag. 120. 



( 95 ) 

the bulb of a thermometer. After it had been 
made to communicate with the mercurial air- 
holder, and placed in a furnace, the heat of 
which could b? eafily regulated, the thermo- 
meter wa3 introduciSid, and the retort filled with 
the iait, an.d carefully lut^d; fo that the ap- 
pearances prodqced by different temper^^tures 
(:ou)d be accurately obferved^ and the products 
^yplvcd obtain edf 

From a number of experiments made in this 
inanner on difFcrcnt laUs, the fpllowing con- 
plufipngwcr? drawn. 

Ift. ConjpaiSt, or dry nitrate of itjnmoniac, 
undergoes little or no change at temperatures 
below 2^. 

2dly. At temperatures between 275^ and 
.300°, it flowly fublimcs, without decompofition, 
or without becoming fluid. 

3dly. At 320° it becomes fluid, decon)- 
pofes, and fl:ill flowly fublimcs; it neither 
^iflSiming, or continuing in, the fluid (late, witfj^ 
out decompofltioi)« 



( 86 ) 

4thly. At temperatures between 340° and 
480*^, it decbmpofes rapidly. 

5thly. The prifmatic and fibrous nitrates of 
ammoniac become fluid at temperatures belovr 
300% and undergo ebullition at temperatures 
between 36o® and 400% without dccompofitibh. 

fithly. They are capable of being heated to 
430® without decompofition, or fqblimatioti, 
till a certain quantity of their water is ^vApo- 
rated. 

7thly. At temperatures above 450° th^ 
undergo decompofition^ without previoufly 
Ic^ng their water of cryftalifation. 

II. Decomj^ojiiion of Nitrate of Ammoniac ; 
produSAon of refpiraih Nitrous Oxide; its^ro^^ 
perties. 

1200 grains of compa6l nitrate of ammoniac 
were introduced into a glafs retort, and dccbm- 
pofed flowly by the heat of a fpirit lamp. The 
firft portions of the gas that came over were 
reje<Sled, and the laft received in jars containing 



( 8M 

meri:iiry. No lumitiaas appearance Wasper- 
Odived in the retort daring the procels, and 
almoft the whole of the fah was r dblved into 
Am^ and gas. The fluid had a "(sAat actd tafie^ 
and contained fbme undecomponiid^d nitrate. 
The gas colledied exhibited the foMowing pro- 
jperfies.— 

a. A candle burnt ki it •with a brilliant 
flame^ and crackling noife. Before its extinc- 
tion^ the white itiner flame became fdrrounded 
with aii exterior blue oi^. 

i. Fhofphoriis tntrodueed itito it in a flate 
of inflammation, burnt With iHlfiriHdy greater 

r 

vividneft than before. 

c. Sulphur introduced iiito it when burning 
with a feeble blue flame, was frtftai^tly 6xtitti- 
guifhed ; but when in a fl:ati of adive inflam* 
mation (that is, fbrnriiing fulphurrc acid) |t 
burnt with a beautiful and vivid rofe-colored 
t\ame. 

d. Inflamed charcoal, deprived of^ hydro- 
gene, introduced into it, burnt with much 
greatet vividnefs than in the atiriofphcre. 



( 88 ) 

t. To (bme fine twifted iron wire a fmall 
piece of cork was affixed : this was inflamed^ 
and the whole introduced into a jar of the air. 
The iron burned with great vividnefs^ and threw 
out bright fparks as in oxygen e. 

/. 30 meafures of it expofed to water pre- 
vioufly boiled, was rapidly abforbcd ; when the 
diminution was complete, rather more than a 
meafure reiiiained. 

g. Pure water (aturated with it, gave it out 
y again on ebullition, and the gas thus produced 
• retailed all its former properties. 

h* It was abfbrbed by red cabbage juice ; 
but no alteration of color took pUce. 

u Its tafte was di(lin6lly fweet, andjts odor 
flight, but agreeable. 

. ]. It underwent no diminution when min- • 
gled with oxygene or nitrous gas. 

Such were the obvious properties of the ' 
Nitrous Oxide, or the gas produced by the 
decompofition of nitrate of ammoniac in a tem* 
perature not exceeding 440^ Other proper^ 



( 89 ) 

ties of it will be hereafter demonftrated^ and its 
affinities folly invefligated. 

.« . 

III. Of the gas remaining after the ahforptton of 
Nitrous Oxide by Water. • 

In expofing nitrous oxide at different times 
to rain or fpring water^ and water that had 
been lately boiled, I found that the gas re- 
maining after the abforption was always lead 
when boiled water was employed, though from 
the mode of production of the nitrous oxide, I 
had reafon to believe that its compofition was 
generally the lame. 

This circumfiance induced me to fuppole 
that fome of the refiduum might be gas pre- 
vioufly contained in the water, and liberated 
fronj it in confequence of the ftronger affinity 
of that fluid for nitrous oxide. But the greater 
part of it, I conjedlured to confift of nitrogcne 
produced in confequence of a complete decom- 
pofition of part of the acid, by the bydrogene. 
Jt wa^ in endeavoring to afcertain the relative 



( 90 ) 

purity of nitrous oxide produced at difierent 
periods of the procefs of the decompofition of 
nitrate of ammoniac, that I difcovered the true 
reafon of the appearance of reiidual gs». 

I decompofed fome pure nitrate of ammoniac 
in a fmall glais retort ; and after fufFering the 
firft portions 'to efcape with the cotnmon air, I 
caught the remainder in three feparate v^llels 
fianding in the fame trough, filled with Water 
that had been long boiled, and which at the 
time of the experiment was fo warm that I touM 
fcarcely bear my hands in it. The different 
quantities colledlcd gave the fame intenfe bril- 
liancy to the flame of a taper. 

26 meafures of each of thetti were feparately 
inferted into 3 graduated cylinders, of nearly 
the fame capacity, over the famre boiled water. 
As the water cooled, the gas was abforbed by 
agitation. When the diminution was com- 
plete, the refiduiim in each cylinder filled, 
as nearly as poflible, the fame ipace ; about 
two thirds of a meafure. 

To each of the refiduums I added two mcl^k- 



< pi ) 

lures <if tiitroas^;; they gave oppious red 
y^fOTj aod after ttie. aofidehratioit filled a fpaec 
rather lefs than two meafures. 

Hence the refidaal gas cooftaiaed more ' 
oxygene than common air, 

I now introduced lQ meafures of gas froilv 
bhciof the "vcflels into a cylinder filled ^^h 
lanboiled fpring water of the fame kind. * After 
ifre abforption was complete, near two meafures 
remained., Thcfe added to two meafures of 
nitixms air, diminiihed to 2,5 nearly. 

^hefe experiments induced me to lidicve 
that the refidua! gas was not produced in the 
decompofition of nitrate of ammoniac, but that 
it was wholly liberated from the water. 

To afcertain this point with precifion, I 
diftilled a fmall quantity of the fame kind of 
water, which bad been near an hour in ebul- 
lition, into a graduated cylinder containing 
mercury. To this I introduced about one third 

* Two meafurq^ of ajr difp^Uod .from this water by 
boUitigy mingled with 'Z of nitrous gas> diminiihed to 2^4 
tieaitj. 



( 91 > 

of its bulkj !• e. 12 meafures of nitrous oxide^ 
which bad been carefully generated in the mer* 
curial apparatus. After tbp abforption, a fmall 
globule of gas only remained, which could 
hardly have equalled one foqrth of a meafure. 
On admitting to this globule a minute quantity 
of nitrous gas, an evident diminution took place. 

Though this experiment ^proved that in pro- 
portion as the water was free from air^ the reiS- 
duum was lefs, and though there w^s no reaibn 
to fuppofc that the ebullition and diftillation 
had freed the water from the whole of the air 
it had held in folution, dill I confidered a 
decifive experiment wanting to determine whe- 
ther nitrous oxide was the only gas produced in 
the flow decompofition of nitrate of ammoniac, 
or whether a minute quantity of oxygene was 
not likcwife evolved, 

I received the middle part of the produd of 
a decompofition of nitrate of ammoniac, under 
a cylinder filled with dry mercury, and intro- 
duced to it fome ftrong folution of ammoniac. 
After the white cloud produced by the combir- 



( 0S ) 

nation of the ammoniacal vapor with the nitric 
acid fufpended in the nitrous oxide^ had been 
completely precipitated, I introduced a fmall 
quantity of nitrous gas. No white vapor was 
produced. 

Now if any gas combinable with nitrous gas 
had exifted in the cylirtder, the quantity of 
nitrous acid produced, however fmall, would* 
have been rendered perceptible by the ammo^ 
niacal fumes ; for when a minute globule of 
common air was admitted into the cylinder, 
white clouds were inftantly perceptible. 

It feems therefore reafonable to conclude, 

1. That the refidual gas of nitrous oxide, is 
air previoufly contained in the water, (which 
in no cafe can be perfe6l]y freed from it by 
ebullition), and liberated by the ftronger attrac- 
tion of that fluid for mtrous oxide, 

2. That nitrate of ammoniac, at temperatures 
below 440^, is decompounded into pure nitrous 
oxide, and fluid. 

3. That in afcertaining the purity of nitrous, 
oxide from its abforption by water, corredlions 
ought to be made for the quantity of gas dif- 



( 9* ) 

pelled from the water. This quantity io com:- 
mon water dillilled under mercury being about 
~ ; in water (imply boiled, and ufcd when hot, 
about ^; and in common fpring water, Ij^^ 

IV. Specific gravity of Nitrous Oxidt. 

To underfland accurately the changes taking 
place during the decompofition of nitrate of 
ammoniac, we mud be acquainted with the 
fpeciflc gravity and compofition of nitrous 
oxide. 

90 cubic inches of it, containing about — 
common air, introduced from the mercurial 
airholder into an cxhaufled globe, increaied it 
in weight 44,75 grains ; thermometer being 
51°, and atmofpheric preflure 30,7* 

106 cubic inches, of iimilar compofition, 
weighed in like manner, gave at the fame tem- 
perature and preflure nearly 52,25 grains ; and 
in another experiment, when the thermometer 
was 41°, 53 grains. 

So that accmmting for the fmall quantity of 



( 95 ) 

eonimon air contained in the gafes weighed^ %e 
may condode,, that 100 cubic inches of pure 
nitrous oxide weigh 50,1 grains at temperature 
50°, and atmofpheric prefTurc a7. 
. I was a little furprifed at this great fpccific 
gravity, particularly as I had expelled, from 
Dr, Prieftley's obfervations^ to find it lefs heavy 
than atmofpherical air. This philofopher fup- 
pofed, from fome appearances produced by the 
mixture of it with aeriform ammoniac, that it 
was even of Icfe fpccific gravity than that gas.* 

V. Analyfis of Nitrous Oxide. 

The nitrous oxide may be analifed, either by 
charcoal or hydrogenc ; during the combuflion 
of other bodies in it, fmalt portions of nitrous 
acid are generally formed, as will be fully ex- 
plained hereafter. 

4 

The gas that I employed was generated' from 



* Experiments and Obfervations, vol. 2, pag, 89. Laft 
Edition. 



( 96 ) 

compact nitrate of ammoniac, and was in Itf 
bigbeil (late of purity^ as it left a reliduum of 
38 only, when abforbed by boiled water. 

10 cubic inches of it were inferted into ajar 
graduated to ^1 cubic inches, containing dry 
mercury. Through this mercury a piece of 
charcoal which had been deprived of its hydro-* 
gene by long expofarc to heat, Weighing about 
a grain, was introduced, while yet warm: No 
perceptible abforption of the gas took place.* 

Thermometer being 46^, the focus of a lens 
was thrown on the charcoal, which infiantly 
took fire, and burnt vividly for about a minute^ 
the gas being increafed in volume. After the 
vivid combufiion had ceafed, the focus was 

m 

again thrown on the charcoal ; it continued to 
burn for near ten minutes, when the proceis 
flopped. 

The gas, when the original preflure and tena- 
perature were reftored, filled a fpace equal to 
12,5 cubic inches. 

* A minute quantity, however, muft have been abforbed^ 
and given out again when the charcoal was heated. 



( 97 ) 

On introducing to it a ftiiall quantity of* 
ftrong folution of ammoniac*, white vapor 
was inftanlly perceived, and after a (hort time 
the reduction was to about 10,1 cubic inches; fo 
that apparently, 2,4 cubic inches of carbonio 
acid had been formed* The 10,1 cubic inches 
of gas remaining were expofed to water which 
had been long in ebullition, and which was 
introduced whilA boilings under mercury. 
After the abforption of the nitrous oxide 
by the water, the gas remaining was equal to 
6,3. 

But on combining a cubic inch of pure nitrous 
oxide with fome of the fame water, which had 
been received under mercury in a feparatc veflel, 
nearly j^ remained. Confequcntly we may 
conclude, that 5,1 of a gas unabforbable by 
water, was produced in the combuflion. 

This gas extinguiflied flame, gavenodimi- 
nution with oxygene, and the flighteft poffible 



* Strong folution of amrnoniac has no atlradfon f(^t' 
nitrotis oxide. 



t: 



( 98 ) 

with nitrous gas. When an cledlric fpark was 
pafled through it^ mingled with oxygene ; rio 
inflammation, or percepltble diminution took 
placcf- We may confequcntly conclude that 
it was nitrogenc, mingled with a minute por- 
tion of common air, expelled from the water. 

The charcoal was diminiflied in bulk to one 
half nearly, but the lofs of weight could notJ 
be afcertained, as its pores were filled with 
mercury • 

Now 5 cubic inches of nitrous oxide were 
abforbed by the water, confequjsntly 5 were 
decompounded by the charcoal ; and thefc pro- 
duced 5,1 cubic inches of nitrogene; and by 
giving their oxygene to the charcoal, apparently 
2,4 of carbonic acid. 

But 5 cubic inches of nitrous oxide weigh 2,5 
grains, and 5,1 cubic inches of nitrogene 1,55 ;. 
then 2,5 — 1,55 = ,05. 

So thut reafoning from the relative fpecific 



f The gas was examined by thofe tefts in order to prove 
tliat no water had been decompofed. 



i 9^ ) 

grdviticd of nitrogenc and nitfous oitide, 2,5 
grains bf the larft arti bompofcd of 1,55 tiitro-, 
gerie, arid ,g5 oAygeqe. 

But from many experiments made on thei 
fpecific gravity of c^fbotttc acid, in Augiift, 
^7Q^9 I concluded that 100 cubic inches of it 
weighed 47,3 grains, thermometer being 60jl^i 
and bafomWcr 20,5. Confec(uently, making 
th^ heceHary correflifartis, 2,4 cubic tricheJA bf 
it weigh h,14 grains; and on Lavoifier's atid 
Guyfon'^ * eftimation bf its coihpofition, thefe 
1,13 grains cbtttain 8,2 6f o*ygen^. 

8b that, drawing dbncliifions from the quan- 
tity of carbonic acid foriiiied in this fexperimcnf,- 
2,5 grains of nitrous o^ide will be conipofed of 
jSibXygene, atid 1,68 nitrogenc. 

The difference betVveen ihele eftiniatiohs M 
confiderable, and yet not more than might 
havebeeii ex^eded, if wdconfider theprofbible 
fburces of erroi* in the experiment* 

* See the curious pdperof this excellent philofophcr, on 
the combiiftion of the diamond, in which he proves that 
charcoal 1.^ in fad, oxide of diamond. Annales de Chixnie. 
xxxi. 



( 100 ) 

}. It is likely that variable mirrute quan> 
titles of hydrogene remain combined with char- 
coal, even after it has been long expofed to a 
red heat. 

2. It is probable that the riitrogenc and car- 
bonic acid produced were capable of diflblving 
more water than that held in folution by the; ni- 
trous oxide; and if fo, they were more condenfed 
than if faturated with moifture, and hence the 
quantity of carbonic acid under-rated. 

We may confequently fuppofe the eftimation 
founded on the quantity of nitrogene evolved^ 
mod correal ; and making a fmall allowance 
for the difference^ conclude, that 100 grains 
of nitrous oxide are compofed of about 37 
oxygene, and 63 nitrogene ; exifting in a much 
more condenfed ftate than when in their fimplc 
forms. 

The.tolerable accuracy of this fiatement will 
be hereafter demonftrated by a number of expe- 
riments on the combuftion of different bodies 
in nitrous oxide, detailed in Refcarch IF. 



( 101 ) 

VI. Mmute examination of the decompojition of . 
Nitrate of Ammoyiiac. 

Into a retort weighing 413,75 grains, and 
of the capacity of 7j5 cubic inches, 100 grains 
of pulverifed compacSl nitrate of ammoniac were 
introduced. To the neck of this r<!tort was 
adapted a recipient, weighing 711 grains, tubu* 
lated for the purpofe of communicating with 
the mercurial ajrholder, and of the capacity of 
B,3 cubic inches. 

Temperature being 50°, and atmofpheric 
preflure 30,6, the recipient was inferted into a 
veflel of cold water, and made to communicate 
with the airholden The heat o{ a fpirit lamp 
was then flowly applied to the retort : the fait 
quickly began to dccompofe, and to liquify. 
The temperature was fo regulated, as to keep 
up an equable and flow decompofition. 

During this decompofition, no luminous 
appearance was perceived in the retort; the 
gas that came into the airhojdcr was very little 



\ 



( 1©2 ) 

clouded, and much Water cQiidenfed in the 
receiver. 

After the procefs was finifhed, the commu- 
nication between the mercurial airholder and 
the recipient was preferved till the common 

« 

temperature was reftored to the retort. 

The volume of the gas in the cylinder was 
85,5 cubic incJies. The abfolute quantity of 
nitrous oxide in thofe 85,5 cubic inches, it was 
difficult to afcertain with gregt nicefy, on ac- 
count of the common air previoufly contained 
in the veflels. 

45 ipeafures of it, expofcd to well boiled 
water, diminiflied by agitation to 8 mca- 
furcs. So that reafoning from the (quan- 
tity of air, which fliould have been expelled 
from the water by the nitrous oxide, we may 
conclude that the 85,5 cubic inches were nearly 
pure. 

The retort now weighed 41t),25 grains, con- 
fcquently 5,5 grains of fait remained in it. 
This latt was chiefly collcfled about the lower 
parf of the neck, and contained rather more 



( 103 ) 

water than the compad nitrate^ as in fome 
places it was cryftalifed. 

The recipient with the fluid it contained, 
■weighed 759 grains. It had confequcntly 
gained in weight 48 grains. 

Now the 85,5 cubic inches of nitrous oxide 
produced^ weigh about 42,5 grains; and this ad- 
ded to 48 and -5,5, = q6 grains ; fo that about 4 
g^ins of fait and fluid were loft, probably by 
being carried over and depofited by the gas.* 

As much of the fluid as could be taken out of 
the recipient, weighed 46 grains, and held in fo- 
lution much nitrate of ammoniac with fupet- 
dbundance of acid. This acid required for its 
Saturation, 3 \ of carbonate of ammoniac (con- 
taining, as well as I could guefs), about 20 per 
cent alkali. 

The whole folution evaporated, gave 18 
grains of compa<5l nitrate of ammoniac. But 



*This was aftually the cafe 5 for on examining the con- 
du^Dg tube the day after the experiment^ fome minute 
ciyiUli of prifcnatic nitrate of ammoniac we're perceived- 
in it» 



( lOO ) 

I 

But 15^4 alkali contain 3^08 hydrogene^ and 
J^jSa nitrpgcne ;* and 3fi& hydrogene require 
J 7,4 of oxygene to form 20,48 of water. 

Now 32,5 grains of water cxifted before the 
f^iEperiiaent ; 4,7 grains of water were con- 
teined by the fait dccompofed, and 32,5— 4,7 
33= 37,8 : and 37,8 — 20,48, the quantity gene- 
i»t^d, zzz 7,52, the quantity exifting in the nitric 
ftcid.. 

But the nitvic acid decompoied ts 58^ — 3,35 
?= to 54,7 ; and 54,7 — 7,5 =5? 47,2, which 
entered into new con>binations. Tbefe 47,2 
confift of 33,2 oxygene, and 14, nitrogene. 
And ,33,2 — 17,4, the quantity employed to 
form the water, = 15,8, which combined with 
14„ nitrogene of the nitric acid, «nd 12,32 
of that of the ammoniac, to form 42,12 of 
nitrous oxide. And on this eflimation, 100 parts 
of nitrous oxide would contain 37,6 oxygene, 
and 62,4 nitrogene ; a <x>mputation much 
nearer the refults of the analyfis than could 

* Owing part of their weight to an unknown quantity 
of water. 



( 107 ) 

have been expected, particularly as fo many 
unavoidable fources of error exifted in the 

proccfs. 

The experiment that I have detailed is the 
fnoft accurate of four, made on the fame quan- 
tity of felt. The others were carried on at 
ratlsrer higher temperatures, in confequence of 
whieb^ more water and fait were fublimed with 
^he 2»a8. 

iPo Berthollct^ we qwo the difcovery of the pro* 
dads evolved during the flow decompofition of 
liitrttta of ammoniac; but as this philofopher 
In hift examination of this procefs, chiefly de- 
igned to prove the exiftence of hydrogene in 
pnunoiiiao^ he did not afcertain the quantity of 
gas produced, or minutely examine its proper- 
ties ; from two of them, its abforption by water 
and it« capability of f6pporting the vivid com- 
buftion of a taper, he inferred its identity with 
thq dephlogifticated nitrous gas of Prieftley, and 
Gonoludtd that it was nitrous gas with cxcefs 

*Mein. deTatis. 1785, and Journal dc Phvfiqnc, 1/86. 



( JOS ) 

VII. Of the heat produced during the deconu 
fofition of nitrate of ammoniac. 

Ta afcertain whether the temperature of 
nitrate of ammoniac was increafed or diminifhed 
after it had been railed to the point eifential to 
its decompofition, during tbe^ evolution of ni- 
trous oxide and water ; that is, in common lan- 
guage, whether heat was generated or abforbed 
in the procefs ; I introduced a thermometer into 
about 1500 gi^ins of fibrous nitrate of ammo- 
niac, rendered liquid in a deep porcelain cup. 
During the whole of the evaporation, the temi'- 
perature was about 380% the iire being care^ 
fully regulated. 

As foon as the decompofition took place, the 
thermometer began to rife ; in lefs than a quar'- 
ter of a minute it was 410% in two minutes it 
was 460°. 

The cup was removed from the fire ;. the de- 
compofition fiill went on rapidly, and for about 
a minute the thermometer was fi^tioni^ry. It 



( 109 ) 

then gradually and flowly fell ; in three minutes 
it was 440°, in five minutes 420o, in fcven 
Hiinutes 405°, in nine minutes 36o°, and in 
thirteen minutes 307% when the decompofition 
had nearly ceafed, and the fait began to folidify. 
From this experiment, it is evident that an 
increale of temperature is produced by the 
decompoiition of nitrate of ammoniac : though 
the capacity of water and nitrous oxide for 
heat, fuppoling the truth of the common doc- 
trine, and reafoning from analogy, muft be 
confiderably greater than that of the fait. 

VIII. Of tie decompofition of titrate of Am- 
momac at high temperatures^ and prodiiSion of 
Nitrous gas y Nitrogene, Nitrous Acid^ and Water. 

At an early period of my inveftigation relating 
to the nitrous oxide, I difcovered that when a 
heat above 600^ was applied to nitrate of ammo- 
niac, fo that a vivid luminous appearance was pro- 
duced in the retort^ certain portions of nitrous 
gas, and nitrogcne, were evolved with the 



( lid ) 

flitrous oxide. , Bat I was for fonife time igtitt- 
rant of the precife natutc of this decompo(iti6n> 
arid doubtful with fdg^fd to the poflibility df 
effe^ing it ifi iuch a itiannef a^ ttr pttvtnt tb6 
prodiiflion of nitroUs oxide ^Itog^thei*. 

I fifft attempted to d^ebfripofc nitrate of 
attitnoniae at high temperatures, by introducing 
it into a well boated green glafs retdrt, hiving 
a wide neck, communicating with the pneii^ 
matic apparatus, and ftrongly heated in an air- 
furnace. But though in this procefs a detotr^- 
tion always took place, and much light w^s pro- 
duced, yet ftill the greater portion of the gas 
generated was nitrotis oxide ; the nitrous gas 
and nitrogene never amounting to more than 
one third of the whole. 

After breaking many retorts by explofion^, 
without gaining any accurate refults, I em- 
ployed a porcelain tube,^ curved fo as to ht 
capable of introdu<£lion into the pneumatic 
apparatus, arid clofed at one end. 

The clofed end was heated red, nitrate of 
ammoniac introduced irito it^ and all the latter 



( 111 ) 

portions of gas produced in the explofion, re- 
ceived in the pneumatic apparatus^ filled with 
yfattn water. 

Three explofions were required to fill a jar 
of the capacity of 20 cubic inches. The gas 
produced in the firfl:^ when it came over, was 
tranfparent and dark orange, fimilar in its 
appearance to the nitrous acid gas produced in 
the firft experiment ; but it fpeedily became 
white and clouded, whilft a flight diminution 
of volume took place. ' 

When the fecond portion was generated and 
mingled with the clouded gas, it again became 
tranfparent aidd yellow for a fhort time, and then 
afibmed the fame appearance as before. 

The water in the trough, after this experi- 
ment^ had an acid tafte, and quickly red- 
dened cabbage juice rendered green by an 
alkali 

6 cubic inches of the gas produced were 
expofed to boiled water, but little or no abforp- 
tion took place. Hence, evidently, it con- 
tained no nitrous oxide. 



( 112 ) 

They were then expofed to folution of ful- . 
pbate of iron : the folution quickly became dark 
colored, and an abforption of 1,6 took place 
on agitation.* 

The gas remaining inftantly extinguilhed the 
taper, and was confequently nitrogene. 

This experiment was repeated, with nearly . 

• • • ' 

the fame refults* 

We may then conclude, that at high tem- . 
peratures, nitrate of ammoniac is wholly re- . 
folved into water, nitrous acid, nitrous gas, 
and nitrogene ; whilft a vivid luminous appear* 
ance is produced. 

The tranfparency and orange color produced 
in the gas that had been clouded, by new por- 
tions of it, doubtlefs arofe from the folution of 
the nitric acid and water forming the cloud, in. 
the heated nitrous vapor produced, fo as to con-* 
ftitute an aeriform triple compound ; whilft the 
cloudinefs and abforption fubfequent were pro- 



* The abforption of nitrous gas by fulphate of iron^ &c, 
will be treated of in tlie next divifiOD. 



( 113 ) 

duced by the dimiDiihed temperature^ which 
deflroyed the ternary combination^ and feparated 
the nitrous acid and water jfrom the nitrous 
gas. 

From the rapidity with which the deflagra- 
tion of nitrate of ammoniac proceeds, and from 
the immenfe quantity of light produced, it is 
rcaibnable to fuppofe that a very great increafe 
of temperature takes place. The tube in which 
the decompofition has been efTedted, is alwayi 
ignited after the procefs. 

IX. Speculations on the decompofitions of 
Nitrate of Ammoniac. 

All the pha&noniena of chemiftry concur in 
proving, that the affinity of one body. A, for 
another, B, is not deftroyed by its combinatioa 
with a third, C, but only modified ; either by 
condenfation, or expanfion, or by the attradtion 
of C for B. 

On this principle, the attradlion of compound 
bodies for each other muft be revolved into the 

H 



( 114 > 

reciprocal dttra<3ions of their conflituenfs, and 
confequently the changes produced in them by 
variations of temperature explained, from the 
alterations produced in the attradlions of thofe 
conftitucnts. 

Thus in nitrate of ammoniac, four affimties 
may be fuppofed to exift : 

1. That of hydrogene for nitrogenc^ produ- 
cing ammoniac. 

2. That of oxygene for nitrous gas, producing 
' nitric acid. 

3. That of the hydrogene of ammoniac for the 
oxygene of nitric acid. 

4. That of the nitrogenc of ammoniac for 
the nitrous gas of nitric acid. 

At temperatures below 300^, the felt, from 
the equilibrium between tl^efe affinities^ prc- 
ferves its exiftence. 

Now when its temperature is raifed to 400°, 
the attractions of hydrogene fornrtrogene,*and 



* As is evident from the decoropofition of ammoniac by 



( 115) 

of nitrous gas for 6xygene,:|: are diminiflied ; 
wbilft the attraction of hydrogene for oxygenef* 
is idcreafed ; and perhaps that of nitrogene for 
nitrous gas. 

Hence the former equilibrium of affinity is 
deftroyed, and a new one produced. 

The hydrogene of the ammoniac combines 
with the oxygene of the nitric acid to generate 
water ; and the nitrogene of the ammoniac 
enters into combination with the nitrous gas 
to form nitrous oxide : and the water and ni- 
trous oxide produced^ mofl probably exift ia 
binary combination in the aeriform ilate^ at the 
temperature of the decompofitipn. 

But when a heat above 800^ is applied to 
nitrate of ammoniac, the attra(5lions of nitro- 

« 

gene and hydrogene for each other^ and of 



X Nitric acid is phlogifticated by heat^ as appears from 
Dr. PrietHcy's experiments. Vol. 3^ p. 26, 

f As is evident from the increafe of temperature required 
for the formation of water. 



( H6 > 

€ixygcne for nitrous gas,* are ftill more dimf-^ 
Aiflied ; whilft that of nitrogcne for nitrous gas 
18 deftroyed, and that df hydrogene for o^cy- 
gene increafed to a great extent : likewife 
a new attraction . takes place; that of nitrous 
gas for nitric acid, to form nitrous vapor.-f^ 

* « 

Hence a new arrangement of principles is 
rapidly produced; the nitrogene of ammoniac 

" For ammooiac and nitrous oxide arc both decompofed at 
the red heat, and oxygene given out from nitric acid when 
it is paiTed through a heated tube. 

f Whenever nitrous acid is produced at high tempera- 
tares, it is always highly phl^ogifticated, provided it has not 
been long in contact with oxygene. When Pr. Prieftley 
pafTed nitric acid through a tube heated red, he procbred 
ttiuch oxygene, and phlogifticated acidj and the water 
in the apparatus employed was fully impregnated with 
nitrous air. Hence it would appear, that heat diminiihes 
the attradion between oxygene and nitrous gis, and inf- 
creafes the affinity of nitrous gas for nitrous acid. Mr. 
James Thomson, whofe theory of the Nitrous Acid 1 have 
already mentioned, from fome experiments on the phlo- 
giflication of Nitric Acid by heat, which he has commu- 
nicated to me, concludes with great judnefs, that a portion 
of the acid is always completely decompofed in this procefs: 
the oxygene liberated, and the nitrous gas combined with 
the remaining acid. 



( 117) 

having no afHnity for any of the fingle principles 
at this temperature^ enters into no binary com- 
* poun.d : the bxygene of the nitric acid forms 
water with the bydrogene, and the nitrous gas 
combines with the nitric acid to form nitrous 
vapor. All thefe fubftances moft probably 
exift in combination at the temperature of their 
production ; and at a lower temperature^ alTun^e 
the forms of nitrous acid^ nitrous gas, nitrogene, 
mid water, 

I have avoided entering into any difculfioos 
concerning the light and heat produced in this 
procefs ; becaufe thefe phaenomena cannot be 
rcafoned upon as ifolated fadls, and their relation 
to generall theory will be treated of hereafter^ 

X. On the preparation of Nitrous Omdefqr 
€xperiments on Refpiratmi. 

When compad nitrate of ammoniac is flowly 
decompofed, the nitrous oxide produced is 
almoft immediately fit for refpiration ; but as 
one part of the fait begins to decompofc before 



( 118 ) 

^e other is rendered fluid, a coiiliderable lofs is 
produced by fublimation. 

For the produAion of large quantities of 
nitrous oxide, fibrous nitrate of am moniac fhould 
be employed. This fait undergoes no decom* 
pofition till the greater part of its water is evapo- 
rated^ and in confe(}uence at the commencement 
of that procefs^ is uniformly heated. 

The gas produced from fibrous nitrate/ muft 
be fufTered to reft at leaft for an hour after its 
generation. At the end of this time it is gene- 
rally fit for refpiration. If examined before, it 
will be found to contain more or left of a white 
vapor, which has a difagreeable acidulous tafte, 
and flrongly irritates the fauces and lungs. This 
vapor, moft probably, confifls of acid nitrate 
of ammoniac and water, which were diflblved 
by the gas at the temperature of its produ<51ion, 
and afterwards flpwly precipitated. 

It is found in left quantity when compact 
nitrate is employed, becaufe more fait is fub- 
limed in this procefs, which being rapidly pre- 
cipitated, carries with it the acid and water. 



^ 



( 119 ) 

Whatever fait is employed^ the laft portions 
of gas produced^ generally contain lefs vapor^ 
and may in confeq|Uence he refpired fooner than 
the iirft. 

The nitrate of ammoniac fhonld never be 
decompofed in a metallic veflel^^ nor the gas 
produced fuficred to come in contact with 
any metallic furface ; for in this cafe the free 
nitric acid wiil be decompofed, and in confe- 
^aence, a certain quantity of nitrous gas pro- 
duced. 

The apparatus that has been generally em- 
ployed in the medical pneumatic inilitution, for 
the pirodudtion of nitrous oxide, coniifts 

1:, Of a glafs retort, of the capacity of two or 
three quarts, orificed at the top, and fiirnifhed 
with a ground flopper. 

2, Of a glafs tube, conical for the purpofe 
of receiving the neck of the retort ; about ,4 
inches wide in the narrowed part, 4 feet long, 
curved at the extremity, fo as to be capable of 

* Except it be gold or pUtina, 



•\ 



( 120 ) 

introdudlton into an airholder^ and inclofed by 
tin plate to preferve it from injury. 

8- Of airholders of Mr. Watt's invention, 
filled with water faturated with nitrous oxide. 

4. Of a common air-furnace, provided with 
dampers for the regulation of the heat. 

The retort, after the infertion of the fait, ia 
connedled with the tube, carefully luted, and 
expofed to the beat of the furnace, on a con«-* 
venient ftand. The temperature is never fuf- 
fered to be above 600^. After the decompofi-- 
tion has proceeded for about a miqute, fo that 
the gas evolved from the tube enlarges the 
ilame of a taper, the curved end is inferred 
into the airholder, and the nitrous oxide pre^ 
ferved. 

The water thrown out of the airholders in 
confequence of the introdu^ion of the gas, 
is preferved in a veflel adapted for the pur- 
pofe, and employed to fill them again ; for if 
common water was to be employed in every ex- 
periment, a great lofs of gas would be prodqced 
from abforption. 



C 121 ) 

A pound of fibrous nitrate of ammoniac^ de« 
compofed at a heat not above 500^^ produces 
nearly 5 cubic feet of gas ; whilft from a pound 
of compact nitrate of ammoniac^ rarely more 
than 4^25 cubic feet can be coUedled. 

For the produdlion of nitrous oxide in quan- 
tities not exceeding 20 quarts, a mode fiill 
more fimple than that I have juft defcribed may 
be employed. The fait may be decompofcd by 
the heat of an argands lamp, or a common fire, 
in a tubulated glafs retort, of 20 or 30 cubic 
inches in capacity, furnifhed with a long neck, 
curved at the extremity ; and the gas received 
in fmall airholders. 

Thus, if the pleafurablc efFcdls, or medical 
properties of the nitrous oxide, fhould ever 
make it an article of general rcqueft, it may be 
procured with much lefs time, labor, and 
cxpence,* than moft of the luxuries, or even 
neceflaries, of life. 

• A pound of nitrate of ammoniac cofts about 5s. lOd. 
This pounds properly dccompofed, produces rather more 
than 34 moderate dofcs of air j fo that the cxpence of a 
dofc is about 2d, What fluid ftimulus can be procured at 
fo cheap a rate ? 



(124) 

comtnoti charcoal was employed^ the gas was 
neither increafed or diminifhed in bulk^ but 
wholly converted into nitrogcne ; when char- 
coal of copper was oied^ the yolume was a little 
increafed, and the gas remaining confided 
of J nitrogene, and y carbonic acid. 

In his experiments on the iron and pyropby^ 
rus, the nitrous gas was evidently decompoled. 
From thcr great quantity of nitrogens produced 
in thofe on the charcoal, it feems likely that both 
the common charcoal,* and the charcoal of 
copper employed contained atmofpherical air, 
which being difpelled by the heat of the lene^ 

* Dr. Prieftlcy fays, " having heated iron in nitrous air, 
I proceeded to heat in the fame air, a piece of charcoal 
not long after it had been fubjeded to a ftrong heat covcrW 
with fand. The fun not fhining immediately, aftar the 
charcoal was introduced into the vcfTel of air, through the 
*' mercury by which it was confined, part of the air wks 
*' abforbed 5 but on heating the charcoal, the quantity was 
" increafed. Having continued the progrefs as long as I 
^' thought necefiary, I examined the air and found it to be 
" about as much as the original quantity of nitrous air -, 
" but it was all phlogirticated air cxtinguifhing a candle 
^' and having no mixture of fixied air in it/'— -Experiments 
and Obfcrvations, Vol. 11, page ip. 



He 



( 129 > 

was decompofed by the nitrous gas : indeed^ 
till I made the following experiment, I fufpedled 
that the carbonic acid produced, when the char- 
coal of copper was employed, arofe from a dc- 
compofition of the nitrous acid, formed in this 
way. 

I introduced a piece of well-burnt charcoal, 
which could hardly have weighed the eighth of 
a grain, whilft red hot, under a cylinder filled 
with mercury, and admitted to it half a cubic 
loch of nitrous gas. A flight abforption took 
place. 

The fun being very bright, I kept the char- 
coal in the focus of a fmall lens for near a quar- 
ter of an hour. At the end of this time the gas 
occupied a fpacc nearly as before the expcri- . 
ment, and a very minute portion of the charcoal , 
bad been confumcd. On introducing into 
the cylinder a fmall quantity of folution 
of ftrontian, a white precipitation was per- 
ceived, and the gas flowly diminifhed to 
about three tenths of a cubic inch. To thefe 



( 126 ) 

three tenths a little common air was admitted^ 
when very flight red fumes were perceived. 

This experiment convinced me, that the si^ 
tradlion of charcoal for the oxygcne of ni*- 
trous gas, at high temperatures, was fufH- 
ciently ftrong to efFedl a flow decompofition of 

To be more accurately acquainted with this 
decompofition, and to learn the quantities of 
carbonic acid and nitrogene produced from a 
known quantity of nitrous gas, I proceeded in 
the following manner* 

II. jinalyjs of M/rous Gas ly Charcoal. 

A quantity of nitrous gas was procured in a 
water apparatus, from the decompofition of 
nitrous acid by mercury. A portion of it was 
. transferred' to the mercurial trough. After the 
mercury and the jar had been dried by bibulous 
paper, 40 meafures of this portion were agitated 
in a folution of fulphate of iron. The gas re-? 
maining after the abforption was complete. 



( 127 ) 

filled about a mcafure and balf ; fo that tlie 
nitrous gas contained nearly ^ nitrogene. 

Thermometer being 53°, a fmall piece of 
well burnt charcoal, the weight of which could 
hardly have equalled a quarter of a grain, was 
introduced ignited, into a fmall cylinder filled 
with mercury, graduated to ,10 grain meafurcs ; 
to this, l6 meafures, equal to l6o grain in. of 
nitrous gas, were admitted. An abforption of 
about one meafure and half took place. When 
the focus of a lens was thrown on the charcoal, 
a flight increafe of the gas was produced, from 
the emillion of that which had been abforbed. 

Afterthe procefs had been carried on for about 
a half an hour, the charcoal evidently began 
to fume, and to confume very flowly, though 
no alteration in the volume of the gas was ob- 
ferved. 

The fun not conftantly fhining, the progrefs 
of the experiment was now and then flopped : 
but taking the whole time, the focus could not 
have been applied to it for lefs than four hours. 
Whea the procefs was finiflied, the ga& was 



( 12® ) 

increafcd in bulk nearly three quart efs 6fH 
meafure. 

A drop of water was introduced into 
the cylinder, by means of a fmall glaft 
tube, on the fuppofition that the carbonic acid, 
and nitrogene, might be capable of holding 
in folution, more water than that contained 
in the nitrous gas decompofed ; but no 
alteration of volume took place. 

When 20 grain meafures of folution of pale 
green* fulphatcofiron were introduced into the 
cylinder, they became rather yellower than before, 
but not dark at the edges, as is always the cafe 
when nitrous gas is prefent. On agitation, a 
diminution of nearly half a meafure was pro- 
duced, doubtlefs from the abforption of fome 
of the carbonic acid by the folution. 

A fmall quantity of cauflic potafh, much 
more than was fufficient to decompofe the ful- 
phateofiron, was now introduced. A rapid 
diminution took place, and the gas remaining 

* That is, fulphate of iron containing oxide of iron, in the 
firft degree of oxygenation. 



( 120 ) 

filled aboQt 8 iheafuresi This g^ wad ilgitdted 

fbr fbme time over wiitcir, but no dbforption 

took place. Two meafurea of it were then 

transferred into a detdnating cylinder with two 

ibeafares of oxygene. The elediric fpark was 

palled thibugh them, but no ditbinution was pro« 

duced. Hence it was nitrogene, mingled with 

no afeertainable quantity of hydrogene : con- 

fequently little or no water could have been 

decoibpofed in the procefs^ o 

Now fuppofing^ for the greater eafe of calcu- 
lation, each of the meafares employed^ eubio 
itiches* 

16 of nitrous gas — ^^ = 15,4 were decom- 
pofed, and thefe weigh, making the neceflary 
. corrediidns, 5,2 ; but 7,4 nitrogene were pro- 
duced, and thefe weigh about 2,2. So that 
reaibning from the illative fpecific gravities of 
(ixtroas gas and nitrogene, 5,2 grains of nitrous 
gas will be compofed of 3 oxygene, and 2,2 
nitrogene. 

But 8,7 of carbonic acid were produced^ 

which weigh 41 grains, and cpnGft of 2,9 oxy- 

I 



(130) 

ges^s) .^nd ,1,2 charcoal.* Confcquently^ 
dra^ii^g condufions from the quantity of car;^ 
faofijc acid formed^ 5^2 grains of nitrous^ gas 
vriU cpn^ft of 2iQ oxygene^t and 2,3 nitrogene. 

The difFereacc in thefe eilimations is much 
le& than, could have been expedicd $ and taking 
the mean proportions^ it wonld be infi^rred 
from thein, that lOOgrains of nitrous gas> con- 
tain 56,5 oxygene^ and 43>^ nitrogene. 

I repeated this experiment with refults not 
very dtfierenty except tha|: the increafe of 
volmne was rather greater, and that more 
unabibrbable gas remained; which probably 
depended oa the decompofition of a mii^ute 
quantity of wata',, that had adhered to the 
.harcoal in paffiag throagh the mercury. ' 

Aa nitrous gas is decomppfable into nitrous 

acid^. and nitrogene, by the eledlriq fpark ; It 

« 

CBCCurred to me, that a certain quantity of 
nitrous acid might have been poffibly produced, 
in the experiments on the decompofition., of 
nitfH>iia gas, by the intenfely ignited charcQah 

"^Thatis^ carbos^ or oxido of diamond. 



( 131 ) 

To afcertain this circumftarlce, I introduced 
into I'i meaCures of nitrous gas^ a fmall piete 
of charcoal which had been juft reddened* 
The fun being very bright^ the focus of the 
lens was kept on it for rather more than an 
hour and quarter. In the middle of the proccfi 
it began to fume and to fparkle, as if in com- 
buftion. In three quarters of an hour^ the 
gas was increafed rather more than half a 
mcafure; bnt no alteration of volume took 
place afterwards. 

The mercury was not white on the top as is 
ufoally the cafe when nitrous acid is produced. 
On introducing into the cylinder, a little pale 
green fulphate of iron^ and then adding pruiiate 
ofpotalb, a white ^precipitate only was produ- 
ced. Now^ if ' the minuted quantity of 
nitxic add bad been formed, it would have 
been decompofed by the pale green oxide of 
iron^ and hence, a vifible quantity of pruflian 
blue* produced^ as will be fully explained here- 
after^ 

* Hiat isj blue pruOliatG of iroo. 



( 132) 



III. Analyjis of Nitrous Gas by PyrophortiS* 

I placed (bme newly made pyrophorus, about 
as much ad would fill a quarter of a cubic 
inch, into a jar filled with dry mercury, and 
introduced to it, four cubic inches of nitrous 
gas, procured from mercury and nitric acid. 

It infiantly took fire and burnt with great 
vividnefs for fome moments. 

After the combuftion bad ceafed, the gas 
V92& diminifhed about three, quarters of a cubic 
iiich. The remainder was not examined ; for 
the diminution appeared to go on for fome 
time, after ; in an half hour, when it was com-^ 
pleat, it was to 2 cubic inches, A taper, 
introduced into thefe, burnt with an enlarged 
flame, blue at the edges; from whence it 
appeared^ that they were compofed of nitrogene 
and nitrous oxide* 

I now introduced about half a cubic inch of 
pyrophorus to two cubic inches of nitrous gas ; 
the combuftion toak place, and the gas was 



( 133 ) 

rapidly diminiflied to one half; and on fufFerlng 
it to remain, five minutes to one-third nearlj ; 
which extinguifhed flame. 

Sufpedling that this great diminution was 
owing to the abforption of fome of the nitro- 
gene formed, by the charcpal of the pyrophorus, 
I carefully made a quantity of pyrophorus; 
employing more than two-thirds of alumn^ to 
one-third of fugar. 

Tq rather more than half of a cubic inch of 
thiSj two cubic inches of nitrous gas^ which 
contained about ^ nitrogene^ were admitted. 
After the combuftion^ the gas remaining, appa-' 
renily filled a fpace equal to 1,2 cubic inches; 
hut^ as on account of the burnt pyrophyrus in 
the jar^ it was impoilible to afcertain the volume 
with nicety, it was carefully and wholly trans- 
ferred into another jar. It filled a fpace equal 
to 1>15 cubic inches nearly. 

When water was admitted to this gas* no 
abibrption took place. It underwent no dimi« 
nution with nitrous gas, and a taper plunged 
into it was infiantly extinguifhed. We may 
confequently conclude that it wais nitrogen^* 



Now 2 cabic inches of tiitroiis gas weigh 
,686 grains, and l,l of nitrogenc — ,05, 
the quantity previoafly contained in the gas 

« 

= to 1,05, 3,19. Hence ,686 of nitrous gas 
would be cbrapofeB of ,367 oxygen^, and ,319 
oitrogene ; and IDO grains would contain 5854 
oxygene, and 46^9 nitrogene. 

■ ■ ■ . / ; . 

• I - 

. IV. Additional ohfervations on the comhuJHon 
of bodies in Nitrous Qas^ and oh its Corhfofi^ 
Aohf 

* * ■ ■ . 

Thoogli phoCpborus may be fu&d3 and even 
labliaied, • in nitroqs gas, without producing 
the flighteft luminous iappe^raQQe^**^ yet w^a 

• No luminous appearance is produced when pbofphorus 
is introduced into pure nitroqs gas! It has been often ob- 
&TVttd^ that phofphoroa is luminous 10 nitrous gas^ tl^^t has 
not been long in contact with water after its production. 
This phaenomenon, I fufped^ depends either on the decom- 
pofitioA of the nitric, acid held in folution by the nitrous 
l^as } or on the combination of the [Aofphorus with oxygene 
loofely adhering to the binary aeriform compound of nitric 
add and nitrons gas. I have not yet examined if xutrous 
gaf can be converted into nitrouft oxide by long exppfure 
fp be^te4 phofphorus : it appears^ however^ very probable. 



I 

6. 



( 135 ) 

it is introduced into it in a ilate of a^ive in-> 
flammation, it burns with almoft as much 
vividoefs as in oxygene.'"' Hence it is evident^ 
that at the heat of ignition^ phofpborus is 
capable of attradling the oxygene from the 
nitrogene of nitrous gas. 

I attempted to analife nitrous gas, by intro^ 
ducing into a known quantity of it, confined 
by mercury, phofphorus, in a veflel containing 
a minute quantity of oxygene.-f- The phofpho- 
rus was inflamed with an ignited iron wire, by 
vrbicb^ at the moment of the combufiion, the 
Veflel containing it was raifed from the mercury 
into the nitrous gas. But afler making in this 
way, five of fix unfuccefsful experiments, I 
defified. When the communication between 
the vefiels was made before the oxygene was 
nearly combined with the phofpborus, nitrous 

* Perhaps this faA has been noticed before 3 I have not, 
however, met with it in any chemical work. 

I 

f This mode of inflaming bodies in gafes, not capable of 
fupporting combailion at low temperatures^ will be par- 
ticialarly defcribed hereafter. 



(J36) 

^cid was formed, which inftantly deftroyed the 
COmbuftioQ ; when, on the contrary, the phof- 
phorus was fufFered to confume almoft the 
whole of the oxygene, it was not fpfficiently 
ignited when introduced, to decompof^, the 
nitrons gas. 

In one experiment, indeed, the phofphorus 
burnt for a moment in the nitrous gas ; the 
diminption, however was flight, and not more 
than f of it was decompoied. 

« ■ " ' ■ 

; Sulphur, introduced in a date of vivid in- 
flammb|tion, into njtrous gas, was in^antly 
extinguiflied. 

I pafled a flrong ele(5lric (hock through equal 
parts pf hydrogene and nitrous gas, confined by 
mercury in a detonating tube ; but no inflam- 
mation, or perceptible (diminution, was prq- 
duced. 

19,2 grain meafures of hydrogene were fired 
by the cle6lric ihock, with }Q of nitrous oxide, 
and 6 of nitrous gas ; the diminution was to 17 ; 
and pale green fulphate of iron admitted to the 
refldpuip, was not difcplored* Confeqiiiently the 



( 137 ) 

fiitrous gas was decompofed by the hydrogene, 
90d as will be hereafter more clearly underftood^ 
pearly as much nitrogene fumiihed by it^ as 
would bavQ been produced from half the quao«^ 
tity of nitrous oxide. 

Sufpe^ing that phofphorated bydrogene 
might inflame with nitrous gas^ I pafled the 
^e^ric fpark through I meafure of phofphorated 
bjdrogeoe^ and 4 of nitrous gas ; but no dimi- 
qution W9S perceptible, I likewife pafled tbe 
elei^ric (park through ] of nitrous gas, with 2 
of phofphorated bydrogene^ without inflamma- 
tion. 

Perhaps if I had tried many other different 
proportions of the gafes, I fhould have at laft 
discovered one, in which they would have in- 
ilaroed ; for, as will be feen hereafter, nitrous 
oxide cannot be decompofed by the compound 
combufiible gafes, except definite quantities are 

employed. 

From Dr. Prieftley^s experiments on iron and 
pyrpphorus, and from the experiments I have 
d^tailed^ on ct)arcoal, phofphorus, and hydro- 



( 138 ) 

» gene, it appears that at certain temperature53, 
nitrous gas is deconnipofable by nioH: of the cottt- ' 
buftible bodies : eVcn the cxtin<Sttori of fulphur, 

''when introduced into it in a ftate oif'ibfliinfha^ 
tion, depends perhaps^ on the fmaller quantity 
of heat produced by the combuftion^ of f his body> 
than that of moft otiiers, 

» . ... * . . , . 

The analy (is of nitrous gas by charcoal, as 

aflfbrding data for determining immediately flie 

■ ■. • . ' . " ■ ■ •. • '■.•.•' 

quantities of oxygene and nitrogcne, ought to 

... 

be coniidered as moft accurate ; and corre<3ing 
it by mean calculations derived from the decom- 
pofition of nitrous gas by pyrophorus and hydro- 
gene, and its converfion into nitrous oxide, a 
procefs to be defcribed hereafter, we may con- 
clude, that lOOgrains of nitrous gas are compofed 
of 55,95 oxygene, and 44,05 nitrogcnej or 
taking away decimals, of 56 oxygene, and 44 
nitrogene. 

This eflimation will agree very well with the 
mean proportions that would be given from Dr. 
Prieftley*s experiments on the decompofitioa 
of nitrous gas by iron ; but as h& never afcer- 



( 139 ) 

tained the purity of bis nitrous gas^*' and proba- 
bly employed different kinds in different expe- 
rimentSy it is impoilible to fix on any one, from 
vbich acourate conclufions can be drawn. 

Lavoifier's eilimation of the quantities of oxy- 
ll^neaad xu.trogene entering into the compofitioo 
of niiti?cms gas> Jbas been generally adopted. 
Hf Cupppfes 64 parts of nitrous gas to be com- 
pofed qf 43^ of oxygene,^ and 20^ of nitro* 

The difference between this account and 
mine is very great indeed ; but I have already, 
iil^Divilion ift, pointed out iburces of error in 
the experiments of this great man^ on the d^ 
coQipofijtion of nitre by charcoal ; which expe- 
noients were fundamental, both to his accounts 
of the conflitution of nitrous acid, and nitrous 



* EkmcntB Englifli Tranf. edit. I pag. 216. 
f j:g^pcrime»t» an4 Obfervations, Vol. II. pag. 40, 2tl. Ed. 



( 140 ) 

v., Of the abforpfiakr of Nitrous Gas hy 

Water. 

Amongii the properties ot nitrous gas noticed 
by its ^reat dlfcoverer, is that of abforbability 

by water. 

In expofing nitrous Atio diftilled water^ Dr. 

■ ■ • . *■" 

Prieftlcy found a diminution of the volume bf 

gas^ neaHy eq&al to btie tenth of the 1)alk of 

the water ; and by boilmg the water Ihus irki* 

pregnated^ he procured again a certain ipdhioii 

of the nitrous gas. 

Humbolt^ in his paper on eudiometiy, men- 

^ ttons the diminution of nitrous gas by water. This 

" diminution, he fuppofes to arife from the decom- 

pofition of a portion of the nitrous gas^ by the 

water, and the conlequent fornlation of nitrate 

of ammoniac.* 

♦ He fays, " On a obferv6, (depuis qu*on travaille fur le 
^ purete de Tair) que le gaz nitreux, fecoue avec Teaoj ea 
fouffire une dimiDution de Tolume. Quelques phjficiens 
attribaent ce cbaDgement ^ une vraie abforptipn, a une 
*' diflblutioD da gaz nitreux dans Teau 3 d*autres ^ Tair con- 
" tenn dans les interilices de tons les fluides. Le dt. 
<' Vanbreda^ i Delft, a fsut des recherches tr^-exa6^ for 
Mnflnence des eaux de pluie et de poit, for les nombres 
endioiii^triques | et les belles experiences da cit. Haflen^ 






4e 

u 



( 141) 

1 confefsj that even before the following ex- 
periments were made, I was but little inclined 
to adopt thfs opinion : the fmall diminution 
of nitrous gas by water, and the uniform limits 
of this diminution, rendered it extremely im^ 
probable. 

a. To afcertain the quantity of nitrous gas 

" fratSj fur l^aboodanoe d'oxygc^oe, conteaue dans les caux 

*' de Jtieige ct dc pluie, font fuppofer que I'air des interdices 

'' de I'eau joue aa role important dans Tabforption du ga2 

^'.nhrenx. Enconaparant ces effets avec les ph6nomene8 

obferv^ dans la decompofition du fulfate de fer^ nous fup- 

" poitoes^ le cit. TalTaert et moi^ que le iirople contadi: du 

gaz Ditreax avec Teau diilillce pourroit bien caufer une 

d6oompofition de ce dernier. Nous examinilmes foign- 

*J eafement une petite quantity d'eau diflillde, fccou6e avec 

" beaaopup de gas nitreux tres-pur, et nous trouvumes^ 

" ao mojen de la terre calcaire, et Tacide muiiatique, qui! 

*' **y ferme du mtrate eTammQniaque, L'eau fe decoropofe 

** CQ 'Cette op6ration, par un double affinity de Toxygene 

" pour le gaz nitreux^ et de Thydrogene pour Tazote -, il fe 

forme de I'acide nitrique et de Vammoniaqite', et, quoiqne 

la quantity da derAier paroifTe trop petite pour en ^valuer 

** €xa6trocnt la quantite, fon exiftence oependant fe mani- 

fefie, (^ ne pas fans douter) par le degagement des va- 

peurs, qui blanchifient dans la proximit6 de Tacide mu - 

riatique. Voila un fait bien frappant que la compofition 

*' d'une fubflance alcaline par le contad d'une adde^ et de 

" I'ran. 

Annales dc Chimie, t. xxviii. pag. 153, 



<€ 
4t 
if 
4€ 






U 

4t 



( 142 ) 

abtorbable by pure water, and the HoaitB of ab- 
forpticm, I introduced into a glals retort about 
5 ounces of w^ter, which bad been previouily 
boiled for fome hours. The neck of the retort 
was inverted in mercury, and the water made 
to boiK After a third of it had been difiilled^ 
fo that no air could poffibly remain in the re- 
tort, the remainder was driven over, and cort-* 
denfed in an inverted jar filled with mercury. 
To three. cubic inches c^this water,* confined 
an a cylinder graduated to ,o5 cubic inches, 5 
cubioinches of nitrous gas, containing nearly one 
thirtieth nitrdgene, were introduced. 

After agitation for near an hour, rather mor^ 
*ban ^ of a cubic inch appeared to be abforbcd; 
but though the procefs was continued for near 
two hours longer, no further dimitiotioii took 
place. 

The remaining gas was introduced into a 
tube graduated to ,04 cubic inches. It mea- 



14 1 11 



fured ^ ; hence ~ had been abforbed. 



* Which was certainly as free from air as it cyer can he 
•btained. 



f^ 



( 143 ) 

Confeqiiently^ 100 cubic inches of pure wa- 
ter are capable of abfbrbing 1 1,8 of nitrous gas. 
In the water thus impregnated with nitrous 
gas I could diftinguiOi no peculiar taftc ;* it 
did not at all alter the color of blue cabbage 
juice. 

i. To determine if the abforption of nitrous 
gas was owing to a decompofition of it by the 
water^ as Humbolt has fuppofed, or to a fimple 
iblution ; I procured forae nitrous gas from 
nitrous acid and mercury^ containing about 
oiie ieventieth nitrogene. ^S cubic inches of 

ft 

it, mingled with 25, of oxygene, from ful- 
phurie acid and mangahefe left a refiduum of 
,03. 5 cubic inches more were introduced 
to 3 of water, procured in the fame manner as 
in the laft experiment, in the fame cylinden 

* Dr. Pricftley found diftillcd water, faturated with 
nitrous air, to acquire an aftringent tafte and pungent 
fmoll. In feme unboiled impregnated pump water, I onct- 
thought that I perceived a fubacid tafte ; but it was ex- 
tremely flight, and probably owing to nitrous acid formed 
by the ilmon of the oxygene of the common nirin the wa- 
ter, with fcraeof the nitious gas. 



( 144) 

After tbe diiiiination was complete^ the cyiitjdtt 
tvas transferred in a fmall veilel contaitifbig nier-«> 
cury, into a water bath, aod nrearly eOfircfred by 
tbe water. 

As tbe bath was heated, fmatl globules of 
gas were given out from tbe impregnated water, 
and when it began to boil, tbe produ£lion of 
gas was ftill more rapid. After an hour's ebul^ 
lition, the volume of heated gas was equal to 
1,4 cubic inches nearly. 

The cylinder was now taken out off the bdth> 
and quickly rendered cool by being placed in 
a water apparatus. At tbe common temperature 
the gas occupied, as nearly as poi&ble, the fpace 
of ,5 cubic inches : thefe ,5 mingled with ,25 of 
oxy gene, of the fame kind as that employed 
before, left a refiduum nearly equal to fiS. 

From this experiment, which was repeated 
with nearly the fame refults, it is evident, 

1, That nitrous gas is not decompofable by 
pure water. 

2, That the diminutbn of volume of nitrous 
gas placed in contadl with water, is oHving to A 
iimple folution of it in that fluid. 



( 143 ) 

d. That at the temperature of 212^, nitroui 
gas is incapable of remaining in combination 
with water. 

Humbolt's opinion relating to the decompo'* 
fiti.dn of nitrous gas by water, is founded upon 
the difengagement of vapor from diflilled water 
inipregnated with nitrous gas by means of lime^ 
which became while in the proximity of the mu- 
riatic acid. But this is a very imperfedl^ and 
fiillacious teft, of the prefencc of ammoniac. I 
have this day, April 2, 1800, heated 4 cubic 
inches of diftilled , water, impregnated with 
nitrous gas, with caudiclime; the vapor cer« 
tainly became a little whiter when held over a 
veflel containing muriatic acid ; but the vapor 
of difiilled water produced precifely the fame 
appearance,'* which was owing, mod likely, to 



* As carbonic acid and ammoniac are both produ6b of 

I 

aoixnalifation, is it not probable that our common waters 
particdlsrlj thofe in^ and near towns and cities, contain car- 
bonate of ammoniac ? If fo, this fait will always exifl in 
them after difHllation. In the experiments on carbonate of 
amraoDtac^ to which I have often alluded, I found, in 
diflilling a folution of this fait in watcr^ that before half of 

K 



( 146 ) 

tile dHnbintition of the acid \iv4th tire aquedos 
▼apor. Indeed^ when I added a particle of 
nitrate of ammoniac, which might have equalled 
one twentieth of a grain^ to the lime and im- 
pregnated water, the increafed whitenefs of the 
vapor wa8{ biit barely perceptible, though this 
quantity of nitrate of ammoniftc is much moro 
confiderable than that which could have beett 
formcdi even Tuppofing the nitrous gas decom- 
ipofed. 

' * r - 

Vl. Of the ahforpion - of Ulifous Gas ly 
Water of different kinds. 

In agitating nitrous gas over fprlng water, 
the diminution rarely amounts to more than 
dne thirtietb, the volume of water beiWg taken 
as unity. I at firft fufpedled that this great dif- 



the water had pafled into the recipient, the carbopate 
of ammoniac had -fublimed^ fo that the ^(lilled fplation 
was'much (Ironger than before, whilft the water remaining 
in the retort was taftdefs. Will this fuppofition at aU ex- 
plain HumboU's mifiafce ? 



(147) 

ferehce in the quantity of gas abforbed by fprirlg 
water, and pure water, depended on carbonic 
tLcid contained in tbe lad, diminiihing the at- 
tra^ion of it for nitrous gas : but by long boil- 
ing a quantity of fpring water confined by mer- 
cury^ I obtained from it about one twentieth of 
its bulk of air, which gave nearly the fame 
diminution with nitrous gas, as atmofpheric 
air. 

This fa<Sl induced me to refer the difference! 
.of diminution to the decompofiticm of the at- 
mofpheric air held in folution by the water^ 
the oxygen e of which I fuppofed to be con- 
verted into tiitric acid, by the nitrous gas> 
WbilA the nitrogene was liberated ; and hence 
the increafed refiduum. 

a. I expofed to pure water, that is, water 
procured by didillation under mercury, nitrous 
gaSj containing a known quantity of tiitrogeqc* 
After the abforption was complete, I found the 
:faine quantity of nitfpgene in the refidqum, as 
was contained in a volume of gas equal to tbe 
whole quantity employed. 



( 148 ) 

I 

I. Spring water boiled for Ibme hquns, and 
fdfFered to coiol linder mercury, abibrbeda quart- 
tity of riitro/us gas equal to one thirteenth of its 
bulk ; wbibh is not tnuch Icfs than that 
abfbrbed by pure water. ' * 
' c. I expofed to fpring water, 10 meafures of 
nitrouls gas ; the compofitton of which had 
been accurately afcertairied ; the diminution 
was one twenty-eighth, the volume of water 
^ing taken as unity. On placing the refiduum 
iTi contadl with folution of fulphate of iron, the 
•ttitrogente^r^irhainitig was nearly one-twentieth 
Tnore th^ti Frad been c6ntain(id by Ihe gas 
before its expbfure to water. 

d. Diftilled water was fatural^d with com- 
mon air, by being agitated for feme time in the 
atmofphere. Nitrous gas placed in contadl with 
this watei^, 'Underwent ^ diminution of ~ ; 
the voliime^f watfer teing imity. The gas re- 
maining after the abforption contained about 

■one twenty - feventh nitrogene nK>re than 

' before, 

e. Nitrous gas expofed to water combined 



( 149 ) \ 

with about one fourth of its volun^ of carbonic 
acid, diminifhed to - * nearly. Tfie remainder 
contained little or no fuperabuc^ilant nitro- 
jgene. ( 

From thefe obfervations it appei^rs, that the 
different degrees of diminution of nitrous gas 
by different kinds of«wa|0|j|MiMiy depend upon 
various caufesl^ '' ■i^t'^^ 

1. Lefs nitrous gas will be abibrbed by 
water holding in folutjon earthy falts, than by 
pure water ; and in this cafe the diminution of 
the attraction of water for pitrous gas will pro- 
bably be in the ratio of the quantities of fait 
combined with it. a, h. 

2. The apparent diminution of nitrous 
gas in water, holding in folution atmofphe- 
ric air, will bp lefs th^n in pure water, 
though the abfolute diminution will be 
greater ; for the fame portion will be abforbed, 
whilfl: another portion is combined with the 
oxygene of the atmofpheric air contained in the 
water; and from the difengagement of the 



* The water fiill being- unitj, 



( 150 ) 

nitrogcne of this air, arifes an increaftd refl-r 
duum* c. d. 

3. Probably in waters containing nitrogene, 
hydrogene, and other gafes, abforbable only to 
a flight extent^ the apparent diminution will be 
le!^9 on account of the difengagettient of thofc 
gafes from the water, by the Aronger affinity of 
nitrous gas for that fluid. 

4. In water containing carbonic acid^ and 
probably fome other acid gafes^ the diminution 
will be fmall in proportion to the quantity of 
gas contained in the water : the affinity of 
this fluid for nitrous gas being diminifhed by its 
greater affinity for the fubflance combined 
with it. ^. 

The different diminution of nitrous gas when 
agitated in different kinds of water, has been 
Jong pbferved by experimenters on the conftitu- 
fcnt parts of the atmofphere, and various folutions 
have been given of the phaenomenon ; the mod 
lingular is that of Humbolt.* He fuppofes 



* He fays " lOOparttes^egaz mtrcux, {^ o.l4 d'azote) fe- 
ff cott6es ayecreau difUUee. r^cemmehtcuite. dimiouent ei^ 



( isi ) 

• that the apparent diminution of nitrous gas is 
le& in fpring water than diftilled water^ on ac- 
count of the decompofition of the carbonate of 
lime contained in the fpring water, by the nitrous 
acid formed from the contact of nitrous gas 
with the water ; the carbonic acid difcngaged 
from this dccompofition increafing the reli- 
duum. 

This opinion may be confuted without even 
reference to my obfervations. It is, indeed, 



^f Yolonie de 0.1 1^ ou 0.12. Ce mtuxxc gaz, en contad avec 
'' I'cau de puits, ne perd que 0.02. La caufe de cette dif- 
*' f6rence dc O.p, ou O.IO, nc doit pas t^tre attribute ni k 
''Timparite de Tair almorpberique, contenu daosles intei^ 
*' ftices de I'eau, ni <\ la decompofition de cette eau merae. 
** Bile n'cft qu'apparcDte ; car Tacidc nitriquc, qui fe forme 
5' par le Contat^ du gaz nitreux avec Veau de puits, en de* 
•" Gompofe le carbonate de chaux. II fe dt^gage de Tacide 
^* carbonique, qui^ en augmentant le volume du refidu, rend 
" Tablbrpdon du gaz nitreux moins fcmtible. Pour deter- 
*' miner la quantitc de cet acide carboniquc, je lavai le 
" r6fida avec de I'eau de chaux. Dans un grand noqnbre 
** d'exp6riences, le volume diminua de O.09, ou 0,07* II 
f faul ea concluire que Teau de puits (iblbrbc rcclleraent 
" 9 -{- 2, ou 7 -j- 2 parties de gas nitrcux, c'eft-i^-dire, i 
f* peu-pr^s la meme quantitc que I'eau diftillee." 

Apnales deChimie^ xiLviii. pag. 1.54, 



t 152 ) 

altogether. unworthy of a pfailoiopher, generally - 
acute and ingenious. He feeuis to.bave for^ 
gotten that carboqip dcid is abforbable by 
wat^r. . 

VII. Of th$ abforptim of Nifrqus Gas, by^ 
/(glutton ofpaje gfeen Sulphate of Iron. 

a. The difcovery of the exadl difference be- 
tween the fulphates of iron, is owing to Prouft.* 
According to the ingenious refcarches of this 
chemift, there exift two varieties of fulphate of 
iron, the green and the red. The oxide in the 
green fulphate contains -^ oxygene. This fait, 
"when pure, is infoluble in fpirit of wine ; its 
folution in water is of a pale green color ; it is 
not altered by the gallic acid, and affords a 
white precipitate with alkaline prufliates. 

The red fulphate of iron is foluble in alcohol 
and uncryflalizabl^; its oxide contains ^ oxy- 
gene. It forms a black precipitate with the 
gallic acid, and with the alkaline prufliates, a 
blue one. 

* J^icholfon's Phil. Jour. No. 1, p. 453. 



( 153 ) 

The common falpbates of iron generally con- 
fift of combinations of thefe two . varieties in 
difierent proportions. 

The green fulphate may be converted into 
tiie red by oxygenated muriatic acid or nitric 
acid. The common fulpbate may be converted 

into green fulphate, by agitation ixi contadl 

I 

with fulpburated hydrogene. 

Thergreen fulphate has a flrong affinity for 
^ygene, it attracls it from the atmofphere,. from 
oxygenated marine acid, and nitric acid. The 
alkalies precipitate from it a pale gree^^ oxide, 
which if expofed to the atmofpbere, rapidly be- 
comes yellow red. 

The red fulphate of iron has no alHnity 
for oxygene, and when decompofed by the 
alkalies, gives a red precipitate, which under- 
goes no alteration when expofed to the atmof- 
pbere.* 

b. The abforption of nitrous gas by a (blution 
of fulpbate of iron, was long ago difcovered by 

* I have been able to make thefe obfervations on the 
iulphatcs of iron, mod of them after Proull. 



( 154 ) 

Prieftley* During this abibrption^ he remarked 
a change of color in the folution, analogous to 
that produced by the mixture of ijt A^itb nitHo 
acid, 

X^is chemical (a€t has been lately applied 
by Humbolt, to the difcovery of the nitrogseae 
generally mingled virith iiUrous gas* 

Vauquelin and H^miiolt have ppbli&eijr 
a memoir, on the causes of the absorp- 
tion* of nitrous gas by iblution of fulpjb^te 
of iron. They faturated an ounce and half of 
lulphate of iron, in folution, with 180 cubio 
inches of nitrous gas. 

Thus impregnated it ftrongly reddened tinc- 
tureof turnlbyle ; when mingled with fulphuric 
acid, gave nitric acid vapor ; and faturajted with 
pdta(h, ammoniacal vapor. 

By analyfis, it produced as much ammoniac 
as that contained in 4 grains of ammoniacal 
muriate, and a quantity of nitric acid equal to 
(hat extfting in 17 grains of nitre. Henc^they 



^' Annales 4e chimie^ vol. xxviii. pag. :(82. 



( 155 ) 

concluded, that the nitrous gas and a portion of 
the water of the Iblution, had mutually decom- 
poled each other; the oxygene of the water com* 
bining with the oxygene and a portion of the 
BitFc^ne of nitrous gas to form nitric acid ; 
and its hydrogene uniting with the remaining 
pitrogene^ to generate ammoniac. 

They have taken no notice of the nature of 
the fttlphate of iron employed^ which was mod 
probably the common or mixed fulphate ; nor 
of the attradion of the oxide of iron in this fub- 
ftance for oxygene. 

c. Before I was acquainted with the obfervations 
of Proufti the common fa6ls relating to the 
oxygenation of vitriol of iron induced me td 
fuppofe, that the attraction of this fubilance for 
pxygene was in fome way conne6led with the 
procefs of ablbrption. The comparifon of the 
experiments of Humbolt and Vauquclin, with 
Jhc obfervations of Prouft, enabled me to dif- 
icover the true nature of the procefs. 

I procured a folution of red fulphate of 
\tQti^ by paffing oxygenated muriatic acid 



( 156) 

through a folution of common fulpbate of iron^ 
till it gave oplj a red precipitate, when mingled 
with cauflic pota(h. To nitrous gas confined 
by mercury, a fmall quantity of this folution 
was. iptroduced. jOn agitation, its color altered 
to muddy gr^en ; . bpt. the |E^bfq^ption that took 
place was extremiely trifling : . in half an hour 
it did not amount to ,2, the volume of the 
iblution being unity, when it had nearly rQ«- 
gained the yellow color. 

I now obtained a folution of green ful- 
phate of iron, by diitblving iron filings in diluted 
fiilphuric acid. The folution wai$ agitated in 
contact with fulphurated hydrogepe, and after- 
wards boilcid ; when it gave a white precipitate 
with pruffiate of potafli. 

A fmall quantity of this folution agitated in 
nitrovis gas, qpickly became of an olive brown^ 
and the gas was diminilhed with great rapidity ; 
in two minutes, a quantity equal to four times 
the volume of the folution, had been abforbed. 

Thefe fa6ls convinced me that the folubility 
of nitrous gas in common fulphate of iron. 



( 157 > 

chiefly depended upon the pale green fulphatc 
contained by it ; and that the attraflion of one 
of the conftituents of this fubftance, the green 
oxide of iron, for oxygene, was one of the 
caufes of the phsenomenon. 

d. Green falphate of iron rapidly decompofcs 
nitric acid. - It was confequentiy difficult to 
conceive how any affinities exifting between ni- 
trous gas^ water^ and green~ fulphate of iron^ 
could produce the nitric acid found in the ex- 
periments of Vauquelin and Humbolt. 

To afcertain if the prefence of a great quan- 
tity of water deftroyed the power of green ful- 
phaite of iron to decompofe nitric acid, I intro- 
duced into a cubic inch of folution of green 
fulpbate of iron, two drops of concentrated 
nitric acid. 

The folution affiimcd a very light olive color ; 
pru'ffiate of potafh mingled with a little of it^ 
gave a dark green precipitate. Hence the 
nitric acid had been evidently decompofed. As 
no nitrous gas was given out, which is 
always the cafe when nitric acid is poured on 



.( 15d J 

cryftalifed fulphate of iron, I fufpedied tW 4 
compleat decompbiition of the acid had t^J^oH 
place ; but wbeojthe folotioa was heated, a feivi^ 
minute globules of gas were liberated, and iC 
gradually became flightly clouded. 

Having often remarked that no precipitation 
is ever produced during the converfion of green 
fuiphate of iron intq red, by oxygen^ate^d muri- 
atic acid, or concentrated nitric acid, I cofidd 
refer the cloutddnefs to vtQ other caufe than to 
the formation of ammoniac. 

To afcertain iftbis fubftaiice had* been pro- 
duced, a Quantity of flacked caoftic lime was^ 
thrown into the. folution. On the application 
of heat, the ammoniacal fmell was dHlindlly 
perceptible, and the vapor held over oxange 
nitrous acid, gave denfe white fumes. 

e. When I confidered this fed of thi5 decom-^ 
pofition of nitric acid and water by the ibltttiofi 
of green fulphate of iron, and the change of 
color effedied in it by the abforption of nitrous 
gas, exa<Slly analogous to that produced by the 
decompofition of nitric acid ;^I was induced te 



( 159 ) 

believe that the nitric acid found iti the analy(i<) 
of Vauquclin and Hunibolt, had been formed 
by the combination of fome of the nitrous gas 
thrown into the folution with the oxygene of 
the atmofphere : and that the abforbability of 
nitrous gas, by folution of green fulpbate of 
iron, was owing to a decompofition produced 
by the combination of its oxygene with the 
green oxide of iron, and of its nitrogcne with 
the bydrogcne difengaged from water, decom- 
pounded at the fame time. 

To afcertain this, I procured a quantity of 
nitrous gas: it was fuffered to remain in con- 
tadi: with water for ibme hours after its pro- 
duction. Transferred to the mercurial appa- 
ratus^ it gave no white vapor when placed 
in conta6l with folution of ammonijtc ; and con- 
iequently held no nitric acid in folution. 

' Into a graduated jar tilled wilh mercury, a 
Cubic inch of concentrated folution of pure 
green fulphate of iron was introduced, and 7 
cubic inches of nitrous gas admitted to it. 
The folution immediately became dark olive at 



( 160) 

the edges;t^alulion' agitation this color was xlifw 
fufedthroughfit^l In 3 minutes, when near 5^ 
cubic inches bad been abforbedy thb diminutioa 
ceafed. . 'Thefblution was now of abrightolivfe 
brown, and transparent at t^edges.> After it bad 
refted for a: quarter of an bour^ iio farther at>- 
forption was • observed ; the. color was the 
iame^ and no precipitation could be perceived^ 
A little of it waS'tbrownintaa fmall glafs tube^ 
under the tneroory, and exaihined in the at^ 
mofphere. Its tafle was rather more aftringent 
than that of folution of green fulphate; it 
did not at all alter the color of red cabbage 
juice. When a little of it was [loured on the 
mercury, it foon loft its color, its tafte became 
acid, and it quickly reddened cabbage juice, 
even rendered green by an alkali. 

To the folution remaining in the mercurial 
jar, a fmall quantity of prufiiate of potafh was 
introduced, to afcertain if any red fulphate of 
iron had been formed; but inftead of the pro^ 
duflion of either a blue, or a white precipitate, 
the whole of the folution became opaque^ arid 
chocolate colored. 



( l6i ) 

Sdrprifed at this appearance, I was at firft 
ihducisd to fuppofe, that (be ammoniac formed 
By the aitrogene of the nitrous gas and the 
bydrogene of the watcrj had been fuificient to 
precipitate from the fulphuric acid, the red 
oxide of iron produced, add that the color of 
the ihixture was owing to this precipitation. 
To diilblvc any uncombined oxide that might 
exift in the folutidn, I. added a very minute 
quantity of diluted fulphuric acid ; biit little 
ftlteriition of color was produced. Hence, evi- 
d^iltly, no red oxide had been formed. 

This unexpedled refult obliged me to theorife 
i fecond time, by fuppofing that nitrate of am-- 
xtioniac'had been produced, which by combining 
Witt) the white prtiffiate of iron^ getlerated a 
neW cdnibination. . But on mingling together 
gi^n fiilphate of iron, prufli^te of potafh, and 
nitrate of ammoniac in the atmofphere, the 
tnixture remained pcrfe<31y white. 

To afccrtain if any nitric acid exiAed, com- 
bined with any of the bafes, in the impregnated 

f()lutioD, I introduced into it an equal bulk 

L 



( 1^2 ) 

of diluted lilphuric apjd :^ it becamq ;rattief 
paler ; but no green xn- blue tinge was produced. 

Tbs^theptuffic acid had not beeq decompofed^ 
was evident from ;tbe bright greeA produced; 
when tefs than a gram of dilute nitric acid was 
admitted into the (blution. 

/. From theie experiments it was evident, that 
no red folpbate of iron, or nitric acid, and conie- 
quently no ammoniac^ had been produced after 
the abforptioa of nilroui gas by green folpiiat^ 
of iron^ And when I c^ompared them with tiic 
obfervatioos^ of Prieftlay, who had expelled, fay 
Keat a minute quantity of nitrous gas from an 
impregmted (blutipn of common fulpbate of 
iron, and who found common air phlogifticated 
by fianding i|i conta6l with it, - 1 beg^n to fiif- 
pe6t that nitrous gas was limply diilblved in 
the fblution^ without undergoing deebmpofi^ 

lion. ' . 

g. To determine nwre accurately the nature of 
the proceik^ I introduced into a mercurial 
cylinder 410 grains of folution of green fulphat^ * 
of iroo> occupying a fpace nearly equal to a 



( I6d ) 

cubic iiich and quarter ; it was faturat^d with 
nitrous gas, by abforbing 8 cubic inches^ Thift 
faturated folutioii exhibited the fame appearance 
as the lad ; and after remaining near an hour 
UBtouched; bad evidently depofited nd oxide 
of iron, nor gained any acid properties. 

Into a fmall mattrafs filled with mercury^ 
having a tight ftopper with a curved tube 
adapted to it, the greater part of this folution 
waa introduced ; judging from the capacity of 
the mattrafs, about 50 grains of it might have 
been loft. To prevent common air from coming 
in conta6t with the folution, the ftopper was 
introduced into the mattrafs under the mercury ; 
the curved tube connected with a graduated 
cylinder filled with that fubftance ; and the 
mattrafs brought over the fide of the mercurial 
trough. But in fpite of thefe precautions a 
]arg« globule of common air got into the top of 
the mattrafs, from the curvature of the tube« 
When the heat of a fpirit lamp was applied to 
the folution, it gave out gas with great rapidity, 
AQd gradually loft its color* When 5 cubic 



( 1«4 ) 

inches t^ere 'c6lle6led it became perfeAly pale 
green, whilft a yellow red precipitiale was depo*- 
fited on the bottom of the mat trafs. 

On pouring a little of the clear folution into 
pruffiate of pota(b, it gave only white praffiate 
of iron. 

But on introducing a particle of fulpburic 
acid into the folution^ fuiHcient to diilblve (bine 
of the red precipitate, and then pouring a 
little of it into a iblution of pruffiate of potafb, 
it gave a fine blue pruffiate of iron. 

Hence the red precipitate was evidently red 
•yellow oxide of iron. 

I now. examined the gas, fufpeding that it 
was nitrous oxide. On mingling a little of it 

with atmofpheric air, it gave red vapor, and 

♦ 

diminifhed. Solution offulphateof iron intro- 
' duced to the remainder, almoft wholly abforbed 
it ; the fmall refidual globule of nitrogen^ could 
not equal one thirtieth of a cubic inch. 
' Confequently it was nitrous gas, nearly pure. 
Cauftic potafh was now introduced into the 
folution^ till all the oxide of iron was precipi- 
tated. The folution, when heated, gave a 



( 165 ) 

llrong fmell of ammoniac, and denfe white 
fumes when held over muriatic acid. It was 
kept at the heat of ebullition till the evapora-^ 
tion had been nearly compleated. Sulphuric 
acid poured upon the refiduum gave no yellow 
fumdi^ or nitric acid vapor in any way per- 
eeptible ; even when heated and made to boil, 
there was no indication of the production of 
any vapor, except that of the fulphuric acid. 

i. This experiment, compared with the other?t, 
ieemed almoft to prove, that nitrous gas 
eotnbined with folution of pale green fulphate 
of iron, at the common temperature, without 
dcKrompofition ; and that when the impregnated 
Solution was heated, the greater portion of gas 
was difengaged, whilft the remainder was de- 
compounded by the green oxide of iron ; which 
attracted at the fame time oxygene from the 
water and the nitrous gas ; whilft their other 
conftituent principles, hydrogerjc and nitrogcne, 
entered into union as ammoniac. 

■ Whilft, however, I was rcafoning iipon this 
iingular chemical change, as affording prev 



{166) 

fiiinptive proofs in favor of the exertion ot fim-« 
pie affinities by the coniiituent parts of com-r 
pound fubftances, a doubt concerning tfa^ 
decompofition of the nitrous gas occurred to 
xne. As near as I could guefs at the quantity 
of nitrous gas contained by the impregoated 
fblution, at lead ^ of it inuft have been expelled 
undecompounded. 

More than a quarter of a cubic inch of com^ 
mon air had been prefent in the mattrais : the 
oxygene of this common air mail have comt 
bined with the nitrous gas, to form nitric acid* 
Might not this nitric acid have been decoiii-^ 
pofed, and furniihed oxygene to (he red OKi4tt 
of iron, .and nitrogene to the fmall quantity gf 
ammoniac found in the folutioi), ^s in if? , 

i. I now introduced to a folution of green ful- 
phate con^ned by mercury, nitrous gas, per? 
fedly free from nitric acid. When the folutioi) 
was faturated, a portion of it was introduced 
into a fmall mattrafs filled with dry mercury, in 
the mercurial trough. The curved tube was 
clofcd by a fmall cork at the top, aiid filM 



« 



i^Ufa^. citrous gas ( it was the» adapted to the 
m^^trsUsy which was raifed from the trough, and 
the (qlution thus elfedlvially preferved from the 
4^iitfl<^ of the atmofpbere* 

When the h^at of a fpirit lamp was applied 
to the mattrafsi it began to give out gas with 
great rapidity. After fome time the folntion 
Joft its dark color^ and became tarbid. Whea 
the produdlion of nitrous gas bad ceafed^ it was 
/uffered to cooK A copious xcd precipitate 
liadv fallen down ; which, examined by the fame 
tefip as in the laft experinoent^ proved to be 
red oxide of iron. 

The folution treated with lime,, as before, 
gave ammoniac ; but with fuiphuric acid, not 
the flighteH indications of nitric acid. 

i. Having thus procured full evidence of the 
decompofition of nitrous gas in the heated foUi^ 
tion, in order to gain a more accurate ac- 
quaintance with the affinities exerted, I endea^ 
voured to afcertain the quantity of nitrous gai 
decompofed by a given folution^ under known 
circumftances. 



; 



( 168 ) 

Into a bylinder of the capacity of ^W> cubk 
inches, inverted in merciity,' 1 1 50 grains of 
ibhition 6f greeafulphate of fron, of f|>€dific 
gravity 1.4^ were introduced. Nitrous gas was 

• • • 

admitted to if, and after ibme tiirie 21 cubic 
inches were ablbrbed. 

The impregnated fblutiori was thrown into a 
mattrafs, in the (ame manner as in the laft ex- 
pcriment, and the fame precautions taken to 
prefervc it from the Contadl of a tmofpheric air, 
A quantity was loft during the procefs of tranf- 
ferring, which, reafoning from the fpace occu- 
pied in the mattrafs by the remaining portion, 
as determined by experiment afterwards, muft 
iave amounted nearly to 240 grains. 

The curved tube from the mattrafs was now 
ifiade to communicate with the mercurial' air- 
holder. By the application of heat 12,5 cubic 
inches of nitrous gas were collected, after the 
common temperature had been reftored to the 
mattrafs ; which was fuffered to remain in com- 
munication with the conducting tube. 

'!f he folution was now pale green, thatis, of its 



(169) 

liafural color, and a coniiderable quantity of 
red oxide of iron had been depoiited. 

Solid cauftic potafli was introduced into it, 
till' all the green oxide of iron had been precipi* 
fatcd^ and till the folution rendered green, red 
cabbage juice, 

A tube was, now accurately connected with 
the mattrafs, bent, and introduced into a fmall 
quantity of diluted fulphuric acid. Nearly half 
of the fluid in it was flowly diftillcd into tk^ 
fiilphuric acid> by the heat ofafpirit lamp. 
The impregnated acid evaporated at a heat 
above 212^ and gave a fmall quantity of cryf- 
talifed fait, which barely amounted to two grains 
and quarter : it had every property of fulpbate 
of ammoniac. Sulphuric acid in exccfs was 
poured on the refiduum, and the whole difiillcci 
by a heat not exceeding 300®, into a fmall quan- 
tity of water.. This water, after the procets, 
tailed ftrongly of fulphuric acid ; it had no 
peculiar odpr. Tin thrown into it when healed, 
was not perceptibly oxydatcd ; mingled with 
ilroptitic lim^ water, it gave a copious \y\\\\t 



( 17^ ) 

(&,S green f* t= 2,41 ful. acid -f- 4,1 gr.ox. iiori. 

4- 

1,44 nit. gas =: ,64 nitrogerie + ,8 oxygene. 

1 water ] =: ,85 oxygene + ,4^5 hydrogen?, 

. equal ^ 

3,2 fill, am, 2= 2,41 f. ^cid -f- ,64 nit. -}-,15 hydr 

6r7 r, ox, iron ?;?: 4,1 gr, tox.iron + IpO oxyg.. 

4 

r > ... 

■ - . * , . . • 

Though the eftin^ation of the quantities in 
this ecjuation mull not be qoiilidered as firidtl^ 
accurate^ on account of the degree of uncer-* 
tainty th^t remains concerning the exadl nu- 
inerical expreflion of the (quantities of tpe con- 
ilfituents of water, ammoniac^ ^nd the other 
compound bodies employed ; yet as founded 
qn a limple quantity, that is, the nitroqs 

' • ■ - • 

gas decompofed, it cannot be very diftant 
fron^ the truth. 

The fulphate of ammoniac given by experi^ 
ment, is coniiderably lefs than that which was 
rea|ly produced ; much of it was probably carried 
off during the evaporation of the fuperabundant 
acid. 



( 173 ) 

The conclulions that may be drawn from this 
experiment, afford a ftriking inftance of the im- 
portance of the application of the fcience of 
quantity to the chemical changes : for the data 
being one chemical fa(5), the decompoiition of 
a given quantity of nitrous gas by known agents ; 
the compoHtion of nitrous gas, of water^ am-. 
moniac, the oxides of iron, and fulphatc of 
ammoniac ; we are able not only to determine 
the quantities of the fimple conflitucnts that 
have entered into new arrangements, but like- 
wile the compoiition of two compound bodies^ 
the green and red fulphates of iron. ^ 

m. Though from the experiments in e it 
appeared that no decom|x>(ition of nitrous gas 
hod been produced during or even after its 
abfbrption by folution of futpbate of iron at 
the common temperature ; yet a fufpicion 
that it might take place flowly, and that 



* According to the eftimatiori in the eqnatfon, 6.3 of 
dry green fulphate of iron contain 4.1 green oxide of iron* 
and 2.4 of Kirwan*s real fulphuric acid: and 8.1 redful- 
pbate of iron, contain 2.4 acid, and 5.7 red oSLide of iron. 



t J 74 ) 

indications of it might be given by depofi- 
tion, induced me to examine minutely two 
impregnated folutions, one of which had been 
at reft, confined by mercury, for 19 hours, and 
the other for 27. In neither of them could I 
diicover any d^pofi tion, or alteration of color, 
which might denote a change. 

Two cubic inches of o-xygene were admitted 
to half a cubic inch of one of thefe folutions* 
The oxygertewasflowly abforbed, and the folu- 
tion gradually loft its color. 

To afcertain if during the converfion of the 
nitrous gas held in folutioo by fulphate of 
iron, into nitric acid, by the oxygene of the 
atmofphere at the common temperature, any 
water was decompofed ; I fufFered an impreg- 
nated folution, weighing nearly two ounces, to 
remain in contaft with the atmofphere at b^^ — 
&1^^ till it was become perfedlly pale. It then 
bad a flrongacid tafte, efFervefc^d with car- 
bon St e of pot a(b, and gave a blue prepipitate 
with ptuffiate of potafli. — It was faturated 
with quicklioie, and heated ; ilight indicatioq^ 



( 175 ) 

of the prefence of ammoniac were perceived. 

As in this experiment the nitric acid had been 
mod probably decompofed by the green oxide 
of iron, as in/, I f^nt oxygenated muriatic acid 
through an impregnated folution, till all the 
green axide of iron was converted into red, and 
all the nitrous gas into nitric acid. 

Tbisfolution faturated with potafh, and heated, 
gave no ammoniacal fmell. 

prom tbefe expcriincnls we may conclude, 
ift. That folution of red fulphate o( iron 
faais Uttle or no affinity for nitrous gas*; and 
tbMlplution of common fulphate ablbrbs nitrous 
ga9 only in proportion as it contains green 
fulphate. 

adly. That folutions of green fulphate of 
iron diflS)lve nitrous gas- in quantities propor- 
tionable to their concentration, without effci5ling 



* The muddy green color produced in a folution of red 
fulphate of iron agitated in nitrous gas, depended upon 
impurities in the mercury. I have fince found, that when 
the folution is completely oxygenated, the diminution is 
baxdy perceptible. 



( 170 ) 

any decompofition of itatcommontemperaturef?. 
And the Iphibility of nitrous gas in folution 
of green fulphate^ n>ay be fuppofed to depend 
on an equilibrium of affinity, produced by the 
fbUowing fin>ple attradiions : 
. 1 • That of green oxide of iron for the oxy-^ 
gene of nitrous gas and water. 

.2. That of the hydrogene of the wat6r 
for the nitrogene of the nitrous gas. 
, 3. That of the principles of the fulpbu- 
ric acid, for nitrOgeneand hydrogene. 
» 3dly. That at high tenrrperatures, that is, 
from 200^ to 300^ the equilibrium of affinity 
producing the bmary combination between 
nitrous gagrand folution of green fulphate of 
iron is dcftroyed ; the attraction of the green 
oxide of iron for oxygene bemgincreafed ; whilft 
probably that of nitrogene for hydrogene is 
diminifhed. 

Hence the nitrous gas is either liberated,* in 



Perhaps the liberation of nitrous gas from the folution 



I 177 ) 

cohfequencc of the affinity betv^'cen oxygfehc 
lind hydrogene, and oxygene and nitrogene not 
following the fame ratio of alteratibn on in- 
creafed temperature ; or decompofed, becaufe 
at a ceHain temperature the green oxide exerts 
fuch affinities upon water and nitrous gas^ as to 
Mtradl oxygene from both of them to form red 
oxide; whilft the fiill exiting affinity between 
the hydrogene of the one, and the nitrogene of 
tbfc other, difpofes them to combine to form 
ammoniac, 

. 4thly. That the change of color produced by 
introducing nitric acid to folutidn of common 
iulphate of iron, exadtly analogous to that oc- 
cafioned in it by impregnation with nitrous gas, 
i8,cwing to the decompoiition of the acid, by 
the combination of its oxygene with the greeni 



: . «'' 



takes place at a lower temperature than its decompoiition. 
t taVe ailArays obferved that the quantity df yellow prc- 
is^itbte iai greater when the folution is rapidly made td 
boil. Were it poffible to heat it to a certain tem- 
|)erature at once> probably a compleat decompofitiool 
Irould take place. 

M 



(178 ) 

I 

oxide of tron, and of its nitrous gas with tbe^ 
folution. 

Sthly. That nitrous gaa in combination with 
iblution of green fulphate of iron, is capable of 
exerting a ftrong affinity upon free oe loofcly 
combined oxygene, and of uniting with it to 
form nitric acid. 

^« The prodii^6ls obtained from a folatioff 
of fulphate of iron faturated with nitrous gasy 
by Vauquelio and Humboft^ and their conjR^- 
quent miftake with regard to the nature of tbe 
procefs of ablbrption,* muft have arifen from 
expofure of their in^prognated folution to the 
atmofphere. 

Indeed, from the acidity of ify on eitamink^ 
tton, from the fmall portion of ammoniac, ^andi 
the large quantity of nitric acid obtained, it 
appears moft probable that the whole of the 
nitrous gas employed was converted into nitric 
acid^ by combining with atmofpheric ox)^ae^ 
for no nitric acid could have been (Stained ifi 

* Annales de Chimle. T. 38^ pag* lajr. 



( 179) 

tiie inode In which they operated, unlefs the 
green oxide of iron in the folutioh had been 
previdufly converted into red. 

VlII. On the ahforplion of Nitroits Gas hy 
folution of green Muriate of Iron. 

a. The analogy between thie affinities of the 
Cbnflitueiits of the muriate and fulphate of iron^ 
induced me to conjedlure that they poflefled 
iimilar powers of abforbing nitfous gas ; and I 
ibon fdund that this was adually the cafe ; for 
on agitating half a cubic inch of folution of 
muriatcd iron, procured by difiblving iroa 
iilings in muriatic acid, in nitrous gas, the gas 
wad ablbrbed with great rapidity, whilft the 
folution airuihed a deep and bright brown 
iin^. 

h. Proud,* who as I have before mentioned> 
fuppofes the exiftence of tvKp oxides of iron only, 



* AoQales de Cbimie^ xxiii. pag. 85 3 or Nlcholf^nji 
PhiU Journal vol. i. pag. 45. 



( i*o ) 

one containing — oxygene, the other—, Karf 
aflumed, that the muriatic acid, and moft othtr 
acids as well as the fulphuric, are capable of 
combining with thefe oxides, and of forming 
with each of them a dirtindl fait. He has, 
however, detailed no experiments on the mu- 
riates of iron. 

As thefe falts are ftill more diftinfl from each 
other in theJr properties than the fulphates, and ^ 
as thefe properties are connected with the 
phaenometion of the ablbrption and decompo- 
iition of nitrous gas, I (hall detail the obfer- 
' vations I have been a^le to make upon them. 
c. When iron filings have been diflblved in 
pure muriatic acid, and the folution preferved 
from the contadt of air, it is of a pale green 
color, and gives a whrte precipitate with alkatine 

« 

prufliates. The alkalies throw down from it a 
light green oxide of iron. 

When evaporated, it gives cryftals almoft 
white, which are extremely foluble in water ; 
Ibut infoluble in alcohol. 

The folution of green muriate of iron has a 



( lei ) 

I 

g^reat affinity for oxygene, and attradls it from 
the atmofpbere^ from nitric acid^ and probably 
rrom oxygenated muriatic acid. 

When red oxide of iron is diflblved in muri- 
atic acid, or when nitric acid is decompofed by 
iblution of green muriate of iron ; the red 
muriate of iron is produced. The folution of 
this fait is of a deep brown red, its odor is pe- 
euliar, and its tafic, even in a very diluted flate^ 
highly aftringent. It ^6is upon animal and 
vegetable matters in a manner (bmewhat analo- 
gous to the oxygenated muriatic acid, rendering 
them yellowifti white, or yellow.* 

Sulphuric acid poured upon it, produces a 
fmell refembling that of oxygenated muriatic 
acid. Evaporated at a low temperature, it 
gives an .uncryftalifable dark orange colored 
lalt, which is foluble in alcohol, and when de- 
compofed by the alkalies, gives a red precipitate. 
With pruffiate of potalh it gives pruffian blue. 



* Probably by giving them oxygene -, whereas the 
green muriate and fulphate blacken animal fubdances; moft 
likely by abib^6ting from them oxygene. 



( 1«2 ) 

■ 

Thfe cominon muriate of iron confiils pf dift 
ftrent proportions oft hefe two falts. It may 
be converted into red miiriate by concentratec} 
iiitric acid^ or iqto greerf by fulphurated hydro- 
g^ne. 

d. To afcertaiq if folution of red muriate 
pf iron was capable of abforbing nitrous gas, I 
. introduced into i jar filled with mercury, a cubic 
inch of uitKt)qs gas, ^nd admitted tp it nearly 
half a cubic inch of foiutiqn of red muriate of 
Sroq. No difcoloration took place. By tnucl^ 
agitation, however, pn abforption of nearly, a 
v^as produced, and the folution became of a 
jnuddy green. But this change of color, ^nd 
probably the abfprptipn, was in confequencc pf 
the oxydation of either the mercury, or fome 
3mperfe<ft metals combined wi|h it, by tha 
oxygene of the red ipuriate. For I after- 
awards found, that precifely the fame change 
pf cjolor was produced when a folution was 
agitated over mercury. 

e I introduced to a cubic iqcb of concon- 
trated folution of green muriate of iron, 7 ci|bic 



( "3 ) 

fucfm of nitrous gas, free from nitric acid ; thi^ 
A>ltttio9 inilantly became colored at the edges^ 
mad on agitation abforbed the gas with much 
gfftattr rapidity than even fulphate of iron ; i^ 
B mimit^ only a quarter of a cubic inch re- 
pnained. 

The folution appeared of a very dark brown^ 
iwt evidently no precipitation bad taken place 
in ity -and tbe edges^ when viewed againft the 
Jigbt, were tranfparent and puce colored. 

Five cubic inches more of nitrous gas were 
now diflblved in the folution. This intenfity 
at the color increafed^ and after an hour no 
depofitbn bad taken place. A little of it was 
then e^amiped in the atmofphere ; it had jGt 
much more afiringent tafte than the unimpreg- 
ceted folution, and effedjled no change ih red 
cabbage juice. When pruffiate of potaih was 
iatroduced intp it^ its color changed to olive 
brpwn. A few drops of the folution, that had 
accidentally fallen on the mercury, foon became 
Qolorleis, and then effervefced with carbonate 
of pqtafhj and tailed firongly acid. 



( ld4 ) 

The remainder of the impregnated (blotioQi 
ivi^bich muft have nearly equalled ,75 cubt<9 
inches, was introduced into a n^atttafs, having 

A 

|i (lopper and curved tube, ias in the experi- 
^ents on the ibiution of fulphat^ of irortJ; great 
care being taken to prefcrve it from the cot)ta6t 
of air. 

The mattrafs was heated by a (^iritlamp, th^ 
curved tube being in communication with a 
mercurial cylinder. Near 8 cubic inches of 
nitrous gas were coUeded, when the folution 
became of a muddy yellow. It was AiiFered to 
cool, and examined, A fmall quantity of 
yellow precipitate covered the bottom of the 
mattrafs; the fluid was pellucid, and light 
green. A little of it thrown on prufiiate of 
potafli, gave a \yhite precipitate, colored by 
flreaks of light blue. When the yellow pre- 
cipitate was partly diflblved by fulphuric acid, 
a drop of the folution, mingled with pruffiate of 
potafh, gave a deep blue green. 

Hence, evidently, the precipitate was red 
pxideof iron. 



( 185 ) 

C>auftic potafli in excefs was introduced into 
the remainder of the folution^ and it was heated. 
^t gave an evident fmell of ammoniac, and 
flenfe white fumes, when held over firopg phlo- 
^ifiicated nitrous acid. 

When half of it was evaporated, fulpl)uric 
^cid in excefs was poured on the remainder ; 
ji^uriatic acid was liberated, pot perceptibly 
jcombined with any nitric acid. 

f. In an experimeqt that I madp to afcertain 

tbe quantity of nitrous gas capable of combining 

with folution of green muriate of iron ; I found 

that ,75 cubic inches of faturated folution ab- 

forbed about 18 of nitrous gas, which is nearly 

double the quantity combinablc with an equal 

portion of the ftrongeft folution of fulphate of 

iron. A part of this impregnated folution, 

heated flowly, gave out more gas in proportion 

to the quantity it contained, than the laft, and 

confequently produced lefs precipitate ;^fo that 

I am inclined to fuppofc it probable, that at a 

certain temperature, all the diflblved nitrous 

gas may be difpelled from a folution. 



( we ) 

From tbefe experiiQentti we tnvj eon^liKfa^, 

ift. That the folution of green muriate of 
Iron abforbs nitron^ gas in confequence of deadly 
ihe (kmc affinities as folution of green iulpbate 
of iron ; its capability of abforbing larger qoati* 
titles depending mod probably on its greater 
concentration (that is, on the greater folubility - 
of the muriate of iron)^ s^nd perhaps^ in fome 
pieafuije, on a new combining alRnity, that of 
muriatic j^cid for pxygene. 

2dly. That M.certaiij temperatures nitrous 
gas is either liberated from folution of green 
muriate^ or decompo(e(}^ by the combipation 
of its oxygene with green oxide of iron, and of 
its nitrogene with hydrogene, produced by 
water decompounded by the oxid^ at the fam^ 
time. 

IX. jihforplon of Nitrous Gas hy Solnfion of 
Nitrate of Iron. 

a. As well as two fulphates and two muriates 



( 187 ) 

0f itan^ there exift two filtrates.''^ When con- 
jeentrated nitric acid is made to ad upon iron, 
Bitrolis gas is difengaged with great rapidity, 
and with great increafe of tennpepature : the 
Iblntion aflumes a yellowifh tinge, and as the 
prdcefs goe9 pn^ a yellow red oxide is pre* 
pipitated. 

Nitrate of iron made in this way, gives a 
|)rigbt blue mingled with pruffiate of potafh, 
Mid decompofed by the alkalies^ a red precipi* 
tate. Its rplution has little or no affinity for 
nitrous ga$. 

b. "V^hen very dilute nitric acid, that is, 
fach as of fpecific gravity 1,1 6, is made to 
pxydate irQn, without the ailidance of heat, 
tbe fblc^tion give^ out no gas for fome time, and 
becomes dark olive brown : when neutralifcd 
it gives, decompofed by the alkalies, a light green 
precipitate ^ and mingled with proiliate of pot- 

m 

a(h, pale green pruffiate of iron. 



* The crfftence of green nitrate was not fufpe^ed by 



( IM ) 

It (nffts its colot' to t}ie nitrous gas it holds m 
folution. By ^xpbfure to. the atmofphere it 
becomes pale^ the nitrous gas combined with it 
being converted into nitric acid. - 

It is then capable of abforbing nitrous gas^i^ 
and confifisof pale nitrate of iron^ mingled with 
red nitratt. 

I have not yet obtained a nitrate of iron giving 
only a white precipitate with « pruiiiate of pot^ 
afli, that ts^ fuch as contains only oxide of iron 
at its mtnimum of oxydation; for when pure 
green oxide of iron is diflblved by very dilute 
nitric acid, a fmalh quantity of the acid is 
generally decompofed, which is likewife the cafe 
in the decompofition of nitre by green fulphate 
of iron. The folutions of nitrate qf iron, how- 
ever, procured in both of thefe modes', abforb 
nitrous gas with rapidity, and by fulphurated 
hydrogenc might probably be converted intq 
pale nitrate. 

As it is impofiible to obtain concentrated 
folutions of pale nitrate of iron, chiefly 
containing green oxide, its powers of abforbing 



( 189 > 

nitrous gas cannot be compared with the nf)ir- 
rtatic and fulphuric folutions, unlefs they are 
iflade of nearly the fame fpecific gravity. 

Nitrous gas is difengaged by heat from the im- 
pregnated folution of nitrate of iron, at the fame 
time that much red oxide of iron is precipitated. 
Whether any nitrous gas is decompofed^ 
. I have not yet afcertained ; for when un- 
impregnated pale nitrate of iron is heated, a 
part of the acid, and of the water of the folu- 
tion, is decompofed by the green oxide of iron ;* 
and in confcquence ammoniac, and red nitratef 
df iron formed, wbilft red oxide is precipi- 
tated. 

X. Abforption of Nitrous Gas hy other Metah 
lie Solutions. 

a. White pniffiate of iron in conta6l wifh 
\Vater abforbs nitrous gas to a great extent^ and 



. * lo this procefs nitrous oxide is fometinies given out, 
as will bo ieen hereafter. 



«,». 



( 10) 

becCHtnes dark chcicplate*^ 

h. Concentrated iblation of fulph^tieof ti0j 
probably at it$ minimum of oxydation, abiorbi 
> one eighth of itsbdik ofnUrous gas^ and becomes 
brown, -without depofition; 

c. Solution of fulphate di zinc:}; ablbrbs aboiit 
one tenth of its volume of nitrous gas, iind be*' 
com^ gretin: 

d. Solution of mtiriateof zinc^ abforbs nearly 
the iame quantity « and becomes orange brown. 

e. Thefe are all the metallic fubftaaces on 
iivhich I have experimented* It is more than 
jMrobable that there exift others ppflbifing iimilar 
powers of abforbing nitrous gas. 

Whenciver the metals capable of de:compd(ing 
Water exift in Iblutions at their minimum of 
oxydation^ the affinities exerted by thetn od 



* Hence we lo^rn why oo: oitrbus g^s is dif^sogaged whjcn 
impregnated folution of fulphate of iron is decompbfed by 
prufliatc of potaih, as in Div. IV. Sec. vii. 

X In both of thefe folutions the metal is at its mihimum 
ofoxydation. The abforptien of a fmall quantity of di-* 
trods gas by white vitriol was obferytd by Friefiley. 



( 19* ) 

llitrofiis gals and water, will be Aich as fa pfo^ 
duce combination. The powers of metallic 
iblutioos to combine with nitrous gas at com- 
mon temperatures, as well as to dccompofe it 
at higher temperatures, will probably be in the 
ratio of the affinity of the metallic oxides tbey 
contain, for okygene. 

SlI. Tie aSion of Stdfhurated Uydrogme on 
fohition of Green Sulphate of Iroriy impregnated 
Nitrofus Gas. 



a. In an experiment on the abforption of 
tnKXQxsA gas by fd ution of green fulphate of iron^ 
I introduced an unboiled fol ution of common 
fulpibote, deprived of red oxide of iron by ful- 
pburated bydrogenc, into a jar filled with ni* 
tfOQS gas ; the abforption took place as ufual^ 
and nearly (ix of gas entered into combination^ 
tbe volume of the folution being unity. Onr 
applying beat to a part of this impregnated 
folution, the whole of tbe nitrous gas it con* 
tulned-^nearly-asl could guefs), was expelled 



tindecompodnded; and no yellow precrpitate 
produced. Pruffiate of potafli ponred into it 
gave only white prufliate of iron ; and when it 
was heated v^ith lime, no ammoniacal foiell was 
perceptible. 

I could refer this phaenoraenon to no other 
caufe than to the exifience of a fmall quantity 
of fulphurated hydrogene in the folution. That 
this was the real caufe I found from tb6 folloW* 
ing experiment. 

b. One part of a folution of gfeen fulpbate 
of iron, formed by the agitation of conimori 
fulphate of iron in conta6l with fulphurated 
hydrogene, was boiled for fome minutes to' 
expel the fmall quantity of gas retained by it' 
undecompounded. It had then no peculiar 
fmell, and gave a white pruffiate of iron with 
pruffiate of potafh ; the other part had a faint 
odor of fulphurated hydrogene^ and gave & 
dirty white precipitate with pruffiate of potaihi 
Nearly equal quantities of each were faturated 
with nitrous gas, and heated. The unboiled 
itnpregnated folution gave out all its nitrous 



( 193 ) 

gsls uhdecompounded ; wbtlfl in the boiled 
fblution it was partly decompofed^ yellow pre- 
cipitate and ammoniac being formed. 

c. This Angular phaenomenon of the power of 
a minute quantity of fulphurated hydrogene^ in 
preventing the decgmpofition of nitrous gas and 
water, by green oxide of iron, will moft proba- 
bly take place in other impregnated folutions. 
It feems to depend on the firong affinity of the 
bydrogene of fulphurated hydrogene for oxy- . 
gene. 

Xir. Additional Ohjervations. 

a. For feparating nitrous gas from gafes ab- 
forbable to no great extent by water ; a well 
boiled folution of green muriate of iron fhould 
be employed. Nitrous gas agitated in this is 
rapidly abforbed, and it has no affinity for, or 
adion on, nitrogene, hydrogene, or hydro- 
carbonate. 

h. Nitrous gas carefully obtained from xmcX'^ 
tury and nitric acid, when received under raer- 

N 



\ 



( 194 ) 

cury, or boiled water, and abforbcd by fblution 
of greeti mufriate, or fulphate of iron, rarely 
leaves a refiduum of— -of its volume: pre- 

200 *^ 

ferved over common water, and abforbed, the 
remainder is generally from ^^ to ^, from Ihc 
nitrogene difengaged by the decompofition of 
the common air contained fn the water. 

c. The nitrous gas carefully obtained from 
the decompofition of nitric acid of 1 .26, by 
copper, I have hardly ever found to contain 
more than from ^ to - nitrogene, when received 
through common water : when boiled water is 
employed, the refiduum is nearly the fame as 
that of nitrous gas obtained from mercury. 

d. Confequently the gas from thofc ^two 
Iblutions may be ufed in common. It is rnore 
than probable, that the fmall quantities of 
nitrbgiene generally mingled with nitrous gis 
from copper and mercury, arife either from the 
common air of the veflfels in which it was pro- 
duced, or that of the water over which it Was 
received. There is iio reafon for fuppofing that 
it is generated by a complete decompofition of 



( 199 ) 

& portioo of the acid.* 

e. Whenever nitrous oxide Is mingled With 
tiitrous gas and nitrogene^ it muft be feparatcd 
by well boiled water ; and after the corredlions 
are made for the quantity of air difengaged 
from the water, the nitrous gas abforbed by the 
tnuriatic fohition. 



* Hambolt> who is the fird phUofopber that has applied 
the fiiliitibn of fulphate of iron to afcertain the parity of 
nittons gas, ailerts that he uniformly found nitrous 
gas obtained from folution of copper in nitrous acid, to 
ctmtaia Iran £x tenths to one tenth nitrogene. 

Annales de Chimie, vol. xiviii. pag. \A7\ 



mm 



DIVISION V. 

EXPERIMENTS and OBSERVATIONS on the 
produaion 9f NITROUS OXIDE from NITROUS 
OAS and NITRIC ACID, in different modes. 



I. Preliminaries, 

a. X he opinions of Prieftley* and Kirwalif^t 
relating to the caufes of the converfion of nitrous 
g^s into nitrous oxide, were founded on the 
theory of phlogiflon. The firft of thefe philo^ 
fophers obtained nitrous oxide by placing nitrous 
gas in contadl with moifiened iron filings, ot 
the alkaline fulphures. The lad by* expofing it 
to fulphurated hydrogene. 

The Dutch chemifts, :|: the lateft expeai- 

* Vol. ii. pag. 55. f Phil. Tranf. vol. Ixxvi. pag, 13S. 
X Journal de Phyfique^ torn, xliii. 323. 



( 197 ) 

mentalifts on nitrous oxide, have fuppofed that 
the produdlion of this fubilance depends upon 
the iimple abftrai^ion of a portion of the oxy- 
gene of nitrous gas. They obtained nitrous 
oxide by exppfing nitrous gas to muriate of 
tin^ to copper in (blution of ammoniac, and 
likewife by pacing it over heated fulphur. 

The diminution of volume fuilained by 
nitrous gas during its converiion into nitrous 
ozide^ has never been accurately afcertained ; 
it has generally been fuppofed to be from two 
thirds to eight tenths. 

h. Nitrous gas may be converted into nitrous 
oxide in two modes. 

Firft, by the fimple abftracSlion of a portion 
of its oxygene, by bodies pofleffing a ftrong 
afEnity for that principle, fuch as alkaline 
fulpbites, muriate of tin, and dry fulphures. 

Second, by the combination of a body 
with a portion both of its oxygene and 
nitrogene, fuch as hydrogene, when either in a 
nafcent form, or a peculiar ftate of combir 
jjatioo. 



( m ) 

i. Each of thefe modes will be diftindly 
treated of; and to prevent unneceflary repe* 
titions, I fhall give an account of the general 
manner in which the following experiments o^ 
tbe converfion of nitrous gas into nitrous oxide, . 
have been condu(9e4« 

Nitrous gas, the purity of which has been 
accurately afcertained by folution of muriate of 
iron, IS introduced into a graduated jar filled with 
dry lAercury. If a fluid fubflance is defigned 
for the converfion of the gas into nitrous oxide, 
it is heated, to expel any loofely combined air 
which might be liberated during the proceft j 
and then carefully introduced into the jar, by * 
means ofafmall phial. After the procefs is 
finiflied, and the diminution accurately noted, 
the nitrous oxide formed is abforbed by pure 
water. If any nitrous gas remains, it is con* 
denfed by folution of muriate of iron ; other 
refidual gafes are examined by the common 
tG&s.. The quantity of nitrous oxide diflfblved 
by the fluid is determined by a comparative 
(experiment ; and the corrcdions for tempera- 



{ m) 

lure and prefTure being guefled at, the con- 
cl^fions drawn. 

If a folid fubflance is ufed, rather more nitrous 
gas than that dcfigned for the converfion, is 
introduced into the jar. The fubftance is 
hrpught in contadl with the gas, by being 
carried under the mercury ; and as a little com- 
nion air generally adheres to it, a fmall portion 
of the nitrous gas is transferred into a graduated 
tpbe^ after the infertion, and its purity afcer- 
tained. In other refpedls the proccfs is con- 
duced as mentioned above. 

IL 0/ the converfion of Nih ous gas inlo Ni* 
trous Oxide, hy Alkalme Sulj)h}tes. 

The alkaline fulphites, particularly the ful- 
phite of potafh, convert nitrous gas into nitrous 
oxide, with much greater rapidity than any 
other bodies. 

At temperature 46^, l6 cubic inches of 
nitrous gas were converted, in lefs than an 
hour, into 7,8 of nitrous oxide, by about 100 



( 200 ) 

jgrains of pulverifed fulphite of potafh, contain^ 
ing its water of cryftalifation. No fenfible in- 
creafe of temperature was produced during the 
procefs, no water was decompofed, and the 
quantity of nitrogene remaining after the ex- 
periment, was exactly equal to that previoufly 
contained in the nitrous gas. 

The nitrous oxide produced from nitrous gas 
by fulphite of potafh, has all the properties of 
that generated from the decompofition of ni- 
trate of ammoniac. It gives, as will be feeri 
hereafter, the fame produfls by analyfis. Phof- 
phorus, the taper, fulphur, and charcoal, burn 
in it with vivid light. It is abforbable by water, 
and capable of expulfion from it unaltered, by 
heat. 

Nitrous . gas is converted into nitrous oxide 
by the alkaline fulphites with the fame readinefs, 
whether expofed to the light, or deprived of its 
influence. 

The folid fulphites a6l upon nitrous gas much 
more readily than their concentrated folutions ; 
^hey fhould however always be fufFered tq 



( 201 ) 

retain their water of cryfialifation, or otherwiib 
tfiey attradt moifture from the gas, and render 
it drier^ and in confequence more condenfed 
Allan it would otherwife be. In cafe per- 
feiSHy dry fulphites are employed, the gas 

m 

ihould be always faturated with moifture after 
the experiment, by introducing into the cylin- 
der a drop of water. 

The fulphites, after expofure to nitrous gas, 
are either found wholly, or partially, converted 
into fulphates. Confequently the converfion of 
nitrous gas into nitrous oxide by thefe bodies, 
fimply depends on the abflra6iion of a portion 
of its oxygen e ; the nitrogene and remaining 
oxygene afluming a more condenfed ftate of 
exiftence. 

If we reafon from the difFerent fpecific gra- 
vities of nitrous oxide and nitrous gas, as com- 
pared with the diminution of volume of nitrous 
gas, during its converfion into nitrous oxide, 
100 parts of nitrous gas, fuppofing the former 
eftimation of the compofition of nitrous oxide 
^ven in Divjfion III, accurate, would confift 



( 202 ) 

of 54 oxygene, tod 4& nitrogeoe ; which is pot 
far from the true eftioiation. Or afTumiog tb^ 
compofition of nitrous gas, as given in Divifion 
IV9 it would appear from the diminution^ tl^t 
100 parts of nitrous oxide confided of 38 oxy* 
gene^ and 62 nitrogene. 

III. Converfion of Nitrozis Gas info Nitrous 
Oxide, by Muriate of Tin, and dry Sulphur es. 

a. Nitrous gas expofed to dry muriate pf 
tin, is flowly converted into nitrous oxide : 
during this procefs the apparent diminution is. 
to about one half; but if the produdls are nicely 
examined^ and the neceflary corredlions niade^ 
the real diminution of nitrous gas by muriate of 
tin, will be the fame as by the fulphites ; that 
IS, 100 parts of it will be converted into 48 of 
nitrous oxide. 

During this converfion, no water is decom- 
pofed, and no nitrogene evolved. Solution of 
muriate of tin converts nitrous gas into nitrous 
oxide ; but with much lefs rapidity than the 
folid fait. 



f 

I 



( 203 ) 

b. Nitrous gas cxpofed to dry and perfe(91y 
well made fulphures, particularly fuch as arc 
produced from cryftalifed -alumn* and charcoal 
not fufficiently inflammable to burn in the 
atmofpbere^ is converted into nitrous oxide by 
the limple abilradion of a portion of its oxygene, 
and confequently undergoes a diminution 

/• 53 
100 

It is probable^ that all the bodies having 
ftrong affinity for oxygenfe will, at certain 
temperatures, convert nitrous gas into nitrous 
oxide. Prieftley, and the Dutch chemifts^ 
eSeded the change by heated fulphur. Per- 
haps nitrous gas fent through a tube heated, 
but not ignited, with phofphorus, would be 
(Converted into nitrous oxide. 

IV. Decompojition of Nitrous Gas^ by SuU 
^hurated Hydrogene. 

fi. When nitrous gas and fulphurated hy- 



^ That \s, alumn containing fulphatc of potaih. 



( 204 ) 

drogene are mingled together, a decompofition 
of them flowly takes place. The gafes are 
dimintfhed^ fulpbur depofited, nitrous oxide 
formed, and figns of the produdlion of ammo* 
nia^ * and water perceived. 

In this procefs no^fulphuric, or fulphureous 
acid is produced ; confequently none of the 
fulphur is oxydated, and of courfe the changes 
depend upon the combination of the hydrogene 
of the fulphurated hydrogene, with different 
portions of the oxygene and nitrogene of the 
nitrous gas, to form water and ammoniac, the 
remaining oxygene and nitrogene afluming the 
form of nitrous oxide. 

This lingular exertion of attradlions by a 
limple body, appears highly improbable a priori, 
nor did I admit it, till the formation of ammo- 
niac, and the non-oxygenation of the fulphur, 
were made evident by many experiments. 

In thofe experiments, the diminution of the 
nitrous gas was not uniformly the fame. It 

* The produdion of ammoniac in this procefs was ob- 
ferved by Kirwan and Auftin, 



( 205 ) 

s 

varied from -^ to l^- In the moft accurate of 

20 20 

them^ 5 cubic inches of nitrous gas were con- 
verted into 2.2 of nitrous oxide. Confequently 
the quantity of ammoniac formed was ,04/ 
grains. 

In experiments on the converfion of nitrous 
gas into nitrous oxide, by fulphurated hydro- 
gtoe^ the gafes fhould be rendered as dry as 
poflible. The prefence of water confiderably 
retards the decompofition. 

b. The fulphurcs* diflblved in water convert 
nitrous gas into nitrous oxide. This decom- 
pofition is not; however, produced by the fimplc 
abftradlion of oxygene from the nitrous gas to 
formfulphuric acid. It depends as well on the de* 



* Solution of fulphure of flronljan, or barytes, fhould 
be ufed. During the converfion of nitrous gas into nitrous 
oxide by thofe bodies^ a thin film is depofited on the furface 
of the folution. This film examined^ is found to confift 
of fulphur and fulphate. Poflibly the nitrous gas is wholly 
decompofed by the hydrogene of the fulphurated hydrogenc 
in the folution^ whilfl the fulphate is produced from water 
decompounded by the fulphur to form more gas for tlic 
faturation of the bydro-fulphure. 



( 206 ) 

compofition of the fulphurated hydrogene dif- 
folved in the folution^ or liberated from it. In this 
procefs fulphur is depoiited on the furface of the 
fluid, fulphuric acid is formed, and the diminu-^ 
tion, making the neceflary corredlions, is nearly 
the famei? as when free fulphurated hydrogene 
is employed. 

If is extremely probable that fulphurated hy-* 
drogenc, in combination with the alkalies, ad 
well as with water, is capable of being llowly 
decompofed by nitrous gas. 

V. Decompofiiion of Nitrous Gas hy Nafcent 
Hydrogene. 

a. When nitrous gas, is expofed to wetted 
iron filings, a diminution of its volume flowly 
takes place ; and afler a certain time, it is found 
converted into nitrous oxide. 

In this procels ammoniac* is formed, and the 
iron partially oxydated. 

^ As was firft obferred bj Priefiley and AafUn, and as I 
tuiTe proTcd bj manj experiments. 



(207 ) 

The water in contadl with the iron is decom- 
pofed by the combination of ils oxygene with 
that'fabfiance^ and of its hydrogene with a por- 
tion of the oxygene and nitrogene of the nitrous 
gas, to form water and ammoniac. 

That the iron is not oxydated at the expencc 
of <he oxygene of the nitrous gas, appears very 
probable from the analogy between this proceis^ 
and the mutual decompofition of nitrous gas 
afad fulphurated hydrogene. Befides, dry iron 
filings efFedl no change whatever in nitrous 
* gas, at common temperatures. 

I have generally found about 12 of nitrous 
gas converted into 5 of nitrous oxide in this 
proceft ; which is not very different from the 
diminution by fulphurated hydrogene. It takes 
place equally well in light and darknefs; but 
more rapidly in warm weather than in cold. 

b. Nitrous gas expofed to a large furface of 
zinc, in coptacl with water^, is flowly converted 
into nitrous oxide ; at the fame time that am- 
moniac is generated, and white oxide of zinc 
^rmed. This proccfs appears to depend, like 



( 2ds ) 

the laft, upon the decompofition of water by 
the affinities of part of the oxy gene and nitro- 
gene of nitrous gas, for its hydrogene, to form 
ammoniac and water; and by that of zinc fqr. 
its oxygene. Zinc placed in conta(^ with 
water, and confined by mercury,* decotnpofes 
it at the common temperature. Zinc; when 
perfe<5lly dry, does not in the flighteft degree 
adl upon nitrous gas. 

I have not been able to determine exa(SIy 
the diminution of volume of nitrous gas, during 
its converfion into nitrous oxide by zinc. Id * 
one experiment 20 meafures of nitrous gasy con- 
taining about ,03 nitrogetie, were diminifhed to 
9, after an expofure of eight days to wetted 
zinc ; but from an accident, I was not able to 
afcertain the exadl quantity of nitrous oxide 
formed* 

c. It is probable that moft of the imperfeA 
metals will be found capable of oxydation, by 
the decompofition of water, when its hydrogene 
is abflradled by the oxygene and nitrogene of 

* As I have found by experiment. 



( ^09) 

tiitrous gas. I have this day (April 14, 1800), 
examined two portions of nitrous gas, one of 
which had been expofed to copper filings, and 
tbc other to powder of tin, for twenty-three • 
days. 

l^he gas that had been expofed to copper Was 
diminifhed nearly two iiflhs. The taper burnt 
in it with an enlarged flame, blue at the edges. 
Hence it evidently contained nitrous oxide. 

The nitrous gas in contadl with tin had 
undergone a diminution of one fourth only^ 
and did not fupport flame. 

VI. liSifcellaneous Ohfervaitons on the cowverjion 
of Nitrous Gas into Nitrous Oxide. 

a. t)r. I'riefiley found nitrous gas expofed to a 
mixture of iron filings and fulphur, with water, 
converted after a certain time, into nitrous 
oxide. Sulphurated hydrogene is always pro- 
duced during the combination of iron aiid ful- 
phur, when they are in contadl with water; 
and by the hydrogene of this in the nafcent 

o 



( 210 ) 

ftate, the nitrous gas is moft probably decom-» 
pofed. 

h. Green oxide of iron moiftened with water, 
expofed to nitrous gas, flowly gains an orange 
t;nge, whilft the gas is diminiftied. Moft 
likely it is converted into nitrous oxide ; but 
this I have not afcertained. 

1 1 expofed nitrous gas, to the following bodies 
over mercury for many days, without any^ 
diminution, or apparent change in its properties. 
Alcohol, faccharine matter, hydro. carbonate^ 
fulphureous acid, and phofphorus. 

d. Cryftalifed fulphate, and muriate of iron, 
abforb a fmall quantity of nitrous gas, and 
become dark colored on the outfide ; but after 
this abforption, (which probably depends on 
their water of cryftalifation,) has taken places 
BO change is effedcd in the gas remaining. 

e The power of iron to decompofe water being 
much increafed by increafe of temperature, ni- 
trous gas is converted into nitrous oxide much 
more raipidly when placed in conta6l with a fur- 
face of heated irofi^ than when expofed to it at 



(211) 

cdmnlon temperatures. During the decompo-^ 
fition of nitrous gas in this way, ammoniac * 
is formed. 

/. The curious experiments of Rouppe,"!- 
on the abforption of gafes by charcoal, com- 
jpared with the phaenomena noticed in this 
Divifion, render it probable that hydrogene in 
a ftate of loofe combination with charcoal, will 
be found to convert nitrous gas into nitrous 
oxide. 

VII. Recapitulation of concluftons concerning 
the converfion of Nitrous Gas into Nitrous Oxide. 

a. Certain bodies having a ftrong affinity 
for oxygene, as the fulphites, dry fulphures, 
iburiate of tin, &c. convert nitrous gas into 
tdtrods oxide, by fimply attrafling a portion of 
its oxygene ; whilft the remaining oxygen* 



* As was obfervcd by Milner. Nitrous gas pafled over 
heated zinc, or tin, I doubt not will be found converted 
into nitroos oxide. 

t Annales de Cbimie. xxxii, p. 3. 



( 312 > 

enters ipta combination with the nitrogcne, and 
tbey aifume a more condenfed date of exilic 
cnce. ' 

, h Nitrous gas is converted into, nitrous 
oxide by bydrogene, in a peculiar flate of ex- 
iftence^ as in fulpburated bydrogene ; and that 
by a ferijes of very complex affinities. Botk 
dxygene and nitrogisne are attra<£ted from tbe 
nitrous gas by the bydrogene^ in fucb propor- 
tions as to form water and ammoniac^ whilfl: 
the remaining oxygene and nitrogene * aflume 
tbe form of nitrous oxide. 

c. Nitrous gas placed in contadl with bodies^ 
fucb as iron and zinc decompofiitg water, is 
converted, into nitrous oxide, at the fame time 
that ammoniac is. formed. It is difficult to 
afcertain tbe exad rationale of this procefs. For 
either tbe nafcent bydrogene produced by the 
4ecompo(ition of the water by the metallic fub- 
ilance may combine with portions of both tbe 

* Tht decompofition and reoompofition of water^ in this 
procefs^ arc analogous to ibme of die phaenoineoa obferved 
bj the iogenious Mrs. Folhanie. 



(ftl3) 

axygeae and nitrogene of the mirotia gas ; and 
thus by forming water and ammoniac, convert 
it into nitrous oxide. Or the metallic fubilance 
may attradi at the iame time oxygene from the 
."water and nitrous gas, whilft the nafcent hydro- 
gene of the water ieizes upon a portion of the 
sitrbgene of the nitrous gas to form ammo* 
niac 

The degree of diminution, and the analogy 
.between this procefs and the detompofition of 
citrous gas by fulphurated hydrogene, render 
ithe firft opinion moil probable. 

VIIL The frodu3ion of Nitrous Oxide during 
4he oxydation ofTin^ Zincy and Iron^ in Nitric 
Jlcid. 

• 41. Dr. Prieftley difcovcred, that during the fo- 
lution of tin, zinc, and iron, in nitric acid, cer- 
tain portions of nitrous oxide were produced, 
mingled with quantities of nitrous gas, and 
nitrogene, varying in proportion as the acid 
employed was more or lefs concentrated. 



It has Icoig thsea known that ammpniac i$ 
formed diiribg ihe folution of. tin» zinc^ and 
iron, in diluted nitric acid. Gonfequently^ in 
thefe proeefles water is decompofed. 

I had designed to inveftigate minutdy theie 
phsenomena^ £b as to afcertain the quantiti$f» 
of water and acid decompounded^ and ipf the 
new products generated. But after going 
through fome experiments on the oxydation of 
tin without gaining conclufive refults, the labor> 
and facrifice of time they demanded^ obliged 
me to defift from purfuing the fubjedl, till I 
had completed more important invefiigations. 

I (hall detail the few obfervations which have 
occurred to me^ relating to the produdlion of 
\ nitrous oxide from metallic folutions. 

b. When tin is diflblved in concentrated 
nitric acid^ fuch as of l.;^;: nitrous oxide is pro-i 
ducedy mingled with generally more than twice 
its bulk of nitrous gas. In this procefs but little 
free nitrogene is evolved, and the tin is chiefly 
precipitated in the form of a white powder^ : If 
the iblution^ . aftcor the generation of thde pro* 



- I 



( 215 ) 

du6ls^ is faturated with lime^ and heated^ the 
jiinmoniacal fmell is diftindl. 

When nitric acid of fpccific gravity 1.24, is 
made to adl upon tin; in the beginning 
of the procefs, nearly equal parts of nitrous gas 
9pd nitrous oxide are produced ; as it advances, 
the proportion of nitrous oxide to the nitrous 
gas increafes : the largefl quantity of nitrous 
pyide that I have found in the gas procured 
^m tin is |, the remainder being nitrous gas* 
and nitrogene. 

When tin is oxydated in an acid of lefs fpe- 
cific gravity than I.09, the quantities of gas 
ijifengaged are very fmall, and confift of nitro- 
^ae, nningled with minute portions of nitrous 
oxide^ and nitrous gas. 

Whenever I have faturated folutions of tin 
in nitric acid of different fpecific gravities, with 
Umf?, and afterwards heated them, the ammor 
niacal fmell has been uniformly perceptible, 
9Pd generally moft diftindl when diluted acids 
have.be^n employed. 

^.. When zinc is diflblved in nitric acid. 



(416) 



whatever is its fpecinc gravity^^ certain quanli* 
ties of nitrous oxide are produced. 

Nitric acids of greater fpecific gravity than 
1.2, aA upon zinc with great rapidity, and 
great increafe of temperature. The giafes dii^ 
engaged from thefe folutions confift of nitrous 
gas^ nitrous oxide, and nitrogene ; the nitrous 
oxide i'arely equals one third of the whole. 

When nitric acid of 1,104 is made to diilblve 
zinc, the gas obtained in the middle of the pro- 
cefs conlifts chiefly of nitrous oxide. From 
fuch a folution I o]^tained gas which gave a 
refiduum of one fixth only when abforbed by 
water. The taper burnt in it with a brilliant 
flame, and fulphur with a vivid rofe-colored 
light. 

100 grains of granulated zinc, during 
their folution in 300 grains of nitric acid, of 
1,43, diluted with 14 times its weight of water^ 
produced 26 cubic inches of gas. Of this 
gas ^ were nitrous, i^ nitrous oxide^ and the 
remainder nitrogene. The folution faturated 
with lime and heated, gave a diftin^ fmell of 
ammoniac. 



( 217 ) 

d. During the folution of iron in concen-* 
trated nitric acid^ the gas given out is chiefly 
nitrous ; it is however generally mingled with 
minute quantities of nitrous oxide. When 
very dilute nitric acids are made to adl upon 
Iron^ by fhe alliftance of heat^ nitrous oxide is 
produced in confiderable quantities, mingled 
inritb nitrous gas and nitrogene ; the proportions 
of which are fmaller as the procefs advances** 
The fluid remaining after the oxydation and 
iblution of iron in nitric acid, always contains 
ammoniac. 

e. As during the folution of tin, zinc, and iron, 
in nitric acid, the quantity of acid is diminifhed 
in proportion as the procefs advances, it is rea- 
ibnable to fuppofe that the relative quantities of 
Ihc gafes evolved are perpetually varying. In 
the beginning of a diflblution, the nitrous gas 



* From one of Dr. Pricftley's experiments, it appears 
that hydrogene gas is fometimcs difengaged during the 
folution of iron in very dilute nitric acid by beat. This 
fhsenomei^on has never occurred to me. 



( 218 ) 

generally predominates^ in the middle nitrous 
oxide^ and at the end nitrogene. 

/. During the generation of nitrous gas, 
nitrous oxide, and ammoniac, from the decom- 
pofition of folution of nitric acid in water, by 
tin, zinc, and iron, very complex attractions 
mud exift between the conftituents of the fub« 
fiances employed. The acid and the water are 
decompofed at the fame time, and in proper- 
tions different as the folution is mor^ coq^ 
centrated, by the combination of their oxygenc 
with the metallic body. 

The nitrous gas is produced by the combina- 
tion of the metal with ^ of the oxygene of the 
acid. The nitrous oxide is moft probably 
generated by the decompofition of a portion of 
the nitrous gas difengaged, by the nafcent hy- 
drogene of the water decompounded; fome of 
it may be poflibly formed from a more com- 
plete decompofition of the acid. 

The produdlion of ammoniac may arife, 
probably from two caules ; from the de- 
compofition of the nitrous gas by the combi- 



p«tipo of the nafcent bydrqgene of the w^ter, 
nrith portipns of its oxygene and iiitrogcne a( 
^bp iaRie time; ^nd from the union of hy- 
4|i!Qg6Qe with naicent nitrogene liberated in 
Goniequeoce of a complete deeompoiition of 
^ part of the acid. 

IX. jidditionat Obfervations on she pro- 
ifuAon of Nitrous Oxidi. 

,4$. When nitric acid is combined with mu- 
riatic, acid, or fulpburic acid^^ the quantities 9.f 
nitrous oxide produced from its deeompoiition 
by tin, 2inc» and iron, are rather increafed than 
dimini(hed. The nitrous oxide obtained from 
thefe foliations is, however, never fufficiently 
pure for phyfiological experiments.. It is always 
mingled with either nitrous gas, nitrogene, or 
bydrogene, and fometimes with all of theiin. 
b. From the folutions of bifmuth, uigjcel. 



* As was difcovered by Prie^ley, and the Dutch Che- 
snifis. 



t 220 .) 

lead, and copper^ in diluted nitric acid^ I faavo 
never obtained any perceptible quantity of 
nitrous oxide t the gas produced is nitrous^ 
ipingled with different portions of nitrogene. 
Antimony and mercury, during their foluti<m 
in aqua regia, give out only nitrous gas. 
Probably none of the metallic bodies, except 

r 

thofe that decompofe water at temperatures 
below ignition, will generate nitrous oxide from 
nitric acid. On cobalt and manganefe I have 
never had an opportunity of experimenting : 
manganefe. will probably produce nitrous oxides 
r. During the iblution of vegetable matters^ 
in nitric acid, by heat, very minute portions of 
nitrous oxide are fometimes produced, always 
howler mingled with large quantities of nitrous 
gas, and carbonic acid. 

When nitric acid is decompounded by 
ether, fixed oils, volatile oils, or alcohol^ 
towards the end of the procefs fmall quan- 
tities of nitrous oxide are produced, and 

* Such as the leaves, bark, and wood, of trees» 



( ^1 ) 

ibtnetlmes fufficiently pare to fupport the 

flame of the taper.^ 

d. When green oxide of iron is diilblved in 
nitric acid, nitrous oxide ts produced, mingled 
with nitrogene and nitrous gas. 

^ During the con veriion of green fulphate, or 
green muriate of iron into red, by the decom- 
pofition of dilute nitric acid, nitrous oxide is 
formed, mingled with different proportions 
ef nitrous gas and nitrogene. 

f. When folution of green nitrate of iron is 
heated, a part of the acid is decompofed, red 
oxide is precipitated, red nitrate formed, and 
impure nitrous oxide evolved. 

■ 

g. When iron is introduced into a folution of 
nitrate of copper, the copper is precipitated in 
its metallic flate, wrhilft nitrous oxide, mingled 
with froall portions of nitrogene, is produced.'* 

Both zinc and tin precipitate copper in its 
metallic form from ibiution in the nitric acid. 

f As I have obfervcd after Prieftley. 
* As was difcovcred by Prieftley. 



( 222 ) 

Duririg thefe precipitations, certain Qnaritiffes 
of nitrous oxide are generated^ mingled how- 
ever with larger qaantities of nitrogene tlian 
that produced from decompofition by irdn; 
In all thefe procefles ammoniac is formed^ alnd 
water cdtiiequentiy decompofed. 

Tne decompofition of water arid nitric acid, 
during the precipitation of copper from (blutioh 
of nitrate of copper, by tin, zinc, and irdn, 
depends upon the ftrong affinity of thofe metat^ 
for oxygene, and their powers of combining 
with a larger quantity of it than copper. 

X. Decompofition of Aqua Regia hy Plafina, 
and evolution of a Gas analogous to Oxygenated 
Muriatic Acid, and Nitrogene. 

a. De la Metherie, in his efl[ay on different 
airs, has aflerted that the gas produced by the 
folution of platina in nitro-muriatic acid, is 
identical with the dephlogifticated nitrous gas 
of Priefiley • He calls it nitrous gas with excels 



( 223 ) 

of pure air, and affirms that it dimininies, both 
with nitrous gas and common air. 

^ I introduced into a veflel containing 3(> 
grains of platina, 2050 grains of aqua regia, 
compofed of equal parts, by weight, of concen- 
trated nitric acid of 1^43^ and muriatic acid of 
l,l6. At the common temperature, that is, 
49^> no action between the acid and platina 
appeared to take place. On the application 
of the heat of a fpirit lamp, the folution gra- 
dually became yellow red, and gas was given 
out with rapidity. Some of this gas received 
in ajar filled with warm water, appeared of a 
bright yellow color. On agitation, the greater 
part of it was abforbed by the water, and the 
remainder extinguiftied flame. When it was 
received over mercury, it adlcd upon it with 
great rapidity, and formed on the furface a 
white cruft. 

As fhe procefs of folution advanced, the 
color of the acid changed to dark red, at the 
fame time that the produdtion of gas was much 
increafed ; more than 40 cubic inches were 
iboQ colleded in the water apparatus. 



( 224 ) 

DifFerent portions of the gas were examined; 
it exhibited the following properties : 

1. Its color was orange red^* and its fmgli 
exadlly refembled that of oxygenated muriatic 

acid. 

2. When agitated in boiled water, it was 
rapidly abforbed, leaving a reliduum of rather 
more than one twelfth. 

3. The taper burnt in it with increafed bril- 
liancy, the flame being long, and deep red at 
the edges. 

4r. Iron introduced into it ignited, barot witb 
a dull red light. 

5. Green vegetables expofed to it were in- 
ilantly rendered white. 

6. It underwent no dirpinution, mingled with 
atmoipheric air. 

7. When mingled with nitrous gas, it gave 
denfe red vapor, and rapid diminution. 

*" This deep color depended^ in fome meafure^ upon the 
nitro-muriatic vapor fufpended in it. I have (ince obfenrecf 
that it is more intenfe in proportion as the heat employed 
for the produdion of the gas has been fbonger. The 
natural color of the peculiar gas is deep yellow. 



(225 ) 

I 

r'(^.'.' From the exhibition of thefe propertied^ 
it w^ evident that the gas produced during the 
folutlon of platina In aqua regia^ chiefly con^ 
filled of oxygenated muriatic acid, or of a gas 
highly analogous to it. It was, however, dif- 
ficult to conceive how a body, by combining 
with a portion of the oxygene of nitro-muriatic 
acid, could produce from it oxygenated muriatic 
acid, apparently mingled with very fmall por- 
tions of any other gas. 

J. To afcertain vvhether any permanent gas 
was produced during the ebullition of aqua 
regia, of the fame compolition as that ufed for 
the ibiution of the platina ; I kept a large quan- 
tity of it boiling for fome time, in communica- 
tion with the water apparatus ; the gas generated 
appeared to be wholly nitro-muriatic^ and was 
abforbedas faft as produced, by the waten 

e. To determine whether any nitroias oxide 

v^as mingled with the peculiar gas, as well as 

the nature and quantity of the unabfotbable gas, 

iiitirous gas was gradually added to 21 cubic 

inches of the gas produced from a new foIutioDj 

P 



( 226 ) 

till the dimtnotion was complete i the ga^ re- 
niaioing equalled 2,3 cubic incbes ; it was 
tinabforbabie by water, and extinguifhed flame. 

In another experiment, when the the laft 
portions of gas from a folution were carefully 
leceived in water previoufly boiled, 12 cubic 
inches agitated in water left a refiduum of 1.3 $ 
wbilft the fame quantity decompofed by nitrous 
gas, containing ,02 nitrogcne, left about 1.5 

Hence it appeared that the aeriform products 
6f the foiutfon confifted of the peculiar gas 
analogous to oxygenated mnriatio^acid, and of 
a fmall quantity of nitrogene. 

/. Confi^uently a portion of the nitric acid 
of the aqua regia had been decompofed ; but if 
it had given oxygene both to the platina and 
muriatic acid, the quantity of nitrogene evolved 
ought to have been much more confiderable. 

g. To afcertain if any water had been de- 
compofed, and the nitrogene condenfed in t^e 
iblution by its hydrogene, to form ammoniac^ 
I faturated a folution with lime, and heated it, 
Imt no ammoniacal fmell was perceived. 



( 227 ) 

A. To determine if any nitrogene had entered 
into cbetnical combination with muriatic acid 
and oxygene, fo as to form an aeriform triple 
compound, analogous in its properties to oxy- 
genated muriatic acid, I expofed fome of the 
gas to mercury, expelling that this fubftance^ 
by combining with its oxygene, would efFcdl k 
complete decompofition ; and this was adiually 

m 

the cafe : for the gas was at firft rapidly dimin- 
iihed, and the mercury became oxydated ; its 
volume, however, foon increafed; and the 
refidual gas appeared to be nitrous^ mingled 
with much nitrogene. The exa6l proportions 
of each, from an accident, I could not deter-^ 
mine. 

This experiment was inconclufive, becaufe 
the nitro-muriatic acid fufpended in the pecu* 
liar gas, from which it can probably be never 
perfedtly freed, adled in common with it upoa 
the mercury, and produced nitrous gas : and 
this nitrous gas^ at the, moment of its produce- 
tion, formed nitrous acid by combining with th^ 
pxygene of the peculiar gas ; and the nitrous 



I 

" '.J 



( 228 ) 

acid generated * was again decompofed by th^ 
niercury ; and hence nitrons gas evolved, and 
pdffibly fome nitrogene. 

/. Peculiar circumftances prevented me at 
this time from completely inveftigating the 
fubjedl. It remains doubtful whether the gas 
confifts (imply of highly oxygenated muriatic 
acid and nitrogene,'!- produced by the decom- 



* The decompofition of aeriform nitrous acid by mercury, 
was firft noted by Prieftley j vol. iii. pag. 101. This decoca* 
pofition I have often had occafion to obferve. In reading 
HuQibolt*s paper on eudiometry, Annales deChiraie,xxviii, 
pag. 150^ I was not a little furprlfed to £nd that he takes 
no notice of this fa6t. He feems to fuppofe that nitrous 
Bcid can remain aeriform, and even be condenfed, in con- 
ta6t with mercury, without alteration. He fays, " In 
mingling 100 parts of atmofpheric air with 100 of nitrous 
air, the air immediately became red, but all the acid pro- 
duced remained aeriform } and after eighteen hours fome 
drops only of acid were formed, which fwam upon the 
me|;cury. 



»» 



t Lavoifier has faid concerning aqua regia, " In folci- 
'' tions of metals in this acid, as in all other acids, the 
'^-metals are firft oxydated, by attra6ting a part of the 
// 03^ygene from the compound radical. This occaiioas the 
" difengagement of a particular fpecies of gas not hitherto 
*" deicribed, which may be called Ditro-rauriatic gas. It 



( a2d ) 

I 

pofition of nitric acid from the coalefcing affin- 
ities of platina and muriatic acid for oxygene ; 
or whether it is compofed of a peculiar gas, 
jl-nalogous io oxygenated muriatic acid, and. 
nitrogene, generated from fomp unknown 
li^itiies.f' 

XI. Oti the aSion of the Ele£iric Spark on a 
Wicfure of Nitrogene and Nitrous Gas. 

Thinking it poilible that nitrous gas and 

** 'has a very difagrecable fmcll^ and is fatal to animal life 
*' when refpired 3 it attacks iron, and caufes it to ruft 5 it 
•* is abforbed in considerable quantities by water.*' Elera. 
Eng. 237. 

f T have no doubt but that the gas procured from the 
ilplution of gold in aqua regia, is analogous to that produ- 
ced from platina. 

Soiac very uncommon circuniftances are attendant on the 
folution of platina : 

ift. Theimmenfe quantity of acid required for the folu- 
tioq of a minute quantity of platina. 

2d. The great quantity of gas produced during the folu- 
tion of this minute quantity. 

j3d. The intenfe red color of the folution, and its per- 
fe6tly acid properties after it ceafe^ to a^5l upon tfie meta}. 



9 i 



( 230 ) 

nitrogeae might be made to combine by the 
a6lion of the electric fpark^ fo as to form nitrous 
oxide, I introduced 20 grain meafures of each 
of therh into a fmall detonating tube^ graduated 
to grains^ (landing over mercury, and con- 
taining a very fmall quantity of cabbage juice 
rendered green by an alkali. After eledric 
fparks had been palled through the gafes for an 
liour and half, they were diminiihed to about 
32, and the cabbage juice was flightly red- 
dened. On introducing about lO meafures of 
hydrogene, and palling the eledlric fpark 
through the whole, no inflammation or dimi- 
nution was perceptible. Hence the condenla- 
tion moft probably arofe wholly frjom the forma- 
tion of nitrous acid,* by the more intimate 
union of the oxygene of nitrous gas with fome 
of its nitrogene, as in the experiments of 
Prieftley. 

As the nafcent nitrogene, in the decoropo- 



* For if nitrous oxide had been formed, it would have 
iMCeo decompofed by the bydrogene. 



( ^31 ) 

iition of nitrate of ammohiac, combines ivitl) a 
portion of oxygene and nitrogene, to form 
iiitl^us oxide ; it is probable that nitrous oxide 
may be produced during the pailage of nitrous 
gas and ammoniac through a heated tube. 



%IL General Remarks. 

There are no reafons for fiap(X)(ing that ni- 
trous oxide is formed ia any of the proceiles of 
nature; and the nice equilibrium of aiHnity by 
rnvhich it is conftituted, forbids us to hope for the 
power of compofing it from its limple princi- 
ples. We muft be content to produce it, 
cither direfily or indiredily, from the decom- 
pofition of nitric acid. And as in the decom- 
pofition of nitrate of ammoniac, not only all the 
nitrogene of the nitric acid enters into the com- 
pofition of the nitrous oxide produced, but 
likewife that of the ammoniac, this procefs 
is by far the cheapeft, as well as the moft expe- 
i]itiou$. A mode oi producing ammoniac at 



RESEARCH II. 
DIVISION I. 

EXPERIMENTS and OBSERVATIOUS on the 
COMBINATIONS of NITROUS OXIDE. 



I. Combination of Water with Nitrous Oxide. 

a. jL he difcoverer of nitrous oxide firft 
obferved its iblubility in water; and it has 
fince been noticed by different experimen- 
talifis. 

Dr. Prieftley found that water diflblved about 
one half of its bulk of nitrous oxide, and that at 
the temperature of ebullition^ this fubftance was 
incapable of remaining in combination with it.* 



^ Experiments and obferyations, vol. ii. pag» 81. 



( 236 ) 

h. lintroduccd to 9 cubic inches of pure 
water, i. e. water diftilled under mercury, 7 
cubic inches of nitrous oxide, which had been 
obtained over inerctiry, frorti'-thc decompofition 
of nitrate of ammoniac, and in confequence was 
perfedlly pure. After they had remained toge- 
ther for 1 1 hours, temperature being 46^, during 
which time they were frequently agitated, the 
gas remaining was 2,3 ; confequently 4^7 cubic 
inches had been abforbed. And then, lOO 
cubic inches, =: 25300 grains of water, will 
abforb 54 cubic inches, =27 grains, of nitrous 
oxide. 

c. The tafte of water impregnated with 
nitrous oxide, is diftin6lly fweetifh ; it is fofter 
than common water, and, in my opinion, much 
more agreeable to the palate. It produces no 
alteration in vegetable blues, and efFedls no 
change of color in metallic folutions. * 

d. Thinking that water impregnated with 
nitrous oxide might probably produce ibme 
effects when taken into the ftomach, by giving 
out its gas, I drank, in June, 1799, about 



( 23f7 ) 

N 

3 ounces of it, but without pcrceiviag any 
efFedls, 

- A few days ago, confidering this quantity as 
inadequate, I took at two draughts nearly a 
pint, fully faturated ; and at this time Mr. 
Jofeph Prieftley drank the fame quantity. 

- We neither of us perceived any remarkable 
effciSls. 

Since that time I have drank near three pints 
of it in the courfe of a day. In this inftance it 
appeared to adl as a diuretic, and I imagined 
that it expedited digeftion. As a matter of 
tafte, 1 ftiould always prefer it to common 
water. 

e. Two cubic inches of pure water, that had 
been made to abforb about 1,1 cubic inches of 
nitrous oxide ; when kept for fome time in 
ebullition, and then rapidly cooled, produced 
nearly I of gas. Sulphur burnt in this gas with 
a vivid rofe-colored flame. 

In another experiment, in which the gas 
was expelled by heat from impregnated water, 
arid abforbed again after much agitation on 



( MS ) 

cooling ; the refiduum was hardly pcrcq>tibley 
and mod likely depended upon fomegas which 
had adhered to the mercury, and W£^s liberated 
during the ebullition. Hence it appears that 
nitrous gas is expelled unaltered from its aqueous 
folution by heat. 

/• I have before mentioned, Divifion III, 
that nitrous oxide, during its combination with 
fpring water, expels the common air diflolVed 
in it. This common air generally amounts tq 
one fixteenth, the volume of the water being 
unity. A corredlion on account of this circum- 
fiance mud be made for the apparent deficiency 
of diminution, and for the common air mingled 
in confequence, with nitrous oxide during its 
abforption by common water. 

g. Water impregnated with nitrous gas ab» 
forbed nitrous oxide ; but the refidual gas was 
much greater than that of common water, and 
gave red fumes with atmofpheric air. Nitrous 
gas agitated for a long while over water highly 
impregnated with nitrous oxide, was not in the 
flightefl; degree diminifhed^ in one experiment 
indeed it was rather increafed ; doubtlefs from 



the liberation of fbme nitrous oxide from the 
"vmiet by the agitation. 

Ir. Nitrous oxide kept !n coQta<5t with aque- 
ous folution of fulpburated hydrogene and often 
agitated^ was not in the flighted degree dimi- 
nifhed. 

Sulphurated hydrogene, introduced into a 
Iblution of nitrous oxide, was rapidly abforbcd, 
and as the procefs advanced, the nitrous oxide 
waa given out. 

L Water impregnated with carbonic acid, 
poilefled no adlion upon nitrous oxide, and did 
not in the flighted degree abforb it. When 
carbonic acid was introduced to an aqueous 
folution of nitrous oxide ; the aeriform acid was 
abforbed, and the nitrous oxide liberated. 

k. From thefe obfervatipns it appears that 
nitroue oxide has lefs affinity for water, than 
even the weaker acids, fulpburated hydrogene 
and carbonic acid ; as indeed one, might have 
conjefiured a priori from its degree of folubility : 
likewife that it has a flronger attraction for 
water than the gafes not pofleifed of acid or 



( 24a) 

alkaline properties '^ it expelling from wat(# 
nitrous gas^ oxygene, and common air ; probs-^ 
bly hj^dro^carbonate^ bydrdgene^ and nitrogene. 

II. Combinations of Nittous Oxide viiith 
Fluid Inflammahh Bodies. 

r. a. Vitriplic ether abforbs nitrous oxidef 
in much larger quantities than water. -. ; 

A cubic inch of ether, at temperature 50,^^ 
combined with a cubic inch and feven tenths of 
nitrous oxide. 

Ether thus impregnated was not at all altered 
in its appearance ; its fmell was precifely the 
fame, but the tafte appeared lefs pungent, and 
more agreeable. Nitrous o;xide is. liberated 
unaltered from ether at a very low temperature, 
that is, at about the boiling point of this fluid. 

For expelling nitrous oxide from impregnated 
ether, and for afcertaining in general the quan- 
tity of gafes combined with fluids, I have lately 
made ufe of a very iimple method, which it 
may not be amifs to defcribe. 



( 241 ) 

The impregnated fluid is introduced into a 
ftnall thin tube, graduated to ,05 cubie inches^ 
through mercury. The quantity of fluid fhould 
never equal more than a fifth or iixth of the 
capacity of the tube. 

The lower part of the tube is adapted to an . 
orifice in the fhelf of the mercurial apparatus^ 
fo as to make an angle of about 40^ with the 
furface of the mercury. 

The flame of a fmall fpirit lamp is then 
applied to that part of the tube containi^ng the 
fluid ; and afler the expulfion of the gas from 
it, the heat is raifed fo as to drive out the fluid 
through the orifice of the tube. Thus the 
liberated gas is preferved in a flate proper for 
accurate examination^ 

Impregnated ether, during its combination 
with water, gives out the greater part of its 
nitrous oxide. During the liberation of nitrous 
oxide from ether, by its combination with water, 
a very curious phaenomenon takes place. 

If the water employed is colored, fo that it 
may be feen in a flratum difiindt from the im* 

Q 



( ^^^ ) 

pregfiated ether, at the point of contai^ a num- 
ber of fmall fpherules of fluid will be perceited, 
apparently repulfive both to water and ether ; 
thi^ fpherules become gradually covered with 
minute globules of gas, and as this gas is 
.liberated from fheir furfaces, they gradually dis- 
appear. 

h. Alcohol difl[blves confiderable quantities of 

« 
nitrous oxide. 

2 cubic inches of alcohol, at 52^, combined 

w 

with 2,4 cubic inches of nitrous oxide. The alco- 
hoi thus impregnated had a tafte rather fweeter 
than before, but in other phyfical properties 
was not perceptibly altered. 

Nitrous oxide is incapable of remaining in com- 
bination with this fluid at the temperature of ebuU 
lition ; it is liberated from it unaltered by heat. 
Impregnated alcohol, during its combination 
with water, gives out the greater part of its com^ 
bined nitrous oxide : on mingling the two fluids 
together, at the point of contadl the alcoboi 
becomes covered with an infinite number of 
fmali globules of gas, which continue to be 



( 243 ) 

generated during the whole of the combination, 
and in palling through the fluid render it almofl 
opaque. 

c. The eflential oils abforb nitrous oxide t^ 
a greater extent than either alcohol or ether. 

^5 cubic inches of oil of carui combined with 
3,2 cubic inches of nitrous oxide at 51®. The 
color of the oil thus impregnated was rather 
paler than before. 

Nitrous oxide is expelled unaltered from im- 
pregnated oil of carui, by heat. 

1 of oil of turpentine abforbed nearly 2 of 
nitrous oxide, at 57°. Its properties were ijot 
ienfibly altered from this combination, and the 
gas was expelled from it undecompounded, by 
heat. 

d. As well as the eflential oils, the fixed oils 
diflblve nitrous oxide at low temperatures, whilft 
at high temperatures they do not remain in com- 
bination. 

1 of olive oil abforbed, at 6l°, 1,2 of nitrous 
oxide, but without undergoing any apparent 
phyfical change. 



( 244 ) 

III. ABion of "Fluid Acids on Nitrous Oxidd. 

a. Nitrous oxide expofed to concentrated- 
itolphuric acid, undergoes no change, and fuf- 
fers no din^inution, that may not be accounted 
for from the abftra<3ion of a portion of its water 
by the acid. 

h. Nitrous oxide is fcarcely at all folubfe in 
nitrous acid, , and expofed to that fubftance, 
undergoes no alteration. 

c. Muriatic acid, o{ fpecific gravity 1,14 
abforbs about a third of its bulk of nitrous oxide. 
It fufFers no apparent change in its properties 
from being thus impregnated, and the gas is again 
given out from it oa the application of heat. 

d. Acetic acid abforbs nearly one third of 
its bulk of nitrous oxide. 

e. Aqua regia, that is, the nitro-muriatic 
acid, abforbs a very minute portion of nitrous 
oxide. 

/. Nitrous oxide was expofed to a new com- 
pound acid, conlifting of oxygenated muriatic 
Acid^ and fulphuric acid, which I difcovered in 



( 045 ) 

Joly^ 1799, and of which an account will b^ 
fliortly publiihed; but it was neither abforbed or 
altered. 

I have before mentioned that the aqueous 
iUations of fulphurated hydrogene and carbonic 
acid^ neither diilblve or alter nitrous oxide. 

" IV. ASion of Saline Solutions^ mid other 
Suhfiances^ on Nitrous Oxide. \ 

^.. Nitrous oxide expofed to concentrated 
iblution of green fulpbate of iron, at 58°, un- 
<lerwent no perceptible diminution ; not even 
after it had been fuffered to remain in conta6l 
l^ith it for half an hour. 

i. It underwent diminution of nearly ,2 when 
agitated in contact with a folution of red ful- 
pbate of iron^ the volume of the folution being 
unity. 

c. Solution of green fulphate of iron, fully 
impregnated with nitrous gas, did not in the 
ilighteft degree abforb nitrous oxide, and ap- 
peared to have no adlion upon it. 



d^ Soluttoo of green nuiriate of iron, wlie* 
ifaer impregnated with nitrotts gas, or nniiii- 
pregnated, has no affinity for^ or adlion upon, 
nitrous oxide. 

€. Solution of red muriate pf iron in alcoholy 
abforbed nearly one fifth of its bulk^ of nitMns 
oxide, 

f. Solution of pruiltate of potaih abforbed 
nearly one third of its volume, of nitrous Odide, 
which was again expelled from it by heat. 

g. Solution of nitrate of copper appeared to 
bave no affinity for nitrous oxide. 

b. Concentrated folution of nitrate of am* 
inoniac, at 58^ abforbed one eighth of its bulk 
of nitrous oxide. 

/• Solutions of alkaline fulphures abforb 
nitrous oxide in quantities proportionable to 
the water they contain ; it is expelled from 
them unaltered by heat. None of the hydro- 
fulphures diflblve more than half their bulk of 
nitrous oxide. 

k. Concentrated folutions of the fulpbites 
poflefs little or no adion on nitrous oxide : 



(247 ) 

diluted folutions abforb it in fmall quantities. 

/. Concentrated folution of muriate of tin 
abfbrbs about one eighth of nitrous oxide; 
more dilute folutions abforb larger quantities. 

From thefe obfervations we learn, that neutro- 
ialine folutions in general, have very feeble 
attradlions for nitrous oxide ; and as folutions of 
green muriate, and fulphate of iron, whether free 
from nitrous gas, or impregnated with it, poffefs 
no a6lion uppn nitrous oxide, nitrous gas may be 
feparated from this fubftance by thofe folutions 
i«rith greater facility than nitrous oxide can be 
feparated from nitrous gas, by water or alcohol. 

Charcoal abforbs nitrous oxide as well as 
all other gafes ; and it is difengaged from it 
by heat. 

I have as yet found no other folid body, not 
poflefled of alkaline properties, capable of ab- 
forbing nitrous oxide in any flate of exiftence. 

The bodies poflcffing the ftrongeft affinity 
for oxygene, the dry fulphitcs, muriate of tin, 
the common fulphures, white pruffiate of pota(h, 
and green oxide of iron, do not in the flighteft 



( 248 ) 

degree a<5l on nitrous oxide at common tem^ 
peratures. 

V. A&ton of different Gafes on Nitroi/ts 
Oxide. 

a. 12 meafures of muriatic acid gas were ming- 
led with 7 meafuresof nitrous oxide at 56''. After 
remaining together for a minute^ they filled a 
ijpace equal to 19^ meafures. When water 
was introduced to them^ the muriatic acid was 
abforbed much more flowly than if it had been 
unmingled. 

. In another experiment^ when the gafes were 
faturated with water^ 9 meafures of each of 
them^ when mingled and fufFered to remain in 
contadl for a quarter of an hour^ filled a fpace 
nearly equal to 19 ; and after thQ muriatic acid 
had been abforbed by potafh, the nitrous oxide 
.remained unaltered in its properties. 

From the expaniion, it appears moil proba- 
ble that aeriform muriatic acid^ and nitrous 
oxide^ have a certain aiHnity for each other^ an^ 



( 249 ) 

that they combine when mingled together ; fpr 
in the lad experiment, the increafe of volume 
cannot be accounted for by fuppofing that ni- 
trous oxide undergoes lefs change of volume 
than muriatic acid, by aeriform combination 
\vith water, and that the cxpanfion depended 
upon the folution of fome of its combined water 
hy the muriatic acid. That muriatic acid and 
nitrous oxide have a flight affinity for each 
other, likewife appears from the abforption of 
citrous oxide by aqueous folution of muriatic 
acid. 

m 

Thinking that nitrous oxide might attract 
muriatic acid from its folution in water, I ex- 
pofed a minute quantity of fluid muratic acid 
to nitrous oxide; but no alteration of volume 
took place in the gas. 

b. 6 meafures of nitrous oxide were mingled 
with 11 nieafuresof fulphurcousacid, faturated 
with water ; after remaining at reft for fix 
njinutes, they filled a fpacc nearly equal to 18 
pieafures. Expofed to water, the fulphureous 
fLCid was abforbed, but not nearly fo rapidly as 



( 250 ) 

when in a free ilate. Sulpbar burnt with a 
vivid flame m the refidual nitrous oxide. 7 
meafures of fulphureous acid were now mingled 
with 8 of nitrous oxide. They filled a fpace 
nearly equal to I5f , and no farther expanfion 
took place afterwards. 

From thefe experiments it appears probable 
that fulphureous acid^ and nitrous oxide^ have 
fbme affinity for each other. 

c. 11 meafures of carbonic acid were mingled 
with 8 of nitrous oxide ; they filled a fpace 
nearly equal to IQ meafures. On expofing the 
mixture to cauftic potafh^ the carbonic acid was 
abfbrbed^ and the nitrous oxide remained ptire. 
Hence it appears that carbonic acid and mtixms 
oxide xlo not combine with each other. 

d Oxygenated muriatic acid, and nitrons 
oxide^ were mingled in a water apparatus : there 
was a flight appearance of condenfation ; hot 
this was mod probably owing to abfbrptibn by 
the water ; on agitation^ the oxygenated muri- 
atic acid was abforbed, and the greater part of 
the nitrous oxide remained unaltered. 



( 251 ) 

e. Sulphurated hy drogenc and nitrous oxide, 
mingled together; neither expanded or con- 
traded ; expofed to folution of potafb^ the acid* 
Only was abforbed. 

f. 10 meafures of nitrous gas were admitted 
to 12 of nitrous oxide at bgp. They filled a fpace 
equal to 22^ and after remaining together for 
an bour^ had undergone no change. Solution 
of muriate of iron abforbed the nitrous gas 
without affedling the nitrous oxide. 
" g. Nitrous oxide was fucceffivefy mingled 
with oxygene, atmofpheric air, hydro-carbonate, 
phofphoratcd hydrogene, hydrogene, and nitro- 
gene, at bT^ ; it appeared to poflefs no adiion 
on any of them, and was feparated by water, 
the gafes remaining unaltered. 

h. As nitrous oxide was foluble in ether, ^ 
alcohol, and the other inflammable fluids, it 
was reafbnablc to fuppofe that its afiinity for 
thofe bodies would enable them to unite with 



* The experiments of Berthollet have tlearly proved 
the perfe^ acidity of this fubflance. 



( 252 ) 

it in the aerifoim fiate. At the fuggefiion of 
Dr. Beddoes I made the following experiment: 

To 12 meafures of nitrous oxide, at 54°, I 
introduced a lingle drop of ether ; the gas im- 
xnediately began to expand, and in four minutes 
i^lled a fpace equal to lixteen meafures and a 
quarter. When an inflamed taper was plunged 
into the gas thus holding ether in folution, a 
Hght blue flame flowly pafled through it. 

A confiderable diminution of temperature is 
mofl: probably produced, from the great ex- 
panfion of nitrous oxide during its combination 
with ether. 

A drop of alcohol was admitted to 14 mea- 
fures of nitrous oxide. In Ave minutes, the 
gas filled a fpace' equal to fifteen and a third ; 
but no farther diminution took place afterwards. 

A minute quantity of oil of turpentine was 
introduced to 14 meafures of nitrous oxide ; it 
filled, in 4 minutes, a fpace rather lefs than 14; 
and no farther change took place afterwards. 
Moft likely this contradlion arofefrom the pre- 
cipitation of the water diflblvcd in the gas by 



( 0.53 ) 

the ftronger affinity of the oil for nitrous 
oxide. To afcertain with certainty if any oil 
bad been diflblved by the gas, I introduced 
into it a fmall quantity of ammoniac. It imme- 
diately became flightly clouded, moll probably 
from the formation of foap, by the combination 
of the diflblved oil with the ammoniac. 
' From thefe experiments we learn, that when . 
nitrous oxide is mingled with either carbonic 
acid^ oxygene, common air, hydro-carbonate, 
fulphuratcd hydrogene, hydrogcne, or nitro- 
gene, they may be fcparatcd from each other 
without making any allowance for contra6tion 
or cxpanfion : but if a mixture of either muri- 
atic acid, or fulphureous acid gas, with nitrous 
oxide, is experimented upon ; in the abforption 
of the acid by alkalies, the apparent volume of 
gas condenfed will be lefs than the real one, by 
a quantity equal to the fum of cxpanfion from 
combination. Confcquently a corredlion muft 
be made on account of this circumftance. 

Though alcohol, ether, eflential oils, and the 
fliiid inflammable bodies in general^ diflblve 



( 234 ) 

nitrons oxide with much greater rapidity than 
water^ yet as we are not perfedlly acquainted 
with their adlion on unabforhable gafei^ it is 
better to employ water for feparating nitroo» 
oxide from thefe fubftances; particularly as that 
fluid is more or lefs combined with all gaies^ 
and as we arc acquainted with the extent of its 
adtion upon them. 

By purfuing the fubjedl of the folution of 
cilential oils in gafes, we may probably difcover 
a mode of obtaining them in a ftate of abfblute 
drynefs. For if other gafes as well as nitrous 
oxide, have a flronger affinity for oils than for 
water, water moft probably will be precipitated 
from them during theii^ folution of oils ; and 
after their Saturation with oil, it is likely that 
they are capable of being deprived of that fub- 
flance by ammoniac. 

VI. A£iion of aeriform Nitrous Oxide in the 
Alkalies. History of the discovery of the comUna^ 
iions of Nitrous Oxide with the Alkalies. 

a. When nitrous oxide in a free flate is 



( 255 ) 

expofed to the folid cauftic alkalies and alka* 
line earths, at common temperatures, it is nei- 
ther ablbrbed nor a6ted upon ; when it is placed 
in conta^l with folutions of them in water^ a 
foiall quantity is diflblved ; but this combina^ 
tion appears to depend on the water of the folu- 
tioUp for the gas can be expelled unaltered, at 
the temperature of ebullition. 

h* Cauftic potafti was expofed to nitrous 
oxide for 13 hours : the diminution was not to 
tHie Hftieth, and this flight condenfation moil 
probably depended upon its combination with 
the water of the gas. 

^ Concentrated folation of potafh abforbed 
• a fourth of its bulk of nitrous oxide. When 
the impregnated folution was heated, globules 
of gas were given out from it rapidly ; but the 
quantity colleded was too fmall to examine. 
Soda, whether folid or in folution, exhibited 
' exa<Sily the fame phaenomena with nitrous oxide. 
The folution of foda abforbed near a quarter of 
its bulk of gas. 

c, 31 meafures of ammoniacal gas were 



( 2&6 ) 

tniogled with 8 nrieafures of nitrous oxide over 
dry mercury, both of the gafes being faturated 
with water. No change of appearance was 
poduced by the mixture, and they filled^ after 
two minutes, a fpace equal to IQ. On the in- 
trodudion of a little water, the ammoniac was 
abforbed, and the nitrous oxide remained un- 
altered, for it was diflblved by wat6r as rapidly 
as if it had never been mingled with ammo- 
niac.* 

7 meafures of nitrous oxide, expoied to 6 
meafures of folution of ammoniac in water^ was 
in an hour diminifhed to 4^ nearly. When 
the folution was heated over mercury, permanent 
gas was produced, which was unabforbable by 
a minute quantity of water, and foluble in a 
large quantity ; confequently it was nitrous 
oxide. 



* The Dutch chemifts have afferted, that mixturie with 
ammoniac prevents the abforption of nitrous oxide by wa- 
ter, either wholly or partially. Journal de Phyfiqae, 
t. xliii. part ii. pag. 32/. It is difficult to accotmt for 
their miftake. 



( 267 ) 

J. Nitrous oxide was expofed to dry catldic 
ftrontian ; it underwent a diminution of nearly 
one fortieth, which moft likely was owing to 
'the combination of the ftrontian with its water, 

1 1 meafures of nitrous oxide were agitated 
in contadl with 8 of ftrontian lime water : nearly 
4 meafures were abforbed. The impregnated 
folution expofed to heat^ rapidly gave out its 
. gas ; 3 meafures were foon colledied, which 
mingled with a fmall quantity of hydrogene, 
and inflamed by the taper, gaVe a fmart deto- 
nation. 

e. Nitrous oxide expofed to lime and argil, 
both wet and dry, was not in the flighteft de- 
gree afled upon. 

From thefe experiments it is evident that 
nitrous oxide in the aeriform ftate cannot be 
combined either with the alkalies, or the alka- 
line earths. That a combination may bfe effedied 
between nitrous oxide and thefe fubftances, it 
muft be prefented to them, in the nafcml ftate. 

The falts compofed of the alkalies and nitrous 

oxide, are not analogous to any other compound 

R 



( 258 ) 

fabfbnceff^ being poflefled of very fingufar pro^ 
perties. Before tbefe properties are detailed, if 
may not be amifs to give an account of the 
accidental way in wbich I difbovcred the mode 
of combination. 

In December, 1799> dcfigning to make ar 
very delicate experiment, with a view to 
aiibertain if any water was decompofed dii«- 
ring the converHon of nitrous gas into nitrous- 
oxide^ by fulphite of potafh, I expofed 20O 
grains of cryflalifed fulphite of potafh, con- 

« 

taining great fuperabundance of alkali, to^ 14 
cubic inches of nitrous gtis, containrng one 
eighteenth nitrogene. The alkali was cnff- 
ployed to preferve any ammoniac that might be 
formed, in the free ftate, as it would otherwife 
combine with fulphureous acid.* 

The volume of gas diminifhed with great 
rapidity ^ in two hours and ten minutes it wtt 



* Sttlphureoug acid faturate* more potafh than ftilpfatnfc: 
acid> fo that moft probably during the converiion of ful- . 
phite of potafh into fulphate^ portions of fulphureous acid 'j 

«e £feDgagjBd. 



-i 



fel- 






ۥ1 



( 239.) 

rctluced to 67, which I con(idere(l as the IiAiC 
of diminution. Accidentally, however, fufFer- 
ing it to remain for three hours longer, I vr$s 
much furprifed by finding tliat not quite 12 
cubic inches remained, which confiftcd of 
nitrons oxide, mingled With the oitrogene that 
exifted before the experiment. 

In accounting theoretically for this pbaeno- 
menon, ditFerent fuppolitions necelTanly pre- 
fentcd themfelves. 

ift, It was poiTible, that though fulphiteofpot- 
afti, and potath, feparately pofleffed no adion ott 
fi-ee nitrous oxide, yet in combination they might 
esert fnch affinities upon it ns either to abibrb 
it, or mak« it enter into new combinations. 

2dly. It was more probable tbat the caaflio 
potefh, though incapable of condenfing aeriform 
ftHrous oxide, was yet poflefled of a ftrot^ 
affinity for jt when in the najient Jta/e, and that 
the^nifroHS oxide condenfed in the expeiiment 
had been combined in this Hate with the freti 
nlkali. 

To^afoeMain ifthecompoDadof potafh md 



^ 



( 260 ; 

futphite of polafh with fulphalc, was capable of 
acting upon nitrous oxide, I fufFered a quan- 
tity of this fubftancc to remain in contaft with 
the gas for near a day : no change whatever 
took place. 

• To determine whether the diminution of 
nitrous oxide depended upon its abforption in 
the nafcent (late, by the peculiar compound of 
potafh and fulphite of potafh, or if it was fimply 
owing to the alkali. 

I mingled a folution of fulphite of potalh with 
cauftic foda ; the fait, after being evaporated at 
a low temperature, was expofed to nitrous gas* ' 
The nitrous oxide formed was abforbed, but 
in rather lefs quantities than when alkaline 
fulphite of potafh was employed. 

Hence it was evident that the alkali was the 
agent that had condenfed the nitrous oxide in 
thofe experiments, for ibda is incapable of com- 
bining either with fulphate, or fulphite of pot- 
afh. 

To afcertain whether any change in the con- 
ftitution of the nitrous oxide had been produced 



(261 ) 

by the condcnfation^ I introduced a fmall quan- 
tity of fulphiteof potafli, with exccfs of alkah", 
that had abforbed nitrous oxide, into a long 
and thin cylindrical tube filled with mercury ; 
and inclining it at an angle of 35° with the 
plane of the mercury, applied the heat of a fpirit 
lamp to that part of the tube containing the 
falts ; when the glafs became very hot, gas was 
given out with rapidity ; in lefs than a minute 
the tube was full. This gas was transfered into 
another tube, and examined ; it proved to be 
nitrous oxide in its higheft ftate of purity ;* for 
a portion of it abforbed by common water, left 
no more than a refiduum of-, and fulphur 
burnt in it with a vivid rofe-colored flame. 

Being now fatisfied that the alkalies were 
capable of combining with nitrous oxide; to 
inveftigate with precifion the nature of thefe 
new compounds, I proceeded in the following 
manner. 



* Hence we learn that fulphite of potaih, when flrongly 
hesLted, does not decompofc nitrous oxide, even ia 
Ihe nafcent Jiate , 



( 262) 



VII. ^Comiination of Nitrous Oxide with 
Pota/b. 

a. Intoafolution offulphiteof pota(h^ which 
had been made by palling fulphureous acid gas 
fi'om a mercurial airholder into cauftic potafh 
diiiblved in water^ I introduced 17 grains of 
dry potafh. The whole evaporated at a low 
temperature, gave 143 grains of fal^t This iait 
was not wholly compofed of fulphitc of potaih 
and potaih ; it contained as well, a minute quan- 
tity of carbonate, and fulphate of potaOi, formed . 
during the evaporation.* 

120 grains of it finely pulverifed^ and retain- 
ing the water of cryftalifation, were expofed 
to 15 cubic inches of nitrous gas, over mercury. 
The nitrous gas diminifhed with great rapidity, 
and in three hours a cubic inch and nine tenths 



* See the excellent memoir of Fourcroy and Vauquelin 
on the fulphureous acid, and its combinations. Annales de 
Chimie, ii^ 54, Or ^icholfon's Phil. Journal^ vol. i^ 
pag. 313. 



( 263 ) 

only remained, which coniified of nearly one 
third nUrous oxide, and two thirds nitrogeoe 
that had pre-exifted in the nitrous gas. The 
increafe of weight of the fait could not be deter^ 
mined, as fome of it was lofl by adhering to the 
veflel tn which the combination was efFe<9ed^ 
and to the mercury. It prefented no diflind 
ieries of cryftalifations, even when examined by 
the magnifier; rendered green vegetable blues, 
and its tafte was very different from that of the 
remaining quantity of fait that had been expofed 
to the atmofphere. A portion of it ftrongly 
heated over mercury, gav^ out gas with great 
rapidity, which had all the properties of the 
pureft nitrous oxide. 

When water was poured upon fome of it, no 
gas was given out, and the whole was equably 
and gradually diflblved. Alcohol, as well as 
ether, appeared incapable of diflblving any part 
-of it. 

When muriatic acid was introduced into it, 
<:onfined by mercury, a rapid effcrvefcence took 
place. Part of the gas difengagcd was Tulphu- 



( 264 ) 

reous acid^ and carbonic acid ; the remainder 
was nitrous oxide. 

. h. I made a- number of experiments upon 
falts procured in the manner I have juft de- 
fcribed, with a view to obtain the compound of 
nitrous oxide and potafh, free from admixture 
of other falts. ^ 

When the mixed fait was boiled in alcohol 
or ether, no part of it appeared to be diflblved. 
Finding that little or no gas was given out 
during the ebullition of concentrated folutions 
of the mixed falts, I attempted to feparate the 
fulphate, fulphite, and carbonate of potafh, from 
the combination of nitrous oxide and potafli, 
by fucceffive evaporations and cryftalifations. 
But though in this way it was nearly freed from 
fulphate of potafh, yet the extreme and nearly 

equal folubility of the other falts, prevented me 

« 

from completely fcparating them from each 
other. 

By expofing, however, very finely pulverifed 
fulphite of potafh, mingled with alkali, for a 
great length of time to nitrous gas, it was alnioil 



( 265 ) 

wholly converted into fulphatc ; and after thi 
reparation of this by folution, evaporation, and 
cryftalifation, at a low temperature, I obtained 
the new combination, mingled with very little 
carbonate of potafh, and ftill lefs of fulphite. 

The minute quantity of fulphite chiefly ap- 
peared in very fmall cryftals ; diftinrl from the 
mafs of fait, ^hich poflelTed no regular cryf- 
talifation, and was almoft wholly comp>fed of 
the new compound^ intimately mingled with 
a little carbonate. The new compound, as 
nearly as as I could eftimate from the quantity 
of nitrous oxide abforbed, confifted of about 
3 alkali, to 1 of nitrous oxide, by weight. 
It exhibited the following properties : 
Iw Its tafte was cauftic, and poflefled of a pun- 
gency different from either potafh or carbonate 
ofpotafh. 

2. It rendered vegetable blues green, which 
might pofBbly depend upon the carbonate of 
potafli mixed with it. 

3. Pulverifed charcoal mingled with a few 
grains 'of it, and inflamed, burnt with flight 



( 266 ) 

fcintillations. Projedled into zinc in a fiate of 
fufion, a flight inflammation was produced. 

V 

4. When either fulphuric^ muriatic^ or 
nitric acid was introduced to it under mercury^ 
it gave out nitrous oxide, mingled with a little 
carbonic acid. 

5. Thrown into a folution of Tulphurated 
bydrogene, gas was difengaged fiom it, but m 
quantities too minute to be examined. 

6. When carbonic acid was thrown into a 
folution of it in water, gas was difengaged s 
on examination it proved to be nitrous oxidc» 

7. A concentrated folution of it kept in 
ebullition in a cylinder, confined by mercjufy, 
gave out a few globules of gas^ which were too 
minute to be examined, and probably con6ftcd 
of .common air previoufly contained in the 
water. 

c. In the experiments made toafcertain thefe 
properties all the fait was expended, otherwife I 
fhould have endeavoured to afcertain what quan- 
tity of gas would have been liberated by heat from 
a given weight ; and likewife what would have 



(267 ) 

r 

been the efFefls of admixture of it with oih 
When fome of the mixed fait was mingled with 
oil of turpentine, part of it was diflblvedj and 
the fluid became white ; but no gas was given 
out. On this coarfe experiment, however, I 
canaot place much dependance. Jf the com^ 
binatipn of nitrous oxide and pota(h is capably 
of cofnbining with oil without decompofition, 
barytos apd firontian^ will probably feparate th^ 
oil from it^ and thus it may poflibly be obtained 
in a ftate of purity. 

_ ■ 

In a rough experiment made on the conver- 
fion of nitrous gas into nitrous oxide, by con^ 
centrated folution of fulphitc of potafli with 
cxcefs of alkali, very little of the nitrous oxide 
was abforbed. Hence it is probable that water' 
]e0en6 the affinity of potaih for nafcent nitrous 
oxide. 



* Unlefs the fum of affinity of the potaih, oil, nitrous 
oxide, and earths, ihould be fuch as to enable the nitrous 
loxide to combine with the earth, whild the oil and alkali 
reflaaiaed in combination^ &c. 



( 268 ) 



VIII. Comhination of Nitrous Oxide wHb 
Soda. 

The union of nitrous oxide with foda' is 
cfFedled in the fame manner as with potafh. 
The alkali^ mingled by folution and evaporation^ 
with either fulphite of foda, or of potaih, is ex- 
pofed'to nitrous gas ; the nitrous oxide is con- 
denfed by it at the moment of generation, and 
the combination efFefled. 

As far as I have been able to obferve, nitrous 
oxide is not ablbrbed to fo great an extent by • 
foda, as potaQi. 

I have not yet been able to obtain the com- 
bination of nitrous oxide with foda in its pure 

■ • • - 

ftate. To the attainment of this end, difficul- 
ties identical with thofc noticed in the laft fec- 
tion prefent themfelves. It is extremely difficult 
to procure the foda perfedlly free from carbonic 
acid, and though by ufing fulphitc of potafh the 
fijlphate formed is eafiily feparated, yet ftill evapo- 
ration and cryftalifation will not difengage the 



( 269 ) 

ihlphite and carbonate from the new com* 
pound. 

The compound of foda and nitrous oxide, 
mingled with a little fulphite and carbonate of 
foda, was /apidly foluble, both in warm and 
cold water, without efFervefcence. Its folulion, 
heated to ebullition, gave out no gas. The 
tafte of th6 folid fait was cauftic, and more 
acrid than that of the mixture of carbonate and 
fulphite of foda. When caft upon zinc ih 
fuiion, it burnt with a white flame. When 
heated to 400° or 500^, it gave out nitrous 
oxide with rapidity. Nitrous oxide was ex- 
pelled from it by the fulphuric, muriatic, and 
carbonic acids, 1 believe, by fulphurated 
hydrogene.* 

IX. Combination of Nifrous Oxide with 
Ammornac, 

I attempted to efFed this combination by 

* For when a little of the mixed fait was introduced into 
a folution of fulphurated hydrogcne, globules of gas were 
given out during the folution. 



( 270 ) 

converting nitrous gas into nitrous oxide, hf ' 
fulphite of ammoniac, wetted with ftrong ibla^ 
tion of cauliic ammoniac ; but without fuceiefs j 
for the whole of the ^litrous oxide produced 
remained in a free (late. 

When I expofed fulphite of potaHi, miogled 
by folution and evaporation with highly alkaline 
carbonate of ammoniac^^ to nitrous gas, ttie 
diminution was nearly one fourth more than if 
pure iulphite of potafh had been employ^^ 
Hence it appears mod likely that ammoniac ia 
capable of combination with nitrous oxide in the 
nafcent Aate* 

In the experiments on the convcrfion of ni- 
trous gas into nitrous oxide, by ruifcent hydro- 
gene, and by fulphurated hydrogcne, R^f. L 
Divif. V. probably the water formed at the fame 



f Carbonate of ammoniac formed at a high tempera-' 
ture^ c^taining near 60 per cent alkali^ and capable of* 
combining with fmall quantities of acids without giving 
out its carbjonic acid. Of this fait a particular account will 
be given in th6 experiments on the ammoniacal falts^ which 
I have often mentioned in the courfo of this worlc. 



( 271 ) 

time with the ammoniac and nitrous oxide, pre- 
ventcid tbem from entering into combination ; 
poffibly the peculiar compound was formed, but 
in quantities fo minute as not to be difiinguifhed 
from iimple ammoniac \* for even the exigence 
of ammoniac in tbefe procefles, is but barely 
perceptible, » 

If it fhould be proved by future experiments, 
that in the decompofition of nitrous gas by 
nafcent bydrogene, a peculiar compound of 
nitrous oxide, water and ammoniac, is forn^d, 
it will afford proofs in favor of the doctrine 
of predifpofing affinity ;^ for then this dccom- 



'«. 



* It may not be amifs to mention fome appearances taking 
place in the decompofition of nitrous gas by fulphurated 
hydft>gene^ thongh it is ufelcfs to theorifc concerning them. 
The fulphur depofited is at firft yellow -, as the procefs pro- 
ceeds, it becomes white, and in fome inftances I have fuf- 
pe^ed a diminution of it. 

'f PnedifpofiDg affinity, the eKiftefice of which at £rfi 
confiiieration it is dlfBcnk to- admit, may be eaiiiy mGCOUDted 
for by fufpofing the attradions of the fimple principles of 
compound fubftances. And this dodrine will apply in all 



{in) 

poiitton might be fuppofed to depend upon tfad 
difpofition of oxygene, hydrogene and nitro^ 
gene to affume the iftates of combinatioti in 
which they might form a triple compound^ of 
water, nitrous oxide, and ammoniac. 

Nitrous oxide might probably be made to 

« 

combine with ammoniac by expofing a mixture 
of nitrous gas and aeriform ammoniac, to the 
fulphites. 

It is probable that nitrous oxide may be com- 
bined with ammoniac, by means of double 
affinity. Perhaps, fulphate of ammoniac and 
the combination of potafh with nitrous oxide 
mingled together in folution, would be con-' 
verted into fulphate of potafli and the com- 
pound of nitrous oxide, and ammoniac. 



inftances where the conftitution of bodies is known. Pre- 
difpofing affinity ought not to be coniidered as the affinity of 
non-exifting bodies for each other; buf as the mutual 
affinity of their iSmple principles^ difpofing them tp afiume 
new arrangements. 



( i73 ) 

X. Prohahilliy of forming Com^omids of 
Nitrous Oxuifi and the Alkaline Earths. 

I attempted to combine nitrous oxide with 
lime and flrontijm, by expofing fulphites of lime 
and ftrontian with excefs of earth, to nitrous 
gas; but this procefs did not fuccced : the 
diminution took place fo flowly as to deftroy all 
hopes of gaining any refults in a definite time. 
Sulphite of potalh is decompofable by barytes, 
ftrontian, and lime ;* confequently it was im- 
pofRble to employ this fubftance to efFedl the 
combination. 

As the dry fulphures, when well made, con- 
vert nitrous gas into nitrous oxide, it is probable 
that the union of the earths with nafcent nitrous 
oxide may be efFedled by expofing nitrous gas 
to their fulphures, containing an excefs of 
earth. 

Perhaps the combination of nitrous oxide with 



* See the above-mentioned elaborate memoir of Four 
croy and Vauquclin. 



(274) 

firontian may be efFefled by introducing the 
Gonnbination of potafti and nitrous oxide into* 
firontian lime water. 

It is probable that nitrous oxide may be com- 
bined with clay and magnefia, by expofing. 
thefe bodies, mingled with fulphite of potaih- 
or foda, to nitrous gas. 



9 



XI. Additional Ohfervations on the combp- 
nations of Nitrous Oxide with the Alkalies. 

A defire to complete phyfiological inveftiga- 
tions relating to nitrous oxide, has hitherto 
prevented me from purfuing to a greater extent,, 
the experiments on the combination of thisfub- 
ftance with the alkalies, &c. As foon as an^ 
opportunity occurs, I purpofe to refume the 
fubjedl. 

The ohfervations detailed in the foregoing, 
fedions are fufficient to (how that nitrous oxide 
is capable of entering into intimate union with 
the fixed alkalies : and as the compounds 
formed by this union are infpluble in alcohol^. 



( ^75 ) 

decompofable by the acids^ and heat^ and pof* 
ieiled of peculiar properties, they ought to be 
conlidered as a new clafs of faline fubftances. 

If it is thought proper, on a farther invefti- 
gation of their properties, to fignify them by 
fpecific names, they may, according to the ufu- 
ally adopted faChion of nomenclature, be called 
niiroxis : thus the nitroxi of pofajb would fignify 
the fait formed by the combination of nitrous 
oxide with potafh. 

Future experiments mufl determine the 
different affinities of nitrous oxide for the alka- 
lies, and alkaline earths. 

With regard to the ufes of thefe new com- 
pounds it is difficult to form a guefs. When 
they are obtained pure, and fully faturated with 
nitrous oxide, on account of the low temperature 
at which their gas is liberated, they will proba- 
bly confiitute detonating compounds. From 
tbeir facility of decompofition by the weaker 
acids, they may poffibly be ufed medicinally, if 
ever the evolution of nitrous oxide in the ftomach 
fhould be found beneficial in difea^. 



( 276) 

XIL The properties of Nitrotis Oxide refemhU 
ihofe of Acids. 

If we were inclined to generalife, and to 
place nitrous oxide among a known clais of 
bodies, its properties would certainly induce us 
to coniider it as more analogous to tbe acid& 
than to any other fubflances ; for it is capable 
of uniting with water and the alkalies, and is 
infoluble in moft of the acids. It differs, how- 
ever, from the ftronger acids, in not pofleffing 
the four tajfte,'* and the power of reddeniog 
vegetable blues : and from both the ftronger 
and weaker acids, in not being combinable when 
in a perfe611y free ftate, at common tempera- 



* The different pcrfons who have refpired nitrous oxide 
have, as will be feen hereafter, given different accounts of 
the tafle -, the greater number have called it fweet, fome 
metallic. One of my friends, in a letter to me dated Nov. 
^^» 1799> containing a detail of fome experiments made 
on the refpiration of nitrous oxide, at Birmingham, denotes 
the tafte of it by the term " fweetiih faintly acidulous.** 
To me the tafte both of the gas and of its folution in water^ 
has always appeared faintly fweetiih. 



( 277 ) 

fureSy with the alkalies. If it (hould be proved 
by future experiments, that condenfation by 
coldgave it the capability of immediately forming 
neutro-faline compounds with the alkalies ; it 
ought to be confidered as the weakeftofthe 
acids* Till thofe experiments are made^ its 
extraordinary chemical and phyfiological pro- 
perties are fufficient to induce us to coniider it 
as a hoAyfui generis. 

It is a lingular fa<5l that nitrous gas» which 
contains in its compofition a quantity of oxygene 
fo much greater than nitrous oxide, fhoul4 
nevertbelefs poflefs no acid properties. It is 
uncombinable with alkalies, very little foluble 
in water, and abforbable by the acids* 



J ■ "^,jaitj t a> ..^ _ __^ fc,_a_^.^_^^^^^^.^_^_L^_^-l.^l— »— ^— ^^— ^g^ M. A 



rfi 



DIVISION 11. 

Oh ibe DECOMPOSITION of NITROUS OXIDE 
by COMBUSTIBLE BODIES. Its' ANALTSIS. 
OBSERVATIONS on ibe different combinaUam if 
OXTGENM and NITROGENS. 



Ip Preliminaries* 

Ir ROM the phasnomena mentioned in Ref. L 
Divif. Ill/ it appears that the combuflible bodies 
burn in nitrous oxide at certain temperatures. 
The experiments in this Divifion were inflitated 
for the purpofe of inveftigating the precife 
nature of thefe combuftions, with a view of 
afcertaining exa6Hy the compofition of nitrous 
oxide. 

It will be feen hereafter that very high tem- 
peratures are required for the decompofition of 

* Seaion 2. 



( V9 ) 

nitrous OKtde, by mod of the combuilible bodies^ 
and that in this procefs heat and light are pro- 
duced to a very great extent. Thefe agents 
alone are poflefled of a confiderable power of 
aiSion on nitrous oxide ; of which it is neceflary 
to give an account^ that we may be abk to un- 
derftand the phasnomena in the following 
iedions. 

. IL CoTwerfion of Nitrt>us Oxide into Nitrous 
jiddf and a Gas analogous to Atmofpheric Air^ 
fy Ignition. 

.a. I>. Prieftley aflerts, that nitrous oxide 
•expded for a certain time to the adlion of the 
;^Iedtric fpark^ is rendered immi (bible with 
water^ and capable of diminution with nitrous 
;gas, without fufFeringany alteration of volume ; 
and likewife that the fame changes are efFedled in 
it by expofure to ignited incombuftible bodies.* 

The Dutch chemifls (late^ that the elei5lric 



*Vol. ii. pag. 91. 



( 280 ) 

fpark pafled through nitrous oxide, occafions, a 
fmall diminution of its volume, and that the 
gas remaining is analogous to common ain-f* 
They conclude that this change depends on the 
reparation of its conftituent parts, oxygene and 
nitrogene, from each other. 

None of thefe chemifts have fufpedted the 
produ6lion of nitrous acid in this procefs. 

i. Nitrous oxide undergoes no change 
whatever from the fimple a6lioq of light. I 
expofed fome of it, confined by mercury, for 
many days to this agent, often palling through 
it concentrated rays by means of a fmall lens. 
When examined it appeared, as well as I could 
eflimate, of the fame degree of purity as at the 
beginning of the experiment. 

c. A temperature below that of ignition 
efFedts no alteration in the conftitution of 
nitrous oxide. I palled nitrous oxide from a 



t Journal de Phyfiquc, torn, xliii, part ii. pag. 330. Thcj 
cffeded the fame change by pafling it through a heated 
tube. Dr. Prieftlcy had publilhed an account of iimilar 
experiments more tj^an two yc^rs before. 



A 



( 281 ) 

retort containing decompofing nitrate of am- 
moniac, through a green glafs tube, ftrongly 
.heated in an air-furnace, but not fufFered to 
undergo ignition. The gas, received in a water 
apparatus exhibited the fame properties as the 
pureft nitrous oxide ; fomc of it abforbed by 
water, left a refiduum of not quite one thir- 
teenth. 

d. The adlion of the eletlric fpark for a 
long while continued, converts nitrous oxide 
into a gas analogous to atmofpheric air, and 
nitrous acid* 

I palled about 1 50 ftrong (hocks from a fmall 
Lcyden phial, through 7 ten grain meafures of 
pure nitrous oxide. After this it filled a fpace 
rather lefs than fix meafures : the mercurv was 
rendered white on the top, as if it had been 
adled on by nitric acid. Six meafures of nitrous 
gas mingled with the refidual gas of the experi- 
ment, over mercury covered by a little water, 
gave red fumes, and rapid diminution. In five 
minutes the volume of the gafes nearly equalled 
ten. Thermometer in this experiment was bB!". 



til 



( 282 ) 

EIe<ftric fparks were pafled for an hour and half 
through 7 ten grain meafures of nitrous oxide 
over mercury covered wtth a little red cabbage 
juice, previoufly faturated with nitrous oxide* 
and rendered green by an alkali. After the 
process the gas filled a fpace equal to rather 
more than fix meafures and half, and the juice 
was become of a pale red. The gas was intro-' 
duced into a finall tube filled with pure water* 
and agitated ; no abforption was perceptible : 
7 meafures of nitrous gas added to it gave red 
fumes, and af\er fix minutes a diminution to 
g^ nearly, 6§ meafures of common air from 
the garden, with 7 of nitrous gas, gave ex-- 
aaiy 9. 

In this experiment it was evident that nitrous 
oxide was converted into a gas analogous to 
atmofpheric air, at the fame time that an acid 
was formed. There could be little doubt but 
that this was the nitrous acid. To afcertain it, 
however, with greater certainty, the elecSric 
fpark was paflfed through 6 meafures of nitrous 
oxide, over a little folution of green fulphate of 



f 



( 283 ) 

iron, confined by mercury. As the procefs went 
on, the color of the folution became rather 
darker. When the diminution was com- 
plete^ a little prulliate of potafh was added 
to the folution. A precipitate of pale blue 
prulliate of potafh was produced. 

/:. Nitrous oxide was pafled from decompofing 
nitrate of ammoniac, through a porcelain tube 
well glazed iniide and outfide, iirongly ignited 
in an air-furnace, and communicating with the 
water apparatus. The gas colle<5led was ren- 
dered opaque by denfe red vapor. It appeared 
wholly unabforbable by water. After the pre- 
cipitation of its vapor, a candle burnt in it with 
nearly the fame brilliancy as in atmofpheric air. 
20 meafures of it that had been agitated in 
water immediately after Its produdlion^ min- 
gled with 40 meafures of nitrous gas, diminiflied 
to about 47.5 ; whereas 20 meafures that had 
remained unagitated for fome time after their 
generation, introduced to the fame quantity of 
nitrous gas, gave nearly 49. 20 meafures of 
atmofpheric air, with 40 of the fame nitrous gas, 
were condenfed to 46. 



( 284 ) 

The water with which the gas had been 
in contadJ:, was ftrongly acid. A little of it 
poured into a folution of green fulphate of iron, 
and then mingled with pruflian alkali, produced 
a green precipitate. Hence the acid it con- 
tained was evidently nitrous. 

That no fource of error could have exifted 
in this experiment from fifTure in the tube, I 
proved, by fending water through it whilft 
ignited, after the procefs, from the fame retort 
in which the nitrate of ammoniac had been 
diecompofed ; a few globules of air only were 
produced, not equal to one tenth of the volume 
of the water boiled, and which were doubtlcfs 
previoufly contained in it. 

I have repeated this experiment two or three 
times, with fimilar refults; whenever the air 
was agitated in water immediately after its pro* 
duAion, it gave almoji the fame diminution with 
nitrous gas as common air ; when, on the con- 
trary, it has been fufFered to remain for fome time 
in contact with the phlogifticated nitrous acid 
fufpended in it, the condenfation has been lefs 



( 285 ) 

with nitrous gas by five or fix hundred parts. 
Hence I am inclined to believe, that if it were 
poffible to condenfe all the nitrous acid formed, 
immediately after its generation, fo as to pre- 
vent it from abforbing oxygene from the per- 
manent gas, this gas would be found identical 
with the air of the atmofphere. 

The changes effected by fire on nitrous 
oxide are not analogous to thofe produced by 
it in other bodies ; for the power of this agent 
feems generally 'wwi/brw, either in wholly fepa- 
rating the conflituent principles of bodies from 
each other, or in making them enter into more 
intimate union. '^^ 

It is a Angular phsenomenon, that whilft it 
condenfes one part of the oxygene and nitrogene 
of nitrous oxide, in the form of nitrous acid ; 



* On the one band^ it dccompofes ammoDiac into hydro-' 
gene and nitrogene^ whilft on the other, it converts free 
oxygene and nitrogene into nitrous acid. It likewife con- 
verts nitrous gas into nitrous acid and nitrogene. Till 
we are more accurately acquainted with the nature of heat^ 
light, and ele6tricity, we Ihall probably be unable to ex- 
plain thefe phaenomena. 



( 286 ) 

it fhould caufethe remainder to expand, in the 
fiate of atmofpheric air. Does not this fa6l 
afford an inference in favor of the chemical com^ 
pofition of atmofpheric air ? 

III. Decom^ojihon of Nitrous Oxide hy 
HydrogenCy at the temperature of Ignition^ 

' In the following experiments on the decom- 
pcffition of nitrous oxide by bydrogene, the 
gafes were carefully generated in the mercurial 
apparatus, and their purity afcertained by the 
tefts mentioned in Refearch I. They were 
meafured in fmall tubes graduated to grains^ 
and then transferred into the detonating tube, 
which was eight tenths of an inch in diameter, 
and graduated to ten grain meafures. 

The fpace occupied by the gafes being noted 
after the inflanmiation by the elecSric fhock, 
green muriate of iron, and prufliate of potalh, 
were fucceffively introduced, to afcertain if any 
nitrous acid had been formed. The abforption, 
if any took place, was marked, and the gafe* 



{ 267 y 

transferred into a narrow grain meafure tubcy 
and their bulk and compofitioji accurately afcer- 
tained. 

h. The hydrogene employed was procured from 
water by means of zinc and fnlphuric acid. 50 
grain meafures of it fired by the eledlric fpark, with 
30 grain meafures of oxygene containing one 
eleventh nitrogene, gave a refiduum of about 4. 
Nitrous gas mingled with thofe 4, indicated the 
fwrefence of rather lefs than 1 of unconfumed oxy- 
gene. In another experiment 23 of it, with 20 of 
the (ameoxygeneleft rather more than 6refiduum^ 

ITjc nitrous oxide was apparently pure, for 
it left a remainder of about ,05 only, when ab- 
ibrbeA by common water. 

€. 30 of hydrogene were fired with 40 of 
nitrous oxide ; the concuffion was very great, 
and the light given out bright red ; no percep- 
tible quantity of nitrous acid was formed ; the 
refidual gas filled a^fpace equal to 52. No part 
of it was abforbable by water, it gave no dimi- 
nution with nitrous gas, when it was mingled 
with a little oxygene, and again a<Sed on by the 



( 288 ) 

cleiSlric ipark^ an inflammation and flight drtnt'^ 
nution was produced. 

d. 33 of hydrogene were fired with 35 of 
nitrous oxide : nitrous acid was produced in 
very minute quantity ; the gas that remaified 
was not ablbrbable by water, and filled a fpace 
equal to 37 grains. Nitrous gas mingled with 
thefe, underwent a very flight diminution. 

e. 46 hydrogene were fired with 46 nitroixs- 
oxidc. The quantity of nitrous acid fornied 
was jufl: fufficient to tinge the whrte prufliate 
of potafli. The gafes filled a fpace equal to ^g, 
gave no perceptible diminution with nitrous 
gas, and did not inflame with oxygene. 

/. 40 hydrogene were fired with 39 mtrous 
oxide ; no perceptible quantity of nitrous acid 
was formed. The refidual gas filled a fpace 
equal to 41 .; was unabforbable by water, un» 
derwent no diminution when mingled with 
nitrous gas ; cw when a6led on by the eledlric 
fpark in contadl with oxygene. 
g. 20 hydrogene were fired with 64 nitrous 
'""oxide ; after detonation the expanfion of the 



( 289 ) 

gales was greater in this experiment than 
any of the preceding ones ; denfe white ' 
fumes were obferved in the cylinder, and 
a flow contradlion of volume took place. 
After a little green muriate of iron had been 
admitted, the gafes filled a fpace equal to 
73 : pruffiate of potafh mingled with the mu- 
riate, gave a deeper blue than in any of the 
preceding experiments. The reiidual gas was 
unabibrbable by water: 65 of it, mingled with 
65 of nitrous gas, diminifhed to 93 ; whilft 65 
of common air, with 65 of nitrous gas, gave 
84. 

h. 8 of hydrogene were fired with 54 of 
nitrous oxide ; the fame phaenomena as were 
obferved in the laft experiment took place ; 
nitrous acid was formed ; after the abforption of 
which the refidual gas filled a fpace equal to 
55. 50 of this, with an equal quantity of 
nitrous gas, diminifhed to tQ, In thefe pro- 
cefi[es the temperatures were from 56® to 610. 

Thefe experiments are feledled as the moft 

aQcqrate of nearly fifty, made on the inflamma* 

T 



( "290 ) 

tion of different quantities of nitrous oxide and 
bydrogene. 

As Mr. Keir found muriatic acid in the fluids 
produced by the inflammation of oxygene and. 
hydrogene in clofed veflels, in Dr. Prieftley*s 
experiments, I preferved the refidual gas of 
about 3 cubic inches of nitrous oxide, that b^d 
been detonated at different times with lefs than 
a cubic inch and half of hydrogene ; but fblu- 
tion of nitrate of lilver was not clouded 
when agitated in this gas, nor when intro- 
duced into the detonating tube in which the 
inflammation had been made. 

From thefe experiments we learn that nitrous 
oxide is decompofable at the heat of ignition^ 
by hydrogene, in a variety of proportions. 

When the quantity of hydrogene very little 
exceeds that of the nitrous oxide, both of the 
gafes difappear, water is produced, no nitrous 
acid 18 formed, and the volume of nitrogenc evol'- 
ved is rather greater than that of the nitrous ox- 
ide decompofed. 
When the quantity of hydrogene is left tbair 



( 291 ) 

that of the nitrous oxide, water, nitrous acid, 
oxygene and nitrogene, are generated , in dif- 
ferent proportions; one part of the nitrous 
oxide is moft probnbly wholly decompofed by 
the hydrogene, and the other part converted 
into nitrous acid and atmofpheric air^ in conie- 
quence of the ignition. 

From experinricnts c^ J, and e^ the compofi- 
tioQ:of nitrous oxide may be deduced. In 
experiment dy 3g of nitrous oxide were decom- 
ppfed by 40 of hydrogene, and converted into 
41 of nitrogene. 

Now from h it appears that 40 of hydrogene 
require for their condenfation about 20.8 of 
oxygene in volume ; fo that founding the efti- 
mation upon the quantity of hydrogene con- 
funoed, 100 parts of nitrous oxide would con- 
lift nearly of 63.1 of nitrogene, and 36.9 of 
oxygene. But 4] of nitrogene weigh 12.4^ 
Ref. I. Div. I. Confequently, deducing the com- 
pofition of nitrous oxide from the quantity of 
nitrogene evolved, 100 parts of it would coniift 
of 63.5 nitrogei>e, and 36,5 oxygene. 



( ^92 ) 

Thefe eftimations are very little difFerewt 
from thofe which may be deduced from the? 
other cxperin>ents, and the coincidence is inr 
favor of their accuracy. 

From the following experiment it appears that 
the temperature required for the decompofition 
of nitrous oxide by hydrogene mud be higher 
than that which is neceflary to produce the in- 
flammation of hydrogene with oxygene. I in* 
troduced into fmall tubes filled with equal parts 
of nitrous oxide and hydrogene, flanding on a 
furface of mercury, iron wires ignited to different 
degrees, from the dull red to the vivid white 

■ 

heat. The gafes were always inflamed by the 
white and vivid red heats ; but never by the 
dull red heat, though the lafl uniformly inflamed 
mixtures of oxygene and hydrogene, and at- 
iliofpheric air and hydrogene. 

Dr. Prieflley * firft detonated together nitrous 
oxide -and hydrogene ; his experiment was 
repeated by the Dutch chemifls, who found 
that when a fmall quantity of hydrogene was 

* Vol. ii. pag. 83. 



( ^93 ) 

employed, the nitrous oxide was partially^ con- 
verted into a gas analogous to common air. 
Their,eftimation of its compofition, which is 
not far removed from the truth, was founded 
on this phaenomenon.* 

IV. Decompofiiion of Nitrous Oxide by Pbof- 
fborus. 

a. Phofphorus introduced into pure nitrous 
oxide at common temperatures, is not at all 
' luminous. It is capable of being fufed, and 
even fublimed in it, without undergoing acidifi- 
cation, and without efFedting any alteration in 
itscompofition. 

About 2 grains of phofphorus were fufed, and 
gradually fublimed, in 2 cubic inches of pure 
nitrous oxide, over mercury, by the heat of a 



♦Journal de Phyfique, torn, xliii. p^rt 2, pag. 331. 
They fuppofed it to coniift of about 37,5 oxygenc, and 
62,5 nitrogene. The nearnefs of this account to the truth 
ia fingular^ when we confidcr that they were neither ac- 
quainted with the fpecific gravity of nitroqs ox.ide, uqi' 
with the produ6tion of nitrous acid in this experiment. 



( 294 ) 

burning lens. No alteration was produced in 
the volume of gas^ and a portion of it abibrbed 
by water, left a refiduum of one twelfth only. 

Fhofpborus was fublimed in pure nitrous 
oxide over mercury, in, a dark room, by an 
iron heated nearly to ignition ; but no luminous 
appearance was perceptible, nor was any gas 
decompofed. 

h. Phofphorus decompofes nitrous oxide at 
the temperature of ignition, with greater or Ie& 
rapidity, according to the degree of heat. We 
have already feen, that when phofphorus in adlive 
inflammation is introduced into nitrous oxide, it 
burns with intenfely vivid light. 

Phofphorus was fublimed by a heated wire in 
; ^ar filled with nitrous oxide, Handing over warm 
mercury. In this ftate of fublimation an iron 
heated dull red was introduced to it by being 
rapidly pafled through the mercury; a light 
blue flame furrounded the wire^ and difappeared 
as foon as it ceafed to be red. 

To phofphorus fublimed as before, in nitrous 
oxide^ over warm mercury, a thick wire ignited 



( 295 ) 

to wbitenefs was introduced ; a terrible detona* 
tion took place, and the jar was {battered in 
pieces. 

By employing thick conical jars,* containing 
only a fmall quantity of nitrous oxide, lefFedled 
ibe detonation feveral times with fafety ; but 
on acdount of the great expaniion of the elaftic 
produdlsy the jar was generally either raifed 
from the mercury^ or portions of gas were 
thrown out of it. Hence I was unable to aicer^i- 
tain the exaiSl changes produced by this mode 
of decompofition. 

c. As my firft attempts to afoertain the confti- 
tution of nitrous oxide were made on its decom- 
pofition by phofphorus, I employed many dif- 

* Experiments on the detonatiou of nitrous oxide with 
phofphorus in this way require great attention. The deto- 
nating jar fhould be very conical 3 the nitrous oxide em- 
ployed fhould never equal more than one eighth of the 
capacity of the jar. The wire for the inflammation muft 
be very thick, and curved fo as to be eafily introduced into 
the jar. When ignited, it muft be inftantaneouily pafTed 
through the heated mercury into the jar. 

Perhaps the eledric fpark might be advantageoufly ap- 
plied for detonating phofphoric vapor with nitrous oxidf. 



(296) 

ferent modes of partially igniting this fubdance 
in it over mercury, fo as to produce a com. 
bullion without explofion. 

The firft method adopted was inflammation 
by means of oxygenated muriate of potalh. A 
fmall particle of oxygenated muriate of potafti 
vras infcrted into the phofphorus to be burnt. 
On the application of a wire, moderately hot^ 
to the point of infertion^ the fait was decom- 
pofed by the phofphorus, and lufiicient fire 
generated and partially applied by the flight 
explofion^ to produce the combuftion of the 
phofphorus, without the previous fublimation 
of any part of it. 

The fccond way employed was the ignition 
of a part of the phofphorus, by means of the 
combuftion of a fmall portion of tinder of cot- 
ton,* or paper, in contact with it, by the 
burning glafs. 

The third, and mod fuccefsful mode, was 
by introducing into the graduated jar containing 

* It will be feen hereafter that thefe bodies arc eafily 
iDflamed in nitrous oxide. 



( 297 ) 

the nitrous oxid6^ the phofphorus in a fmall 
tube containing oxygene, fo balanced as to 
fwim on the lurface of the mercury, without 
communicating with the nitrous oxide. The 
phofphorus was fired in the oxygene with an 
ignited iron wire, by which at the moment of 
combuftion, the tube containing it was raifed 
into the nitrous oxide, and thus the inflamma- 
tion continued. 

d. In different experiments, made with accu* 

racy,Ifoundthatthcwholeofaquantity of nitrous 
oxide was never decompofable by ignited phof- 
phorus ; the combuftion always flopped when 
the nitrous oxide remaining was to the nitro- . 
gene evolved as about 1 to 5 ; likewife that the 
volume of nitrogene produced was rather lefe 
than that of the nitrous oxide decompofed, and 
that this deficiency arofe from the formation of 
nitrous acid by the intenfe ignition produced 
during the proceft. 

Of one ejiperiment I fhall give a detail. 

Temperature being 48°, two cubic inches 
of pure nitrous oxide, which had been generated 



( 298 ) 

over mercury, were introduced into a jar of the 
capacity of 9 cubic inches, graduated to ,1 cubic 
inches, and much enlarged at the bafe. A grain 
of phofpborus was inferted into a fmall ve&l 
about one third of an inch long, and half an 
inch in diameter, containing about 15 grain 
meafures of very pure oxygene ; this veflel, 
which fwam on the furface of the mercury, was 
carefully introduced into the jar containing the 
nitrous oxide. The phofpborus was fired by 
means of a heated wire, and before the oxygene 
was wholly confumed, the veffel containing it 
elevated into the nitrous oxide. The com- 
buflion was extremely vivid and rapid. Aftqr 
the atmofpheric temperature was refiored, the 
gas was rendered opaque by denfe white vapor. 
When this had been precipitated, and the fmall 
veflel removed from the jar, the gas filled a 
fpace nearly equal to l.g cubic inches. On 
introducing to it a little folution of green mu- 
riate of iron, and prufiSate of potafli, green 
prufiiiate* of iron was produced : hence, evi- 
dently, njitrous acid had been formed. 



( 299 ) 

On the admiffion of pure water, an abforp- 
tion of rather more than ,3 took place* 

The 16 meafures remaining underwent no 
perceptible .diminution with nitrous gas ; the 
taper plunged into them was inftantly extin- 
guiOied. 

To afcertain if the phofphoric acid produced 
in the experiments made under mercury did 
not in fome meafure prevent the decompofition 
of the whole of the nitrous oxide by the phof- 
phorus, I introduced into a mixture of 5 nitro- 
gene and 1 nitrous oxide, ignited phofphorus: 
but it was immediately extinguifhed.* 

The Dutch Chemifls found that phofphorus 
might be fufed in nitrous oxide without being 
luminous; They aflcrt that phofphorus in a 
ftate of inflammation, introduced into this gas, 
was immediately extinguifhed ; though when 
taken out into the atmofphere, it again burnt 
of its own accord.^ It is difficult to account 
for their miftake. 

* Phofphorus burnt feebly with a white flame in a mix- 
ture of 4 nitrogene and 1 uitrous oxidp. 

t Journal de Pbylique^ xliii. 328. 



( 300 ) 



V. Decompofitlon of Nitrous Oxide by Pbof- 
fborated Hydrogtne. 

a. It has been mentioned in Ref. IL Div. L 
that phofphorated hydrogene and nitrous oxide 
poflefs no a6lion ovi each other, at atmoipheric 
temperatures. 

Phofphorated hydrogene mingled with ni- 
trous oxide, is capable of being inflamed by the 
eledlric fpark, or by ignition. 

h.E.l. 10 grain meafures of phofphorated bj* 
drogene, carefully produced by meansof phofpbo- 
rus and folution of cauilic alkali, were mingled 
with 52 meafures of nitrous oxide. The eledtric 
Ipark pafled through them, produced a vivid 
inflammation. The elaftic produdls were 
clouded with denfe white vapor, and after fome 
minutes filled a fpace nearly equal to 6o. On 
the introduction of water, no abforption took 
place. When 43 of nitrous gas were admitted, 
the whole diminifhed to 70. 

E. 2. 25 of nitrous oxide were jfired with ijO 



( 301 ) 
of phofphorated hydrogene, by the ele<3rie 

« 

fpark. After detonation* they filled a fpace 
exactly equal to 25. On the admillion of 
folution of green fulphate of iron, and pruiliate. 
of potaQi, no blue or green precipitate was pro- 
duced. On the introdudlion of water, no dimi- 
nution was perceived. 25 of nitrous gas ming- 
led with them, gave exactly 50. 

E. 3. 10 of nitrous oxide, mingled wkh 20 of 
phofphorated hydrogene, could not be inflamed. 

25 of nitrous oxide, with 20 phofphorated 
hydrogene, inflamed. The gas after detonation, 
was rendered opaque by denfe white vapor, and 
filled a fpace nearly equal to 45. No abforption 
took place when water was introduced. On 
admitting a little oxygene no white fumes, or 
diminution, was perceived. The eledlrip fpark 
paflfed through the mixture, produced an ex-, 
plofion, with great diminution. 

c. From E. 1 it appears, that when a fmall quaa* 
tity of phofphorated hydrogene is inflamed with 

* In this experiment, as in the laft, denfe white vapor 
was produced. 



( 302 ) 

f ititrooi oxide^ Both the pfaofphorus and hydf gm 
gene are eonfumed ; whilft the fuperabundanf 
flitrous oxide^ is converted into nitrous acid and 
atmofpheric air^ by the ignition ; or a certain 
quantity is partially decompofed into atnnofpberic 
air by the combination of a portion of its oxygene 
with the combuftible gas. 
From £.2 we learn, that when the phofphorated 
hydrogene and nitrous oxide are to each other 
as 25 to 10 nearly, they both difappear, whilft 
nitrogene is evolved, and water and phofphoric 
acid produced. Reafbning concerning the 
oompolition of nitrous oxide from this experi- 
ment, we (hould conclude that it was compofed 
of about 38 oxygene, and 62 nitrogene. 

The refult of jB. 3 is interefting ; we are taught 
from it that the affinity of phofphorus for the 
oxygene of nitrous oxide is ftronger than that 
of hydrogene, at the temperature of ignition ; 
fo that when phofphorated hydrogene is min- 
gled with a quantity of nitrous oxide, not con- 
taining fufficient oxygene to burn both its con- 
ilituent parts, the phofphorus only is eonfumed^ 
whilA the hydrogene is liberated. 



( 303 ) 

In repeating the experiments with phofphcM 
rated hydrogene that had remained for fbme 
hours in the mercurial apparatus^ I did not gain 
exadlly the fame refults ; for a larger quantity 
of it was required to decompoie the nitrous 
oxide^ than in the former experiments ; doubt- 
lefe from its having depofited a portion of its 
phofphorus. They confirm, however, the 
above mentioned conclufions. 

In the courfe of experimenting, I pafled the 
eleflric fpark, for a quarter of an hour, through 
about 60 meafures of phofphorated hydrogene. 
It underwent no alteration of volume. Phof- 
phorus was apparently precipitated from it, and 
it had wholly loft its power of inflaming, in 
contadl with common air. 



VI. Decompqfition of Nitrous OxUe hy SuU 
pbur. 

\ r 

From the phaenomena before mentioned,*, 

* Ref . I. Diy. III. S. II. 



( 304 ) 

relating to the combofiion of fulpbur in nitf6u$ 
oxide^ it was evident that this gas was only de^ 
compofable by itj at a much higher temperature 
than common air. 

I introduced into fulphur in contadl with 
nitrous oxide, over mercury heated to ] 12^ — 
114^, a wire intenfely ignited. It loft much 
of its heat in palling through the mercury, but 
Hill appeared red in the veflel. The fulphur 
rapidly fufed, and fublimed without being at 
all luminous. This experiment was repeated 
five or fix times, but in no inftance could the 
combufiion of fulphur, by means of the ignited 
wire, be cfFe6led. 

I inflamed fulphur in nitrous oxide in the 
fame manner as phofphorus ; namely, by intro- 
ducing it into the fmall veflel filled with oxy- 
gene, and igniting it by means of the heated 
wire. In thefe experiments the fulphur burnt 
with a vivid rofe-colored light, and much ful- 
phuric, with a little fulphureous acid, was formed. 

Experimenting in this way I was never, how- 
ever, able to decompofe- more than one third 



( 30^ ) 

» 

t)f the quantity of nitrous oxide employed j 
dot only the nitrogene evolved, but likewife the 
fulphuric and fiilphurcous acids produced, ftop* 
ping the combuftion. 

I found that fulphur in a ftate of vivid in- 
flammation, when introduced into a mixture of 
bne fourth nitrogene, and three fourths nitrous 
oxide, burnt with a flame very much enlarged, 
and of a vivid rofe color. In one third nitro* 
gene, and two thirds nitrous oxide, it burnt 
feebly with a yellow flame. In equal parts of 
nitrous oxide and nitrogene, it was inflantly 
extinguiflied. 

Sulphur burnt feebly, with a light yellow 
flame, when introduced ignited into a mixture 
of 5 nitrous gas, and 6 nitrous oxide. In one 
third nitrous oxide, and two thirds nitrous gas, 
it was inftantiy extinguiflied. From many 
circumftances, 1 am inclined to believe that ful- 
phur is incapable, at any temperature, of flowly 
decompofing nitrdus oxide, fo as to burn iri it 
with a blue flame, forming fulphureous acid 

filoiie. it appears to attradl oxygene from it 

U 



{306) 

only when intenfely ignited, fo as to (otm 
chiefly fulphuric acid, and that with great 
rapidity, and vivid inflammation. 

VII. Decompojihon of Citrous Oxide hy Sul- 
pburated Hydrogene. 

a. -Though nitrous oxide and fulphurated 
hydrogene do not adl upon each other at com- 
mon temperatures, yet they undergo a mutual 
decompofition when mingled tojgether in certain 
proportions, and ignited by the ele<Slric fpark. 

From more than twenty experiments made 
on the inflammation of fulphurated hydrogene 
in nitrous oxide, I fele^l the following as the 
mofl: conclufive and accurate. The temperature 
at which they were made was from 41^ to 49®, 

h. E. \. About 35 meafures of nitrous 
oxide were fired with 10 of fulphurated hydro- 
gene ; the expanfion during inflammation was 
very great, and the flame Iky-blue. Imme- 
diately after, the gafes filled a fpace equal to 
48 nearly. White fumes were then formed^ 
and they gradually contradled to 40. On the 



( 307 ) 

admiffion of a little ftrontian lime water^ a flight 
iabforption took place, with white precipitation ; 
and the volume occupied by the refidual gas 
nearly equalled 37* On admitting nitrous gas 
to thefe, no perceptible diminution took place. 

jE. 2. 20 fulphurated hydrogene, with 25 
Ditrous oxide^ could not be inflamed. 

30 nitrous oxide, with 22 fulphurated hydro- 
gene, could not be inflamed. 

35 nitrous oxide, with 20 fulphurated hydro- 
gene, inflamed with vivid blue light, and great 
expanfion. After the expIoHon, the gafes filled 
.cptaflly the fame fpace as before the experiment; 
no white fumes were perceived, and no farther 

coQtracSlion occurred. On the addition of 

/ 

4irontian lime water, a copious precipitation^ 
with diminution, took place ; and the refidual 
gas filled a fpace nearly equal to 35^. 

E. 3. 47 nitrous oxide, and 14 fulphurated 
hydrogene, inflamed. After the explolion, the 
,gafes filled a fpace nearly equal to 65 ; then white 
.fpqies formed, wand they gradually dimiqifhe^ 
to 52. On the introdudion of muriate pf ftrpo^ 



( 310 ) 

ga8 analogous to atmofpheric air^ or Into nitro-- 
gene^ nitrous acid, and atmofpheric air. E. 1. 

E. 3. 

By purfuing thofe experiments, andufinglarger 
quantities of gas, we may probably be able to 
afcertain from tbcm with accuracy, the com* 
pofition of fulphuric and fulphureous acids. 

I own I was disappointed in the refults, for I 
cxpedled to have been able to afcertain from 
them, the relative affinities of fulphur, and 
hydrogene for the oxygene of nitrous oxide;, 
zt The temperature of ignition. I conje<9:ared 
that nitrous oxide, mingled with excefs of ful- * 
phurated hydrogene, would have been decom-^ 
pofed, and one of the principles of it evolved 
unaltered, as was the cafe with phofpborated' 
hydrogene. 

If we eftimate the compoiition of nitrous 

* 

oxide from the quantity of nitrogene produced in 
jS. 2, it is compofed of about 6l nitrogene, and 
3p oxygene, 



< 311 ) 

VJII. Pecompojition of Nitrous Oxide ly 
CharcoaL 

An account of the analyfis of nitrous oxide 
by charcoal is given in Ref. I. Div. III. I have 
lately made two experiments on the combuftion 
of charcoal in nitrous oxide, in which every 
precaution was taken to prevent the exigence of 
fources of error. Ofoneofthefe I fhall give 
a detail. 

E. Temperature being 5 IV about a grain of 
charcoal, which had been expofed for forae 
hours to a red heat, was introduced whilft 
ignited, under mercury, and transferred into a 
graduated jar, containing 3 cubic inches of pure 
nitrous oxide. Handing over dry mercury. 

The focus of a burning lens was thrown on 
the charcoal ; it inftantly inflamed, and burnt 
with great vividnefs for near a minute, the gas 
being much expanded. The focus was con- 
tinually applied to it for ten minutes, when the 
procefs appeared at an end. The gafes, when 
the common temperature and prefliire were 



( 312 ) 

reftored, filled a fpace equal to 4,2 cubic 
inches. 

On introducing intp them a few grain mea- 
frires of fqlution of green muriate of iron, for 
the double purpofe of faturating them with 
xnoifture, and afcertaining if any nitrous acid 
had been formed, no change of volume took 
place ; and prqlliate qf potafh gave with the 
xnuriate a white precipitate oAly. 

On the admiilion of a fmall quantity of con- 
centrated folution of cauftic potafh, a, diminu- 
tion of the gas flowly took place ; when it wa§ 
complete the volume equalled about 3.05 cubic 
iijches. By agitation in well boiled w^ter, 

about ,Q of thefe were abforbed ; the remainder 

» 

appeared to be pure nitrogene. 

The difference betwieen the eftimation founded 
lipon the nitrogene evolved, and that deduced 
fi^om thp carbonic acid generated in this experi- 
inent, is not nearly fo great as in that Ref. I. 
Piv. III. Taking about the mean proportions, 

wefhould conclude that nitrous oxide was com- 

"... . • ■ / t 

pofed of about 38 oxygene, and 62 nitrogene. 



(313) 

jCfaarcoal burnt with greater vjvidnefs than in 
jcopmon air^ in a mixture of one third nitrogene 
and two thirds nitrous oxide. In equal parts of 
nitrous oxide and nitrogene, its light was barely 
perceptible. In one third nitrous oxide, and 
two thirds nitrogene, it was almofl immediately 
jextinguifhed. 

As charcoal burns vividly in nitrous gas, 
when it has been previoufly ignited to white- 
nefs, I introduced it into a mixture of equal 
parts of nitrous oxide and nitrous gas ; it burnt 
w^th a deep and bright red. 

IX. Decompofition of Nitrous Oxide by 
HydfO'Carhonate. 

Nitrous oxide, and hydro-carbonate, poflefs 
no adlion on each other, except at high tem- 
peratures. When mingled in certain propor- 
lions, and expofed to the eledlric fhock, a new 
arrangement of their principles takes place. 

E. 1. Temperature being 53^, 35 of 
nitrous oxide, mingled with 15 of hydro- 



( 318) 



XI. CowUmfiion of Pyropborus in Nitrous 



Pyrophorus, which inflames in nitrous gas, 
3nd atmofpheric air, at or even below 40°, re- 
4|iures for its combufiion in nitrous oxide a 
Much higher temperature. It will not burn in 
ity pr alter it, even at 212^ 

I have often inflamed pyrophorus in nitrpus 
oxidp Qver mercu/y, by means of a wire ftrongly 
heated^, but not ignited. The light produced 
ty the ignition, of pyrophorus in nitrous oxide 
is white, likq that produced by it in o^ygene : 
io nitrous gas it is red. 

When pyrophorus burns out in nitrous oxide^ 
a little increafe of the volume of gas is produqed. 
Strontian lime water agitated in this gas becomes 
clouded; but the quantity of carbonic acid 
formed is extremely minute. I have nevcx 
snadeanydelicate eicperimeqtsqn the combufiiqa 
of pyropborius in nitrous oxidis* 



(319) 

/■ 

XII. Combuftion of the Ta^er in Kttrous 
Oxide. 

It has been noticed by difFerent experi- 
mentalifts, that the taper burns with a flame 
confiderably enlarged in nitrous oxide : fome- 
times with a vivid light and crackling noife, as 
in oxygene ; at other times with a white central 
ilame^ furrounded by ^ feeble blue one. 

My experiments on the combuftion of the 
taper in nitrous oxide, were chiefly made with 
a view to afcertain the caufe of the double 
flame. 

When the inflamed taper is introduced into 
pure nitrous oxide, it burns at firft with a bril- 
- liant white light, and fparkles as in oxygene. 
As the combuftion goes on, the brilliancy of the 
flame diminiflies ; it gradually lengthens, and 
tecomes furrounded with a pale blue cone of 
light, from the apex of which, much uiibumt 
charcoal is thrown off^ in the form of fmoke. 

m m 

The flame continues double to the end of the 
procefs. 






( 320 ) 

When the refidual gafes are examined after 
combufiion^ much nitrous acid is found fui^ 
pended in them ; and they are compofed of * 
. carbonic acid^ nitrogene, and about one fourth 
of undecompounded nitrous oxide* 

The double flame depends upon the nitrous 
acid formed by the ignition ; for it can be pro^ 
duced by plunging the taper into common air 
containing nitrous acid vapor, or into a mix* 
ture of nitrous oxide and nitrogene^ throughi 
which nitrous acid has been difFufed. It ii 

never perceived in the combuflion of the taper; 

« 

till much nitrous acid is formed. 

In attempting to refpire fome reiidual gas of 
nitrous oxide, in which a taper had burnt out^ I 
found it fo highly impregnated with nitrous acid, 
as to difable me from even taking it into my 
mouth. . , 

The taper burns in a mixture of equal parttf. 
nitrous oxide and nitrogene, at firft ii^ith a 
ilame nearly the fame as that ofacandle.ini 

4 

common air ; white. Before its extindlion thb 
interior white flame, and exterior blue flame,- 
are perceived. 



( 321 ) 

The taper is inflantly extinguifhed in a mix- 
ture of one fourth nitrous oxide^ and three 
fourths nitrogene. 

In a mixture of equal parts nitrous oxide and 
nitrous gas, the taper burns at firft with nearly 
as much brilliancy as in pure nitrous oxide; 
gradually the double and feeble flame is pro- 
duced » 

XI It. On the Combujiion of different Com^ 
pound Bodies in Nitrous Oxide. 

All the folid and fluid compound inflammable 
bbdies on which I have experimented, burn in 
nitrous oxide, at high temperatures. Wood, cot- 
ton, and paper, are eaflly inflamed in it by the 
burning glafs. During their combuftion, ni- 
trous acid is always formed, carbonic acid, and 
water produced, and nitrogene evolved, rather 
lofs in bulk than the nitrous oxide decompofed* 

I have already mentioned that alcohol and 
ether are folub'e in nitrous oxide. When an 
ignited body is introduced into the folution of 

w 



( 322 ) 

alcohol^ or ether in nitrous oxide, a flight 
explofion takes place. 

XIV. General Coticlufimis relating to ih6 
Decompofiriion of Nitrous Oxide ^ and to its 
Analyjis. 

From what has been faid in the preceding^ 
fedlions, it appears that the inflammable bodies^ 
io general, require for their combliftion in 
nitrous oxide, much higher temperatures than 
thofe at which they burn in atmofpheric air, or 
oxygene. 

. When intenfely heated they decompofe it, 
with the pro^ludlion of much heat and light, 
and become oxygenated. 

During the combuftion of folid or fluid bodies, 
producing flame, in nitrous oxide, nitrous acid 
IS, generated, moft probably from a new arrange** 
iDcnt of principles, analogous to thofe obferved 
in Sedl. II, by the ignition of that part of the 
gas not in conta(5l with the burning fubftance. 
Likewife when nitrous oxide in excefs 13 4ecQi»- 



( 323 ) 

pofed by inflammable gafesy »itroiia acid, ^4 
ibmetimes a gas analogous to coainaK>n air, 19 
produced, doubt lefs from the fame caqfe^ 

Pyrophorus is tbe only body that inflames if| 
nitrous oxide^ belovr tbe temperature pC 
ignition. 

Fbofphorus' burns tn it with tbe blue flamen 
probably forming with its oxygene only pbpi^ 
pboreofus acid at the dull red heat^ and with tb^ 
intenfely vivid flame, producing phofphoric a^cid 
at tbe white beat. 

Hydrogene, charcoal, fulphur. Iron, ami tbe 
compound inflammable bodies^ decompofe it 
only at heats equal to, or above, that of igoritioii :i 
frohably each a different temperature. 

From the phaenomena in Se6l. V- it appeurs^ 
that at the temperature of intenfe ignition, pbolE^ 
phorus has a fironger affinity foj the oxygene 
of nitrous oxide than bydrogene ; and reafoning 
from the different degrees of eombuftibiiity « , 
tbe inflannnable bodies, in mixtures of nitrous 
oxfde and nitrogeue, and from otber pbaencH 



( 3^4 ) 

mena, we may conclude with probability, that 
at about the white heat, the affinity of the com-* 
buftible bodies for oxygene takes place in the 
following order. Phofphorus, hydrogene, char* 
coal,* iron, fulphur, &c. 

This order of attraction is very different 
from that obtaining at the red heat ; in 
which temperature charcoal and iron have a 
mttch ftronger affinity for oxygene than either 
phofphorus or hydrogene.^ 

The fmalleft quantity of oxygene given in 
the different analyfes of nitrous oxide juft de- 
tailed, is thirty five hundred parts ; the greateft 
proportion is thirty-nine. 

>Taking the mean eftimations from the moft 
accurate experiments, we may conclude that 
100 grains of the known ponderable matter of 



• As is proved by the decompofition of oxide of Iron and 
iulphuric acid by charcoal, at that temperature* 

f Hydrogene at or about the red heat, appears to attra^ 
oxygene ftropger than pbofphprus. See Dr. Prieftlcy's 
e^peninent3^ vol, i. page ^2, 



( 325 ) 

nitrous oxide^ confift of about 36,7 oxygcne, 
and 63,3 nitrogene ; or taking away decimals, 
of 37 oxygene to63 nitrogene ; which is identical 
vith the eftimation given in Refearcb I. 

XV. Obfervations on the combinations of 
Oajigene and Nitrogene. 

During the decompoiitions of the combina- 
tions of oxygene and nitrogene by combuftible 
bodies^ a coniiderable momentary expanfion of 
the adling fubftances, and the bodies in contadl 
tirith them is generally produced, connedled with 
increafed temperature ; whilft light is often 
generated to a great extent. 

Of the caufes of thefe phaenomena we are at 
prefent ignorant. Our knowledge of them 
muft depend upon the difcovery of the precife 
nature of heat and light, and of the laws by.» 
which they are governed. The application of 
general hypothefes to ifolated fa6ls can be of 
little utility ; for this reafon I fhall at prefent 
forbear to enter into any difcufiions concerning 



( 326 ) 

thofe agents, which are imperceptible to the 
fenfcs, and known only by folitary efFedls. 

Analylis and lynthelis clearly prove that 
oxygene and nitrogepe conAitute the knowa 
ponderable matter of atmofpheric air, nitroua 
oxide, nitrous gas, and nitric acid. 

That the oxygene and nitrogene of atmof** 
pheric air exift in chemical union, appears 
almoil demoniirable from the fdlowing wu 
4ences. 

ift. The equable difiufion of oxygene and 
nitrogene through every part of the atmofpherc^ 
vrhich can hardly be fuppofed to depend oa 
any other caufe than an affinity between theie 
principles.* 

2dly. The difference between the fpecific 

* That attra^oD mufl be called chemical, which enables 
bodies of different fpecific gavities to unite in fuch a maimer 
ae to produce a compound^ in every part of which the cob- 
&tuents are found in the fame proportions to each other, 
Atmofpheric air, examined after having been at perfe^ 
reft in clofed vcflels, for a great length of time, containt ia 
every part the fame proportions of oxygene and nitrogeDe'i 
whereas if no affinity exified between thefe principles^ 
following the laws of fpccific gravity, they oug^t to fepa^ 



< 827 ) 

gravity of atmofpheric air^ and a mixture of 27 
parts oxygene and 73 nitrogene^ as found by 
calculation ; a difference apparently owing to 
expanfion in confequence of combination . 

ddly. The converiion of nitrous oxide into 
nitrous acid^ and a gas analogous to common 
air^ by ignition. 

4thly. The folubility of atmofpheric air un- 
decompounded in water. 

Aticosfheric Air^ then^ may be confi- 
dered as the leafl intimate of the combinations 
of nitrogene and oxygene. 

It is an elaftic fluids permanent at all known 
temperatures^ confifting of ^73 nitrogene, and 
,27 oxygene. It is decompofable at certain tem** 
peratures, by moft of the bodies poilefling 
affinity for oxygene. It is foluble in about 
thirty times its bulk of water^ and as far as we 
are acquainted with its affinities, int^apable of 

rate j the oxygene forming the inferior, the nitrogene the 
fuperior flratum. 

The fnppofitibn of the chemicai compofition of atmof- 
phoric atr, has been advanced bj many philofophers. The 
two &i& eyidences haye been often noticed. 



( 328 ) 

combining with moil of the iimple and com-« 
pound fubftances. 100 cubic inches of it 
weigh about 31 grains at 55° temperature, and 
30 atmbfpheric preflure. 

Nitrous Oxide is a gas unalterable in its 
Gonftitution, at temperatures below ignition. 
It is compofed of oxygene and nitrogcne, exift* 
ing perhaps in the mod intimate union which 
thofe fubftances are capal>le of aifuming.* 
Its properties approach to thofe of acids. It 
is decompofable by the combuftible bodies at 
very high temperatures, is foluble in double its 
volume of water, and in half its bulk of moft of 
the inflammable fluids. It is combinable with 
the alkalies, and capable of forming with them 
peculiar falts. 100 grains of it are compofed 
of about 63 nitrogene, and 37 oxygene. 
100 cubic inches of it weigh 50 grains, 
at 55° temperature, and 30 atmofpheric pref* 
fure. 



* For it is unalterable by thofe bodies which are capable 
of attradiQg oxygene from nitrous gas and mtrovis acid> a| 
common temperatures. 



( 329 ) 

Nitrous Gas is compofed of about ,56 
oxygene, and ^44 nitrogene, in intimate union. 
It is foluble in twelve times its bulk of water, 
and is combinable with the acids, and certain 
metallic folutions ; it is poflelled of no acid 
properties, and is decompofable by mod of the 
bodies that attradl oxygene flrongly, at high 
temperatures. lOO cubic inches of it weigh 
about 34 grains, at the mean temperature and 
preflure. 

Nitric Acid is a fubftance permanently 
aeriform at common temperatures, compofed of 
about 1 nitrogene, to 2,3 oxygene. It is folu- 
ble to a great extent in water, and combinable 
with the alkalies, and nitrous gas. It is decom- 
pofable by moll of the combuftible bodies, at 
certain temperatures. 100 cubic inches of it 
weigh, at the mean temperature and preflure, 
nearly 76 grains. 



/ 



RESEARCH III. 



ftELATING TO THE RESPIEATION OF 



NITROUS OXIDE, 



AND OTHER 



GASES. 



- RESEARCH III. 
DIVISION I. 

EXPERIMENTS and OBSERVATIONS on the 
^EFFECTS produced upon ANIMALS by the RES" 
PIRATION of NITROUS OXIDE. 



L Preliminaries* 

L HE term refpirahUy in its pKyfiological 
application^ has been differently employed. Some 
times by the refpirability of a gas has be^n 
meant^ its power of fupporling life for a great 
length of time, when repeatedly applied to the 
blood in the lungs. At other times all gafes 
have been confidered as refpirable, which were 
capable of introduftion into the lungs by volun- 
tary efforts, without any relation to their 
Vitality. 



( 334 ) 

In the lad fenfe the word refpirable is mod 
properly employed. In this fenfe it is ufed in 
the following fedlions. 

Non-refpirablc gafes are thofe, which when 
applied to the external organs of rcfpiration^ 
flimulate the inufcles of the epiglottis in fucb a 
way as to keep it perfectly clofe on the glottis ; 
thus preventing the fmallefi particle of gas from 
entering into the bronchia, in fpite of voluntary 
exertions ; fucb are carbonic acid, and acid gafes 
in general.* ^ 

Of refpirable gafes, or thofe which are capa« 
ble of being taken into the lungs by voluntary 
efforts. 

One only has the power of uniformly fup- 
porting life ; — atmofpheric air. Other gales, 
when refpired, fooner or later produce death ; 
but in different modes. 

Some, as nitrogene and hydrogene, effeA no 
pofitive change in the venous blood. Animals 



* See the curious experiments of Roiier, Journal de • 
Phyfique, 17S6, vol. ij pag. 419. 



( 335 ) 

immerfed in thefe gafes die of a difeafe pro« 
educed by privation of atmofpheric air^ analogoug 
to that occafioned by their fubmerfion in watefj 
or non-refpirable gafes. 

Others, as the different varieties of hydro- 
carbonate, deflroy life by producing (bme poii-* 
tive change"^ in the blood, which probably im- 
mediately renders it incapable of fupplying 
the nervous and mufcular fibres with principles 
eilential to fenftbility and irritability. 

Oxygene, which is capable of being refpired 
ibr a nnuch greater length of time than any 
other gas, except common air, finally deflroys 
life ; firft producing changes in the bloody 
conneded with new living acSlion.'f' 

After experiments; to be detailed hereafter, 
99ade upon myfelf and others, had proved that 
nitrous oxide was refpirable, and capable of 



* As appears from the experiments of Dr. Bcddoeij 
likcwife thofe of Mr. Watt. 

> As appears from the experiments of Laroxfier and Dr. ' 
Seddoes } and as will be feea hereafter. 



( 33(J ) 

fupporttng life for a longer time than atfy 
of the gafes^ except atmofpheric air and oxygene, 
I Was anxious to afcertain theefFedls of it upon 
animals^ in cafes where its adtion could be 
carried to a full extent ; and to compare the 
changes occafioned by it in their organs^ with 
thofe produced by other powers. 

I 

II. On tie refpiration of Nitrous Oxide by 
xvarm* blooded Animals. 

The nitrous oxide employed in the following 
experiments, was procured from nitrate of am- 
moniac, and received in large jars, filled with 
water previoufly faturated with the gas. . Tho 
animal was introduced into the jar^ by being 
carried under the water ; after its introducStion, 
the jar was made to reft on a (helf, about half 
an inch below the furface of the water ; and the 
animal carefully fupported, fo as to prevent 
his mouth from refting in the water. 

This mode of experimenting, either under 
water or mercury, is abfolutely neceflary, to 



( 337 ) 

afcertain with accuracy the effecSls of pure gafed 
on living beings. In fome experiments that I 
made on the refpiration of nitrous oxide, by 
animals that were plunged into jars of it opened 
in the atmofphere, and immediately clofed after 
their introdu6lion, the unknown quantities of 
common air carried in, were always fufficient 
to render the refults perfedlly inaccurate. 

Animals fufFer little or nothing by being pafled 
through water. 

That the phsenomena in thefe experiments 
might be more accurately obferved, two or three 
perfbns were always prefent at the time of their 
execution, and an account of them was noted 
dawn immediately after. 

a. A ftout and healthy young cat, of four 

or five months old, was introduced into a large 

jar of nitrous oxide. For ten or twelve moments 

he remained perfe<31y quiet, and then began 

to make violent motions, throwing himfelf round 

the jar in every direction. In two minutes he 

appeared quite exhaufled, and funk quietly to 

the bottom of thejar^ On applying my hand 

X 



( 339 ) 

to <he thorax, I found that the heart btjit with 
extreme violence ; on feeling about the neck, I 
could diftin6Hy perceive a ftrong and quick 
pulfatidn of the carotids. In about three, 
minutes the animal revived, and panted very 
much ; but ftill continued to lie on his fide. 
His infpirattons then became longer and deeper, 
and he fometimes uttered very feeble cries. lof 
four minutes the pulfations of the heart appeared 
quicker and feebler. His infpirations were at 
long intervals, and very irregular ; in five 
minutes the pulfe was hardly perceptible; htr 
made no motions, and appeared wholly fenlelefi. 
After five minutes and quarter he was taken out, 
and expofed to the atmofphere before a warm 
fire. In a few feconds he began to move, and 
to take deep infpirations. In five minutes 
he attempted to rife on his legs ; but foon fcU 
again, the extremities being flightly convulfed. 
In eight o> nine minutes he was able to walk, 
but his motions svere ftaggering and unequal, 
the right leg being convulfed, whilft the other 
Vas apparently ftifF and immoveable ; in about 



( 339 ) 

half an hour Jie was almoft completely recoveffid^ 
h. A healthy kitten, of about fix weeks old^ 
was introduced into nitrous oxidd. She very 
loon began to niake violent exertions, and ia 
lefs than a minute fell to the bottom of the 
receiver, as if apopledtic. At this moment, 
applying my hand to her fide, I felt the heart 
beating with great violence. She continued 
gafping, with long infpirations, for three 
minutes and half; at the end of five minntes 
and half {be was taken dlit completely dead. 

c. Another kitten of the fame breed was 
introduced into nitrous oxide, the day after. 
She exhibited the fame phaenomena, and died 
in it in about five minutes and half. ^ 

d. A fmall dog that had accidentally met 
with a diflocation of the vertebrae of the loins, 
and was in great pain, as manifefted by his 
moaning and whining, was introduced into a 
latrge jar of nitrous oxide. He immediately 
became quiet, and lay on his fide in the jar, 
breathing very deeply. In four minutes hii ■ 
teijpiration became noify, and his eyes fparklcd 



( 340 ) 

very much. I was not able to apply my band 
to tbe thorax. In five minutes he appeared 
fenfelels^ and in feven minutes was perfedily 
dead. 

e. A ftrong rabbit, often or twelve months 
old, was introduced into nitrous oxide. He 
immediately began to ftruggle very much, aoid 
in a minute fell down fenfelels : in two minuter 
the legs became convulfed, and his infpirations 
were deep and noify : in lefs than five minuter 
he appeared pcrfe£lly dead. 

/. A rabbit of a month old introduced into 
nitrous oxide, became fenfelefs in lefs than a 
minute ; the pulfations of the heart were very 
ftrong ^t this moment : they gradually became 
weaker, and in three minutes and half the 
animal was dead. 

g. Another rabbit of the fame breed, after 
being rendered fenfelefs in nitrous oxide in a 

minute' and half, was taken out. He foon 

» 

became convulfed ; in a minute began to breathe 
quickly ; in two minutes attempted to rife, but 
ftaggered, and fell again on his fide. His hinder 



( 341 ) 

legs were paralytic for near five minutes. In 
twenty he had almoft recovered. 

g. A middle fizcd guinea-pig was much con- 
vulfed, after being in nitrous oxide for a minute. 
In two minutes and half he was fenfelefs. 
Tal^n out at this period, he remained for fome 
minutes by the fide of a warm fire, without 
moving ; his fore legs then became convulfed ; 
his hind legs were perfedily paralytic. In this 
ftate he continued, without attempting to rife 
or move, for near an hour, when he died. 

h. A large and old guinea-pig died in nitrous 
oxide, exhibiting the fame phaenomena as the 
other animals, in about five minutes and quar- 
ter. A young one was killed in three minutes 
^nd half. 

u A fmall guinea-pig, after breathing nitrous 
oxide for a minute and half, was taken out, and 
placed before a warm fire. He was for a few 
minutes a little convulfed ; but in a quarter of 
an hour got quite well, and did not relapfe. 

k. A large moufe introduced into nitrous 
oxide, was for a few feconds very aflive. In 



I 

# 



( 342 ) 

half a minnte be fell down fenfelefs ; in a minute 
and quarter he appeared perfecSily dead. 

/• A moufe taken out of nitrous oxide, after 
being in it for half a minute, continued coa«- 
vulfed for fome minutes, but finally recovered. 

m. A young hen was introduced intoavefliel 
filled with nitrous oxide. She immediately 
began to ftruggle very much ; fell on her breaft 
in leis than half a minute, and in two minutes 
was quite dead. 

n. A goldfinch died in nitrous oxide ia 
lefs than a minute. 

In each of thefe experiments a certain ablbrp- 
tion of the gas was always perceived, the water 
rifing in the jar during the refpiration of the 
animal. From them we learn 

ift. That nitrous oxide is defiru6live when 
refpired for a certain time to the warm blooded 
animals, apparently previoufly exciting them to 
a great extent. 

2dly. That when its operation is flopped 
before compleat exhauflion is brought on, the 
healthy living adlion is capable of being grar 
dually reproduced, by enabling the animal to 
Tefpire atmoipheric air^ 



( 343 ) 

• 

adiy. That exhauiiion and death is produ- 
ced in the fmall animals by nitrons oxide fooner 
than in the larger ones^ and in young animals 
of the fame fpecies, in a (horter time than in 
old ones, as indeed Dr. Beddoes had conjedured 
a priori would be the cafe. 

Moft of the animals deftroyed in thefe 
experiments were examined after death ; the 
appearances in their organs were pecnliar. To 
prevent unneceflary repetitions, an account of 
them will be given in the fourth fediion. 

III. Effe3s of the respiration of Nitrous 
Oxide upon animals^ as compared with thofe 
produced by their mmerfttm in Hydrogene and 
Water. 

Before the following experiments were made, 
a number of circumftances had convinced me 
that nitrous oxide aded on animals by produ- 
cing fome poiittve change in their blood, con- 
Defied with new living a6lion of the irritable 
and fenfitive organs, and terminating in their 
death« 



( 344 ) 

To afeertain however, the difference between 
the effects of this gas and thofe of hydrogene 
and non-refpirable gafes^ I proceeded in the 
following w^y. 

a. Of two healthy rabbits of about t wd 
months old, of the fame breeds and nearly of 
the fame fize. 

One was introduced into nitrous oxide. In 
a half a minute, it had fallen down apparently 
fenfeleis. On applying my hand to the thorax, 
the adlion of the heart appeared at firft, very 
quick and Arong, it gradually became weaker, 
and in two minutes and half, the animal was 
taken out quite dead. 

* The other was introduced into a jar of pure 
hydrogene through water. He immediately 
began to flruggle very much, and in a quarter 
of a minute fell on his fide. On feeling the 
thorax, the pulfations of the heart appeared very 
quick and feeble, they gradually diminifhed ; 
his breathing became momentarily (horter, and 
in rather more than three quarters of a minute, 
he was taken out dead. Dn Kinglpke was 



( 346 ) 

prcfent at this experiment, and aflerwarils 
difle^led both of the animals. 

h. Of two limilar rabbits of the fame breed, 
nearly three months old. One was introduced 
into nitrous oxide, and after being rendered 

■ 

fenfelefs by the refpiration of it for nearly a 
minute and half, was expofed to the atmof- 
phere, before a warm fire. He recovered gra- 
dually, but was occafionally convulfed, and had 
a paralyfis of one of his hinder legs for fome 
minutes ^ in an hour he was able to walk. The 
other, after being immerged in hydrogene for 
near half a minute, was reftored to the atmof- 
phere apparently inanimate. In lefs than a 
minute he began to breathe, and to utter a 
feeble noife ; in two minutes was able to walk, 
and in lefs than three minutes appeared perfedily 
recovered . 

b. A kitten of about two months old, was 
introduced into a jar of nitrous oxide, at the 
fame time that another of the fame breed was 
plunged under a jar of water. They both 
Aruggled very much. The animal in the nitrous 



( 346 ) 

oxide fell fenfelefs before that under water bad 
ceafed to firuggle, and to throw out air from 
its lungs. In two minutes and three quarters^ 
the animal under water was quite dead : it was 
taken out and expofed to heat and air, but didi 
not fhew the flighted figns of life. At the end 
of three minutes and half, the animal in nitrous 
oxide began to gafp, breathing very flowly; 
at four minutes and three quarters it was yet 
alive ; at the eod of five minutes and quarter 
it appeared perfedly dead. It was taken out, 
and did not recover. 

From thefe experiments it was evident, that 
animals lived at leafl twice as long in nitrous 
oxide as in hydrogene or water. Confequently 
from this circumflance alone, there was every 
reafon to fuppofe that their death in nitrous 
oxide could not depend on the fimple privation 
of atmofpheric air; but that it was owing to 
fome peculiar changes effedled in the blood by 
the gas. 



( 34/ ) 

IV. Of the changes effected in the Organifa" 
tion of warm-hlooded Ammals^ by the refpiration 
of Nitrous Oxide. 

The external appearance of animak that have 
been deftroyed in nitrous oxide, 16 very littlie 
different from that of thofe killed by privation 
of atmofpheric air. The fauces and totigtie 
appear of a dark red, and the eyes are dull, ^nd 
a little protruded. Their internal organs, how* 
ever, exhibit a very peculiar change. The 
lungs are pale brown red, and covered here 
and there with purple fpots ; . the liver is of a 
very bright red, and the laufcular fibre in 
general dark. Both the auricles and ventricles 
of the heart are filled with blood. The auricles 
contradl for minutes after the death of the animal. 
The blood in the left ventricle, and the aorta, is of 
a tinge between purple and red, whilft that in 
the right ventricle is of a dark color, raither more 
purple than the venous blood. But tbefe appear** 
ances, and their caufes, will be better Underflood 
after the following comparative obfervatioas are 
read. 



( 348 ) 

•17. Of two fimilar rabbits, about eight months 
old, one A, was killed by expofure for near fix 
minutes to nitrous oxide , the other, B, was 
dcftroyed by a blow on the head. 

They were both opened as fpeedily as poffible. 
The lungs of B were pale, and uniform in 
their appearance; this organ in A was redder, and 
every where marked with purple fpots. The 
liver of A was of a dark and bright red, that of 
B of a pale red brown. The diaphragm of B, 
when cut, was ftrongly irritable; that of A 
rather darker, and fcarce at all contradlile. 
All the cavities of the heart contracted for more 
than 50 minutes in B. The auricles contradted 
for near 25 minutes with force and velocity in A : 
but theventricles were almoft ina6live. The vena 
cava, and the right auricle, in A, were filled with 
blood, apparently a (hade darker than in B. The 
blood in the left auricle, and the aorta, appeared* 
in A of a purple, a (hade brighter than that of the 
venous blood. In the left auricle of B it was red. 
I opened the head of each, but not without 
injuring the brains, fo that I was unable to 



( 349 ) 

make any accurate comparifon. The color of 
the. brain in A appeared rathe^r darker thaa 

in;B. 

b. Two rabbits, C and D, were, deftroyed, 
C. by immerfion in nitrous oxide, D in hydro- 
gene; they were both difle(3ed iby Dr. King- 
lake. The blood In' the. pulmonary vein and 
thd.left auricle of C was of a different tinge, 
from that in D more inclined to purple red, 
The membrane of the lungs in C was covered 
with purple fpots, that of D was pale and 
uniform in its appearance. The brain in C 
was rather darker than in D ; but there was no 
perceptible effufion of blood into the ventricles 
either in D or C. The liver in C was of a 
brighter red than in health, that in D rather 
paler. 

c. In the laft experiment, the comparative 
irritability of the ventricles and auricles of the 
heart and the mufcular fibre in the two ani- 
mals^ had not been examined. That tbefe 
circumilances might be noticed, two rabbits, 
£ andF were killed ; £ under water in about 



( 350 ) 

a minute^ and F in nitrous oxide iiY threcr 
miQute9. Tbey were immediately opened^ 
and after a minute, the appearance of the 
heart, and organs of refpiration obferved. 

Both the right and left vcntriclesof the heart 
in F eontradled but very feebly ; the auricles 
regularly and quickly contra6ied ; the aorta 
appeared perfedtly full of blood. In E, a feeble 
contradlion of the left finus "venosus and 
auricle was obferved ; the left ventricle did 
not contrail : the right contradled, but 
more flowly than in F. In a few minutes, 
the contradlions of the ventricles in F had 
ceafed, whilst the auricles contracted as 
ftrongly and quickly as before. ' The blood in 
the pulmonary veins of F was rather of a red- 
der purple than in E ; the difference of the 
blood in the veiia cava was hardly perceptible,, 
perhaps it was a little more purple in F. The 
membranous fubflance of the lungs in F was 
fpotted with purple as from extravafated blood, 
whilft that in £ was pale. The brain in F was 
darker than in £. On opening the ventricles 
1)0 extrayafation of blood was perceptible^ 



( 351 >■ 

The auricles of the heart in F co<itra<9:^' 
flrx!>ngly •for near twenty minutes, and then 
gradually their motion became lefs fre- 
quent ; in twenty-eight minutes* it had 
wholly ceafed; The right auricle and ventri- 
cle in E, Occafionally contra^cd for half ah 
hour. The livers of both animals were fimilar 
when they were firft opened, of a dark ttd ; 
that of F preferved its color for fome time . 
when expofed to the atmofphere ; whilft that 
ofEalmoft immediately became paler under 
the fame circumftances. 

The periftaltic motion continued for nearly 
an equal time in both animals. 

d. The fternum of a young rabbit was re-- 
moved fo that the heart and lungs could be 
perceived, and he was introduced into a veflel 
filled with nitrous oxide ; the blood in the 
pulmonary veins gradually became more purple^ 
and the heart appeared to beat quicker than 
before, all the mufcles contrading with 
great force. After he had been in about 
a minute/'fpots began to appear on the lungs. 



( 9M) 

tfaough (he contra6lions of the heart becaoltf 
quicker and weaker; in three minutes and 
half he was quite dead ; after death the 'ventri- 
cles contradled very feebly, though the con- 
tra£iions of the auricles were as ftrong almoft 
after the end of five minutes as at fir ft. This 
animal was pailed through water faturated with 
nitrous oxide ; poflibly this fluid had ibme 
efFei^ on his organs. 

Befides thefe animals, many others, a& 
guinea-pigs, mice and birds, were difiedted 
after being deflroyed in nitrous oxide ; in ' all 
of them the fame general* appearance was 
oblerved. Their mufcular fibre almofl always 
appeared lefs irritable than that of animals 
deftroyed, by organic Isefion of part of the ner* 
vpus fyftem, in the atmofphere. The ventricles 
of the heart in general, contracted feebly and 
for a very Qiort time ; whilft the auricles con- 
tinued to a<Sl for a great length of time. The 
lungs were dark in their appearance, and 
always fufFufed here and there with purple ; 
the blood in the pulmonary veins when flightly 



\. 



( 353 ) 

obferved, appeared dark, like venous blood, but 
when minutely examined, was evidently much 
more purple. The blood in the vena cava^ 
was darker than that in the pulmonary veips. 
The cerebrum was dark. 

.In a late experiment, I thought I perceived 
a flight extravafation of blood in one of the 
ventricles of the brain in a rabbit deftroyed 
\n nitrous oxide ; but as this appearance had not 
occurred in the animals I had examined before^ 
or in thofe difleded by Dr. Kinglake, and Mr* 
King, Surgeon, I am inclined to refer it to ,an 
accidental caufe. At my requeft, Mr. Smith, 
Surgeon, examined the brain of a young rabbit 
that had been killed in his prefence in nitrous 
oxide ; he was of opinion that no. effulion of 
blood into the ventricles had taken place. 

In comparing the external appearance of the 
crural nerves in two rabbits that had been dif* 
re<5ied by Dr. Kinglake, having been de(lroye4 
one in hydrogene, the other in nitrous oxide, 
w^ could perceive no perceptible difference. 

It deserves to be noticed, that whenever the 



( 354 ) 

gall bladder and the urinary bladder have been 
examined in animals deftroyed in nitrous oxide, 
they have been always diftended with fluid ; 
ttrhich is hardly ever the cafe in animals killed by 
privation of atmofpheric air. 

In the infancy of my experiments on the 
adion of nitrous oxide upon animals, I thought 
that it rendered the venous blood lefs coagu* 
lable; but this I. now find to be a miftake. Thd 
blood from the pulmonary veins of animals kil- 
led in nitrous oxide, does not fenfibly differ in 
this refpedl from the arterial blood of thofe de* 
ftroyed in hydrogene, and both become rcfr- 
milion nearly in the (ame time when expofed tt^ 
the atmofphere. 

In defcribing the various (hades of color df 
the blood in the preceding obfervations on the 
difTerent difiedied animals, the poverty of the 
language of color, has obliged me to adopt 
terms, which I fear will herdly convey to the 
mind of the reader^ diflindl notions of the 
difibrences obfervable by -minute examina- 
tion in the venous and arterial b)6od of 



( ^5i ) 

aoiriials. that die of privation df atmofphehd 
air, andofthofe defiroyed by the adioti 6f 
nitrous oxide. This difFetence can only be 
observed in the vcflels by means of a flrong 
light ; it may however be cafily noticed in the 
fluid blood by the ir^trodudion of it from the 
arteries or veins at the moment of their inci* 
fion, between two polifhcd furfaces of white 
glafs,* fo clofely adapted to each other^ as to 
prevent the blood from coming in cdntad) with 
the atmofphere. 

Having four or five times had an opportunity 
of bleeding people in the arm for trifling coai- 
plaintSi I have always received the blood in • 
phials, filled with various gafes, in a mode 
to be defcribed hereafter. Venous blood 
agitated in nitrous oxide, compared with flmi-^ 
lar blood in common air, hydrogene, and ni- 
trogene, iVas always darker and niore purple 



* The cblonr of common venom blood, examined in 
tbk way, refombles that of the paint called by colour-itiefi 
red ochre $ that of blood fatnrated with nitrous oxide^ ap- 
't>roadieB to tfa« tinge of lake. 



( 356 ) 

than the firft, and much brighter and more 
florid than the two laft, which were not differ- 
cnt in their color from venous blood, received 
between two furfaccs of glafs. It will be {cen 
hereafter, that the coagulum of venous blood 
is rendered more purple when expofed to ni- 
trous oxide, whilil the gas is abfbrbed ; likewife 
that blood altered by nitrous oxide, is capable 
of being again rendered vermilion, by expo^ 
iure to the air. 

The appearances noticed in the above men* 

^ fioned experiments, hi the lungs of animals 

defiroyed in nitrous oxide, arefimilar to thoie 

^ obferved by Dr. Beddoes, in animals that bad 

been made to breathe oxygene for a great 

length of time. 

There were many reaibns for fuppoling that 
the large purple fpots in the lungs of animaU 
deftroyed in nitrous oxide, were owing to ex- 
travafation of venous blood from the capillary 
veilels ; their coats being broken by the highly 
increafed arterial adiion.* To afcertain whether 
thefe phaenomena exiflcd at a period of the 



< 357 ) 

aflion of nitrous oxide, when the animal was. 
recoverable by expofure to the atmofphere, 

I introduced a rabbit of fix months old, into 
a veiTelpf nitrous oxide, and after a minute, 
when it had fallen down apparently apopledlic.^ 
plunged him wholly underwater; he immediately 
began to ftruggle, and what furprifed me very 
much, died in lefs than a minute after fubmer- 
(ion. On opening the thorax, the blood in the 
pulmonary veins was nearly of the color of that 
in animals that have been fimply drowned. 
The lungs were here and there, marked with a 
few points ; but there were no large purple 
fpots, as . in animals that have been wholly 
deftroyed in nitrous oxide : tha right fide of 
the heart only contracted. In this experiment, 
the excitement from the action of the gas was 
probably carried to fuch an extent, as to pro- 
. duce indiredl debility. There are reafons for 
fuppofing, that animals after having been ex- 
cited to but a fmall extent by the refpiration of 
nitrous oxide, will live under water for a greater 
length of time, than animals previoufly made tp 
breathe common air. 



( 358 ) 

V. Of the refplralion of mixtures of Hitrom 
OxiJe^ and other gafcs, by warm-blooded Ammahm 

a. K rabbit of near two months old, was 
introdaced into a mixture of equal parts hydro- 
geni^ and nitrous oxide through water* He 
immediately began to ftruggle ; in a minate 
fell on his fide ; in three minutes gafped^ and 
made long infpirations ; and in four minates 
and half, wad dead. On difledtion, he exhibited 
the fame appearances as animals deflroyed in 
nitrous oxide. 

h. A large and firong moufe was introduced 
into a mixture of three parts bydrogene to one 
part nitrous oxide. He immediately began to 
ftruggle very much, in half a minute^ became 
convulled^ and in about a minute^ was quite 
dead. 

c. Into a mixture of one oxygene, and three 
Tiitrous oxide^ a fmall guinea-pig was introdu- 
ced. He immediately began to ftruggle, and 
in two minutes repofed on his fide, breathing 
Y?ry deeply. He made afterwards no violent 



( 359 ) 

mufcular motion ; but lived quietly for near 
fourteen minutes: at the end of which tim^, 
his legs were much convulfed. He was taken 
out, and recovered. 

d. A moufe lived apparently without fufFer- 
ing, for near ten minutes, in a mixture of l 
ahnofpheric air, and 3 nitrous oxide, at the end 
ordeven minutes be began to iiruggle, and \n 
thirteen minutes became much convulfed. 

e. A cat of three months old, lived for feven- 
teen minutes, in a very large quantity of a mix- 
ture of 1 atmofpheric air, and 12 nitrous oxide. 
On her firft introdudlion fhe was very much 
agitated and convulfed, in a minute and half 
fhe fell down as if apople<!^ic, and continued 
breathing very deeply during the remainder 
of the time, fometimes uttering very feeble 
cries. When taken out, fhe appeared almoft 
inanimate, but on being laid before the fire, 
gradually began to breathe and move; being 
for fome time, like moil of the animals that have 
recovered after breathing nitrous oxide, con- 
vulfed on one fide, and paralytic the pther. 



>.*» 1 






(360 ) 

y. A goldfinch lived for near five minutes in 
a mixture of equal parts nitrous oxide and oxjr* 
gene^ witUbut {apparently fuffering. Taken 
out^ he appeared faint and languid, but finally 
recovered.* 

. VI. Recapitulation of faffs relating to jfie 
rsffiiration of Nitrous OxiJe, by warm-blocded 
Aninuils. 

1. Warm-blooded animals die in nitroas 
oxide infinitely (boper than in common air or 
oxygene ; but not nearly in Ho (hort a time as 
in gafes incapable of effedtiag pofitive changes 
in the vcuous bloody or in non-refpirable 

« 

gafes. 

2. The larger animals live longer in nitrous 
oxide thai! the fmaller ones, and young animals 



* SmaU birds fuffer much from cold when introduced 
into gafes through water. In this experiment, the gold- 
finch was inmiediately inferted into a large mouthed 
phial, filled with the gafes, and opened in the atmof^ 
phere. 



( 361 ) 

die in it fooncr than old ones of the fame 
fpecies, 

3. When animals, after breathing nitrons 
oxide, are removed from it before com pleat 
exhauftion has taken place, they are capable of 
being reftored to health under the adlion of 
atmofpheric air. 

4. Peculiar changes are efFedied in the organs 
of animals by the refpiration of nitrous oxide. 
In animals deftroyed by it, the arterial blood 
is purple red, the lungs are covered with purple 
fpots, both the hollow and compact mufcles 
are appareruly very inirritable, and the brain is 
dark colored. 

5. Animals are deftroyed by the refpiration 
of mixtures of nitrous oxide and hydrogene 
nearly in the fame time as by pure nitrous ox- 
ide; they arecapableof living for a great length 
of time in nitrous oxide mingled with very mi- 
nute quantities of oxygene or common air. 

Thefe fa6ls will be reafoned upon in the next 
divifion. 



( 362 ) 

VII. Of the refpiration of Nitrous Oxide hy 
amphibious Animals. 

As from the foregoing experiments, it dp* 
peared that the nitrous oxide deftroyed warm* 
blooded animals by increadng the living a6)ion 
of their organs to fuch an extent, as finally to 
exbauil their irritability and fenfibility ; it was 
reaibnable to conje(9^ure that the cold*blooded 
animals, poflefled of voluntary power over ref- 
piration, would fo regulate the quantity of 
nitrous oxide applied to the blood in their luUgs 
as to bear its a6lion for a great length of titne. 
This conjedlure was put to the teft of experi-r 
ment ; the following fafls will prove its error. 

a. Of two middle-fized water-lizards, one was 
introduced into a fmall jar filled with nitrous 
oxide, over moift mercury, by being palled 
through the mercury ; the other was made to' 
breathe hydrogene, by being carried into it in 
the fame manner. 

The lizard in nitrous oxide, in two or three 
minutesj began to make violent motions, ap« 



( 3d3 ) 

peared very unealy, and rolled about, the jar in 
every diredtion, fometimes affempting to climb 
to the top of it. The animal in bydrogene was 
all this time very quiet, and crawled about the 
veflel without being apparently much afFecSed. 
At the end of twelve minutes, the lizard in 
pitrous oxide was lying ort his back feemingly 
4ead; but on agitating the jar he moved a little ;. 
fit the end of fifteen minutes he did not move 
on agitation, and his paws were reftingonhisbelly. 
He WHS now taken out ftifFand apparently life- 
lefe, but after being expofed to the atmofphere 
for three or four minutes^ took an infpira- 
4ion> and moved his head a little; he then 
raifed the end of his tail, though the middle of 
it was flill ftifFand did not bend when touched. 
J3is four legs remained clofe to his fide, and 
were apparently ufelcfs ; but on pricking them 
with the point of a lancet, they became con- 
vulfed. After being introduced into (hallow 
water, he was able to crawl in a quarter of 
an hour, though his motions were very irrc- 
jgular^ In an^feour be was quite well.. The 



( 364 ) 

animal in hydrogenc appeared to have fuffered 
very little in three quarters of an hour,, and 
had raifed himfelf againft the iide of thejar. 
At the end of an hour he was taken out^ and 
very foon recovered, 

b. Some hours after, the fame lizards were 
again experimented upon. That which had 
been inferted into hydrogene in the laft 
experiment, being now inferted into nitroug 
oxide. 

This lizard was apparently lifelefs in foqrteeo 
minutes^ having tumbled and writhed himlelf 
very much during the firft ten minutes. Taken 
out after being in twenty-five minutes, he did not 
recover. The other lizard lived in hydro- 
gene for near an hour and quarter, taken out 
after an hour and twenty minutes, he was dead. 

Thefe animals were both opened, but the 
vifcera of the nitrous oxide lizard were fo much 
injured by the knife, that no accurate compa- 
rifon of them with thofe of the other could be 
made, I thought that the lungs appeared rather 
redder. 



( 365 ) 

e. Of two (imilar large water-lizards, one 
was introduced into a veliel flanding over mer- 
cury, wholly filled with water that had been 
long boiled and fufFered to cool under mercury. 

The animal very often rofe to the top of the 
jar as, if in fearch of air, during the firft half 
hour ; but (hewed no other figns of unea(ine(s. 
At the end of three quarters of an hour, he 
became very weak, and appeared fcarcely able 
to fwim in the water. Taken out at the end 
of fifty mrnutes, he recovered. 

The other was inferted into nitrous oxide. 
After much ftruggling, he became feufelefs 
in about fifteen minutes, and lay on his back. 
Taken out at the end of twenty minutes, he 
remained for a long time motionlefs and ftiflT, 
but in a quarter of an hour, began to move 
fome of his limbs. 

From thefe experiments, we may conclude, 
that water-lizards, and moft probably the other 
amphibious animals, die in nitrous oxide in a 
much (horter time than in hydrogene or pure 
water ; confequehtly their death in it qannot 



( 366) 

depeodon the fimple prifation of atmofpheric air/ 
At the feafon of the year in which this in- 
Yeftigation was carried on, I was unable to 
procure frogs or toads. This I regret very mocb^ 
Suppoling that cold-blooded aninoala die^ 
in nitrous oxide from poiitive changes ef- 
fc&ed in their blood by the gas^ it would be 
extremely interefling to notice the appareat aU 
terations taking place in their organs of relpiran 
tion and circulation during its adlion, which 
could eafily be done, the membranous fubftance 
of their lungs being tranfparent. The increafe ot 
diminution of the irritability of their mufculat 
fibre, might be determined by comparative gaI-« 
vanic experiments. 

. VIII. Rffe£ls of folution of nitrous omde in 
water on Fijhes. 

a. A fmall flounder was introduced . into a 
veilel filled with folution of nitrous oxide ia 
water over mercury. He remained at reft for 
tea Bjinutes and then bc^an to move aboirt ti^ 



(387) 

jar in different diredlions. In a half an hour he 
was apparently dying, lying on his fide in the 
water. He was now taken out, and introduced 
into a veilel filled with water faturated with 
common air, he very foon recovered. 

i. Of two large thornbacks,* equally brilk 
-and lively. One, A> was introduced into a jar 
containing nearly 3 cubic inches of water^ 
faturated with nitrous oxide, and which pre- 
vious to its impregnation had been long boiled ; 
the other, B, was introduced into an equal 
quantity of water which had been deprived of 
air by diftillation through mercury. 

A, appeared very quiet for two or three 
minutes, and then began to move up and down 
in the jar, as if agitated. In eight minutes his 
motions became very irregular, and he darted 
obliquely from one fide of the jar to the other* 



* I ufe the popular name. This fiAi is veiy cominbo ill 
every port of England; it is nearly of the fataie £fto atod 
color. as the minnow, and is diftinguiihed from it by two 
fmaQ bony excrefences at the origin of the belly. It is 
txtratuely Cufcepftbb. 



( 368 ) 

In twelve minutes^ he became iiitl^ and. moved 
his gills very flowly. In fifteen minutes hflr 
appeared dead. After iixteen minutes he Vkra9 
taken out^ but (hewed no ligns of life. 

B was very quiet for four minutes and half. 
He then began to move ^about the jar. In 
ieven minutes he had fallen on his back, bat 
ftill continued to move his gills. In eleven 
minutes he was motionlcis ; taken out after 
thirteen minutes, he did not recover. 

c. Of two thornbacks, one, C was introduced 
into about an ounce of boiled water in contadi 
with hydrogene, (landing over mercury. The 
other^ D, was introduced into well boiled wa- 
ter faturated with nitrous oxide, and (landing 
in contact with it over mercury. C lived near 
thirteen minutes, and died without being pre- 
vioufly much agitated. D was apparently 
motionlefs, after having the fame afFedlions as 
A in the laft experiment, in fixteen minutes. 
At the end of this time he was taken out and 
introduced into common water. He foon began 
to move his gills, and in lefs than a quarter of 



( 360 ) 

an hour was fo far recovered as to be able tti 
fwim. 

The laft experiment was repeated on twd 
fmaller thornbacks ; that in the aqueous iblution 
of nitrous oxide lived near feyenteen minutes^ 
that in the water in conta6l with hydrogene, 
about fifteen and half. 

The experiments in Ref. I. Div. 3, prove 
thq difficulty, and indeed almoftimpoffibility of 
driving from water by boiling, the whole of the 
atmofpheric air held in folution by it ; they 
likewife fhow that nitrous oxide by its ftrong 
affinity for water, is capable of expelling air from 
that fluid after no mere can be procured from it 
by ebullition. 

Hence, if water faturated with nitrous oxide 
had no pofitive efFecSs upon fifhes ; they ought 
to die in it much fooner than in water deprived 
of air by ebullition. From their living in it rather 
longer;* we may conclude, that they are de- 
ilroyed not by privation of atmofpheric air, but 



* A priori I expeded that fiihes, like amphibious ant^ 
tnals would have been very quickly deflroycd by the a6dou 
of nitrous oxide. 

z . 



\ 



( 370 ) 

from fome pofilive change efFedled in their 
blood by the gas. 

A long while ago, from obferving that the 
gills of fifh became rather of a lighter red du- 
ring their death, in the atmofphere ; I con- 
jedlured that the difeafe of which they died, 
was probably hyperoxygenation of the blood 
connedled with highly increafed animal heat. 
For not only is oxygene prefented to their 
blood in much larger quantities in atmofphe- 
ric air than in its aqueous folution ; but like- 
wife, to ufe common language, in a ftate in 
which it contains much more latent heat. 
Without however laying any ftrefs on this 
fuppofition, I had the curiofity to try whether 
thornbacks would live longefl: in atmofpheric 
air or nitrous oxide. In one experiment, they 
appeared to die in them nearly in the fame 
time. In another, the fifli in nitrous oxide lived 
nearly halfas long again as that in atmofpheric air. 

XL EffeBs of Nitrous Oxide on Infe&s. 
The winged infeils furnilhed with breathing 



(571 ) 



holes, become motionlefs in nitrous olddt vtty 
fpe^dily ; being however poflefled of a certain 
voluntary power over refpiration, they fometimes 
recover, after having been expofed to it for (bm0 ^ 
minutes, under the adiion of atraofpheric air. 

A butterfly was introduced into a fmall jar, 
filled with pure nitrous oxide, over mercury. 
He ftruggled a little during the firft two or 
three fcconds ; in about feven feconds, his leg3 
became convulfed, and his wings vi^ere wrapt 
round his body ; in about half a minute h^ 
was fenfelefs ; taken out after fix minutes, he 
did not recover* 

, Another butterfly introduced into hydrogene^ 
became convulfed in about a quarter of a minute^ 
was fenfelefs in tw6nty feconds, and taken out 
after five minutes, did not revive. 

A large drone, after being in nitrous oxide 
for a minute and a quarter, was taken out fenfe- 
lefs. After being for fome time expofed to the 
atmofphere, he began to move, and at lafl: rofe 
on his wings. For fome time, however, he was 
unable to fly in. a firaight line ; and often after 



i 
t 



( 372 ) 

I 

defcribiDg circles in the air, fell lo the ground 
as if giddy. 

A large fly, became motionlefs in nitrous 
oxide after being convulfed, in about half a mi- 
nute. Another was rendered fenfelefs in hydro- 
gene, in lefs than a quarter of a minute. 

A fly introduced into hydfocarbonate, dropt 
immediately fenfelefs ; taken out after about a 
quarter of a minute, he recovered ; but like the 
fly that had lived after expofure to nitrous 
oxide, was for (bme time vertiginous. 

Flies live much longer under water, alco- 
hol, or oil, than in non*refpirable gafes, or 
gafes incapable of fupporting life. A certain 
quantity of air always continues attached in the 
fluid to the fine hairs furrounding their breathing 
holes, fufficient to fupport life for a fliort time. 

Snails and earth-worms, live in nitrous oxide 
a long while , they die in it however, much 
fooner than in water or hydrogene ; probably 
from the fame caufes as the amphibious animals. 



\ 



DIVISION II. 



Of tbe CHANGES effeSled in NITROUS OXIDE, 
and other GASES, by tbe RESPIRATION of 
AiflMALS. 



5 •'' 



I . Preli m inaries, 

jtIlS foon as I had difcovered that nitrous oxide 
was refpirable, and poflefled of extraordinary 
powers of a6lion on living beings, I was anxious 
to be acquainted with the changes efFe6led in 
it by the venous blood. To inveftigate thefe 
changes, appeared at firft a fimpfe problem ; 
I foon however found that it involved much 
preliminary knowledge of the chemical proper- 
ties and affinities of nitrous oxide. After I had 
afcertatned by experiments detailed in the pre- 
ceding Refearches, the compofition of this gaa 



( 374 ) 

its combinations^ and the phyfical changes 
efFe<Sled by it in living beings, I began my en-* 
quiry relating to the nvode of its operation. 

Finding that the refidual gas of nitrous oxide 
after it had been breathed for fome time in (ilk 
bags, was chiefly nitrogenc, I at firft conjec- 
tured that nitrous oxide was decompofed in 
refpiration in the fame manner as atmofpheric 
air, and its oxygene only combined with the 
venous blood ; the following experiments foon 
however convinced me of my error. 



II. Abforption of Nitrous Oxide hy venous 
Hood. Changes effe^ed in the blood hy dif^ 
ferent Gafes. 

a. Though the laws of the coagulability of 
the blood are unknown, yet we are certain 
that at the moment of coagulation, a per- 
feclly new arrangement of its principles takes 
place ; confequently, their powers of combina- 
tion muft be newly modified. The affinities of 



•CJ^*!^ 



( 375 ) 

living blood can onjy be afcertained during its 
circulation in the veiTels of animals. At the 
moment of effufion from thofe veflels, it begins 
to pafs through a feries of changes, which 
jgrft produce coagulation, and finally its com- 
pleat decpmpolition. 

Confequently, the adlion of fluid blood upon 
gafes out of the veilels, will be more analogous 
to that of circulating bJood in proportion as it is 
more fpeedily placed in contact with them. 

b. To afcertain the changes efFecSled in ni 
trous oxide by fluid venous. blood. 

Ajar, fix inches long and half an inch wide, 
graduated to ,03 cubic inches, having a tight 
ftopper adapted to it, was filled with nitrogene, 
which is a gas incapable of combining with, and 
pofiefling no power of adlion upon venous blood. 
A large orifice was made in the vein of a tole- ' 
rably healthy man, and the fiopper removed 
from the jar, which was brought in contact with 
the arm fo as to receive the blood, and preffed 
clofe againfl the fkin, in fuch a way as to leave an 
©rifice juft fufficient for the efcape of th^ nitro- 



( 376 ) 

genevas the blood flowed in. When the jarwasfbll, 
it was clofed, and carried to the pneumatie 
apparatus^ the mercury of which had been pre- 
vioufly a little warmed. A fmall quantity of 
the blood was transferred into another jar to 

4 

make room for the gas. The remaining quantity 
equalled exadlly two cubic inches ; to this was 
introduced as fpeedily as poffible, eleven mear 
fures equal to ,55 cubic inches of'nitrous oxide^ 
which left a refiduum of ^ only, when ablbrb- 
ed by boiled water, and was confequently, per- 
fe<Stly pure. On agitation, a rapid diminution 
of the gas took place. 

In the mafs of blood which was opaque, 
but little change of color could be perceived ; but 
that portion of it difFufed over the fides of the 
jar, was evidently of a brighter purple than the 
venous blood. 

It was agitated for two or three minutes, and 
^hen fufFered to reft ; in eight minutes it had 
wholly coagulated ; a fmall quantity of fe- 
rum had feparated, and was difFufed over the 
coagulum. This coagulum was dark; but 



( 377 ) 

evidently of a more purple tinge than that of 
venous blood ; no gas had apparently been libe- 
rated during its formation. 

The nitrous oxide remaining, was not quite 
equal to feven meafures; hence, at lead four 
sneafures of it bad been abfbrbed. 

To afcertain the nature of the refiduum, it 
was neceflary to transfer it into ai:K)ther veflel , 
but this I found very difHcult to accomplifh, on 
account of the coagulated blood. By piercing 
through the coagulum and removing part 
of it by means of curved iron forceps, I 
at laft contrived to introduce about 4^ mea- 
fures of the gas into a fpiall cylinder, gra*- 
duated to ,25 cubic inches, in which it occu- 
pied of courfe, nearly Q meafures ; when a lit- 
tle folution of ftrontian was admitted to thefe^ 
it became very flightly clouded ; but the abforp- 
tion that took place did not more than equal 
half its bulk. Confequently, the quantity of 
carbonic acid evolved from the blood, or formed, 
muft have been extremely minute. 

On the iptrpdudlion of pure water, a rapid 



( 378 ) 

abforption o( the gas took place^ and after agu 
tation^ not quite 3 meafures remained. Thefe 
did not perceptibly diminifh with nitrous gas ; 
their quantity was too fmall to be examined by 
any other teft ; but there is reafon to fuppoie 
that they were chiefly compofed of nitrogene* « 

From this experiment^ it appeared that ni- 
trous oxide is abforbed when placed in contadl 
with venous blood ; at the iame time, that a 
very minute (]|uantity of carbonic acid and 
probably nitrogene is produced. 

c. In another limilar experiment when nearly 
half a cubic inch of nitrous oxide was ablbrbed 
by about a cubic indh and three quarters of 
fluid blood, the refidual gas did not equal more 
than ~, the quantity abforbed being taken as 
unity. This fadl induced me to fuppofe that 
the abforption of nitrous oxide by venous bloody 
was owing to a fimple folution of the gas in that 
fluid, analogous to its folution in water or alcohol. 

To afcertain if nitrous oxide could be ex- 
pelled from blood impregnated with it, by 
heat ; I introduced to 2 cubic inches of fluid 



( 379 ) 

bloocf taken from the medipl vein, about ,6 
cubic inches of nitrous oxide. After agitation, 
in fcven minutes nearly ,4 were abforbed. In 
ten ^minutes, after the blood had completely 
coagulated, the cylinder containing it, was 
transferred in contact with mercury, into a veflel 
offolution of fait in water ; this folution was 
heated and made to boil. During its cbullitioli, 
the whole of the blood became either white or 
pale brown, and formed a folid coherent 
maft ; whilfl: fmall globules of gas were given 
out from it. In a few minutes, about ,25 of 
gas had colledled. After the veflel had cooled, 
J attempted to transfer this gas into a fmall 
graduated jar in the mercurial apparatus, but 
in vain ; the mafs in the jar was fo folid and 
tough, that I could not remove it. By tranf- 
ferring it to the water apparatus, I fucceeded in 
difplacing enough of the coagulum to fufFcr 
the water to come in contact with the gas ; an 
abforption of nearly half of it took place ; hence, 
I conje3ure^ that nitrous oxide had been given 
. pat by the impregnated blood. 



( 380 ) 

d. Some fre(h dark coagulum of venous 
bloody was expofed to nitrous oxide. A very 
flight alteration of color took place at the fur- 
face of the blood, perceptible only in a ftrong 
light, and a minute quantity of gas was ab- 
forbed. A taper burnt in the remaining gas 
as brilliantly as before, hence, it had apparently 
fufTered no alteration. 

e. To compare the phyfical changes efFecfted 
in the venous blood by nitrous oxide, with thofe 
produced by other gafes, I made the follow- 
ing experiments. — I filled a large phial, con- 
taing near 14 cubic inches, with blood from 
the vein of the arm of a man, and immediately 
transferred it to the mercurial apparatus. Dif- 
ferent portions of it were thrown into fmall 
graduated cylinders, filled with the following 
gafes : nitrogene, nitrous gas, common air, 
oxygene, nitrous oxide, carbonic acid, and 
hydrocarbonate. 

The blood in each of them was fucceffively 
agitated till it began to coagulate ; and making 
allowances for the different periods of agitation. 



( 381 ) 

there was no marked difference in the times of 
coagulation. 

The color of the coagulum in every part of 
the cylinder, containing nitrogene, was the 
fame very dark red. When it was. agitated fo 
as to tinge the (ides of the. jar, it appeared 
exadUy of the color of venous blood received 
between two furfaces of glafs ; no perceptible 
abibrption of the gas had taken place. 

The blood in nitrous gas was dark, and much 
more purple on the top than that in nitrogene. 
When agitated fo as to adhere to the jar as a 
thin furface, this purple was evidently deep 
and bright. An abtbrption of rather more 
than -^ of the volume of gas had taken place. 

The blood in oxygene and atmofpheric air, 

•were of a much brighter tinge than that in any 

of the other gafes. On the top, the color was 

vermilion, but no perceptible abforption had 

taken place. 

The coagulum in nitrous oxide, when exa- 
mined in the mafs was dark, and hardly difiin- 
guifhable in its color* from venous blood ; but 
when minutely noticed at the furface where it was 



\ 



( 382 ) 

covered with ferum, and in its difiufion over 
tbe fides of the jar, it appeared of a fine pur- 
ple red, a tinge brighter than the blood in nitrous 
gas. An abforption }iad taken place in this 
cylinder, more confiderable than in any of. the 
others. 

In carbonic acid, the coagulum was of a 
brown red, much darker than the venous blood, 
and a flight diminution of gas had taken place. 

In the hydrocarbonate,* the blood was red| 
a (hade darker than the oxygenated bloody and 
a very flight diminution of the gas'f- was pereep* 
tible. 

/. To human blood that had been fatura^ 
ted with nitrous oxide y^hilfl: warm and con- 
flantly agitated for four or five minutes, to 
prevent its uniform coagulation, oxygene was 
introduced ; the red purple on the furface of it. 



* The hydrocarbonate employed, was procured from 
alcohol, by means of fulphurip acid. This gas contains 
more carbon, than hydrocarbonate from water and charcoaL 

f The curious fa6t of the reddening of venous blood by 
liydrocarbonate^ was difcovered by Dr. Beddoes, 



( 383 ) 

immediately changed to vermilion ; and on 
agitation, this color was difFufed through it. 
On comparing the tinge with that of oxygena- 
ted blood, no perceptible difference could be 
observed. No change of volume of the oxy- 
gene introduced, had taken place ; and confe- 
quently, no nitrous oxide had been evolved 
from the bfood. ' 

g. Blood, impregnated with nitrous gas, was 
ejcpofed to oxygen e ; but after agitation in it 
for many minutes, no change of its dark purple 
tinge could be obferved, though a 'flight dimi- 
nution of the oxygene appeared to take place. 

h. Blood that had been rendered vermilion 
in every part by long agitation in atmofpheric 
air, the coagulum of which was broken and 
diffufed with the coagulable lymph through the 
ferum, was expofed to nitrous oxide ; for fome 
minutes no perceptible change of color took 
place ; but by agitation for two or three hours, 
it evidently aflumed a purple tinge, whilft a 
a flight abforption of gas took place. It never 



( 384 ) 

however^ became nearly fo dark as venoii^ 
blood that had been expofed to nitrous oxide« 

i. Bloody oxygenated in the lame manner 
as in the lad experiment, the coagulutn of 
which bad been broken, was expofed to nitrous 
gas< The furface of it immediately became 
purple, and by agitation for a few minutes^ this 
color was difFufed through it. A flight dimi-^ 
nation of the gas was obferved. On comparing 
the tinge with that of venous blood that had 
been previoufly expofed to nitrous gas^ there 
was no perceptible difference. 

k. Blood expofed to oxygenated muriatic acitl 
is wholly altered in its conflitution and phyfical 
properties, as has been often noticed ; the 
coagulum becomes black in fome parts, and 
brown and white in others. Venous blood, after 
agitation in hydrogene or nitrogene, oxyge- 
nates when expofed to the atmofphere in the 
fame manner as fimple venous blood. I bad 
the curiofity to try whether venous blood 
expofed to hydrogene, would retain its power 
of being oxygenated longer than blood 



( 385 ) 

faturatcd with nitrous oxide : for this puipditc 
fome fimilar black coagulum was agitated fot 
fome time in two phials, one filled with hydrogene, 
the other with nitrous oxide. They were then 
fufFered to reft for three days at a temperature 
from about 56^ to 630. After being opened, no 
ofFenfive fmell was perceived in either of them^ 
the blood in hydrogene was rather darker than 
at the time of their 'expofure, whilfl: that in 
nitrous oxide was of a brighter purple. On 
being agitated for fome time in the atmofphere, 
the blood in nitrous oxide became red, but not 
of fo bright a tinge as oxygenated venous 
bloods The color of the blood in hydrogene 
did not at all alter. 

/• To afcertain whether impregnation with 
nitrous oxide accelerated or retarded the putre- 
fadion of the blood ; I expofed venous blood in 
four phials, the firft filled with hydrocarbonate, 
the fecond with hydrogene ; the third with atmoA 
pheric air, and the fourth with nitrous oxide. 
Exanjined after a fortnight, the blood in hydro- 
gene and common air were both black, and ^utik 

Aa 



( 386 ) 

very much ; that in hydroftarbonatc was red^ 
and perfedlly fweet ; that in nitrous oxide appear- 
ed purple and had no difagreeable fmell. 

In a fecond experinnent, when blood was 
exjpofcd for three weeks to hydrocarbonate and 
nitrous oxide, that in nitrous oxide was darker 
than before and dunk a little ; that in hydro- 
carbonate was flill perfectly fweet. The power 
of hydrocarbonate to prevent the putrefacSlicn' 
of animal matters, was long ago noticed by 
Mr. Watt. 

m. Having accidentally cut one of my fingers 
fo as to lay bare a little mufcular fibre, I intro- 
duced it whilft bleeding ipto a bottle of nitrous 
oxide ; the blood that trickled from the wound 
evidently became much more purple ; but the 
pain was neither alleviated or increafed. When 
however, the finger was taken out of the nitrous 
oxide and expofed to the atmofphere, the wound 
fmarted more than it had done before. After it 
had ceafed to bleed, I inferted it through wa- 
ter into a veflfel of nitrous gas ; but it did not 
become more painful than before. 



( 387 ) 

From allfhefe obfcrvations, wc may coticiudej 

ift. That when nitrous oxide is agitated iii 
fluid venous blood, a certain portion of the gas 
is abforbed ; whilft the color of the blood 
changes from dark red to red purple. 

2dly. That during the abforption of nitrous 
oxide by the venous blood, minute portioiis of 
nitrogcne and carbonic acid are produced, either 
by evolution from the blood, or from a decom-:^ 
pofition of part of the nitrous oxide. 

3dly. That venous blood impregnated with 
nitrous oxide is capable of oxygenation ; and 
vice verfa ; that oxygenated blood may be <:om- 
bined with nitrous oxide. 

When blood feparated into coagulum and 
ferum, is expofed to nitrous oxide, it is moft 
probable that the gas is chiefly ab(brbed by the 
ferum. That nitrous oxide however is capable 
pfadling upon the coagulum, is evident from 
J. In the fluid blood, as we (hall fee hereafter^ 
nitrous oxide is abforbed by the attra(5tion& of 
the whole compound. 



. ( 388 ) 

III. Of the changes effeSed in Nifroiis Oxidef 
hy Refpiraiian, 

Toafcertain whether the changes'efFedted inr 
nitrous oxide by the circulating blood adding 
through the moid coats of the pulmonary vetns^ 
o( living animals, were highly analogous to 
thofe produced in it by fiuid venous, blood*, 
removed from the veflels, I found extremely 
difficullf. 

I have before obferved, that when animals 
are made fo rcfpire nitrous oxide, a certain ab- 
ibrption of the gas always takes place ; but the 
fmaller animals, the only ones that can be 
experimented upon in the mercurial apparatuSj 
die in nitrou$ oxide fo fpeedily and occafion (b 
flight a diminution of gas, that I judged it 
ulelefs to attempt to analife the refiduum of 
their refpiration, which fupports flame as well 
as pure nitrous oxide, and is chiefly abfbrba- 
ble by water. 

In the infancy of my refearches^ I often 
refpired nitrous oxide in a large glafs bell^ fm^ 



( 389 ) 

nifh^d with a breathing tube and ilopcock^ and 
ppifed in water faturated with the gas. 

In two or three experiments in which thenof- 
trils being clofed after the exhauftion of the 
lungs, the gas was infpired from the bell and 
refpired into it, a conliderable diminution was 
perceived, and by the teft of lime water fome 
carbonic acid appeared to have been formed ; 
but on account of the abforption of this carbo- 
nic acid by the impregnated water, and the 
liberation of nitrous oxide from it, it was im- 
pofiible to determine with the leaft accuracy^ 
the quantities of products after retpiration. 

About this time likewife, I often examined 
the refiduum of nitrous oxide, after it had been 
refpired in filk bags. In thefe experiments 
when the gas had been breathed for a long time, 
a conliderable diminution of it was obferved, 
and the remainder extinguifhed flame and gave 
a very flight diminution with nitrous gas. But 
the great quantity of this remainder as well as 
other phasnomena, convinced me that though' 
tiie oiled filk was apparently air tight when 



( 390 ) 

dry^ under flight preflure^ yet during the 9<Sioiv 
of refpiration, the moid and warm gas expired^ 
penetrated through it^ <whilfi common air en- 
tered through the wetted furface. 

To afcertain accurately^ the changes efFedled 
in nitrous oxide by refpiration, I was obliged tq 
make ufe of the large mercurial airholder inen- 
tioned in Refearch I. of the capacity of 20Q 
cubic inches. The upper cylinder of it was 
^curately balanced fo as to be cooilantly un- 
der the prefTure of the atmofphere. To an 
aperture in it, a (lop cock having a very large 
orifice was adapted, curved and flattened at its 
upper extremity, fo as to form an air-tight 
mouth-piece. 

By accurately doling the nofe, and bringing 
the lips tight on the mouth-piece, after a few 

trials I was able to breathe oxygene or com* 

f 

mon air in this machine for two minutes or two 
minutes and half, without any other uneaiy 
feeling than that produced by the inclination of 
the neck and cheft towards the cylinder. The 
power of uniformly exbau(]ttng the lungs and 



( 391. ) 

I 

fauces to the fame extent, I did not acquire till 
after many experiments. At laft, by preferving 
exadlly the fame poftur6 after exhauftion of the 
lungs before the infpiration of the gas to be ex- 
perimented upon, and during its compleat expi- 
ration, I found that I could always retain nearly 
the fame quantity of gas in the bronchial vefTels 
and fauces ; the difference in the volume expi- 
red at different times, never amounting to 3 
cubic inch and half. 

By conncdling the condudling pipe of the 
mercurial airholder, during the refpiration of 
the gas, with a fmall trough of mercury by 
means of a curved tube, it became a perfeA 
and excellent breathing machine. For by ex- 
erting a certain prcffure on the airholding cylin- 
der, it was eafy to throw a quantity of gas 
after every infpiration or expiration, into 
tubes filled with mercury ftanding in the trough. 
In thefe tubes it could be accurately analifed, 
and thus the changes taking place at different 
periods of the procefs afcertained. 

Whenever I breathed pure nitrous oxide in the 
mercurial airholder^ afteracompleat voluntary ex- 



( 392 ) 

baufiion of my lungs, the pleafurable delirium was 
very rapidly produced, andbeing obliged to (loop 
on the cylinder, the determination of blood to 
my bead from the increafed arterial adlion in 
leis than a minute became fo great, as often to 
deprive me of voluntary power over the mufcles 
of the mouth. Hence, I could never rely on 
the accuracy of any experiment, in which the 

gas bad been refpired for more than three 

« 

quarters of a minute. 

I wa.s able to refpire the gas with great accu- 
racy for more than half a minute ; it at firfl*, 
rather increafing than diminifhing the power of 
volition ; but even in this fhort time, very ftrong 
ienfations were always produced, with fenfe of 
fulnefs about the head, fomewhat alarming ; a 
feeling which hardly ever occurs to me when the 
gas is breathed in the natural pofiure. 

In all the numerous experiments that I made 
on the refpiration of nitrous oxide in this way, 
a very confiderable diminution of gas always 
took place ; and the diminution was generally 
apparently greater to the eye during the firft 
fopr or five infpirations. 



\ 



( 393 ) 

The refidual gas of an experiment was always 
examined in the following manner. After being 
transferred through mercury , into a graduated 
c'yiinder^ a fmall quantity of concentrated iblu* 
tion of cauftic potafh was introduced to it, and 
ifufiered to remain in conta£l with it for Ibme 
hours ; the diminution was then noted, and the 
quantity of gas abforbed by the potafh, judged 
to be carbonic acid. To the remainder, twice 
its bulk of pure water was admitted. After 
agitation and reft for four or five hours, the 
abforption by this was noticed, and the gas ab- 
ibrbed confidercd as nitrous oxide. The refi- 
dual unabforbable gas was mingled over water 
with twice its bulk of nitrous gas ; and by this 
means, its compofition, whether it confifted 
wholly of nitrogene, or of nitrogene mingled 
with fmall quantities of oxygene, afcertained, 

# 

From a number of experiments made at 
different times on the refpiration of nitrous 
oxide, I fcle<ft the following as the moft^ accu- 
rate. 



( 394 ) 

£.1. At temperature 54% I breathed 102 
cubic inches of nitrous oxide^ which contained 
near -— common air^ for about half a minute, 
feven infpirationsand feven expirations being 
made. After every expiration^ an evident dimi- 
nution of gas was perceived ; and when the lal^ 
full expiration was made^ it filled a fpace equal 
to 62 cubic inches. 

Tbefe 62 cubic inches analifed^ were found 
to coniifl of 

Carbonic acid . . 3fi 
Nitrous oxide. . . 29^0 • 
Oxygenc .... 4, 1 
Nitrogene .... 25,7 



62,0 



Hence, accounting for the two cubic inches of 
common air previouily mingled with the nitrous 
oxide^ 7 1 cubic inches had difappeared in this 
experiment. 

In the lail refpirations, the quantity of ga» 
was {o much diminifhed, as to prevent the full 
expanfion of the lungs ; and hence the appa- 



, ( 395 ) 

rent diminution was very much lefs after thd 
firft four infpirations. 

E. 2. At temperature 47°,* I breathed 182 
cubic inches of nitrous oxide^ mingled with 2^ 
cubicinchesofatmofphericair, which previouily 
exifted in the airholder, fpr near 40 feconds ; 
having in this time made 8 refpirations. The 
diminution after the firft full infpiration, ap- 
peared to a by-ftander nearly uniform. When 
the laft compleat expiration was made^ the gas 
filled a fpace equal to 128 cubic inches, thp 
common temperature being teftored. Theie 
128 cubic inches analifed, were found to con* 
fift of 

) 

Carbonic acid . . . • 5,25 
Nitrous oxide .... 88,75 

Oxygene 5,00 

Nitrogene ...... 29,00 

Confequently, in this experiment, 93,25 cubic 
inches of nitrous' oxide had difappeared.' 

In each of thefe experiments, the cylinder 
was Qp vered with condenfed. w^try vapor ex- 



( 396 ) 

adiiy in the f^me roaDner as if common air had 
been breathed in it. It ought to be obferved 
that^ £. ]. was made in the morning, four 
hours and half after a moderate breakfaft ; 
whereas^ £. 2. was made but an hour and quar- 
ter after a plentiful dinner ; at which near three- 
fourths of a pint of table-beer had *been drank. 
From thefe experiments we learn^ that nitrous 
oxide is rapidly abforbed by the venous blood, 
through the moid coats of the pulmonary veins. 
But as after a compleat voluntary exhauflior« 
of the lungSj much relidual air mud remain in 
the bronchial veflels and fauces^ as appears from 
their incapability of compleatly collapfing, it is 
evident that the gas expired after every infpira.- 
tion of nitrous oxide muft be mingled with differ- 
ent quantities of the rcfidual gas of the lungs ;♦ 
whilft after a complete expiration, much of.the 
unabibrbed nitrous oxide muft remain as refldual 
gas in the lungs. Now when a complete expi- 



* By lungs> I mean in this place^ all the internal organs 
of i^fpiration. 



ration is made after the breathing ofatmofpheric 
air, it is evident Aat the refidual gas of the 
lungs confifts of nitrogene,* mingled with fmall 
portions of oxygene and carbonic acid. And 
ihefc are the only produ6ls found after the ref- , 
piration of nitrous oxide. 

To afccrtain whether thefe produ6ls were 
partially produced, during the procefs of refpi- 
ration, as I was inclined to believe from the 
experiments in thelaft feiSion, or whether they 
were wholly the refidual gafes of the lungs, I 
found extremely difficult. 

I at firft thought of breathing nitrous oxide 
immediately after my lungs had becB filled with 
oxygene ; and to compare the produces remain- 
ing after the full expiration, with thofe pro- 
duced after a full expiration of pure Oxygene ; 
but on the fuppofition that oxygene and nitrous 
oxide, when applied together to the venous 
blood, muft efFedl changes in it different from 



* Becaufe thefc products are formed during the refpix:a- 
tion of common air. 



( 398 ) 

either of them feparately^ the idea was reliri-' 
quifhed. 

I attempted to infpire nitrons oxide^ after hav- 
ing made two infpirations and a complete expU 
ration of hydrogene ; but in this experiment 
the efFedls of the hydrogene were fo debilitating,- 
and the confequent ftimulation by the nitrous 
oxide fo great, as to deprive me of fenle. 
After the firft three infpirations, I loft all power 
of ftanding, and fell on my back, carrying 
in my lips the mouth-piece feparated from the' 
cylinder, to the great alarm of Mr. PatrickDwyer, 
who was noting the periods of infpiration. 

Though experiments on fucceffive infpira- 
tions of pure nitrous oxide might go fair to 
determine whether or no any nitrogene, car- 
bonic acid and oxygene were produ6ls of 
refpiration, yet I diftindtly faw that it was 
impoffible in this way to afcertain their 
quantities, fuppofing them produced, un- 

lefs I could firft determine the capacity of my 

» 

lungs ; and the difiTerent proportions of the 
gafcs remaining in the bronchial veflels after a 



( 399 ) 

compleat expiration, when atmofpheric air had 
been rcfpircd. . 

In fome experiments (that I made on the ref- 
piration of hydrogene, with a view to determine 
whether carbonic acid was produced by the 
combination of carbon loofely combined in 
the venous blood, with the oxygene refpired, or 
whether it was (imply given out ^s excrementi- 
tious by this blood) I found, without however 
being able to folve the problem I had propoled 
to myfelf, that in the refpiration of pure hydro- 
gene, little or no alteration of volume took 
place ; and that the refidual gaS was mingled 
with fome nitrogene, and a little oxygene and 
carbonic acid. 

From the comparifon of thefe fa(5\s with thofe 
noticed in the laft feflion and in R. Ill, Div. I. 
there was every reafon to fuppofe that hydro- 
'• gene was not abforbcd or altered when refpired; 
but only mingled with the refidual gafes of the 
lungs. Hence, by making a full expiration of 
atmofpheric air, and afterwards taking fix or 
feven refpirations of hydrpgene in the mercurial 



( 400 ) 

airholder^ and then making a compleat eicpira* 
tion, I conjedured that the relidual gas and 
the hydrogene would be fo mingled, as that 
nearly, the fame proportions (hould remain in the 
bronchial vellels, as in the airholder. By afcer* 
taining thefe proportions aqd calculating from 
them, I hoped to be able to afcertaia with 
. tolerable exa<^neis, the capacity of my fauces 
and bronchia, as well as the compofition of the 
gas remaining in them, after a complete expira-^ 
tion of common ,air. 

rV. Refpiration of Hydrogene. 

The hydrogene that I employed^ was procu- 
red from the decompofition of water by means 
of clean iron filings and diluted fulphuric and 
muriatic acids. It was breathed in the fame 
manner as nitrous oxide, in the large mercurial 
airholder. 

After a compleat voluntary exhauftion of 
my lungs in the ufual pofture, I found great 
difficulty in breathing hydrogene for fo long 



(461) 

hi half a minute^ fo as to make a dompleat 
cJxpiration of it. It produced urieafy feelings 
k) the cheft, momentary lofs of mufcular pow-^ 
cr^ and fbmetimes a tranfient giddinefs. 

In fome of the experiments that I made ; on 
account of the giddinefs, the refults were ren- 
dered inconclufive, by my removing my mouth 
IVoiri the mouth-piece after expiration, before 
the affiftant could turn the flopcock. 

The purity of the hydrogene was afcertained 
immediately before the experiment by the tell 
of nitrous gas, and by detonation withoxygene 
oi* atmofpheric air ; generally 12 meafures of 
atmofpheric air were fired with 4 of the hydro- 
gene, and if the diminution was to ten or a little 
more, the gas was judged to be pure. 

After the experiment, when the compleaf 
expiration had been made and the common 
temperature jeftored ; the volume of the gas 
vras noticed, ^nd then a fmall quantity of it 
thrown into the mercurial apparatus by means 
of the condudling tube, to be ejcamined. Thifc 
parbonic acid was feparated by from it by means 



( 4(W ) 

of folutioo of potaih or ftrontian ; the quantity of 
oxygene it contained, was afcertained by means 
of nitrous gas of known compofition ; the 
fuperabundant nitrous gas was abforbed by 
folution of muriate of iron ; and the proportions 
of hydrogene and nitrogene in the remaining 
gas^ difcovered by inflammation with atmof* 
pheric air or oxygene in the detonating tube 
by the eledlric fpark. 

a. The two following experiments made upon 
quantities of hydrogene^ equal tothofeofthe Di" 
trous oxide refpired in the experiments in the laft 
fe^ion, are given as the mod accurate of five. 

£* 1. I refpired at 59^ 102 cubic inches o£ 
hydrogene apparently pure, for rather leis thaa 
half a minute, making in this time feven quicfii, 
refpirations. 

After the complete expiration, when th^^ 
common temperature was reftored^ the gw 
occupied a fpace equal to 103 cubic inches 
nearly. Thefe analifed were found to confi£k 
of 



( 4Q3 ) 

> 

Carboaic acid • • 4,0 

Oxygene 3,7 

Nkrogene • . . . 17,3 

Jlydrogenc .... 78,0 



103,0 



Now 86 in tbi3 experiment, the gas was increafed 
ia bulk only a cubic inch ; fuppofing that after 
tbe compleat expiration the gas in the lungs^ 
bronchia and fauces was of nearly iimilar com- 
pofitioo with that in the airholder, and that no 
hydrogeoe had been abforbed by the bloody it 
would follow that 24 cubic inches of hydrogene 
remained in the internal organs of refpiration^ 
and confequently, by the rule of proportion, 
about 7,8 of the mixed refidual gas of the com- 
mon air. And then the whole quantity of refi- 
dual gas of the lungs, fuppofing the temperature 

59^, would have been 31,8 cubic inches ; but as 

• V 
its temperature was nearly that of tbe internal 

parts of the body, 98^, it muft have filled a 

greater fpace; calculating 6rpm the experimentik 



( 404 ) 

of Guyton and Vernois,* about 37,5t cubic 
inches. 

From the increafe of volume, it would appear 
that a minute quantity of gas had been gene- 
rated during the refpiration, and this was^ 3» 
we (hall fee hereafter, moft probably carbonic 
acid.§ Likewife there isreafon to fuppofe, that 
a little of the refidual oxygene muft have been 
abforbed. Making allowances for thofe circum- 
ftances, it would follow, that the 37>5 cubic 
inches of gas remaining in my lungs, after a 
compleat expiration of atmofpheric air at animal 
heat 98°, equal to 31,8 cubic inches at 5Q% 
were compofed of 

Nitrogene .... 21,9 

Carbonic acid . . 4,9 

Oxygene .... 5,0 



31,8 



* Annales dc Chimic, vol. 1, page 279- 

f This is only an imperfedt approximation 5 the raticr 
of the increafe of expaniibility of gafes to the increafe of 
temperature, has not yet been afcertained. It is probable 
that the expaniibility of gafes is altered by their mixture. 

§ For there is no reafon to fuppofe the production of nitrogene . 



( 405 ) 

E. 2. I refpired for. near a half a minute in 
the mercurial airholder at 6l°, 182 cubic in- 
ches of hydrogene ; having made during this 
time, fix long infpirations. After the laft ex- 
piration, ' the gas filled a fpace nearly equal to 
] 84 cubic inches, and analifed, was found to 
€onfifi of 

Carbonic acid . . • . 4,8 

Oxygene 4,6 

Nitrogene ...... 21,0 

flydrogene 153,6 



184, 

Now in this experiment, reafoning in the fame 
manner as before, 28,4 cubic inchds of hydro- 
gene mufl: have remained in the lungs, and 
likewife 5,5 of the atmofpheric refidual gas. 
Confequently, the whole refidual gas was nearly 
equal to 34 cubic inches at 6 Jo, which at Q8° 
would become about 40,4 cubic inches. And 
reafoning as before, it would appear from this 
experiment, that the quantity of gas remaining 
in my lungs after a compleat voluntary refpira* 



( 408 ) 

fk>D^ equalted at 98, about 40 cubic nicbe^, 
and at 61°, 34 pearly : making tbe neceflaiy 
corredlions ; tbat after common air had been 
breathed^ tbefc 34 cubic inches confifled of 

Carbonic acid • • . • 4, 1 

Oxygcne 5,5 

Nitrogene 24,4 

h. It would have been pofEble to prove tbe truth 
of the poftulate on which the experiments were 
founded, by refpiring common air or oxygene 
after the compleat expiration of the hydrogene, 
for the fame time as the hydrogene was res- 
pired and in equal quantifies. 

For if portions of hydrogene were found in 
the airholder equal to thofe of the refidual gafes 
in the two experiments, it would prove that a 
uniform mixture of refidual gas with the gas 
infpired, was produced by the refpiration. That 
this mixture mud have taken place, appeared^ 
however, fo evident from analogous fads, that 
I judged the experimental proof unneceflary. 
Indeed, as moft gafcs, though of different fpc- 
tnfic gravities^ when brought in contadl with each 



(407 ) 

other, aflfume fome fort of union, it is more 
than probable, that gas infpired into the lungs, 
from being placed in contadl with the reiidual 
gas on fuch an extenfive furface, muu inftantly 
mingle with it. Hence, poffibly one deep in- 
fpiracion and compleat expiration of the whole 
of a quantity of hydrogene, will be fufficient to 
determine the capacity of the lungs after com- 
pleat voluntary exhauftion, and the nature of 
the refidual air. 

That two infpirations are fufficient, appears 
probable from the following experiment. 

E. 3. After a compleat voluntary expiration 
of common air, I made two deep infpirations ofi 
141 cubic inches of hydrogene. After the 
compleat expiration, they filled a fpace equal 
to rather more than 142 cubic inches, and 
analifed, were found to confift of 

Carbonic acid .... 3,1 

Oxygene 4,5 

Nitrogene 18,8 

Hydrogene 11 5,6 

142. 



< 4D8 ) 

Now calculating on the exhauftcd capacity of 
my lungs from this experiment, fuppofing .mil- 
form mixture, they would contain after expi- 
ration of common air, about 30,7 cubic inches 
at 58°, equal to 36 at gs®, compofed of about 

Nitrogene 20,9 

Oxygene .... 5,8 

Carbonic acid . . 4,0 



30,7 

One fhould fuppofe a priori that In this experir- 
ment much lefs of the refidual oxygene of the 
lungs mud have been abforbed, than in Expts. 
1 and 2 ; yet there is no very marked difference 
in the portions evolved. That a tolerably accu- 
rate mixture took place, appears from the quan- 
tity of nitrogene. The fmaller quantity of 
carbonic acid is an evidence in favour of its 
evolution from the venous blood. 

c. It is reafonable to fuppofe that the prefliire 
upon the refidual gas of the exhauftcd lungs^ 
mufl: be nearly equal to that of the atmofphere. 
But as aqueous vapour is perpetually given oujt 



(409) 

by the exhalents, and perhaps evolved from the 
ipoift coats of the pulmonary veflels, it is likely 
that the refidual gas is not only fully faturated 
with moiflure at 98^, but likewife impregnated 
with uncombinpd vapor ; and hence its volume 
enlarged beyond the increment of expanfion 
of temperature. 

Confidering all thefc circumftances, and cal- 
culating from the mean of the three experi- 
ments on the compofition of the refidual gas, 
I concluded, 

ift. That the exhaufted capacity of my lungs 
was equal to about 41 cubic inches. 

!2dly. That the gas contained in my bron- 
chial veflels and fauces, after a compleat refpi- 
ration of atmofpheric air, was equal to about 
32 cubic inches^ its temperature being reduced 
to 55"". 

3dly. That thefe 32 cubic inches were com- 
pofed of about 

Nitrogene . . 23,0 
Caifbonic acid . . 4,1 
Oxygene ... 4,9 



( 411 ) 

I 

the experiments in fedion III^ on the refpiratiofi 
of nitrous oxide. 

In Exp. I. nearly 100 cubic inches of nitrous 
oxide^ making the correcElions on account of 
the common air^ were relpired for half a minute. 
In this time, they were reduced to 62 cubic in- 
ches, which confided of 3,2 carbonic acid, 29 
nitrous oxide, 4,1 oxygene, and 25,7 nitrogene. 

But, as appears from the laft fc6lion, there 
exified in the lungs before the infpiration of the 
nitrous oxide, about 32 cubic inches of gas^ 
confiding of 23 nitrogene, 4,1 carbonic acid^ 
and 4,9 oxygene, temperature being reduced to 
59^ This gas mufl: have been perfeftly ming- 
led with the nitrous oxide duripg the experi- 
ment; and confequently, the refidual gas in the 
lungs after the experiment, was of the fame 
compofition as that in the airholder. 

Suppofing it as before, to be about 32 cubic 
inches : from the rule of proportion, they will 
be compofed of 

Nitrous oxide . . 14,7 
Nitrogene 13,3 



( 413 ) 

Carbonic acid . . l,^ 

Oxygene 2,1 

And the whole quantity of gas in the lungs and 

the airholder, fuppofing the temperature 5g^, 

will equal 94 cubic inches, which are compofed 

of 

Nitrous oxide . . 43,7 

Nitrogene 3g,0 

Carbonic acid . . 5, 2 

Oxygene 6, 1 

94 

But before the experiment, the gas in the lungs 
and airholder equalled 134 cubic inches, and 
thefp, reckoning for the common air, were 
compofed of 

Nitrous oxide . . 100 

Nitrogene, .... 24,3 

Carbonic acid . . 4,] 

Oxygene .... 5,6 
Hence, it appears, that 56,3 cubic inches of 
nitrous oxide were abforbed in this experiment, 
and 13,7 of nitrogene produced, either by evo- 
lution from the blood, or decpmpofition of the 



( 414 ) 

nitrous oxide. The quantities of carbonic acid 
and oxygene approach fo near to tbofe exifting 
after the refpiration of bydrogene^ tbat there i» 
every reafon to believe that no portion of them 
was produced in confequence of the abforption, 
or decompolition of the nitrous oxide. 

h. In Exp. 2^ calculating in the fame manner, 
before the firft infpiration^ a quantity of gas 
equal to 216^5 cubic inches at 47% exifted in 
the lungs and airholder^ and thefe 2 16, 5 cubic 
inches were compofed of 

Nitrous oxide^ .... i82|0 

Nitrogene 24,9 

Carbonic acid .... 4^1 
Oxygene 5,5 . 

216,5 
After the compleat expiration, 160 cubic in- 
ches remained in the lungs and airholder, which 
was compofed of 

Nitrous oxide . . 1 10,6 

Nitrogene 36,$ 

Carbonic acid .... 6,8 
Oxygene # 6>3 



( 4J5 ) 

Hence^ it appears^ that 7^ A cubic inches of 
nitrous oxide were abforbed in this experiment, 
and about 12 of nitrogene produced. The 
quantity of carbonic acid ^nd oxygene is rather 
greater than that which exifted in the expert- 
menta on hydrogene. 

<;. From thefe eilimations^ I learned that a 
fmall quantity of nitrogene was produced during 
the abforption of nitrous oxide in refpir^tion. 
It remained to determine, whether this nitro- 
gene owed its produdlion to evolution from the 
blood, or to the decomposition of a portion of 
the nitrous oxide. 

Analogical evidences were not in favour of the 
hypotheiisofdecompofition. It was difficult to 
fuppofe that a body requiring the temperaturq of 
ignition for its decompo(ition by the mod inflam- 
mable bodies, (hould be partially abforbed and 
partially decompounded at QS^ by a fluid ap- 
parently poflefled of uniform attracSlions. 

It was more eafy to believe, that from the 
immenfe quantity of nitrogene taken into the 
blood in nitrous oxide ; the iyilem foon became 



(416) 

overcharged with this principle, which not beirJgf 
wholly expended in new combinations during' 
living aiStion, was liberated in the aeriform date 
by the exhalents, or through the moift coats of 
the veins. 

Now if the laft rationale were true, it would 
follow, that the quantity of nitrogene produced 
in refpiration, ought to be increafed in propor- 
tion as a greater quantity of nitrous oxide 
entered into combination with the blood. 

d. To afcertain whether this was the cafe, I 
made after full voluntary^ exhauftion of my 
lungs, one full voluntary infpiration and expi- 
ration of 108 cubic inches of nitrous oxide. 
After this, it filled a fpace nearly equal to Qg 
cubic inches. The quantities of carbonic acid 
and oxygene in thefe were not determined ; but 
by the teft of abforption by water, they appeared 
to contain only 18 nitrogene; which is very 
little more than fhould have been given from: 
the refidual gas of the lungs. 

In a fecond experiment, I made two refpira- 
tions of 108 cubic inches of nitrous oi de 



nSariy pure. The diniinution was to ^5. OH 
analyfing thcfe 95, I foiirid ta my great furprile^ ^ 
that they cdritained only 17 nitrogene. Hence^ 
1 could not but flifpecfl fdmc fodrcii of error in * 
the procefs. 

\ now ititroduced into a ftrorig new filk ' 
b^g, the fidds df which Were in perfedl contadl, 
about 8 quarts of nitrous oxidd. From theJ ' 
mode of introdu6lion, this nitrous oxide muft 
have been mingled with a little common air, ' 
not however fufficient to difturb the refults. 

I then adapted a dork cemented to a long 
curved tube to my right noftril ; the tiibe was 
made to communicate with th^ w^ter apparatusj 
and the left noftril being accurately clofed, and 
the mouth'piece of thd filk bag tightly adapted 
to the lips, I made a full expiration of the com- 
mon air of my lungs, infpired nitrous oxide from 
the bag, and by carefully clofing the mouth- - 
piece with my tongue, expired it through 
the curved tube irito the water apparatus. In 
this w^y, I made nine rcfpirations of nitrous 

oxide. The expired gas of the firft refpiratiotli 

Cc 



/ 



( 418 ) 

was not preferved ; but part of tbe gas of the 
iecoD^y third, fifth, fevcnth and ninth, were 
caught in feperate graduated cylinders. The 
fecond, analifed by abforption, confided of 
about 29 abforbable gas, which muft have beei;i 
chiefly nitrous oxide ; and 17 unabforbable gas, 
which muft have been chiefly nitrogene; and tbe 
third of 22 abforbable gas, and 8 unabforbable. 
Tbe fifth was compofed of 27 to 6 * the feventb 
of 23 to 7, and the ninth of 26 to 11. 

€. Though the refults of thefe experiaienta 
were not fo conclufive as could be wifhed ; . yet, 
con) paring them withthofe of the experiments ia 
fe£lion III. it feem€d reafonable to conclude, 
that the production of nitrogene was increafed," 
in proportion as the blood became more fully 
impregnated with nitrous oxide. 

From this concludon, compared with the pbas>- 
nomenod noticed in fedlion 2^ and in Diy. I./ 
fedion 4, I am induced to believe that the pror 
dudlion of nitrogene during the refpiration of 
nitrous oxide, is not owing to the decompofi* 
tion of part of the qhrous oxide, in the 



( '^i0 ) 

aeriform ftate immBdiateJy by the! attrafliori ttf 
the red particles of venous blood for its oxygene i 
but that it is rather owing to a new arrangement 
produced in thd principles of the impregnated 
blood, during circulation ; fVom which, becoming 
fuperfaturated with nitrogene, it gives it out- 
through the moid coats of the veflels. 

Fdrifany poftioti of nitrous ofide were de- 
ctJmpofed immediately by the red particles of 
the blood, one (hould conjedlure, that the quan- 
tity of nitrogene produced, ought to be greater 
during the firft infpirations, before thefe particles 

became fully combined with condenfed oxygetie; 

■» • 

If on the contrary; the whcJe of the nitrogens 

and oxygdtte of the nitrous oxide were both 
combined withtheblood, and carried through the 
pulmonary veins arid left chamber of the heart to 
the arteries ; then, fuppofing the oxygetie chiefly 
expended in living afiion, whilft the nitrogen^ 
was only partially confumed in new combina- 
tions, it would follow, that the venous blood of 
ai^imals made to breathe nitrous oxide, byper- 
faturatfed with nitrogene, muft be different fronj 



( 410 ) 

common venous blood ; and this wc have rea' 
Ibo to believe from the phaenomena in Div. I. 
ledlion 4, is acSlually the cafe. 

f. Befides the nitrogcne generated during 
the refpiration of nitrous oxide, we have noticed 
the evolution of other products, carbonic acid,* 
and water. 

Now as nelkrly equal quantities of carbonic 
acid are produced, whether bydrogene or ni- 
trous oxide is refpired, provided the procels is 
carried on for the fame time ; there is every 
reafon to believe, as we have iaid before, that no 
part of the carbonic acid produced, is generated 
from the immediate decompoiition of nitrous 
oxide by carbon exifling in the blood. 

Confequently, in thefe experiments, it n^uft 
be either evolved from the venous blood ; or 
formed, by the flow combination of the oxygene 
of the reiidual air of refpiration with the char- 
coal of the blood. 



* The oxygene as we have before noticed, moft proba 
bly wholly exifled in the reiidual gas. 



( 421 ) 

. Bat if it was produced by the decompofition 
of refidual atmofpheric air, it would follow, 
that its volume muft be much lefs than that of 
the oicygene of the refidual air, which had 
difappeared ; for fome of this oxygene muft 
have been abforbed by the blood, and during 
the converfion of oxygene into carbonic acid by 
charcoal, a flight diminution of volume is pro** 
duced. 

In the experiments when nitrous oxide and 
bydrogeuQ were refpired for about half a minute, 
the medium quantity of carbonic acid produced, 
was 5fi cubic inches nearly. 

Now we will afTume, that the quantity of 
carbonic acid produced, is in the ratio of the 
oxygene diminifhcd ; and there is every reafon 
to believe, that in the expiration of atmofphe- 
ric air, the expired air and the refidual air are 
nearly of the fame compofition. 

Hence, no more carbonic acid can remain 
in the lungs or be produced from the refidual 
gas after the cpmpleat expiration of common 
air, than that which can be generated from a 



(m) 

IFolume of atiDofpheric dir equal to the rp6<iaal 
gas of the luogs. 

TherefidualgasoftbeluiigSy after oompleaf 
expiration^ equals at 55o, 32 cubic inohet^ aad 
32 cubic ipcbes of cotnmon air cootain 8.6 
cubic inches of oxygede. 

But in the experimenta on the refpirfition 0^ 
hydrogens, not only 5.6 cubic inebes of carr 
bonic acid were produced^ but more thaa 4 of 
feSdual oxygene remained unablbrbed. 

Hence it app^ra impofiible that all the car* 
Iconic acid evolved from the luogs during tbo 
refpiration of nitrous oxide or. bydrogene oouki 
have been produced by the combination of char- 
coal in the venous blood with refidual atmof- 
pheric oxygene i there is confequently ev^ 
reaibn to believe that it is wholly or partially li- 
berated from the venous blood through the moiO: 
coals of the yeflels, 

gn The water carried out of the lung» iq fb~ 
Itttion by the expired gas of nitrous oxide^ could 
neither have been wholly or partially formed 
l^ the decompoiition of nitroqs oxkie. Tim 



( 423 ) 

coats of the ve^Tels in the langs^ and indeed in 
the whole internal furface of the body, are 
always covered with moifture, and the folution 
of part of this moifture by the infpired heated 
gas^ and its depoiition by the expired gas, are 
fufiicient caufes for the appearance of the 
phaenomenon. 

There are no reafons for fuppofing that any 
lofthe refidual atmofpheric oxygene is imme- 
diately combined with fixed or nafcent hydro- 
gene^ or hydrocarbonate, in the venous blood at 
98°, by flow combuftion, and confequently 
none for fuppofing that water is immediately 
formed in refpiration. 

The evolution of water from the veflels in 
the lungs, is almoft certain from numerous 
analogies* 

b. As from the experiments in fe<5tion U. it 
appeared that nitrous oxide was capable of being 
combined with oxygenated blood, and vice verfa, 
mood impregnated with nitrous oxide capable 
of oxygenation ; I was curious to afcertain what 
changes would be efTedled in nitrous oxide when 



( 424 ) 

it w^s refpiredy miogled with atmofphe^. 
ric air or oxygene. For this purppfcp with^ 
out making a very delicate experiment, I breath- 
ed in the large n^ercurial airholder about H^ 
cubic inches of nitrous oxide, mingled with 
44 of common air, for near half a minute^ ip 
the ufual mode. The gas, after expiration, fiU 
]ed a fpace nearly equal to II 9. I did not 
exadlly afcertain the compofition of the reiidqal 
gas ; it fupported flame rather better than CQiH- 

* » • 

inon air, and after the nitrous oxide was ab* 
ibrbed, gave much lefs diminqtion with pitrovis 
gas than atmofpheric air, 

i. I breathed a mixture of four quarts of 
nitrous oxide with three quarts of hydrogene, 
in a dry filk bag, for near a minute \ an evir 
dent diminution was produced ; but on account 
of the mode of experimenting it was impofQble 
to determine the quantity of nitrous oxide ab- 
forbed, or the exadl nature of the produdts. 
When a taper was introduced into a little of tljuj^ 
reiidual gas, it inflamed with a very feeble ex- 
ploiioUr Now a mii^ture of 4 -parts nitrous ox^ 



\ 



(425 ) 

ide and 3 hydrogene, detonates when inflamed 
with very greiit violence. 

i. Nitrous oxide can be refpirpd without 
danger by thehiinian animal for a much longer 
time than that required for the death of the 
fmaller quadrupeds in it. . 

I have breathed it two or three times in ^ 
confiderablc flate of purity, in a dry filk bag, 
for four minutes and quarter and four minutes 
and half; fome difeafed individuals have refpi- 
red it for upwards of five minutes. 

In the infancy of my experiments, from gene- 
ral appearances, I thought that the proportion of 
qitrous oxide abforbed in refpirat jon was greater 
in thefirdinfpirationsthanthelaft^.butthislhave 
fince found to be a miftake. In thelaft refpirations 
the apparent abforptioq is indeed lefs ; but this is 
on account of the increafed evolution of nitro* 
gene from the blood. When nitrous oxide is 
refpired for a long time, thejaft infpirations are 
always fuller and quicker than the firft ; but 
the cpnfumption by the fame individual is nearly 
ii) the- ratio of the time pf refpiration., Thre^ 



( 426 ) 

t|uarts i. e. about 174 cubic inches, areconfumed 
fo as to be unfit for refpiration^ by an healthy 
individual with lungs of moderate capacity, in 
about a minute and quarter ; fix quarts, or 348 
cubic inches, laft generally for two minutes and 
half or two minutes and three quarters ; eight 
quarts, or 464 cubic inches, for more than 
three minutes and half; and twelve, or 6q6 
cubic inches, for nearly five. 

The quantities of nitrous oxide absorbed by 
the fame individual, will, as there is every rea- 
fon to fuppofe, be different under difi^rent 
circumflances, and will probably be governed 
in fome meafure by the flate of the health. It 
is reafonable to fuppofe, that the velocity of the 
circulation mufl have a confiderable influence 
on the abforption of nitrous oxide ; probably in 
proportion as it is greater a larger quantity of 
gas will be confumed in equal times^ 

I am inclined from two or three experiments, 
to believe that nitrous oxide is abfbrbed more 
rapidly afler hearty meals or during flimulation 
from wine or fpirits^ than at other times. As 



Us ab(brption appears to depend on a fimple 
folution in tfae venous blood ; probably dim inu^ 
tion of temperature will increafe its capability 

of being flbforbed. 

/; Tbc quantities of nitrous oxide abforbed by 
diflisrent individuals, will probably be governed 
in feme ipeafure by the fi?e of their lungs an4' 
the forface of the blood veflels, all other cir- 
cumfiances being the fame* 

FVom the obfervattons that I have been able 
to n^ake on the ablbrption of nitrous oxide, as 
compared with the capacity of the lungs, the 
range of the confumption of different individu- 
als does not extend to more than a pint, or 30 
cubic inches at the maximnm dole. 

We may therefore conclude, that the medium 
confumption of nitrous oxide by the refpiratiort 
of different individuals, is not far from two 
cubic inches, or about a grain every fecoqd, 
or 120 ciibic inches, or 6o grains every minute. 

m. When nitrous oxide is breathed in tight 
iilk bags, towards the end of the experiment as 
tbe internal fiirface becomes moid, as I have 



r 448 ) 

before mentioned^ a certain quantity of com- 
mon air penetrates through it add becomes 
mixed with the refidual gas of the es^periinent ; 
but this quantity is always too fmall to deftfoy 
any of the effedls of the nitrous oxide. The 
refidual gas of the common, air^ the nitrogene 
and carbonic acid produced in the proceftj. and 
the reiiduum of the admitted atmofpheric air, 
bardly ever amount after the experimontj to 
one half of the volume of the nitrous oxide 
abibrbed. There is confequently, , a perfedl 
propriety in fucceflively infpiring and expiriog 
the whole of a given quantity of nitrous oxide^ 
till it is nearly confumed. In the refpiration of 
nitrous oxide as the gas is abforbed and not de- 
compofed^ little will be gained in efFcdl, by per- 
petually infpiring and expiring new portions^ 
whilft an immenfe quantity of gas will be idly 
wafted^ and thi3 circumfiance^ cc^lidering 
the expence of the fubfiance^ is of importance. 



im) 



VI. On the refpiration of Atmofpheric Air. 

Having thus afcertained the abforption of 
nitrous oxide in refpiration, and the evolution 
of nitrogene and carbonic acid from the lungs 
during its abforption : confidering atmofpheric 
air as a compound in which principles identi- 
cal with thofe in nitrous oxide exifted, though 
in different quantities and loofer combination, 
I was anxious to compare the changes efre<5led 
in this gas by refpiration, with thofe produced 
in nitrous oxide and oxygene ; particularly as 
they are corine<9;ed with the health and life of 
animals. 

The ingenious experiments of Lavoifier and 
Goodwyn, prove the confumption of oxygene 
in refpiration, and the produ6lion of carbonic 
acid. From many experiments on the refpira- 
tion of common air. Dr. Prieftky fufpedled that 
a certain portion of nitrogene, as well as oxygene, 
was abforbed by the venous blood. 



( ^30) 

L In the following experiments on the relpi^ 
ration of atmofpberic air in the mercuriat air« 
holder ; the compofitic^ of the gas before infpi- 
ration and after expiration, was afcertained in 
the following manner. 

Fof ty meafures of it were agitated over tfiercury 
in (bl ution of caufiic potafh^and fuffered toremaint 
in conta6l with it for two or three hours. The 
diminution was noted, and the gas abforbcd 
judged to be carbonic acid. Twenty meafures 
of the gas, freed from carbonic acid, were ming- 
led with thirty of nitrous gas, in a tube of ,5 
inches diameter ; they were not agitatcdj* but 
fuffered to reft for an hour or an hour and halfi 
when the volume occupied by them was noticed : 
and 50 — m the volume occupied, divided 
by 3 confidered as the oxygene x, and 20 — j? 
confidered as the nitrogene. 



* When they are agitated^ a greater proportion of nitrous 
ga3 is abforbed, condenfed in the nitric add by the water ; 

and to find the oxygene^ 50 — m 50 — jJir 

X = '■ ' ■■ or ■* 

3,4 3,5 



( 431 ) 

c. To afcertain the changes effected in at- 
mofpheric air by fingle iDipirations^ 
I made^ after a compleat voluntary exhauftion of 
my lungs, at temperature 6 1^, oneinfpiration and 
expiration of 141 cubic inches of atmofpheric 
air. After expiration, they filled a fpace equal 
to 139 cubic inches nearly. Thefe ISQ cubic 
inches analifed were found to confift of 



Nitrogene .... 


301 


Oxygene .... 


32 


Carbonic acid . . 


. 6 



The 141 cubic inches before infpiration, 
were compofed of 103 nitrogene, 1 carbonic 
acid and 37 oxygene. The time taken to per- 
form the infpiration and full expiration, was 
nearly a quarter of a minute. 

I repeated this experiment feven or eight 
times, and the quantity of oxygene abforbed 
was generally from 5 to 6 cubic inches, the 
carbonic acid formed frfim 5 to 5,5, and the 
quantity of nitrogene apparently diminifhed by 
from 1 to 3 cubic inches. 



( JS4 ) 

E. 2. I made, after a voluntafry expiration of 
common air, one infpiration and fuTl expiratibn 
of 100 cubic inches of atmofpheric a(ir. It \^a$ 
dimini(hed nearly to QSf or Qg cubic inches/ ' 
and analifed, was found to cOnfift of 

Nitrogcne . . 71,7 
y Oxygene .... 22,5 

Carbonic acid . . 4,5 
This experiment I likewife repeated four or five 
times, with very little difference ofrefult, and 
there always feemed to be a fmall diminution of 
nitrogene. I made no corredlions on account 
of the refidual air of the lungs in thefe pro- 
cefles, becaufe there was every reafon to fup- 
pofc that it was always of firailar cofnpofition. 

c. Before I could afcertain whether (imilar 
changes were efte6ied in atmofpheric air, by 
natural infpirations as by forced ones, I was 
obliged to pradlife refpiration in the mercurial 
airholder, by fuffering the conducing tube to 
communicate with the atmofphere till I had 
attained the power of breathing in it naturally, 
without labor or attention ; I then found by a * 



( 433 ) 

number of experiments, that I took into, my 
lungs at every natural infpiration, about 13 cu- 
bic inches of air, and that I threw out of my 
lungs at every expiration,* rather lefs than this 
quantity; about 12^ cubic inches. 

The mean compofition of the 13 cubic inches 
of air infpired, was 

cub. in. 

Nitrogene . . 9,5 
Oxygene . . . 3,4 
Carbonic acid 0,1 

That of the 12,7 of air expired 
Nitrogene • . 9,3 
Oxygene . . 2,2 
Carbonic acid 1,2 
Thefe refults I gained from more than 20 ex- 
periments, fo that I could not poflibly entertain 
any doubt of this accuracy. 

I found, by making a peribn obferve my ref- 
pirations when I was inattentive to the procef^, 



* The diminution of air by iingle infpirations^ was 
particularly noticed by Dr. Goodwyn, 

Dd 



( 434 ) 

that I made about 26 or 27 natural infpirations 
in a minute. So that calculating from the 
above eftimations, it would follow, that 31,6 
cubic- inches of oxygcne were confumed, and 
5,2 inches of nitrogene loft in refpiration every 
minute, whilft 26,6 cubic inches of carbonic 
acid were produced. 

To colle6l ^he products of a great number of 
natural expirations fo as to afcertdin whether 
r- c^'^pofition correfponded with the above 
::, : wUiitsj i proceeded in the following manner. 

I fafiened my lips tight on the mouth-piece 
of the exhaufted airholder, and fufFering my 
noftrils to remain open, inspired naturally 
through them, throwing the expired air through 
my mouth into the airholder. 

In many experiments, I found that in about 
a half a minute, I made in this way 14 or 15 
expirations. The mean quantity of air colledled 
was 17 1 cubic inches, and confifted of 

cub. in. 

Nitrogene . . 128 
Oxygene . . 29 
Carbonic acid * . 14 



( 435 ) 

Comparing thefe refults with the former oneSj[ 

we find the mean quantities of air refpired in 

ft 

equal terms rather Icfs ; but the proportions of 
carbonic acid, nitrogene and oxygetie in the 
refpired air, nearly identical. 

e. To afcertain the changes efFedled in i 
given quantity of atmofpheric air by continued 
refpirations, I breathed after a cbmplcat expi* 
ration, at temperature 63*, l6'l cubic inches of 
air for near a minute, making in this time, ig 
deep infpii'ations. After the compleat expira- 
tion, which was v6ry carefolly made, the gas 
filled a fpace nearly equal to 152 cubic inches, 
fo that 9 cubic inches of gas had difappeared. 

The 152 cubic inches aiialifed, were founti 
to corrfift of 

chb. in. 

Nitrogene . .■ 11 1,6 
Oxygene . . 23, 
Carbonic acid, 17,>f 

• iThe l'6l cubic inches before fnfpii^ation, wer? 
Compofed of / 



• i 



( 435 ) 

I 

cub. in. 

Nitrogene . . 1 17.O 
Oxygene . . 42,4 
Carbonic acid 1,6 

But the refidual gas in the lungs bef6re the 
experiment, was of different compofition from 
that remaining in the lungs after the expe- 
riment. Making corrections on account of 
this circumftance, as in fedlion IV. it appears 
that about 5,1 of nitrogene were abforbed in 
refpiration, 23,9 ^^ oxygene confdmed, and 
12 of carbonic acid produced. 

I repeated this experiment three times ; in 
each experiment the diminution aft6r refpiration, 
was nearly the fame ; and the refidual gas 
making the neceflary allowances, of iimilar 
compofition. So that fuppofing the exiftence 
of no fource of error in the experiments from 
which, the quantity and compofition of the refi- 
dual gas of the lungs were eftimated in fe6lion 
IV. the abforption of nitrogene by the venoui 
bloody appears almoft demonft rated. 



(437) 

/. To compare the changes efFedled in at-^ 
mofpheric air by refpiration of the fmaller 
quadrupeds, with thofe in the experiments juft 
detailed, I introduced into a jar of the capacity 
of 20 cubic inches filled wjth mercury in the 
mercurial trough, 15 cubic inches of atmofphe- 
ric air which had been deprived of its carbonic 
acid by long expofure, to folution of potaffi'. 

Temperature being 64**, a healthy fmall 
moufe was quickly pafled under the mercury 
into the jar, and fufFered to reft on a very thin 
bit of cheefcj which was admitted immediately 
after. 

He continued for neat 40 minutes without 
apparently fufFering, occafionally raifing him- 
fe!f on his hind legs. At the end of 50 minutes, 
he was lying on his fide, and in 55 minutes 

» 

was apparently dying. He was now carefUlIy 
taken out through the mercury by the t&il, and 
expofed before the fire, where he foon recovered. 
After the cheefe had been carefully removed, 
the gas in the jar filled a fpace nearly equal to 
14 cubic inches; fo that a diminution of a 



( 438 ) 

cubic inch had taken place. Thefe 1 4 cubip 
ipcbps an^lifed, were found to confift of 

cub. in. 

• Carbonic acid . . 2>0 

Oxygene ..•• 1,4 
Nitrogeqe ... 1 0,6 

7{)e; 15 cubic inches before the exp^rimentj^ 
cp^fified of 

cub. in. 

Oxygene . . 4 
Nitrogene ..11 
Hence it appeared, that 2,6 cubic inches of 
oxygene had been confumed, 2 cubic inches 
of carbonic acid produced, and about 0,4 of 
nitrogene loft. 

The relation between the quantities of oxy- 
gpne confumed in this experiment, and the 
carbonic acid produced, are nearly the fame as 
that of thofe in the o^eriments juft detailed ; 
but ,the quantity of nitrogene lof| ip mqch 
fmaller. 



( 439 ) 
VII, Ra/firafion of Oxy^ene. 



t ■ 



The g?ifes before and after refpiratipn, . Were 
analifed in thefe experiments in the manner 
defcribed in the laft fedlion. except that 3 of 
nitrous gas were always employed to one of 
Dxygene., ' , 

E. I, At temperature 53°, after a full forced • 

«* ' • ■ - ' * 

refpiration, I refpired in the mercurial airhplden 
for half a minute, 102 cubic inches of oxygene, 
making feven very long and .fl/^ep infpirations. 
After the copopleat expiratippyj the gafes filled 
a fpace equal to 93 cubic. jjipches; thefe Q3 
cubic inches analifed, were found to confift of 

cub. in. 

Carbonic acid . . 5,9 
Nitrogene .... 33,8 .. 
Oxygene 533^3 

The 102 cuWc incbfes before? the experiment, 
were compofcd of 

cub. io, 

Oxygene ..^ 78 
Nitrogene . . %^ 



< 



X 



( 440 ) 

The refidual gas in the lungs before the expe^ 
riment, was 32 cubic inches, and compoied of 
about 23 nitrogene, 4,1 carbonic acid, and 4,9 
oxygene, Section IV. The refidual gas after 
expiration^ was compofed of 18,2 oxygene, 
2 carbonic acid, and 1 1,8 nitrogene. 

Hence the whole of the gas in the lungs and 
^rholder before infpiration, was 134 cubic 
inches^ compofed of 





cub. in. 


Oxygene 


82,9 


Nitrogene . • 


47,0 


Carbonic acid 


. . 4,1 



And after refpiration, 125 cubic inches^ con- 
lifting of 

cub. in. 

Oxygene .... 71,5 
Nitrogene .... 45,6 
Carbonic acid . . 7,9 

So that comparing the quantities, it, appears^ 
that 11,4 of oxygene and 1,4 of nitrogene, 
were confumed in this experiment, and 3,8 of 
carbonic acid produced. 



( 441 ) 

f 

1 was much furprifed at the fmall quantity 6t 
oxygene that had been confumed in this expe* 
riment This quantity was lefs than that ex- 
pended during the refpiration of atmofptieric 
air for half a minute : the portion of carbonic 
acid evolved was likewife fmaller. ' I could 
dete6l no (burce of inaccuracy, and it was diffi- 
cult to fuppofe that the greater depth and 
' fulnefs of the infpirations could make any 
difference, 

E. 2. I now refpired at the fame tempera- 
ture, after a full expiration, l62 cubic inches 
of gas, compofed of 133 oxygene and 2g nitro- 
gene for two minutes, imitating as much as 
poflible, the natural refpiration. After the ex- 
periment, they filled a fpacc equal to 123 cubic 
inches. And when the analyfis and calcula- 
tions had been made as in the laft experiment, 
it appeared that 57 cubic inches of oxygene, 
and 2 of nitrogene had been abfofbcd, vvhilft 
21 cubic inches of carbonic acid had been 
formed. 

Now from the eftimations in the laft fedlion. 



( 442 ) 
it appears that 63 cpbic inches of osygcne are 

It"'.* > 

confumed, and about 52 cubic inches of car-> 
bpnicacid produced evei^ two minutes during the 
natural refpiration of common air. So that 
fuppofing the experiment accurate, 6 cubic 
inches of oxygene lefs are abforbed, and 30 
cubic inches lefs of carbonic acid produced 
every minute, when oxygene nearly pure is 
refpired, than when atmofpheric air is rcfpired. 

Both thefe experiments were made in the 
morning, at a time when I was in perfedl health ; 
fo that there could be apparently no fource of 
error from accidental circumftances. 

The uncommon and unexpedled nature of the 
refults, made me however, very fceptical con- 
cerning them ; and before I would draw any 
inferences, I refolved to afcertain the compara- 
tive confumption of atmofpheric air and oxy- 
gene by the fmaller quadrupeds, for which purr 
pofe, I made the following experiment. 

E. 3. Of two ftrong and healthy fmall mice, 
apparently of the fame breed, and exadtly 
fimilar. ' 



I 
I 



{ 443 ) 

One was introduce^ into a j^r cantaini«g 1<> 
cubic inches an4 half of oxygene, and 3 cubi^. 
inches of nitrogene^ and made to r^tftpn a bifi 
ofcheefe. 

The other wa^ introduced into a jar qpnt^ip-r 
ing fifteen cubic inches and half of atmofpherJQ 
air, and made to reft in the fame rpanuer on 
cheefe. 

The moufe ip oxygene began apparently tp^ 
fufFcr in about ^|(ialf an hpur, and occafion^lly. 
panted very much; in ^bot^j; ^n hour he l^y: 
down on his fide as if dying. The jar^ Wpf^- 
often agitated^ tbat th€ gafes might he well 
mingled. : i 

The moufe iq atmbfplieric ^ir became vary 
feeble in 40 minutes, and at tbe e^^d of 50 Cfti- 
nutes was taken out through the mercury aliy^-^ 
but unable to f\and. ' 

The i?3iOufe in pxygene was taken out in th* 
fame manner aft^r an ^i^ and. quarter, allve^ 
but motiiOnlefs, aqd breathing v^ry deeply, 

V 

The gas in the jars w^s examined. Th^t ip. 
the oxygene jar filled a fpace exactly equal to 



( 444 ) 

12,7 cubic inches, and analifed, was found to 
confift of 1,7 carbonic acid, 2,6* of nitrdgene, 
and 8,4 of oxygene. So that abfolutely, 2,1 
cubic inches of oxy gene and ,4 ofnitrogenehad 
been confumed, and 1,7 of carbonic acid pro- 
duced. 

The gas in the atmofpheric air jar was dimi- 
nifhed nearly to 14,4, and confified of 2,1 car- 
bonic acid, 1,4 oxygene; and 10,9 nitrogene. 
Sp that 2,7 of oxygene and ,5 of nitrogene, had 
been confumed by the moufe ; and 2,1 of car*, 
bonic acid produced. 

Hence it appears, that the moufe in atmof- 
pheric air confumed nearly one-third more oxy- 
gene and produced nearly one-fourth more 
carbonic acid in refpiration in 55 minutes^ than 
the other in an hour and quarter in oxygene.^ 
And if we confider the perpetual diminution of 
the oxygene of the atmofpheric air ; from which 
at lad it became almoft incapable of fupporting 
the life of the animal ; we may conclude, that 
the quantity of oxygene confumed by it^ had 



.* •- I ^ 



( 445 ) 

the air been perpetually renovated, would have 
been much tnorc confiderable, 

I defign very fhortly, to repeat thefe experi- 
ments, and to make others on the comparative 

confumption of,oxygene and atmofpheric air, 

• •. ' • * 
, by the larger quadrupeds. Whatever may be 

the refults, I hope to be able to afcertain from 

them, why pure oxygene is incapable of fup- 

porting life. 

VIII. Obfervattons on the changes effe&ed 
in the blood, by atmofpheric air and oxygene. 

From the experiments of Mr. Cigna and Dr. 
Prieftley,* it appears that the coagulum of the 
venous blood becomes Aorid at its furface when 
expofed to the atmofphere, though covered and 
defended from the immediate conta6l of air by 
a very thick ftratum of ferum. 



* Dr. Priettley found that it likewife became florid at 
the furface when covered by milk 5 but that it underwent 
little or no alteration of color under water and moft other 
fluids.— Vol. 3. p. 372. 



( 446 ) 

ttencc it Is evident, thut fcrum is capable of 
diflblving either the whole compound atmofphc- 
ric air, or the oxygcne of it. 

Suppofing what indeed is nioft probable from' 
numerous analogies, th^t it diflblves the whole 
compound ; it would follow, that the coloring^ 
of the coagulum of blood under ferum, depended 
upon the dccompofition of the atmofpheric air 
condenfed in the fcrum, the oxygene-f* of it 
combining with the red particles, and the nitro- 
gene cither remaining diflblved in the iBuid, or 
being liberated through it into the atmofphere. 

Now the circulating blood conlifts of red par- 
ticles, floating in and difFufed through ferunr 
and coagulable lymph. 

f There are many analogous decorapofilions. Dr. Prieftlej 
noticed (and I have often made the obfervation) that green 
oxide of iron, or the precipitate from pale greco fulphate 
of iron by cauftic alkali, became red at the furface, when 
covered by a thick flratum of water. In my experiments on 
the green muriate and fulphate of iron, I obferved that part 
of fome dark oxide of iron which was at the bottom of a 
trough of water 9 inches deep, became red at the furfacc 
nearly in the fame time as another portion of the fame preci- 
pitation that was expofed to the atmofphere. This oxyge- 
nation mufl depend upon the decompofition of atmofpheric 
air coniilantly diflblved by the water. 



( 447 ) 

In natural refpiration, the red particles are ren- 
dered of a brighter tinge during the paflage of 
the blood through the. ptihnonary veins. And 
as we have feen in the laft fedions, during ref- 
piration atmofpheric air is decompofcd ; all the 
oxygene of it con fumed, apparently a fmall 
portion of the nitrogcne lofl, and axonfiderable 
quantity of carbonic acid produced. 

It feems therefore reafonable to fuppofe, that 

the whole compound atmofpheric air paffing 

through the moift coats of the veflfels is firft 

diffblved by the ferum of the venous blood, and ia 

its condenfed ftate, decompofed by the affinity 

of the red particles for its oxygene ; the greater 

part of the nitrogene being Kberated unaltered ; 

but a minute portion of it poffibly remaiaing 

condenfed in the ferum and coagulable lymph, 

and paffing with them into the left chamber of 

the heart. 

From the experiments on the refpiration of 
nitrous oxide and hydrogene, it appears that a 
certaia portion of the carbonic acid produced in 
i?efpiration, is evolved from the venous blood ; 



y 



( 448 ) 

but as a much greater quantity is generated 
during the refpiration of common air and oxy- 
gene, than during that of hydrogcnc in equal 
times, it is not impoilible but that fome portion of 
it may be formed by the combination of cbarcoai 
in the red particles with the oxygene diflblved 
in the ferum ; but this can only be determined 
by farther experiments. 

Suppofing that no part of the water evolved 
in folution by the expired gas of common air is. 
formed immediately in refpiration, it will follow 

9 

that a very confiderable quantity of oxygene 
muft be cotiflantly <ro;«Ww^^ with the red par- 
ticles, even allowing the confumption of a 
certain portion of it to form carbonic acid ; for 
the carbonic acid evolved, rarely amounts td 
more than three fourths of the volume of the 
oxygene confumed. 

Perhaps the ferum of the blood is capable of 
diflblving a larger quantity of atmofpheric air 
than of pure oxygene. On this fuppofition, it 
would be eafy to explain the fmaller confumption 
of oxygene in the experiments in the laft (edlion. 



( 449 ) 

IX. Ohfervatiom on the refpration of Nitrous 

' » ' _ • • • , . ..I- 

Oxide. 

• < - . . . t ., . ' ♦ 

a 

The experiments in the firft Divifion of Ihiaf 
Refearch^ prove that nitrous oxide when refpired 
by animals^ produces peculiar changes "xt their 
blood and in their organs, firft con nedled. with 
increafed living aSion ; but terminating m 
d^ath; ... 

'From the experiments in this Divifion, it 
appears, that nitrous oxide is rapidly abforbed 
by the circulating venous blood, and of c6ui'ie 
its condenfed oxygene and nitrogene diftributed 
in the blood over the whole of the lyflem. 

Concerning the changes effected in the prin- 
ciples of the impregnated blood during cirfcula- 
lion arid its adlion upon the nervous andmufcular 
fibre ; it is ufelefs to rcafon in the prefent ftate 
of our knowledge. 

It would be eafy to form theories referrmg / 

the a(5lion of blood impregnated with nitrous 

oxide, to its power of fupplying the nervous and 

liaufcular fibre with fuch proportions of conden- 

Ec 



J 



( 450 ) 

fed niux>gene^ oxygene and light or etberial 
flqidy as enabled' tbem more rapidly to paCs 
through thofe changes which conftitute their 
Kfe : but fucb theories would be only coUe^Slious 
of terms derived from known phaenomena and 
applied by kx>fe analogies of language to un- 
known things* 

We.are unacquainted with the compofitiod 
of dead organifed matter ; and new inftf uments 
of experiment and new modes of refearch muil 
be founds before wo can afcertain even our 
capabilities of diicovcriug the lawa of life. 



V 



/ 



r 



RESEARCH IV. 

RELATIir(3 rb ¥HB 

EFFECTS PRODUCED BY THE RESPtRAtlON 

of 

NITROUS OXIDE 

vroN oirnuHT 
INDIVIDUALS. 



J 



* ' 1 



i ' 



*.->♦ 4^' • 



^^'T99^7^ i 7TfTf^^ it» '^^T^fVfr'^?^^ 



f 



' // ^tH" • -U -J-Mi ...1 .f ■•(•;• '^^ h''* 

i. . RESEARCH, IV. . . . 

« 

THE EFFECTS 

PRODUCED BY THE 

•' RESPrRAT«5N tor NiTRObS OXIDE. = 'I 

, • ' • • • , 



. ! ; 



titStORlt of the DiSi^rikir^.J-Eff't^g-^ddMtat^ 

A* • r . r 

SHORT time after I began the itudy of 

Chebiiftry, in March 'l798/rir)y atterttion witf 

diredled to the dephlogifticated hitroiis gas of 

The fallacy of this Theory was fbon (lemon- 
ftrated, by a few coarfe. experimentis tnade on 
Imall q^aantif les of the gas procured from zinc 

^ * Dr.' !W&^(dttll Attempted Ito pirote Aoto fbnfe^JhottOmtP 




blcefidte when refpireddij^aniiiisda io tbe miQutcft yirotiiAy 
#r even when i^pplif 4 tp t)^ ^n pr coufculat 6>yc. ^ . , 



( ^4) 

AiiA ifittttod AitrMs aekl. ' Wotmds were npo* 
fed to its a£tion^ the bodies of animals were 
immerfed id it' without injury ; and I breathed 
it mingled in fmall iquantrtles with common air, 
without remarkable eSedls. An inability to 
procure it in fiifficient quantitiofl^ prevented me 
at this time^ from purfuiog the experiments to 
any greater extent. I eomimiiucated an ac- 
•mat of tbem to Dr^ Beddoes. 

In 179^> iny fituation in the Medteal Pneu-t 
ipatic; In^itu^ionj^ m^Q it my duty to inveAK* 
gate the phyliolo^cal effods of the aqriforiQ^ 
^uidSjt the properties of which prelented i| 
chance of i^&ful «^qqc^* j^t this, pQrlo4 1 1^ 
commenced the inveftigatioi]^ 

A confiden^ble time elapfed before | wai^ 
able to ^rQcijire the ^as in 4 iiate of purit;|^,,an4 
my firfl: experiments were made on the mixtures 

qC mtXQM^ 9u4^ aitrqgeoe and pip^qiaB,rgiiSr 

#lkieii «re pradwocfd ^or^ Met^e i^AkilwMw 

1^ ih^ bcigiiinipg oi'lVf arebj. I prepared ti?f^ 

trous folation bfzihc. Of thi^ I'dfteii bi^the^ 



( 456 ) 

(he quantiti^ of a quart and t^o <|ttarts gehe- 
rally mingled ^ith more than e<}ual part^ of 
oxygfche or Common air. Iti thi tnoft debifit^ 
of tbofe trials; its eftb6t$ apf)ear6d tb b^ di^^eC^ 
fitig, andl iM^giaed that it piio^uced a tw^ 
dency to fainting : th^ pulfe was eertmoly 
rendered flower Under its opea^alion. 

At this time, Mr. Sdtithey l«(i)iHid it in an 
bighly diltfted ftati^ ; it oceafiofied a Atgbt degrbt 
of giddinefs, and coniideraMy diminiAted tbt 
t^tticknefs of hi6 palfe. 

Mf ; e. Cdatei KkAwifc refpifed it highly dfla+ 
ted, t^ifh finiilar cfffet*l*. 

Tn A^ril,' I ebtai^ed httrbitS «xide 4ft ^ Hiiti 
tf purity, ind afeertatned many of its dbt^cal 
ptbpiehi«s. Re^l66liorfsupbh thc^e prbperfiefc 
andiij^ thfe ibrmer (ri^^ ^d« tnt t€foUt th 
endeavour to infptre it in its ptr& fbtthj fyt I 
&w fttt^htf Way in which 16 tt^ltilt^hy^ br 
^b^v^M cMldf be deterfr^ 






* I did not attampt to experiment upoo animals, becaafe 
t&ey die ntarl^ in equal times in noh-reipiraDli gafes, arid 
gafes incapable of fupporting ]£fe koA pMoiksd ^ xto 
a6tion on the venous blood. 



( 4S6 ) 

I was awarC'Cf tb'e danger of this ^Kperimeiit^ 
It certainly: 4i^oii}d oe^r have been made if the 
hypoik^fis ef X^, Mitchil) b^d.jn tholeai^iofiu- 
enced my mifui«i - I tbougbt that the efFc6)^ 
qiigbtl>efpom]^lydepreffing and paiofal ^ but t beiiei 
wei^ many reafofi;9 which. induGe4 nne to. beli^^yg 
that a lingle.m^iration of.a^g^a^.isapparcQtly 
pofleffipg no irnmediate adlion outhe irfitable 

fibre^ Q0ul4 n^i^^^ ^^Afpy :^r ™a.t^>^i'y injure 
' the powers of life. . . ♦. 

On April 1 itb^ I made the firfl rnfpiration of 
pure nitrons oxide; it pailed through .-the 
bit>nchia without (liniulating the glottis, and 
produced.no uneafy feeling in the lungs. 
^ The refult of this experiinent^ proved that 
th^ gas was refpirable, andrin4uced me lo I^- 
Meve that a farther trial of its efFedis might., be 
made without danger^ .. •,.. 

•V On April l6th9 Dr. Kinglake being acqideat^ty 
prefent, I breathed three quarts of Qitro^s <>Mr 
ide from and into a lilk bag for more than half 
& minute^ without previoufly clofing my nofe or 
^xbaufiing my lungs. 



• ■. a 



Ti)e firft ipfpiratioi»,(^c^fioned ai][ijg;bt degr«|«; 
pfgiddiqefs. ,i This w,as fuccie^<|1^.4 py m,j^- 
common feofe of fuln^fei :Qfr,tbj5, -head, . acqpiiv- 
panied'With lofaof diftioxj^ fenfation and^vplun- 
tary ppwer^a feeliog^anslpgous ^P that produced 
,in tblQ firil il^geofintoKication : but unattendec} 
by pleafurabk/enfatigo. Dr. |^ip|;lake, who felt 
my pulfe^ infprmed me that itwas ren^d^red 
quig}cer:^ndfMller.. ....,, /.....» 

This, trial did not , Satisfy roe with regard 
to its powers; comparing it with, the former 
on^s , I was . unable to dg^erjqfiine whether ihe 
c^eratipn .wa8.ftjmqlant„0it dei^e^flSlpg, .. ,.^. ,. 
. I communicated; the refuU tOrPr. Beddo^s« 
and on April , the 17th>. h,^ was. preftnt, , when 
the fpUpwing experiinen.t. \v9g.n),adc ^ .... 

Haying. prcyiouilyf;l^c<J.[.njy nQlJrih^,and 
e:d)au(led my lungs. I breath^ four quarts of 
nitrws O)fcid0 .from, and i^tp. f J^l^^. J^^^^ | Jhe 
firft feelings were iimilar to thofe produced in 
theilaft.cjsp^rippient; b»t ii>.le6,.than^ half a 
ttiiriute^ thb risfpirafion "beityg 'coiiitinue^ they 
diminifhed gradually, and,wer^£i^'ee^^^ 



t 



458 ) 

tedMibh aktb^m to gentle pteflllit on al) the 
miifcles, attended by an higbly pleafar^ie 
ibrilting, particularly in the cbeft and the tx- 
irkmiiiei. Hie <ibjt3ii aroand tat bieeainii 

» r 

. daz^ltbg and my tte^iti^ more acute, towierda 
the laft infpihitidns, the thrillhig Incrttifed; 
tbe fenfe of iiiuf&ular pdwer b^cAitte grtaker, 
iBnd at laft ^n itteftftible pfopedfity to tt&ion y^k 
indulged in ; I recoiled but indlftini^ly what 
'fbltewed; I khdw thdt my motibnft Werie V&0- 

^ 6u8 and violent. 

iTbefe f&s&iv^ibtib eeafed after re^'^trour. 
In ten mimites, I hiid t^ebvered my tiatut^ ffiate 
Of mind. The thrilling in the eittaMifies, 
continued loH^er than the othet fenfaticm^.* 

This experiment was made in the tudrtAttgi. 
no languor or eihauftion was edUfequent, iny 
feeliUgS througfaoot tl^e d^ were si iifbti, 
and I paflEedttie night iu un^llctrbed I'epitffe. 

• ■ • . • 

^ . * Tk. tieddcieslkrg^en Mae gdcoont bfitfir c j i^ i cat Ai, 
^Vb Jffeticp of Ibino otik^s/^m iDtfde* at :the ,i|^difii4 
Pneomadc Inflitation. It was noticed, in Mc Nichollba's 



JNul./oahal^laylj'g^. 



, ( 459 )' 

The next morning the recohe<%iOQfi dt \ii% 
effedls of the gas were very indiftindl,. and haA" 
not remarks written immediately after the expe- 
rimeni: recalled tliem to my tnihd, I flibiil^ 
have even doubted of their reality. I was wii'^ • 
ling indeed to attribute fome of the ttrong etho-' 
fion to the erithufiafm, whicli 1 fuppofed itiiitt' 
have been neceflarily conne^ed With the per- 
ception of agreeable feelings, wheh I was j)re-' 
pared to experience painful fenfations. 'Twa 
experiments however, n^ade in the cdurite iHr 
thbday, vinihtcGptitta, cdmmbe^ mt ffiit iM 
cflfeflf'' were folely owing To the' fpecific operi- 
tfonoftfegas.' * 

In each of them I breiithed fiv6 qtiartd df 
nitrous oxi()e Ifor rather a longer lime ^fian 
befbre/"'1rhe*fen^tiong p were lihfithV,* 

perhaps not quite fo ple^furable ; the Aufdlw 
motions wert much lefs vibtent. 

Having thus afcertamccl the powers *? ^S 
gas, I'ma'd^e many experiments' to afcertain Hne 
length of time for which it migfet tie brea^n^ 
with i&ffety, ifs*^effe6l« on the" pulfe, arid its 



geperal effe6U pi^^ the health, wb^n often roi^ 

PW^ed- . . . ■ , , . . » 

I found ^bat I could breathe nine quarts of. 

qitrpus pxide for three mjnqtes^.and, twelyct^ 

quarts for rather more than ^ four. I could. 

never breathe it in any quantity, fo long as five 

minutes. Wbeneye^.its oper^itiop was carried 

tothehigheft extent, the pleafurable thrilling 

at its height about the middle^of the experiment. 

gradually diminilhedj^ the fenfc of prefTure on 

^ tbe mufcles was loft ; imprelHons ceafed io be 

perceived;, vivid, ideas pafted rapidly through. 

tl^e mind, and voluntary, power was altogether 

I r 

deftroyed, fo that the mouth-piece generally 
dropt from my unclofed lips, . -, ^ ' 

Whenever the gas wasjn a high.ftate of pu- 
rity, it tafted diftindlly fweet to the tongue and 
palate, ^nd had , an agreeable pdor. I often 
thought that it produced a feeling (bmewhat 
^jialpgous to tafte, in its application. to my lungs. 
In one or two experiments, I perceived a diftindl 

fcnfe of warmth in my cheft. 

.* • ■ ■ ■' • . " • ■ . 

^,1 never felt froni it any thing Ijke oppreifiye 

' * 1 - r • ' 



\ ^ 



( 461 ) 

refpiratiM : my- ibfpiratibn^ bcK^tne deep Ift 
proportion as I breathed it lon^r; but ttitii 
phaenomenon arofe frbm increafed energy of the 
xnufcles of refpiration, atifd'from af defirie ofiiif 
creafihgthe pleafurable feelings;' * ' ' ;•' ' 

Generally when I breathed from fix to fev^n 
quarts^ mufcular motions were produced to ^ 
certain exteht ; fometimes I manifeiled my 
plcafurc by "ftamping or laughirtg only i at dther 

timc», by dancing round the room and vocife- 

... ..'••% 

ratmg. • • .• i . r : ; , 

Aftdr the refpiration of fit^aM dofes, 4he 
cxhiliratidn generally lifted for five or fix 
minutes only. : In one 'or two experiments 
when ten quarts had been breathed for near four 
ininutes^ an exhiliration and a feiK^fe of flight 

• » - . ^ 

Intoxic^ation lafted for two or three hours. 

Oh=May3d. To afcertain whether the gas 
would accelerate or retard thfe jprogrefs of fleep, 
1 breathed at about 8 o'clock in the evening, 

w 

25 quarts of nitrous oxide, in quantities; of H% 
at a time, allowing but (hOrt int&fvals betw^ei 
each dofe. The feelings were much: Iqfs'pleafti*- 



nhh tbao^ nfiial^i and during the coofooiptiQa 
of the twp;l^ dofe, almost indaffereut ; indeed 
Ibe gas waa breathed rather too loon after ita 
]m>dtt£lioQ» aiid contaUied fome fuipc Qded acid ^ 
vapour which ftiauikUed the lung& ib as to induce 

CWghlDg. 

Jlfter the experiments, ibr the firft time I waa^ 
fonewkat deprefled and debilitated; my pro^ 
panfity to fleep however^ came on at the uiiaal 
hoiir, and as u£pal was indulged in» my repoft 
was ibund and unbroken. 

Between May and July, I habitually breathed 
the gas, occafionally three or four times a day 

V 

for a week together ; at other periods^ ibur or 
live times a week only. 

The dofes were generally from fix to pine 
quarts ; their efie^ls appeared undiminiihed by 
habit, and were hardly ever exadUy fimilar. 
Sometimes' I had the feelings of intenfe intoxi* 
cation, attended with but little pleafure; at 
other times, fublime emotions connedled with 
liighly vivid ideas ; my pulfe was genen^ly in- 
oreafed in fulneis> but rarely in velocity. 



( 463 ) 

The g«ner|il effed* ^f iitk open^ion lifmi lny 
benltb Aod, (kate of mifidi er^ Q^tiHUely diffittult 
of defecipttoa ; nor o^q I w^U dtfcrinutnite W 
tween il« agency aod that of otter pkyfioal ati4 
mordl caufta. 

I fl^pt much lefs than ufual^ and previoust- to 
fieep5 mj; mind was long occupied by vHible 
imagery. I bad a oonftaat defire of a(Sitoii> a 
reftleifnefs^ 9od ao uneaiy ^liiQg atout the 
jpr^cordia analpgoi^^ to the fij^kncis of hopt^. 

Bat perhaps tbefe phaenoivena in fome meat- 
fdre diepended on the tntereil and labour cottr 
ne^ed with the experijQientai inwftigatton ref- 
lating to th^ pi!odu<5^iion of ailroua oxide, by 
which I was, at thiatime ineefleniUy occupied. 

My appetite waa as ufua)^ and my pvifo, not 
materially altered^ Sometimes for aii boar after 
the infpiration of the gas, I expc^ieuced a fpe^ 
cies of mental indolence* pleafing rather than 

• • 

♦ MiM phyflcial jJleafure is perhaps always deftru^tive to 
•AiQDk. Almo^ajit.oar poworful voluntary adions^ arife 
either froiQ hoge, fear^ or 4efire ; and the moft powerful 
from defire^ which is an^motion produced by the coalef- 
ceaoe of hope q& ideat pleaihre .with phyficfd pain. 



( 464 ) 

otherwife; and never ending in Itftlefnefs. 
' Dbring the' laft* week in which I breathed il 
unifOi^mly, I imagined'tbat I had increafed' (en- 
iibility of touch : my fingers were pained^' by 
any thing rough, and the tooth edge produced 
from (lighter caufes than ufual. I was certainly 
more irritable^ and felt more < acutftly froni 
trifling circumftanc^B. My bodily firength 
was rather diminiflied than increafed. 

At the latter end of July, I left off my ha^ 
bitual : courfe of refpiration ; but I continued 
occafionally to breathe the gas, either tor the 
fake of enjoyment, or with a view of afcertain- 
ing its operation under particular circuifiilances. 

In one infiance, when I had head* ache from 
indigeflion, it was immediately removed by the 
effects of a large dofe of gas ; though it after- 
wards returned, but with much left violence. In 
a fecond inftance, a flighter degree of headache 
was wholly removed by two dofesof gas. 

The power of the immediate operation ot' 
the gas in removing intenfe phyfical pain, I 
had a very good opportunity,of afcertaining. 



^ ( 469 ) 

}ti cutting one of the unlucky teefh called 
dentes fapientiae^ I experienced an extenfive 
inflammation of the gum, accompanied with 
great pain, which equally deftroyed the poweif 
of repo(e, and of confident adtion. 

Oo the day when the inflammation was mofi* 
troublefome, I breathed three large dofes gi^ 
nitrous oxide^ The pain always diminifhed 
after the flrft four or five infpirati'ons ; the t*hril- 
ling came on as ufual, and uneafinefs was for a 
few minutes, fwallowed up in pleafure. As the 
former ftate of mind however returned, the 
Aate of organ returned with it; and I once 
Imagined that the pain was more fevere after 
the experiment than before. 

In Augufl, I made many experiments with a 
view of afcertaining whether any analogy exifled 
l)etween the fenfible efFe6ls of the different ga* 
fes which are fooner or later fatal to life when 
refpired, and thofe of nitrous oxide. 

J refpired four quarts of Hydrogene* nearly 

* Pare hydrogene has been ofteo relpired by different 
fhiloibpfaers^ psrticularly by Scheele^ Fontana> aosd tho 
^veotUTOus and unfortunate Rofier. 

Ff 



( 466 ) 

pure produced from zinc and muriatic acid^ for 
near a minute, my lungs being previoufly ex- 
hapfted and my noftrils carefully clofcd. The 
firft fix or fcven infpirations produced no fenfe- 
tions whatever ; in half a minute, I perceived » 
a difagreeable oppreffion of the chcft, which 
cAliged me to refpire very quickly ; this op- 
preffion gradually increafed, till at laft the pain 
of fufFocation compelled me to leave off breath- 
ing. I felt no giddinefs during or after the 
experiment ; my pulfe was rendered feebler and 
quicker; and a by-dander informed me that 
towards the laft, my cheeks became purpl<e. 

In a fecond experiment, when the hydlro-i* 
gene was procured from iron and diluted ful- 
phiiric acid, I was unable to refpire it for fo 
long as three quarters of a minute ; a tranfient 
giddinefs and mufcular debility wqre produced, 
the pulfe was rendered very feeble, and the pain 
of fufFocation was greater than before. 

I breathed three quarts of Nitrogene mingfed 
\vith ,a very fmall portion of carbonic acid, for 
near a minute. It produced no alteration in 



( 4^ ) 

my fenfatiotis for the firft twenty feconds ; then 
the painful fenfe of fafFocatton gradually cain6 
an, and increafed rapidly in the laft quarter of 
the minute, fo as to oblige me to deiid froiiii 
the experiment, jyiy pulfe was rendered fecWer 
and quicker. I felt no aflfeflion whatever ia 
the head. 

Mr. Watt's obfervattotifs on the refpiratfoa 
of diluted Hydrocarbohate by men, and !>• 
Beddoes's experiments an the deftriidlion of 
animals by pure hydrocarbonate^ proved tl^t 
its efFe6ls were highly deleterious; 

As it deftroyed life apparently by renderinj^ 
the mufcular fibre inirritable without prodticirigf 
iny previous excitement, I was anxious to coin- 
pare Its fenfible efFc6!s with thofe of nHrout 
oxide, which at this time I believed to deftro/ 
life by producing the Wgheft poffible excite* 
ment, ending in lasfion 6f organifation. 

In the firft Experiment, I breathed for near 
a minute, three quarts of hydrocarbonatd min- 
gled with nearly two quarts of atmfdfpheric air.* 

* I believe it bad never been breathed before by »&/ 
iodivldiial^ in a ilate fo little diluted. 



( 468 ) 

It produced a flight gtddinefs and pain iir the 
bead^ and a momentary lofs of voluntary power ^ 
my pulfe was rendered much quicker and feeb- 
ler. Tbefe efFedls however, went off in five 
minutes, and I had no return of giddinefs. 

Emboldened by this trial, in which the feel- 
ings were not unlike thofe I experienced in tb& 
firft experiments on nitrous oxide, I refblved 
to breathe pure hydrocarbonate. 

For thi^ purpofe, I introduced into a filk bag, 
four quarts of gas nearly pure, which was care- 
fully produced from the decompofition of water 
by charcoal an hour before, and which bad a 
V«ry ftrong and difagreeable fmell. 
. My friend, Mr, James Tobin, Junr. being 
prefent, after a forced exhauftion of my lungs, 
the nofe being accurately clofed, I made three 
ijnfpirations and expirations of the hydrocarbo- 
nate. The firft infpiration produced a fort of 
numbnefs and lols of feeling in the cheft and 
about the pedloral mufcles. After the /fecond 
infpiration, I loft all power of perceiving exter- 
nal things^ and had no diftind fenfation except 



(469) 

a terrible oppreffion on the cheft, Dtlring thfc 
third expiration, this feeling difappeared, I 
feemed finking into annihilation, and had juft 
power enough to drop the mouth-piece from my 
unclofed lips. A fhort interval muft have pal^ 
fed during which I refpired common air, before 
the obje6ts about me were diftinguifhable. On 
recollecting myfelf, I faintly articulated, " / do 
not ibink I Jball die.^* Putting my finger oh 
the wrift, I found my puMe tbread-!ike and 
bedtihg with excei7!v6 quibknefs. 

In lefs than ^ minote, I was able to ^alk, and 

> 

the painfiri oppreffion on the cheft direfted mef 
to the opeti air. 

After making a few ft^ps which carried trie to 
the garden, my head became giddy, my krtees 
trembled, and I had Juft fufficient voluntary 
power to throw myfelf on th& grafs. Here the 
painful feeling ofthe cheft incrtjafed with fuch 
Tioledce as to threaten fuffotation. At this 
moment, lalkdd for fome nitron^ oxide. Mr. 
£>wy^ brought nae a mixture of oaygene and 
Ditrous oxide. I breathed this for a minute, and 



( 47Q ) 

ImU^vid myfelf relieved. In five minutes^ the 
painful feelings begap gradually to diminiih. 
In an hour they h^A nearly difappearedi and I 
felt only exceffive weaknefs and a flight fwim-- 
ming of the head. My voice was very feeble 
and indiftiniSl. This was at two o'clock in the 
afternoon. 

I afterwards walked ilowly- for about half an 
liour^ with Mr. Tobin^ Junr. and on my returo, 
was io much flronger and bettCFj as to believe 
that the efFedls of the gas had difappeared \ 
though my pulfe was 120 and yeiy feeble. I 
continued without pain for near three quarters 
of an hour ; when the giddinefs returned with 
fuch violence as to oblige me to Jie on the bed ; 
it was accompanied with naufea, Ipfe of me^ 
xnory, and deficient fenfatioo. In about an 
hour and half^ the giddineft went ofi^ and was 
fucceeded by an excruciating pain in the fore** 
head and between the eyes^ with tninfient 
pains in the cheft and extremities^ 

Towards night tbeie afiedkms gradually dimi* 



( 471 ) 

t 

aiflied. At ten,t no difagreeable feeling ex- 
cept wenknefs remained. I flept (bund, atld 
a\voke in the morning very feeble and very 
hungfy. No recurrence of the fymptoms took 
place, and I had nearfy recovered my ftrength 
by the evening. . ^ 

I have been minute in the account of this 
experiment becaufe it prbves, that hydrocarbo- 
Hate a(3s as a fedative, i. e. that it produces 
dirhinutiort of vital adlion, and debility, Withot/t 
previoufly exciting. There is every reafoti to 
befiev^e, that if I had taken four or five infpffS^ 
tions inftead of three, (h6y wotrtd have deftroyed 
life hfim6diatefy withotrf producing any pairifol 
^ehfafion. Perhaps moft of the unea'ty fedings 
after the experimthtf, weie connected with the 
retd'rri of the healthy condition of 6rgan€.* 



f I ought to obferve, that between eight and ten, I took 

by the advice of Dr. Beddoes, two or three doles of dilute^ 

# ■ . • 

nitric acid. 

** By whaterdt iianfii the exhaUftion of organs is prodii- 
,ce^, pain is aimolt.utiiformly. connedted- with their return- 
ing health. Painis rarely ever perceived in Umbs debilitate^ 



( 472) 

About a wedL after this experiment, I at^ 
tempted to refpire Carbonic acid, not being at 
the time acquainted with the experinnepts of 
Rofier, ' 4 

I introduced ipto ^ iilk bag four quarts of 
well wafhed carbonic acid produced from carr 
bonate of ammoniac* by heat, and ^fter a 
compleat voluntary exhauftion of my lungci^ 
attempted to infpire it. It tailed ftrongljr aci4 
in the mouth and fauces, and produced a fepifs 
of burning at the tpp of the uvula. In vain | 
made powerful voluntary efforts to dr^w it int0 
the \^indpipe ; at the ipoment that the epiglottis 
was raifed a little, ^ painful Simulation was in- 
duced, fo as to clofe it fpafmodically on. tb^ 
glottis ; and thus in repeated trials I was prcr 
vented from taking a fingle particle of c^rboni^ 
acid into my lungs. 

by fatigue till after they have been for fome hours at re!^ 
Pain is uniformly conneded with the recovery from the 
debility induced by typhus^ often with the recovery froii^ 
that produced by the ftimulation of opium and alcohol. 

* Carbonic acid is produced in this way in a hi^h ,ftat# 
f^ parity, and with great readineft* 



( ^7% ) 

1 tried to breathe a mixture of two quarts of 
joommoil air and t^rtt of carbonic acid^ without 
^ucc^fa ; it ilimulated the epiglottis nearly in 
Ihe fame manner as pure carbonic acid^ an^ 
was perfe<Slly non^refpirable. . # 

I found that a mixture of three quarts of car- 
bonic acid with feveo of common air was refpi* 
jrable^ I breathed it for near a minute. At the 
time^ it produced a flight degree of giddinefi, 
:and an inclination to fleep. Thefe effedts how- 
4sver, very rapidly difappeared after I had ceafed 
|o breathe^^ and no other affedltons followed* 

•I 

During the courfe of experiments on nitrous 
oxide^ I ieveral times breathed Oxygene procu- 
red from manganefe by heat, for from three to 
five minutes. 

In refpiring eight or ten quarts ; for the firfl: 



* Carbonic acid poflTeffes no adion -on arterial blood. 
Hence perhaps^ its flight effedts wl^ieu breathed aiipgled 
with large quantities of common air. Its eiSsds are yerj 
fnarked upon yenous blood ! If it were thrown forcibly 
into the lungs of animalji^ the momentary application of it 
JU> ti^ pulmonary yenous blood would probably dedroy lif^. 



(474 ) 

f WO or three minates I could perceiye no effedtl 

Towards (he end, even whan I breathed vefy 

flovfly, my refpiratton became opprefled, and 

I felt a fenfation analogous to that produced hf 

t^e want of frefh air; though but little of the 

oxygene had been confumed.' 

% 

In one experiment when I breathed from and 
into a bag containing 20 quarts of oxygene for 
near fix minutes ; Dr. KingUke fe!t my putfe, 
and found it not altered in velocity, but r&,ih& 
harder than before. I perceived no efiedis but 
thofe of opprefiion on the cheft*. 



* In a conversation with Mr. Watt, relating to tbc pow- 
ers of gafes, that excellent phUofopher told me he had for 
fome time entertained a fafpicion, that the eifeds attribu- 
ted to oxygene produced from manganefe by heat, in fome 
meafure depended upon nitrous acid fufpended in the gas, 
formed during ignition by the unipn of fome of the oxygene 
of the manganefe with nitrogene like wife condenfed in it. 

In the courfe of experiments on nitrous acid, detailed in 
Befearch I. made in September, OAober, and December, 
^?99> I feveral times experienced a fevere oppreflion on the 
cheft and difficulty of refpiration, not unanalogous to that 
produced by oxygene, but much more violent, from 
breathing an atmofphere loaded with Citrous acid vaponr. 
This fad'feemed to confirm Mr. Watt's fufpidon. I con* 



(475) 

Hftl^ing obferved in my experimeats upon 
venous blood, that Nitrous gas rettdered that 
^yAd of a purple tinge> very like the color 
generated in it by nitrous oxide ; and finding 
no painful effeSs producqd by the application 
of nitrous gas to the bare mufcular fibre, I 
begi^n to imaginelbat this gaa might be breathed 
with impunity, provided it were pollible in any 
way to free the lungs of common air before in- 
fpiration, (6 as to prevent the formation of 
nitrous acid. 

On this fuppofition, during a fit of enthufi- 
afm produced by the refpiration of nitrouA 
oxide, I reibjved to endeavour to breathe 
Nitrous gas. 

114 cubic inches of nitrous gas were intro- 
duced into the large mrercurial airbolder ; t^^o 



fefs, however, that I have never been able to detc^ any 
lisiell of nitrous acid, either by means of iny own or- 
gans or thofe of others, during the produ^ion of oxygene : 
when the gas is fufiered to pafs into the atmofphere. 
The oxygene breathed in the experiments detailed in tlie 
lext^ had been for fome days in contift with water. 



« 



(476) 

finall (ilk bags of the capacity of fevto quarts 
were filled with- nitrous oxide. 

After a forced exhaufiibn of my longs, irfy 
nofe being accut^tely clofed, I madie three ia- " 
fpirations and expirattoas of nitrous oxide in 
one of the.bags, to free my lungs as mucli as 
poffible fratn. atmofpheric oxygene ; then^ after 
a fuUexpirationtif the.nitrous oxide^ Itransfeired 
my mouth from the mouth-piece of the bag to 
that of. the. airholder, and turning the fiop- 
cock^ attempted to infpire the nitrous. gas.— • 
In paffing through my mouth and fauces^ it 
tailed allringent and highly difagreeable ; it 
occ^oned a fenfe of burning in the throaty and 
produced a fpafm of the epiglottis fo painful as 
to oblige me to defift inflantly from attempts 
to infpire it. After moving my lips from the 
mouth-piece^ when I opened them to infpire 
common air, aeriform nitrous acid was inflantly 
formed in my mouthy which burnt the tongue 
and palate, injured the teeth, and produced aa 
inflammation of the mucous membrane which 
lafled for fome haurs. 



I 477 ) 

As after the refpiration of nitrous oxide ia 
the experiments in the lad Reiearch^ a fmall 
portion of the reiidual atmoipherio air r^ained 
in the lungs^ mingled w^tb the gas^ after forced 
expiration ; it is moil probable that a roinute» 
portion of nitrous acid was formed in this expe- 
riment, when the nitrous gas was t^ken into 
the mouth and fauces, which might produce 
its ilimulating properties. If fo, perhaps I 
owe my life to the cirCumfiance ; for fup- 
pofing I had taken an infpiration of nitrous 
gas, and even that it had produced no 
politive effedls, it is highly improbable, that, 
by breathing nitrous oxide, I fhould have freed 
my lungs from it, fo as to have prevente;d the 
formation of nitrous acid when I again infpired 
common air. I never delign again to attenypt 
fo raih an experiment 

In the beginning of September I often ref- 
pired nitrous oxide mingled with different pro- 
portions of common air or oxygene. The 
efFedi^ produced by the diluted gas were much 
leis violent than thofe produced by pure, nitroua 



( 479 ) 

oxide. Tbejr were generally plea(ant i fte 
thrilling was not often perceived, but a ihnf& , 
of exhittratton was almoft conftant. 

Between September and the end of Oftober, 
I made but few experiments on refpiratioft, al- 
moft the whole of my time being devoted^ to« 
chemical experiments on the production and 
analylis of nitrous oxide. 

At this period my health being fbm^what 
injured by the conftant labour of experiment^ 
ing, and the perpetual inhalation of the acid 
vapours of the laboratory, I went into Comwal j 
where new aftbciations of ideas and feelings, 
common exercife, a pure atmofphere, Inxurious 
diet and moderate indulgence in wine^ in a 
month reftored me to health and vigor. 

Nov. 27th. Immediately after my retuvDj 
being fatigued by a long journey, I reipired 
nine quarts of nitrous oxide, having been pre* 
cifely thirty-three days without breathing any. 
The feelings were different from thofe I had 
experienced in former experiments. Aftet the 
firft fix or feven infpirations^ I gradually began 



( 479 ) 

io lofe the perception of exterrtal things^ ai!d a 
vivid and intenfe recollection of fome former 
experiments pafled through my mind, fo that 
I called out ^\what an amazing concatenation of 
ideas r I bad no pleafurable feeling whatever, 
I ufed no mufcular motion, nor did I feel any 
difpofition to it ; after a minute, when I made 
the note of the experiment, all the uncommon 
fenfations had vaniftied ; they were fucceeded 
fay a flight ibreneis in one of the arms and in 
the leg : in three minutes thefe affeftions like- 
wife difappeared. 

From this experiment I was inclined to fup- 
pofe that ray newly acquired health had dimi-' 
niflied my fufceptibility to the efFe<9s of the 
gas. About ten days after, however, I had an 
opportunity of proving the fallacy of this fupfc- 
pofitioQw 

Immediately after a journey of 126 miles, in 
which I h^d no fleep the preceding night, being 
much rabaufted, I refpired feven quarts of gas 
f6r near three mimites. It produced thef iifu^l 
pleaiurablc eftec^, and flight mufe(»lar mott<>ii. 



( 480 ) 

I continued exhiKrated for fome nrinutes ahif^ 
wards: but in half an hour found myfelf neither 
mote or lefs exhaufted than* before the experi- 
ment. I bad a great propenfity to deep. 

I repeated tbe experiment four or five time» 
in tbe following week, with fimtlar effedls. M^ 
fufceptibility was certainly not diminifhed. I 
even thought that I was more afTedted than for^ 
merly by equal dofes* 

Though, except in one inilance, when indeei^ 

the gas was impure, I had experienced no decifiTef 

exhauftion after the excitement from nitrous ox« 

ide^ yet ftill I was far from being fatisiied that it 

was unanalogous to flimulants in generaI»-^-«^ 

No experiment had been made in which the 

excitement from nitrous oxide had been kept up 

for fo great a length of time and carried to fd 

I 
great an extent as that in which it is uniformly 

fucceeded by exceffive debility under the agency 
of other powers. 

It occurred to me, that fuppofing nitrous ox- 
ide to be a ftimulant of tbe common clafs^ it 
would follow that the debility produced in con- 



( 481 ) 

fequence of exceffive Simulation by a known 
agent, ought to be increafed after excitement 
from nitrous oxide.* 

To afcertain whether this was the cafe, I 
made on December 23d, at four P. M. the 
following experiment. I drank a bottle of 
v^ne in large draughts in lefs than eight mi- 
nutes. Whilft I was drinking, I perceived a 
fenfe of fulnefsin the head, and throbbing of 
the arteries, not unanalogous to that produced in 
the firft ftage of nitrous oxide excitement. 
After I had finifhed the bottle, this fulnefs in- 
creafed, the objects around me became dazzling, 
the power of diftindl articulation was loft, and 
I w^ unable to walk deadily. At this moment 
the (enfations were rather pleafurable than pther- 
wife, the fenfe of fulnefs in the head foon how* 
ever increafed fo as to become painful, and in 



» 



* In the fame manner as the debility from intoxication 
by two bottles of wine is increafed by a third. 



Gg 



( 482 ) 

ItSfa than an hour I funk into a date of in&n(»- 
bUity.* 

In this (ituation 1 muft have rernatned for 
two hours or two hours and half. 

I was awakened by bead-ache and paiBfut 
naufea. The naufea continued evieo aA€r tbe 
contents of the fiomach had be6n eje^ed. Tk^ 
pain in the head every minute inoreafed ; I wihfr 
neither feveriih or thirfty ; my bodily and men- 
tal debtKty were exceffive, and the pulfe feeble 
ai>d quick. 

In tbis fiate I breathed for near a mttaute and 
half fiye quarts of gas, which was bfouglit to 
me by the operator for nitrous oxide ; but as it 
produced no feofations whatever, and apparently 
rather increafed my debility, I am almoft cob* 
vinced that it was from ibme accident, eitjier 
commQn air, or .very impure nitrous oxide. 

Immediately after this trial, I refpired 12 quarts 

* I ought tophfcnrctM my pfuaji.^fli^ 4ft watcj-, fhgt 
I had been little ^uftpm^ fo ,t|j^e, wjy^f^ ^ ftwM« ,w4t 
had never been compleatly intoxicated but once before in 
ttie oourfe of my life* This will account for the powerful 
eifeAs of ^ fingle bottle of wine. 



( 468 ) 

« 

of" a3tygetie fbir wear four minutes, ttpfddkicai 
«MD atteration in my fen&tioxis at the fidfie ; but 
ixhmediately after I imagined that I was a littk 
ei^hilirateGL 

The head* ache and debility ftill however 
coittinuing with violence^ I examined feme 
nitrous oxide which had been prepared in the 
mortiing^ and finding it very parc^ refpired 
feven quarts of it for two minutes and half. 

I was unconfcious of beiad-acbe after the &md 
ih(piratioii ; the uliial pleafuf^ble thrilling was 
produced^ voluntary power was deftroyed, and 
vivid ideas rapidly paflcid through Iny mind ; t 
made ftridesr acrois the rooh),^ and con* 
tinned for Ibilie roinuties much ej^bilariatedw 
Immediately after the exhilaration had difap- 
peared^ I felt a flight rdturn of the hedd*aChe ; 
it was conne^ied with tiianiient naofee. Aftekr 
two minutest when a fmall quantity of acidified 
wtne had been thrown ftom the ftomacli, both the 
naufea and hoad-acbe difappeared ;^ but latiguoH: 
anddepreiEon not very different in degree frdtft 
thofe exifting before the experiment^ fticcetded. 



( 484 ) 

They however, gradually went off before bed 
lime. I flept found the whole of the night 
except for a few minutes, during which I ^was 
kept awake by a trifling head-ache. Ihihe 
-morning, I had no longer any debiJity. No 
head-ache or giddinefs came on after I had 
arifen, and my appetite was very great. 

This experiment proved, that debility from 
intoxication was not increaied by excitement 
from nitrous oxide. The head- ache and de« 
preflion^ ibis probable, would have continued 
longer if it had not been adminiftered. Is it 
xiot likely that the flight naufea following 
the efFcds of the gas was produced by new 
jexcitability given to the ftomach } 

To afcertain with certainty, whether the 
moft extenfive a£lion of nitrous oxide compa- 
tible with life, was capable of producing debility, 
J refolved to breathe the ga& for fuch a time and 
in fuch quantities, as to produce excitement 
equal in. duration and fuperior in intenfity to 
that occafioned by high intoxication from opium 
w alcohoK 



( 485 ) 

To habituate royfelf to the excitement, and 
to carry it on gradually 

On December 26th, I was inclofed in an 
air-tight breathing-box,*^ of the capacity of 
about 9 cubic feet and half, in the prefence of 
Dr, Kinglakfe. 

After I had taken a iituation in which I could 
by means of a curved thermometer inferted 
under the arm^ and a ftop-watch, afcertain the 
alterations in my pulfe and animal heat, 20 
quarts of nitrous oxide were thrown into the 
box. 

For .three minutes I experienced no altera* 
tion in my fenfations, though immediately after 
the introdu(9ion of the nitrous oxide the fmell 
^nd tafle of it were, very evidetit^t 

In four minutes I began to feel a flight glow 



* The plan of thrs box was communicated by Mr. Watt. 
An account of it will be detailed in the B^fearcli^i, 

Tp 
*• i ," , '. 

f The nitrous oj^ide was too diluted to aft much j it 
was mingled with near 32 times its bulk of atmofpbcrit 
air. 



( 486 ) 

in the c|ieek9, and a generally difTufed warmth 
ov^r the cbeft, though the temperature of the 

I 

box was not quite 50^. I had negleded to feel 
my pulfe before I went in ; at this time it was 
104 and hard, the animal heat was £f8% In 
ten minutes the animal heat was ndar ggP, ia a 
quarter of an hour gQ.5^, when the pulie was 
,102, and fuller than before. 

At this period 20 quarts more of nitrous oxide 
were thrown into the box, and well^mingled 
with the mais of air by agitation. 

In 25 minutes the animal heat was loo^^ 
pulfe 124. In 30 minutes, 20 quarts noore of 
gas were introduced. 

My fcnfations were now pleafant ; I had a 
generally difTufed warmth without the flighted 
mcHfture of the fkin, a fenfe of exhilfration 
fimilaj to that produced by a fmall dofe of wine, 
and a difpofition to mufcular motion aod to 
merriment 

In three quarter&of an hour the pulfe was 
}04f and animal heat not 99^5^, the tempera* 
ture of the chamber was 64^. The pleafurabfe 



feeth^ c6dtinued td increal^^ the ptM!^ btcame 
fuller and flotrer, till in aboot an hour it ^as 
680, when the animal heat was gg^. 

20 (Juarts more o( air were admitted. I bad 
now a great difpb^tion to laugh, luminous points 
jfeemed fre(](uently to pafs before my eyes, my 
hearing wais c^tafifnly mofe acute and I felt a 
plsf^ant lightnefs and poWer of exertion in rtiy 
mtiifctei. In a diort time the lymptoms became 
fiationary ; breathing was rather oppretffed, and 
on account of the great defire of adlion, . reft 
was painful. 

I n6W came otot of the box, having been in 
precifely att hour artd quarter. 

The moment after, I began to refpire 20 quarts 
of uomingled nitrods o5cide. A thrilling, ex- 
tending from the cheft to the extremities was 
almoft immediately produced." t felt a fenfe of 
tangible cxtenfion highly pleafurable in every 
limb; my*vifible impreffions were dazzh'ng 
and apparently magnified, I heard diftinflly 
every found in the room and was perfeflly aware 






( 488 ) 

of my fitoation;.* By degrees as the pleafurab)^ 
fenfations increafed, I loft all conne6lion with 
external things ; trains of vivid vifible images 
rapidly pafled through my mind and were con- 
nedled with word6 in fuch a manner, as to pro- 
duce perceptions perfe6lly novel. I exifted in 
a world of newly connected and newly modified 
ideas. I theorifed ; I imagined that I made 
difcoveries. When I was awakened from this 
iemi- delirious trance by Dr. Kinglake, who 
took the bag from my mouthy Indignation 
and pride were the firft feelings produced by 
the fight of the perfons about me. My emotions 
were enthufiaflic and fublime ; and for a minute 
I walked round the room perfe6lly regardlefe 
of what was faid to me. As I recovered my 
former ftate of mind, I felt an inclination to 
communicate the difcoveries I had made during 
the experiment. I endeavoured to recall the 
ideas, they were feeble and indiftindl ; one 
colledion of terms, however, prefented itfelf: 

V 

* In all thcfe experiments after the firll minute, my 
cheeks became purple. 



( 489 ) 

isind with the mod tntenie belief and prophetic 
manner, [exclaimed to Dr. Kinglake, " Nothing, 
extfts hut thoughts !—the umverje is compofed of 
imprejjions^ ideas ^ pleafures and pains P\ ■■.. 

About three minutes and half only, had elapr 
fed during this experiment, though the tiqie as 
meafured by the relative vividnefs of the recol- 
ledled ideas, appeared to me much longer. 

Not more than half of the nitrous oxide was 
confumed. After a minute, before the thrilling 
of the extremities had difappeared, . I breathed 
the remainder. Similar fenfations were again 
produced ; I was quickjy thrown intp the plea,- 
furable trance, and continued in it longer th^A 
before. For many minutes after the cxperiipent, 
I experienced the thrilling in the extremities, 
the exhilaration continued nearly two hours. 
For a much longer time I experienced the mild 
c^njoyment before defcribed conne<5led with 
indolence ; no depreffion or f^eblenefs followed. 
I ate my dinner yvith great appetite and fpund 
myfelf lively and difpofedto adlion, immediately 
after. I pafled the evening in executing lexpe- 



»- t 



K » 



riiticiits. At nigfat I foand myfdif vftnfaMy 
Che^fnl and aAive ; and the hours between 
deveti «nd two^ were fpent in copying thfc fbre«^ 
going detail ftom the oommon^place book and 
in arranging the experimefnts. In bed I en- 
Joyed profound rcpoib. When I awoke in the 
^ morning, it w« with con(bioufne& of pleafura* 
ble etiftence^ and this c6oicioufnefi more or 
U4h, continwed throngb the day; 

Since Decefvilwr, I have very often breathed 
nitrous oxide. My fufceptibility to its power 
» rather increafed than dimini(hed« I find fix 
quarts a full dofe, and I am rarely able to ref* 
pire it in any quantity for more than two minutes 
and half 

The mode 4f its operation is fomewhat alte- 
red. It is indeed very different at different 
times. 

I am fcarcely ever excited into violent mui}- 
cular aAion^ the emotions are generally much 
leis intenfe and fublime than in the former 
experiments^ and not often conne<^d with 
thrilling in the extremities. 



(4gi ) 

Wben trimbled with indigeftbn, I have httsk 
two or three times unple^rfaiytly ^6£led lafftet 
the excitement of the gas. Cardiafljgia, ersc- 
tations and unpleafant fulnefs of the head w^e 
produced. 

I haveoften felt very great pleafure wbenbrcath-* 
ing it alone, in darknefs and iilenee^ 6ocd{>t^ 
only by ideal exiAence*/ In two or three i^rftatn 
ces when I have breathed it amidft noife^ the' 
fenfe of hearing has been paififuliy affisdled 
even by moderate intenfity of founds T^e 
light of the fun has fometitnes been diiagreeabty 
dazzling. I have once or twice felt an uiteaiy 
fenfe of tenfion in the oh«efcs and tranfictft 
pains in the teeth. 

Whenever I have breathed the gas after ex- 
citement from ' moral) or phyfieal caafe6> the 
delight has been often intenfe and fuUime. 

On May &tb» at night, aifter Walking for an 
hour amidft the icenery of the Avof», at tiM 
period rendered exquifitelyi beaiottfol by bright 
zDQonfiitoe I my mind being in^ a fiate> of 



( 492) 

I 

agreeable feeling, I refpired fix quarts of neWIy 
prepared nitrous oxide. 

The thrilling was very rapidly prodaced. 
The objedls around me were perfedly difUndl, 
and the light of the candle not as ufual dazzling* 
The pleafurable fenfation was at firil local and 
perceived in the lips and about the cheeks. It 
gradually however, diffufed itfelf over the whole 
body, and in the middle of the experiment was 
for a moment (b intenfe and pure as to abfbrb 
exiftence. At this moment, and not before, I loft 
confcioufiiefs ; it was however^ quickly reftored, 
and I endeavoured to makeaby-ftander acqiiaint- 
ed with the pleafure I experienced by laughing 
and flamping. I had no vivid ideas. The 
thrilling and the pleafurable feeling continued 
for many minutes ; I felt two hours afterwards, 
a flight recurrence of them, in the intermediate 
flate between fleeping and. waking; and I had du- 
ring the whole of the night, vivid and agreeable 
dreams. I awoke in the morning with the 
feeling of reftlefs energy, or that defire of adlion 
connedled with no definite objed, which I had 



( ^93 ) 

often experienced in the courfe of experitneiits 

in 1799- 

I have two or three, times fince refpired ni- 
trous oxide under iinHilarcirqumilances; but 
never with equal plcafure. 

-During the laft fortnight, I have breathed 
it very often ; the efFedls have been powerful 
and the fenfations uncommon ; but pleafurable 
only in a flight degree. 

I ought to have: obferved that a defire to 
breathe the gas iis' always awakened in me by 
the fight of a perfon breathing, or even by that 
of an air-bag or an air-holder, 

I have this day, «' June 5th, refpired four large 
^lofes of gas. The iirft two taken in the morn- 
ing ac^ed very powerfully ; but produced no 
thrilling or other pleafurable feelings. The 
effedls of the third breathed immediately after a 
hearty dinner were pleafant, but neither in- 
tehfe or intoxicating. The fourth Was refpired 
at night in darknefs and filence after the occur- 
reticeofa circumftance which had produced 
fome anxiety. This dofe affcded me power- 



&Mywad plealantly ; a fligfat tirriUing* in iSm 
extremities was produced ; an exhiUratioa oon^ 
tioued for fome time, and I bavie bad bat little 
return of uneafine6« 1 1 F. M. 

From the nature of the language of fe^ngv 
the preceding detail contains maiiiy imperfeo. 
tiont ; I have endeavoured to give as accaratft 
an ztosxant as poi&blc of the fbrange eflfbSts of 
nitrous oxide^ by making ufe of terms ftaodiog 
for the moft fimilar common feelings. - 

We are incapable of recollecting jdeBfiires 
and pains of icnfe.* It is impoffible to reafon 
concerning them, except by means of terms 
which have been ailbdatod with them at the 
moment of their exiftence, and which ane after- 
wards called up amidft .trains of concomitant 
ideas. 

* Fhyfical pleafure and pain generally occur conneded 
with a compound impreffion^ i. e. an organ and Ibme 
objed. When the idea left by the fX}mpound iropreffion^ 
IS called up by being linked accidentally ta fome other 
idea or inopreffioo^ no recutTenee^ or the ffighteft poffible, 
•f the pleafure or p^iaiaany form will take place. Bat 
when the conapound impreffion itfelf exids luitbout the 
phyfical pleafure or pain^ it wiH awaken ideal (nrintdleftoat 



1 40S y 

Wheiv pleafures and* pain* iai« new or^ con*- 
me^ed with new ideas^ they'dan nef^ be iiitel>« 
ligiUy detailed unlefy aflWat^d duiinf ihtir 
^sciftehce with ttrtM &!a^mg^ ¥bf< analogous 
foelitogs* ^ .r 

I have (biniettmea experienced #M^' nHrt^M 
o&idi^ fenfations (imi)ar to n^ t>ttl6r&j fmd ttl^y 
have confequently been Indefcribablei Tbfei 
has been likewife often the cafe with other 
perfbns. Of two paralytic patients who were 
afked what they felt after breathing nitrous 



pleafure or pain, i. e. hope or fear. So that pbyfical plea- 
fure and pain are to hope and fear^ what impreffions 
are to ideas. For inftance^ aifaming no accidental aiTocia-* 
tion, the child does not fear the fire before he is burnt. 
When he puts his finger to the fire he feels the phyfical 
pain of burnings which is conneded with a vifible com- 
pound iraprelfion^ the fire and his finger. Now when the 
compound idea of the fire and his finger^ left by the com* 
pound impreffion are called up by^ his mother^ laying, 
** You hcn^e burnt ymir finger^* nothing like fear or the pain 
•f burning is conneded witK it. But when the finger is , 
brought near the fire> i. e. when the compound inpreffion 
again exifis, the ideal pain of burning or the palfion of fear 
is awakened, and it becomes eonneded with thofe very 
a&ions whicli romoved the finger from the fire. 



( 496 ) 

oxide^ the firft anfwered^ ** I do not know bonv^ 
hut very queer'* The fecOnd faid, ^^ J felt like 
the found of a harpP : Probably in the one cafe, no 
analogous feelings had ever occurred. In the 
other, the pleafurable thrlings were fimilar to 
the (eniations produced by mufic ; and hence, 
they were connedled with terms formerly applied 
to mufic. 



- • -— ■ • - " ■ ' ' -*~ " " ' ' ' 1 ■ I . I . ■ , , II n^ 

DIVISION it 

, ^ 1 

DETAILS oftbe EfFECTS produced by tbe kES^ 
PIRATION of NITROUS OXIDE upon diferent 
INDIVIDUALS furnished by THEMSELVES. 



A HE experiments related in the following 
details, were made in the Medical Pneumatic 
Inftitution. 

Abftradls from many of them have been 
publifhed by Dr. Beddoes.* 

. « 

ft 

I. Detail of Mr. J.W.Toiax. 

Having feen the remarkable efFedls produced 
on Mr» Davy, by breathing nitrous oxide, the 
18tb of April; 1 became defirous of taking fbme. 

A day or two after I breathed 2 quarts of this 

* Notice of ibme Obrervations made at the Medkal 
Pneumatic Inftitution. 

H h 



( 498 ) 

gas^ returning it back again into the fame bag, 
after two or three infpiralions, breathing became 
difficult, and I occafionally admitted common 
' air into my lungs. While the refpiration was 
continued, my fenfations became more pleafant. 
On taking the bag from my mouth, I ftaggered 
a little, but felt no other efFccl. 

On the fecond time of making the experi- 
ment, I took nearly four quarts, but flill found 
it difficult to continue breathing long, though 
the air which was left in the bag was far from 
being impure. 

The effedls however, in this cafe, were more 
ftriking than in the former- Increafed mufcu- 
lar ailion was accompanied by very pleafurable 
feelings, and a ftrong defire to continue the 
iiifpiration. On removing the bag from my 
mouth, I laughed, ftaggered, and attempted to 
fpeak, but Hammered exceedingly, and was 
utterly unable to pronounce fome words. My 
ufual ftate of mind, however, foon returned. 

On the 29th, I again breathed four quarts. 
The pleafant feelings produced at firft, urged 



-^ikt 



the (5 Contirtiie the infpiration with- great feagft^* 

rieft. Tbefe feelings however, went off towards? 

the end of the experiment, and no other elfFedls 

followed. The gas had probably been breathed 

too Im'g, d$ it vi^ould not fuppott flame. I then' 

propbftd to Mr. Davy, to inhale the air by the 

frtotitlv from otie bag, and to expire it (totn the 

t\(!:f^ infto ariotbel^. This method was purfued 

witMefe that) three <juafts, but the eff66ts were 

fo pov^erful as to oblige me to take m a little" 

common arr ocb&fionally. I fobn fotth'd my , 

nervous fyflein agitated by the highefl! fehfa- 

tions of pieafurfe, which are difficult of dfcfcrip- 

tion ; my mufcular powers were very mticH 

irfcreafeji, and 1 Went oh breathing with great - 

Vehemence, not from a difficulty of infpiration^y 

but from an ea^er avidity fdr mete air, Whetf 

the bags were exhaufted and t^en froih ttie?/ 

I continued brearthhig With the fam^ vioJetrce, 

then foddetily ftarting firbnP the chair, a*d vo- 

cifefating with' pleaftiVfe, I ifearf* towards f holb' 

that Wet6 preftlnft, us' I ^ftretf they riibold 

« 
participate in my feelings. I ftrutk gently i* 



( 600 ) 

Mr. Davy and a ftranger entering the room at 
the moment, I m&de towards him, and gave him 
feveral blows, but more in the fpirit of good 
humour than of anger. I then ran through 
different rooms in the houfe, and at lad returned 
to the laboratory (bmewhat more compofed ; 
my fpirits continued much elevated for' fome 
hours after the experiment, and I felt no con- 
fequent depreifion either in the evening or the 
day following, but flept as foundly as ufual. 

On the 5th of May, I again attempted to 
breathe nitrous oxide, but it happened Xo con- 
tain fufpended nitrous vapour which rendered 
it non-refpirable. 

On the 7th, I infpired 7 quarts of pure gas 
mingled with an equal quantity of common air, 
the fenfations were pleafant, and my muicular 
power much increafed. 

On the 8th, I infpired five quarts without 
any mixture of common air, but the efiedls 
were not equal to thofe produced the day before ; 
Indeed there were reafons for fuppofing that the 
gas was impure. 



( 501 ) 

On the ISth, I breathed nearly fix quarts of 
the pure nitrous oxide. It is not eafy to de- 
Icribe my fenfations ; they were fuperior to any 
thing I ever before experienced. My ftep was 
firm, and all my mufcular powers increafed. 
My fenfes were more alive to every furrounding 
impreffion ; I threw myfelf into feveral theatri- 
cal attitudes, and traverfed the laboratory with 
a quick ftep ; my mind was elevated to a moft 
fublime height. It is giving but a faint idea of 
the feelings to fay, that they refembled thofe 
produced by a reprefentation of an heroic fcene 
on the fiage, or by reading a fublime pailage 
in poetry when circumftances contribute to 
awaken the finefl fympathies of the foul. In a 
few minutes the ufual ftate of mind returned. 

r 

I continued in good fpirits for the reft of the 
day, and flept foundly. 

Since the 18th of May, I have very often 
breathed nitrous oxide. In the firft experi- 
ments when pure, its efi^ecfts were generally 
fimilar to thofe juft defcribed. 

lately I have feldom experienced vivid fen- 



( 503 ) 

fatioDS. The pleafure produced by it is (light 
and tranquil, I rarely feel fublime emotions or 
increafed mufcular power. 

J. W. TOBIN. 

qaober, 1799- 

II. Detail of Mr. Wm. Clayfxblp. 

The firft time that I breathed the nitrous 
oxide, it produced feelings analogous to thofe of 
intoxication. I was for fome time unconfcious 
of exiftence, but at no period of the experiment 
experienced agreeable fenfations, a momentary 
naufea followed it ; but unconnedled with lan- 
guor pr head-ache. 

After this I feveral times refpired the gas, but 
on account of the fulnefs in the head and appa- 
rent throbbing of the arteries in thebrain,*always 
defifted to brpathe before the full cfFedls were 
produced. In two experiments however, when 
by powerful voluntary efforts I fucceeded in 
|)reathing a large quantity of gas for fome mi- 

* In fomeof thefeexperiments, hearing was rendered 
fnore acute. 



( 503 ) 

nutes, I had highly pleafurable thrilliags in the 
extremities, and fuch increafe of mufcular 
power, as to be obliged to exert my limbs with 
violence. After thefe experiments, no languor 

or deprefliQn followed. 

William Clayfield. 

III. Letter from Da. Kinglake. 

In compliand^e with your defire, T will en- 
deavour to give you a faithful detail of the 
cffe6is produced on my fenfations by the inha- 
lation of nitrous oxide. 

My firft infpiration of it was limited to four 
quarts, diluted with an equal quantity of atmof- 
pheric air. After a few infpirations, a fenfe of 
additional freedom and power (call it energy if 
you pleafe) agreeably pervaded the region of 
the lungs ; this was quickly fuccecded by an 
almoft delirious but highly pleafurable fenfation 
in the brain, which was foon difFufed over th^ 
whole frame, imparting to the mufcular power 
at once an encreafed difpofition and tone for 
adlion ; but the mental efre(!^ df the excitement 



( 504 ) 

was fuch as to abforb in a fort of intoxicating 
placidity, and delight, volition, or rather the 
power of voluntary motion. TJiefe efFe6ls were 
in a greater or lefs degree protraded during 
about five minutes, when the fornner ftate re- 
turned, with the difference however of feeling 
more cheerful and alert, for feveral hours after. 

It feemed alfo to have had the further effect 
of reviving rheumatic irritations in the fhoulder 
?ind knee-joints, which had not been previoufly 
felt for many months* No perceptible change 
was induced in the pulfe either at or fubfequ^nt 
to the time of inhaling the gas. 

The effe<3ts produced by a fecond trial of its 
powprs, were more extenfive, and concentrated 
on the brain. In this iqftance, nearly fix quarts 
undiluted, were accurately and fully . inhaled. 
As on the former occafion, it immediately proved 
agreeably refpirable, but before the whole quan- 
tity was quite exhaufted, its agency was exerted 
fo flrongly op the brain, as progrefSvely to fuf- 
pend the fcnfes of feeing, hearing, feeling, and 
i^ltinmatelj the power pf volition itfelf. At this 



,* 



( 505 ) 

period, the pulfe was much Augmented both ia 
force and frequency ; flight convulfive twitches 
of the mufcles of the arms were alfo induced; 
no painful fenfation, naufea, or languor, how- 
ever, either preceded, accompanied, or followed 
this ftate, nor did a minute elapfe before the 
brain rallied, and refumed its wonted faculties, 
when a fenfe of glowing warmth extending over 
the ()'ftem, was fpeedily fucceeded by a re-in- 
ftatement of the equilibrium of health. 

The more permanent efFedls were (as in the 
firft experiment) an invigorated feel of vital 
power^ improved fpirits, tranfient irritations in 
different parts, but not fo charadleriftically rheu* 
matic as in the former inftance. 

Among the circumfiances moft worthy of 
regard in confidering the properties and ad- 
miniftration of this powerful aerial agent, may 
be ranked, the faA of its being (contrary to the 
prevailing opinion*) both highly refpirable, and 

* Dr. Mitcbill (an American Chemift) has crroneoufly 
fcrppof^^ its full admi(fioQ to the lungs, in its concentrated 
flate^ to be incooipatible with animal life, and that io a 
pjore diluted form it operates as a principal agent in the 



( 506 ) 

ialutaiy^ that it imprefles the brain and fy&em 
at large with a more or lefs firong and durable 
degree of pleafurable feofation^ that unlike the 
efieiSt of other violently exciting agents^ no fen- 
fiUe exhauftion or diminution of vital power 
accrues from the exertions of its (limalant pro- 
perty, that its mod excei&ve operation even, 
is neither permanently nor tranfiently debilita- 
ting ; and finally, that it fairly promifes under 
judicious application, to prove an extremely 
efficient remedy, as well in the vad tribe of 
difeafes originating from deficient irritability 
^nd fenfibility, as in tbofe proceeding from 
morbid aflbciations^ and modifications, ofthofe 
vital principles. 



produdion of contagious difeafes^ &c. This gratuitous 
potitioD is thus unqualifiedly affirmed. '* If a full infpira- 

tion of gafeous oxyd be made, there will be a fnddea 

extindion of life ; and this accordingly accoants for the 
'' fa6t related by Ruffel (Hiftory of Aleppo, p. 232.) and 
** confirmed bj other obfervers, of many perfons falling 

down dead fuddenly> when flruck with the contagion of 

the plague." 

Vide Remarks on the Gafeous Oxyd of Azote^ by Samael 
Latham Mitchili, M. D. 



€C 






( 507 ) 

I 

If you fhould deem any thing contained iii 
this curfory narrative capable of fubferving in 
any degree the pradical advantages likely to 
refult from your fcientific and valuable invefiU 
gation of the genuine properties of the nitrous 
oxide^ it is perfedlly at your difpofal. 

lam 
Your fincere friend, 

Robert Kinglake. 

BrifioJ, June \Ath, 1799- 
To Mr. Davy. 



IV. Detail of Mr. Southey. 

In breathing the nitrous oxide^ I could not 
diftinguifh between the firft feelings itoccafioned 
and an appreheniion of which I was unable to 
divcft myfelf. My firft definite fenfation was a 
dizzinefs, a fulnefs in the head, fuch as to in- 
duce a fear of falling. This was momentary. 
When I took the bag from my mouth, I im- 
mediately laughed. The laugh was involuntary 



( 508 ) 

but highly pleafurable^ accompanied by a tbrill 
all through me ; and a tingling in my toes and 
fingers^ a fenfation perfedlly new and delight- 
ful. I felt a fulnefs in my chefl afterwards ; 
and during the remainder of the day^ imagined 
that my tafte and hearing were more than com- 
monly quick. Certain I am that I felt myfelf 
more than ufually Arong and chearful. 

In a fecond trials by continuing the inhala- 
tion longer, I felt a thrill in my teeth ; and 
breathing fiill longer the third time, became fo 
full of (irength as to be compelled to exercife 
my arms and feet. 

Now after an interval of fome months, during 
which my health has been materially impaired, 
the nitrous oxide produces an effect upon me 
totally different. Half the quantity afFedts me, 
and its operation is more violent ; a flight laugh* 
ter is firft induced,* and a defire to continue the 

* In the former experiments^ Mr. Southey generally 
refpired fix quarts^ now he is unable to confume two. 

In an experiment made iince this paper was drawn up> 
the cffeft was rather pleafurable. 



( 509 ) 

inhalation, which is countera6led by, fear from 
the rapidity of refpiration ; indeed my breath 
becomes fo fhort and quiok^ that I have no doubt 
but. the quantity which I formerly breathed, 
would now deftroy nac. The fenfation is not^ 
painful, neither is it }n the flighted degree 
pleafijrable. 

Robert Southey. 



V. Letter from Dk. Roget. , - 

The efFedl of the firft infpirations (pf the ni- 
trous oxide \yas that of making me .vertiginous, 
and producing a tingling fenfation in my hands 
and feet : as thefe feelings increafed, I feemed 
to lofe the fenfe of my own weight, and imagined 
1 was finking into the ground. I then felt a 
drowfinefs gradually fteal upon me, ^nd a dif* 
inclination to motion; even tRe adiions of 
infpiring and expiring were not performed . 
without effort ; and it alfo required fome atten- 
tion of mind to keep my noftrils clofed with my 
fingers. I was gradually roufed from this tor- 



( 51b ) \ 

pbr by a kind of delirium, which came on fd 
rapidly that the air-bag dropt from my hands. 
This fenfation increafed for about a minute 
after I had ceafcd to breathe, to a much greater 
degree than before, and I fuddenly loft fight of 
all the objedls around m6, they being appa- 
rently obfcured by clouds, in which were many 
luminous points, fimilar to what is often expe- 
rienced on rifiag fuddenly and ftretching out 
the arms, after fitting long in otie pofition. 

I felt myfelf totally incapable of fpeaking, 
and for fome time loft all confcioufnefs of where 
I was, or who was near me. My whole frame 
felt as if violently agitated : 1: thought I panted 
violently : my heart feemed to palpitate, and 
every artery to throb with violence ; I felt a 
finging in my ears ; all the vital motions 
feemed to be irrefiftiHy hurried on, as if their 
equilibrium had been deftroyed, and every 
thing was running headlong into^ codfufioti. 
My ideas fucceeded one another with extremte 
rapidity, thoughts rufhed Kke a torrent throughf 
my mind, as if their velocity bad been fuddenly 



(511) 

accelerated by the bui'fting of a barrier whicn 
had before retained them in their natural and 
equable courfe. This (late of extreme hurry, 
agitation, and tumult, was but tranfient. Every 
unnatural fenfation gradually fubfided ; and in 
about a quarter of an hour after 1 had ceafed 
to breathe the gas, I was nearly in the lame 
ftate in which I had been at the commence- 
ment of the experiment. 

I cannot remember that I experienced the 
lead pleafure from any of thefe fenfations. I 
can however, eafily conceive, that by frequent 
repetition I might reconcile myfelf to them, 
and poflibly even receive pleafure from the 
fatnc fenfations which were then unp)eafant. 

1 am (enfiWe that the account I have been 
able to give of my f*eer!ngs is very imperfcdl:. 
For however calcukted their violence and 
novfclty were to leave a lafting' irapreffibn on! 
the memory, thefe eirfcumftaaces were {or that 
very realbn unfavourable to ax^curacy of com* 
parifbn with fen-fatiorts already fanffiliar. 

The nature of the feiifatbnc tbemfehes^ 



( 512 ) 

which bore greater refemblance to a half deli<» 
rious dream than to any difiindl flate of mind 
capable of being accurately remembered, con- 
tributes very much to increafe the difficulty. 
And as it is above two months fince I made the 
experiment, many. of the minuter circumftan- 
ces have probably efcaped me. 

I remain 

Yours, &c. 

P. KoGET. 

To Mr. Davy. 



VI. Lener from Mr. James Thomson. 

The firft time I refpired nitrous oxide, the 
experiment was made under a ftrong imprefiion 
of fear, and the quantity I breathed not fuffi- 
cient, as you informed me, to produce the 
ufual efFedl. I did not note very accurately my 
fenfations. I remember I experienced a flight 
degree of vertigo after the third or fourth 
infpiration ; and breathed with increafed vigor, 
my infpirations being much deeper and more 



( 513 ) 

Vbhemfent than ordinary. I was enabled the! 
next time I made the experiment, to attend 
more iiccurately to my fenfations^ and you have 
the obtervations I made on them at the time. 

After the fourth infpiration, I experienced 
the fame incrbafed adlion of the jungs^ as in 
the former cafe. My infpii'ations became un- 
commonly full and flrong, attended with a 
tbrilHog fenfation about the cheft, highly plea- 
furable, which increafed to fuch a degree as to 
induce a fit of involuntary laughter, which I in 
vain endeavoured to reprefs. I felt a flight 
gtddinefs which laded for a few moments only« 
My infpirations now became more vehement 
and frequent ; and I inhaled the air with an 
avidity ftrongly indicative of the pleafure I 
received. That peculiar thrill whiqh I had at 
. firft experienced at the cheft, now perv^ed 
my whole frame ; and during the two or three 
laft infpirationsj was attended with a remarkable 
tingling in my fingers and toes. My feelings 
at this n^oment are not to be defcribed : I f^t a 
bigh^an extraordinary degree of pleafure, different 

I i 



( 514 ) 

ftotb that prodtlced by wine, being divefled of all 
its grofs accompaniments, and yet approaching 
nearer to it than to any other fenfation I am 
acquainted with. 

I am certain that my mufcular firength was 
ibr a time much increafed. My difpofition to 
exert it was fuch as I could not reprefs, and the 
fatisfadlion I felt in any violent exertion of my 
legs and arms is hardly to be conceived. Thefe 
vivid fenfations were not of long duration ; they 
diminiihed infenfibly, and in little more than a 
quarter of an hour I could perceive no difier* 
ence between the ftate I was then in, and that 
previous to the refpiration of the air. 

The obfcrvations I made on repeating the 
experiment, do not differ from the preceding, 
except in the circumftance of the involontary 
laughter, which I never afterwards experienced, 
though I breathed the air feveral times ; and hi 
the following curious fad, which^ as it was de* 
pendent on circumftances, did not always occur; 

Having refpired the fame quantity of atr ai 
ufual^ and with precifely the fiime eSbdi^ I 



( 515 ) 

was furprifed to find, n;v3?feif affe<3ed a few mi-. 
mite& afterwards with the recurrence of sk p^in 
in my back andknees^ which I bad experienced 
the preceding day from fatigue in walking. ( 
was rather inclined to deem this an accideixtf^ . 
coincidence than an efFe<ft of the air ; but the 
fame thing conftantly occurring whenever % 
breathed the air, fhortly after fuffering paii^ 
' either from fatigue, or any other accidental 
caufe, left no doubt on my mind as to the 
accuracy of the obfervation, 

I have now given you the fubftance of ^he , 
notes I made whilft the impreffions were ftrong 
on my mind. I cannot add any thing from 
recolledtOD that will at all add to the accuracy 
of this account, or aflift thofe who have not 
r^fpired this air, in forming a clearer idea of its 
extraordinary efFefls. It is extremely difficult 
to convey to others by means of words, any 
idea of particular fenfations, of which they have 
l)ad no experience. It can only be done by 
making ufe of fuch ternis as are exprcflive of 
fenlations th^t refemble them*", and in thefe our 



( 516 ) 

vocabulary is very defediive. To be able at all 
to comprehend the efFcdls of nitrous oxide^ it 
is neceflary to refpire it^ and after that, we muft 
dther invent new terms to exprefs thefe new 
and particular fenfations, or attach new ideas to 
/ old ones^ before we can communicate intelligi- 
bly with each other on the operation of this 
extraordinary gas. 

I am &c. 

James Thomson. 
Londotiy Sept. 21, 1799- 

To Mr. Davy. 



VII. Detail of Mr. Coleridge. 

The firft time I infpired the nitrous oxide, I 
felt an highly pleafurable fenfation of warmth 
over my whole frame, refembling that which 
I remember once to have experienced after 
returning from a walk in the fnow into a warm 
room. The only motion which I felt inclined 
to make, was that of laughing at thofe who 
were looking at me. My eyes felt diftended^ 



( sir) 

end towards the laft, my heart beat as if it were 
leaping up and down. On removing the mouth- 
piece the whole fenfation went off almoft 

! 

inftantly. 

The fecond time, I felt the fame pleafurable 
fenfation of warmth, but nbt I think, in quite 
fo great a degree. I wiflied to know what efFe<Sl 
it would have on my impreflions ; I fixed my 
pye on fome trees in the diftance, but I did 
not find any other efFedl except that they be- 
came dimmer and dimmer, and looked at laft 
as if I had feen them through tears. My heart 
beat more Violently than the firft time. This 
was after a hearty dinner. 

The third time I was more violently aiSlecJ 
on than in the two former. Towards the laft, 
I could not avoid, nor indeed felt any wiih to 
avoid, beating the ground with my feet ; and 
after the mouth-piece was removed, I remained 
for a few feconds motionlefs, in great extacy. 

The fourth time was immediately after break- 
faft. The few firft infpirations afFeded me fo 
little that I thought Mr, Davy had given n)e 



(518) 

•iiAofpheric a!r : btit Toon felt the winmltb b6- 
ginning about my cheft, and ipreadfng upwinrd 
dnd downward, fo that I could Teel its progfefs 
over my whole frame. My heart did not bcal 
fo violently ; my fenHitions ^erc highly -plea- 
furable, not fo intenfe or apparently Idea!, bflt 
of nlore unmingled pleafure tfaao I bad evfer 
before experienced.* 



VIII. Derail of Mn. Wedgwood. 

July 23, I called on Mr. Davy al the Medi- 
cal Inftitution, who afked me to breathe (bme 
of the nitrous oxide, to which I confebted, 
being rather a fceptic as to ita efFetfts, never 
having feen any perfon afFefled, I firft bt^athed , 
about fix quarts of air which proved to be only 
common atmofpheric air> and which confe- 
quently produced no efFedl. 

I then had 6 quarts of the ojcide gftreo me in 

* The dofes in thefe experiments were from five t« 
feven ^oarts. 



• ( 619 ) 

a bag undiluted^ and as Toon as I had breathed 
three or four refpirations, I felt myfelf affc6led 
and my refpiration hurried, which efFedl increa- 
fed rapidly until I became as it were entranced, 
when I threw the bag from me and kept breath- 
ing on furioufly with an open mouth and hold* 
ing my nofe with my left hand, having no 
power to take it away though aware of the 
ridiculoufnefs of my iituation. Though appa- 
rently deprived of all voluntary motion, I w^s 
fenfible of all that palled, and heard every thing 
that was faid ; but the moil lingular fenfatiopi 
J had, I feel it impollibie accurately to defcribe. 
It was as if all tb6 mufcles of the body were 
put into a violent vibratoryrmotion ; I bad a very 
ftrong inclination to make odd antic motions 
.with my hands and feet. When the firft ftrong 
fenfations went off, I felt as if I were lighter than 
the atraofphere, and as if I was going to mount 
to the top of the room. I had a metallic tafte 
left in my mouth, which foon went ofF. 

Before I breathed the air, I felt a good deal 
fatigue^ from a very long ride I had bad the 



. t 



( 520 ) 

day before^ but after breathing, I loft^^ p]l fenf^ 
pf fatigue. 



IX. Detail of Mr. Gborge Burnet. 



I had never heard of the ef!e6is of the nitrous 
pxide^ when I breathed fix quarts of it. I felt 
a delicious tremor of nerve, which was rapidly 
propagated over the whole nervous lyftem. As 
the adlioQ of inhaling proceeds^ an irreilftible 
appetite to repeat it is excited. There is now si 
general fwell of fcnfations, vivid, ftrong, and 
inconceivably pleafurable. They ftill become 
more vigorous and glowing till they are com- 
municated to the brain, when an ardent flufh 
overfpreads the face. At this moment the tqbe 
inferted in the air-bag was taken from my 
mouth, or I muft have faiqted in extacy. 

The operation being over, the ftrength and 
turbulence of my fenfations fubfided. To this 
fucceeded a ftate of feeling uncommonly ferene 
and tranquil. Every nerve being gently agitfi- 



( 6^1 ) 

ted with a lively enjoyment. It was natural to 
expe6^ that thCjeflTeiSl of this experiment, would 
eventually prove debilitating. So far from this 
I continued in a (late of high excitement the 
remainder of the day after two o'clock, the 
time of the experiment, and experienced a flow 
offpirits not n^erely. chearful, but unufually 
joyous. 

Georqe Buri^et, 



X. Detail of Mr. T. Popj-e. 

A difagreeable fenfation as if breaking out 
into a profufe perfpiration, tendon of the tym- 
panum, cheeks and forehead ; almoft total 
lofs of mufcular power; afterwards increafed 
powers both of body and mind, very vivid fenia- 
tions and highly pleafurable. Thofe plealant 
feelings were not new, they were felt, but in a 
iefs degree, on afcending fome high mountains 
in Glamorgan (hire. 

On taking it the fecond time, there was a 
difagre^blQ feeling about the face. In a few 



( 522 ) 

feconds, the feelings became pleafarable ; ail 
tlie faculties abforbed by the fine pleafing feci- 
ings of exiftence without confcioufnefs ; an 
involuntary burft of laughter. 

' Thomas Popi*k. 



XL Detail of Mr. Hammick. 

Having never heard any thing of the mode 
of operation of nitrous oxide^ I breathed gas in 
a filk bag for fome tinie, and found no efFedls, 
but oppreffion of refpiration. Afterwards Mn 
Davy told me that I had been breathing atmof- 
pheric air. 

In a fecond experiment made without know- 
ing what gas was in the bag, I had not breathed 
half a minute^ when from the extreme pleafure 
I felt, I unconcioufly removed the bag from 
my mouth ; but when Mr. Davy offered to take 
it from mc, I refufed to let him have it, and 
faid eagerly, " let me breathe it again, it is 
highly pleafant ! it is the ilrongeft ftimqiant I 
ever felt !'' I was cold when I beg^n to rejpire. 



( 523 ), 

but had immediately a pleafant glow extending 
to my toes and fingers. I experienced from the 
air a pleafant tafte which I can only call fweetly 
aflringent ; it continued for fome time : the 
fenfe. of exhilaration was lafling;. This air Mr, 
Davy told me vyas nitrous oxide. 

la another experiment, when I breathed a 

fmall dofe of pitrous oxide, the efFedls were 

■ ■ i' ' 

fligh^, and Sometime afterwards I felt an unufual 

' ■ ' .1 

yawning and languor. 

The 1 aft time that I breathed the gas, the 
feelings were the moft pleafurable I ever expe- 
rienced ; my head appeared light, there waai a 
great warmth in the back and a general unufual 
glow ; the tafle was diftinguiftiable for fome 
time as in the former experiment. My ideas 
were more vivid, and followed the natural 
order of aflbciation. I could not refrain from 
mufcular adion.* 



Stephen IIammicki, JuniP. 



Sept, 15th. 



( 524 ) 



XII. Detail of Dr. Blake- 

Dr. Blake inhaled about (ix quarts of the 
aiV, was affeiled during the procefs of refpiring 
it with a flight degree of vertigo, which was 
almoft immediately fucceeded by a thrilling 
feniation extending even to the extremities, 
accompanied by a mod: happy ftate of mind and 
highly pleafurable ideas. He felt a great propen- 
iity to laugh, and his behaviour in fome mea- 
fure appeared ludicrous to thofe around him. 
Mufcular power feemed agreeably increafed, 
the pulfe acquired iirength and firmnefs, but 
its frequency was fomewhat diminiihed.^ He 
perceived rather an unpleaiant tade in the 
mouth and about the fauces for (bme hours 
afterwards, but in every other refpe6l, his feel- 
ings were comfortable during the remainder o£ 
the day. 

December^ ZOtb. 
To Mr. Davy. 



s^ 



( 625 ) 



XIII. Detail of Mr. Wansey. 

I breathed the gas out of a filk bag, believing 
it to be nitrous oxide, and was much furprifed . 
to find that it produced no fenfations. After 
the experiment, Mr. Davy told me it was com- 
mon air. 

I then breathed a mixture of common air- 

•» 

and nitrous oxide. I felt a kind of intoxica-. 
tion in the middle of the experiment, and 
Hopping to exprefs. this, defiroyed any farther 
efFedts. 

I now breathed pure nitrous oxide ; the efFedSl 
was gradual, and I at firft experienced fulnefs 
in the head, and afterwards ftnfations fo de- 
lightful, that I can compare them to no others, 
except thofe which I felt (being a lover of mufic) 
about five years fince in Weflminfter Abbey, 
in fome of the grand chorufles in the Mefliah, 
from the united powers of 700 inftruments of 
mufic. I continued exhilarated throughout the 
day, flept at night remarkably found, and ex- 



( 526 ) 

perienced when I awoke in the morning, a 
recurrence of pleafing fenfation. 

In another experiment, the efFed was ftill 
greater, the pulfe was rendered fuller and 
quicker, I felt a fenfe of throbbing in the head 
with highly pleafurable thrillings all over the 
frame. The new feelings were at laft (b power- 
ful as to abforb all perception. I diftinguifhed 
during and after fhe experiment, a tafte on the 
tongue, like that produced by the contadl of 
zinc and filver. 

Henry Wanset. 



XIV. Detail of Mr. Rickman. 

' On inhaling about fix quarts, the firft altered 
feeling was a tingling in the elbows not unlike 
the efFed of a flight ele6lric (hock. Soon after- 
wards, an involuntary and provoking dizzinefs 
as in drunkennefs. Towards the clofe of the 
inhalation, this fymptom decreafed ; though the 
nofe was ftill involuntary held faft after the air- 
bag was removed. The dofe was probably an 



^ 



( 547 ) 

undercharge, a» no extraordinary icDfktioii watt 
felt more tban half a mi4n{ite after the iahaladion* 

J. RrckMAiy« 



XV. Detail of Mr. Lovell EdgwortX? 

My firft feniatioH was an univerfal and cpn<^ 
fiderable tremor, I then perceived fome giddi- 
nefs in my head, amd a violent dizzinels in iliy 
light ; thofe ienfations by degrees fubfided, and 
I ielt a great propenfity to bite through the 
wooden mouth-piece, or the tube of the bag 
through which I infpired the air. After I had 

\ 

breathed all the air that was in the bag, I 
eagerly wiihed for more. I then felt a flt*otig 
propenfity to laugh, and did burft into a violent 
fit of laughter^ and capered about the room 
without haviiig the power of reftraining mjfdf, r 
By degrees thde feelings fubfided, except the 
treknor which lafted for an hour after I bad- 
breathed the air, and I feh a weaknefs in my 
kneea. The principal feeling through the whole 
of the itme^ or what I (hould call the charadleiV' 



( 528 ) 

iftical part of the effe&t was a total difficulty of 
reftraining my feelings, both corporeal and 
mental, or in other words, not having any 
Gominand of one'self. 



XVI. Detail of Mr. G. Bedford^ 

I inhaled 6 quarts. Experienced a feniatfoif 
of fulnefs in the extremities and in the facey 
with a delire and power of expanfion of the 
lungs very pleafurable. Feelings limilar to 
intoxication were produced, without being dif* 
agreeable. When the bag was taken away, an 
involuntary though agreeable laughter took 
place, and the extremities were warm. 

In about a quarter of an hour after the above 
experiment, I inhaled 8 quarts. The warmth 
and fulnefs of the face and extremities were 
fooner produced during the infpiration. The 
candle and the perfbns about me, alTumed the 
fame appearances as took place during the efFedt 
produced by wine, and I could perceive no 



determinate outline. The defire and powet to 
expand the lungs was increafed beyond that in 
. the former experiment, and the whole body and 
limbs Teemed dilated witbopt the fenfe of tenfion4 
it.was as if the bulk w^s increafed without any 

r 

addition to the fpeeific gravity of the: body^ 
which was highly pleafant. The provocatipa 
to laughter was not i<> great as in the former 
experiment^, and when the bag was rem^ved^ 
the warmth almoft fuddenly gave pla^e to a 
coldnefs of the extremities, particularly of the 
hands which were tfhQ;iii:j(l to become i^arm 
during the infpiratioq. . A flight fenfation of 
fulnefs not amounting to pajn in the bead» has 
continued for fome .i^iputes. After the. firft 
. experiment, a fenfation in, the wrtfts and plbows 
took place, fimilar to that produced by the 
eledlric (hock, 

6. C. B^DF0|19« 

March 30th, 1800. 



. ' .' / 







( SM) 



XVII- Detail ^of Miss Ryiand. 

ii . . . 

After liating breathed five quarts icHT gas, I 
^tperienced for a fiioM thne a quickDei^ ^d 
difEcfulty 'of breatbitig, which was fucceeded hy 
^f ren^e fatiguor, refembKng fainting, wttbout 
ihe very utipTeafant fenfation with which it U 
tifnkify attended. It entirely deprived rbe ' of 
the power of Tpeakiti'g, but nbt of recoUeAion, 
for I heard every thing 'that was i^id in the room 
duritig the time ; arid Mr. Davy's remark ^' that 
triy ptilfe Was very quick land full.*' WheW th6 
languor began to fubflde^ it was faeceeded by 
refileffinefs, accompanied by involuntary n^uf- 
cular motions. I ^as Warmer than ufual^ add 
vbfy ilcepy for feveral hours. 

i 

XVm. Letter from Mr. M. M. Coat£S. 

I will, as you requeft, endeavour to defcribe 
to you the effed produced on me laft Sunday 
fe'nnight by the nitrous oxide^ and will at the 



f^f time tell y<Wi ^b^t was tbe, pri^viPHS- ftatc^ 
pr(^y miiid oa th9 Cubjec^. 

. Wb^o I iat dpvf pt to breathe t^q j^s, J bi4ie«{jd| 
tlKiJ,it owq4 ttw^bi ofMts ^flfe^l |tp -^bq pr^di^P^ 

? - 4 

Having ignorantly brej^tb^^ AJ?^ 7f: cxjrpjiwfl^ 
air withou^4P-yi t^^, niy doubts then arofe 
tQ pofitivje.iwbfJlef. 

After a few infpirations o( Ui^p , nitii;qus ^oxUle, 
I felt a fulnefs in niy bead, which increafed 
with eaeh inhalation, until, experiencing iymp- 
toms which I thought indicated approaching 
fainting, I ceafed to breathe it, aild was then 
confirmed in my belief of its inability to pro- 
duce in me any pleafurable fen fat ion. . 

But after a few feconds, I felt an immoderate 
flow of fpirits, and an irrefiftible propenfity to 
violent laughter and dancing, which, being fully 
confcious of the violence of my feelings, and of 
their irrational exhibition, I made great but 
inefFedual efforts to reftrain ; this was tny ftate 
for fqveral minutes^ During the reft of the day. 



( 532 ) 

I experienced a degree of hilarity altogether 
new to me. For fix or feveo days afterwards^ 
I feemed to feel moft exquifitety at every nerve^ 
fldid was much indifpofed to my fedentary pur- 
ftiits ; this acute fenfibility has been gradually 
diminifhing ; but I ftill fe61 fomewhat of the 
effeds of this norel agent 

Yoar's truly^ 
To Mr. Davy. M. M. Coates. 

June lift, ISOO. 



< 



'■" ■ ^ Ml' ■! 



I 



DIVISION III. 

ABSTRACTS from ADDITIONAL DETAILS.^ 
OBSERVATIOm on the EFFECTS of NITROUS 
OXIDE, by Dr:BEDDOES.^CONCLUSION. 



I. AbstraSs from additional Details. 

JL HE trials related in the following abfiradls, 
have been chiefly made fince the publication 
of Dr. Beddoes*s Notice. Many of the indivi- 
duals breathed the gas from pure curiofity* 
Others with a difbelief of its powers. 

Mr. Wynne, M. P. breathed five quarts of 
diluted nitrous oxide, without any fenfation; 
Six quarts produced fulnefs in the cheft^ 
beat in the hands and feet, and fenfe of tenfion 
3n the fingers, flight but'plealant fenfations. 
Seven quarts produced no new or diflfereot 
effeds. 



( 534 ) 

Mn Mackintosh feveral times breathed 

* 

ititrous oxide. He had fenfe of fulnefs in the 
headf thrillin^^ tiftglmg in tht fingers^ and 
generally pleafurable feelings. 

Mr. JoH)r Cave, Junr. from 4»reatliiqg four ' 
quarts of nitrous oxkle^ felt ienfations as frpm 

fuperior wine^ and general pleafant feelings. 

Mr. Michael Castle, from five quarts^ 
experienced ienfations of test and thrilling, 
general fpirits heightened confiderably as froai 
"wine ; afterwards, flight pain iii fhelbac'k of the 
liead. 

Mr. H. Card WELL, from five quarts, bad 
feelings fo pleafurable as almoft to defiroy 
confcioufnefs ; almoft convulfed with laugh- 
ter; for a long time could not think of the 
feeling without laughing ; fenfation of light- 
nels for fome time after. 

Mr. Jarman, from five quarts, great pica- 
•fure, laughter, certainly better fpirits/ g^ow in 
the cheeks which continued long. 



The gentleman ^bo f^ifniihed thp pr^ec^g 
detail^ b^d beard of the effedls of qitrpus o^ide> 
and was prepared to experience new fenfations: 
I therefore gave him a b^g of common air 
which he refpired^ bflievipg it to be nitrous 
oxide; and was much furprifed thajt no effeds 
were produced. He then breathed five quarts 
of nttrpus o^de, anfl aft^^ the experiipent^ gave 
this ac|COvi;nt of bis ii£;n(at ions. 

Rev. W. A. CAne, after inhaling tbe gas, 
felt the moft delicious fenfations accompanied 
by a thrill through every part of his body. He 
did not think it poflible Co charming an eiffe^t 
could have been produced. He bad beard of 
the gas ; but the refult of the experiment far 
exceeded his expectations. 

May Qtb, 1800. 

Mr. Joseph Priestley from breathing 
nitrous oxide^ generally had unpleafant fulne& 
of the head and throbbing; of the arteries^ which 
prevented him from conjtinuing the reipiration* 



( 53i5 ) 
Dr. Bcddoes mentioned in his Notice, that 

i 

Mr. J08IAH Wedgwood and Mr. Thomas 

« 

Wedgwood, experienced rather • unplealant 
feelings from the gas. Mr. Jos i ah Wedg- 
wood has fince repeated (he trial, the cfFeiSls 
were powerful^ but not in the ilightefl: degree 
pleafant. ^ 

• - • 

Mr. R. BouLTON and Mr. G. Watt have 
been much lefs afFe<Sled than any individuals. 

Many other perfons have refpired the gas, 
but as their accounts contain nothing unnoticed 
in the details, it is ufelefs to particulariie them. 

The cafes of all the males who have been an- 
pleafantly afFedled (ince we have learnt to prepare 
the gas with accuracy, are related in this Sediion 
and in the lad Divifion. Thofe who have beep 
pleafurably afFe6ted after a fair trial and wbo(e 
cafes are not noticed, generally experienced 
iblnefs in the head, heat in the cheft, pleafura- 
ble thrillings, and confequent exhilaration. 

To perlbns who have been unaccuftomed to 
breathe through a t ube^we have ufually given com- 
mon air till they have learnt to refpire with accu- 



\ 



(537) 

rady : and in cafes wh^e tBe fortiiof the filbutfii Kasr 
prevented the lip* from being aceuratdy clofiof 
oti the breathing tube, by ' the advice of Mr; 
Watt, we haVe ufed a tin plate conical mouth^ 
piece fixed to the cheeks, and accurately adapter! 
to the lips ; by tneanis of which precautions; tfR 
our later trials have been perfectly concl alive; 

II. Of the effe£ls of Nitrous Oxide upon per/bn$ 
inclined to b)[fkrical and nervous affe3ions. - 

The cafe of Mifs ^ N. land other cafed; 

detailed by Dr. Beddocs in his Noticei feemed 
to prove th&t the adtioh of nitr&us oxide . was 
capable of producing hyfterical and nervous 
dfFe(Sions in delicate and irritable confti- 
tutions. 

On this fubjedl, we have lately acquired 
additional fadts. 

Mifs E. a young lady who had been fubjedl 
to hyileric fits, breathed three quarts of nitrous 
oxide mingled with much common air, and 



( 538 ) 

feli; op effb^ but 9 flight tendency to f^iptipg. 
$lif tbea breatbed foi^r 4}uaits of pure nitrpuft 
oxifle : her firft inff^ratioD^ were deep^ her 
laft very feeble. At tt^e epi ihe 4rppt jthe bag 
^m her lip«, and continped for ([pgie momenta 
mptiQiDlefs. Her palfe wbic^ ^t the begispjog 
of the experimeot was firpngt appeared tp m^ 
to be at this time^ quicker and weaker. She 
fooa began to iQOvre b^ hands ^d talked for 
ibme minute incoberently, as jSx ignorant of 
what had pailed. In lefs than a quarter of an 
hour^ ihe had reqovered^ bat could give no 
nccount of her fenf^tJQQSi Acert^ d^giiee 4^ 
languor continued thro^gh the day. 

A young lady who never had hyfterical 
attacks^ wifhed to breathe the gas. I informed 
her of the diiagreeable efFedls it had fome- 
times produced, and advifed her if fhe had 
the fligbtdft tendency to nervous afTedion^ 
not to make the trial. She periifted in :her 
resolution. 
To afcertain the infiuwoe «f ikf^g^qatiop^ 



i 



( fi39 ) 

I fiHl gave bcr a bag of comtnoa alr^ whick 
fhe. declared produced no effed. I then oiw 
dered for her a quort of nitrous oxide mingled 
with two quarts of fx>niinon air ; but frqtti the 
aiiftake of the perfon who prepared it, three 
quarts of nitrous oxide were adminiftered with 
one of common air. She breathed thisfor near 
a minute, and after the experiment, defcribed 
her fenfations as unpleafant, and laid (he fek 
at the moment as if (he was dying. The un- 
pleafant feelings quickly went off, and a few 
minutes after, fhe had apparently recovered 
her former ftate of mind. In the courfe of the 
day, however, a viblent head-ache came on, 
and in the evening after (he had taken a medi-* 
oine which operated violently, hyfterical affec- 
tions were produced, followed by great debility. 
They oocaiionally returned for many days, and 
(he continued weak and debilitated for a great 
length of time. 

Mrs. S. a delicate lady, liable to nervous 
affedlians who had heard of the cafes juft de- 



( S4D ) 

iAiAed, chofe to breathe the gas. By three 
•quarts (he was thrown 'into a trance^ which 
lafted for three or four minutes. On recover- 
ing, (he could give no account of her feelingir^ 
and had ibme languor for half an hour after- 
wards, 

Thefe phaenomena have rendered us cautious 
in adminiftering the gas to delicate (eraales. 
In a few inflances however^ it has been taken 
by perfbns of this clafs^ and even by thofe in- 
clined to hyfierical and nervous complaints 
with pleafurable eflfedls* 

Mifs L. a young lady who had formerly bad 
hyfterical fits, breathed a quart of nitrous oxide 
with three quarts of common air without effects. 
Two quartsof nitrous oxide with one of com- 
mon air produced a flight giddinefs ; four quarts 
of nitrous okide produced a fit of immoderate 
laughter, which was fucceeded by flight 
exhilaration, her fpirits were good through- 
out the day, and no depreffion followed; . 



< I 



( 541 ) 

Mifs B.. Y-. — and Mifs S. Y— - both 
delicate but healtiiy yottog ladies* were afFe^ed 
vory pleafaftly ; ^each by ibrefi quarts idfti«t«ou9 
03cide, the firft liaie of refplrmg' it. Mifs B 

Y^ continued epi^ilarated AQd in bigb fpi- 

ritfii for fome hours after the dofe. Mifs S, Y-^ 
had a flight head-acbe, which did not go off 
for fome hours^ 

Mrs. F. inclined to be hyfterical, breathed 
four quarts of nitrous oxide mingled with com« 
mon air. She was giddy and defcribed her 
feelings as odd ; but had not the Aighteft lan- 
guor after the experiment 

III. Obfervations on the effeSs of Nitrous 
Oxidsy by Dr. Bbbboes. 

■i 

Neither my notes nor my recolleilion fupply 
much in addition to what I formerly flated ia 
the Notice of Obfervahons at the Pneumaiie 
Inftituikn. Longman. The gas maintains its 
firil cbar^dter as well in its efiecSis on me^ as in 



( 542 ) 

the benefit it confers on Tome of the pafal^'tic, 
dnd the injury it does of threatens^ to the hyfte- 
rical and the exquifitely fenfiblc. I fiod thit 
five or fix quarts operate as powerfully as^evcr. 
I fttm to make a given qtumtity go farther by 
holding my breath fo that the gas may be ab- 
(orbed in a great degree without returning into 
the bag, and therefore, be as little heated be- 
fore infpiration as poffible. — ^This may be fancy. 
After innumerable trials, I have never once 
felt laflitude or depreflion* Moft commonly 



* Of the fa6ts on which Brown founded his law of in> 
dire6t debility, no prudent man will IqCe iight cither in 
pradiiing or ftudying medicine. They are incontroverti- 
ble. — And our new fa6is may doubtleik be coDciliated to 
the Brunonian do^rioe. ^ 

But to fuppofe that the expenditure of a quality or a fub- 
dance or a fpirit, ^nd its renewal or accumulation are tbe^ 
general principles of anigaalphasnomenaj feems tome a griey- 
ovis and baneful error. I believe it often happens that excite- 
ment and excitability increafe, and that they oftener decreafe 
together; — In fhort, without generalizing in a majmer^ of 
which Brown and (imilar theorifls had no conception, our 
notions of the living world will in my opinion, continue 
to be as confufed as the elements are faid to have been in 
chaos. itOn fome future occaiioo, I may preftime to point 



( 543 ) 

i am fenfible of a grateful gl6w circum prsior* 
did. This hzs cqntinued fbi^ hours.«^Id two oc 
three iofiandes ooly has exbalatiop failed to bd 
followed by jf)le^i»r&ble fiseHng, it h^s never been 
fallowed by thd conttlary. On a few dccafiont 
befori the gas yr^ exfaaolled^ I have Iband \k 
hnpoffible to continue breathing* 

ThA pul fe at fitft becomes fuller and ftrooger^ 
Wben^ever^ after expofure to a cold wind^ tbe 
warmth of the room has created a glow in the 
cheeks^ tbi gas has increafed this to ftroag 
fluibing-r^hieh bommon air breathed in the 
iahie way^ bailed to do. : 

Several times I have found that a cut wbich 
bad ceafed to be painful has fmarted afrefh, and 
on taking two dofes in fucceilioa, the fmarting 
ceaied in the interval and returned during the 
i^o'nd rfefpiration. I had no previous expe^»« 
tion oi tbe firft fmarting. . 

out the region through which I imagine the path tq wind, 
that will lead the obfervers of fbmd (liftaDt g^neratioh to « 
point, whence diejp may enjoj a view of the itibtlev linfjr 
and intricate movements of the organic creation as /dear as 
Newton obtained bt the tnovements of the heaverly maiies. 



(544) 

- . Tbe only, f imcl wa» near renderfa^ i xnyfdf 
inTcnfible to f>reient olgeSs by very carefully 
breathing (everal dofes in quick fuccefiionj I 
forcibly exclaimed^ tqkbs !-^In fad^* befides 
mgenecal thrilling^ there; feemed to be <|aiGk 
and ftrang alterations. in the degree. of iUctiiri-^ 
nation of all furrounding ob)e^ ; and I felt as 
if compofed of finely lobrating firings. ^ On this 
occafion, the Ikin feemed in a ftate of oon*^ 
firiiSlion and the lips glued to the month-piece^ 
and the mucous membrane of the longa con- 
tracted, but not painfully. However, no con- 
firiftion or corrugation of the ikin could be 
(ben. I am confcious of having made a g^reat 
number of obfervations while breathing, which I 
could never recover. 

Immediately afterwards I have often caught 
mylelf walking with a hurried fiep apd buiy in 
foliloquy. The condition of general feniation 
being as while, hearing chearful mufic, or after 
good news, or a moderate quantity of wine. 

Mr. John Cave, Junr. and his three friends, 
as well as otherS;^ compared the effedls to Charn^ 



( 646 ) 

pa^ne. Moft perfons have had the idea of the 
effect of fermented liquors excited by the gas- 
It were to be wifhed that we had, for a Aandard 
of comparifon, obfervations on the^ efFe<Jl of 
thefe fiquors as diverfified and as accurate as 
we have obtained concerning the gas ; nor would 
more uniformity in the adlion of thefe ful)- 
fiances be obferved if the enquiry weft- 
ftri6tly purfued. Opium and fpirits fecm^ in 
particular flates to (icken and diflrefs in the 
firft inftance ; how differently does wine 
at an early hour and fading a& upon thofe 
whoar6 accuftomed to take it only after dinner I 
I thqught it might be an amuflng fpedacle 
to fee the different 'tints of blood floxving from 

f 

a wound by a leech in confequence of breathing 
different airs. The purple from the nitrous 

■ 

oxide was very evident. Oxygene, we thought, 
occafioned a quicker flow and brighter color in 
the blood. In another experiment, an inflamed 
area round the pun<^ure from a leech applied the 
day before^ was judged by feveral fpeflators to 
become much more criaifon oa the refpiration of 



, ( 546 ) 

about 20 Quarts of oxygene gais^ which po0ibly 
nfis more powerfully on inflamed parts.* Tbeie 
and many (imilar experiments, require to be x^-- 
peated on the blood of fingle arteries opened in 
Warm and cold animals. 

It has appeared \o me that I could hold my 
breath uncommonly long when refpiring oxy- 
gene gas mixed with nitrous oxide. While 
trying this tb*day, (17th June)^ I thought tbe 
fenfe of fmell much more acute after the 01- 
^us oxide than before I began to refpire at 
all ; and then I felt confcious that thisincr^aied 
acuteneis had before repeatedly occuired-r^a 

* After vrriting thi8> I was prefent when as ioTalid, in 
whofe foot tbe gout, after much waoderingf had at laft fixed;, 
breathed 12 quarts of oxygene gas. While breathing, be 
eagerly pointed to the inflamed leg ; and afterwards (aid he 
had felt in it a new feniation, fomewhat like tenfioo. — I 
never had feen oxygene refpired where there was io much 
local inflammation. 

JuoQ 1 8. After four quarts^ of oKygene with 6 of nitrous 
•xide and then 6 of nitrous oxide alone, violent itching of 
the wounds made by the leech ; and redneft and tumour. — 
Both had healed, and I did not expcd to UA anj tfaiag 
iQQre from them. — 1 tried this again with two dofet of ni* 
trous oxide — ^The yellow halo round one wound changed 
ta crimfon, and there was fo nuch fitngiog add fWdllsg 
that I feared fuppuration.— Ab^rptioo here was rapid. 




Time by my feelings has always ap^fed 
longer than by a watch. 

I thought of trying to obTervc • whether while 
I alternately breathed quantities of nitrous oxide 
Bnd ©xygene gas land conr^ttion air, I cbuld ob- 
fervte atty diflference irt the operation of a blift* 
begihnjftg to bite tht Ikin. It would be of 
cO*)fetjufence i^ afcer^^in the tffetft of regulatit^ 
by feompreffion the flow of blood, While ftitfitH- 
iKAtB ofvdriouis kinds (dud hi?^t€d*bOdi^s d^^^bllg; 
the reft) wef6 applied to of Mar tht extt^knii- 
ties — becaufe in erifipelas and varioiilrd it^flttni'*- 

* > 

ttiatory affafliofls, ^ ready atid {)leAfettt cure 
inigbt be €fFe<Sied by partial eompreflioii of \tit 
arteries going to the difeafed part %.^iLnd d gteat 
knprovera^nt in pr^^c^ice thtis obfaified. 

But I (hould nan into dti lertdlefi d^t^Mm^ 
trcre I to efmmeratie poffible pbyfiologrcal tt^ 
periai€nts witb artificial aiiH, or to fpecubitfe Ott 
Hie mechanical impmvcmeflt of mediciire, itbich 
at prefent as far as mechanical means of affe^^^ 



< 54$ ) 

ingtbe living (yftem are concerned, is with us 
in a ftate that would almofi diigrace a nation cff 
iavages. 

IV. Conclusion. 



From the fadls detailed in the preceding 
pages, it appears that the immediate efibdl^ Qf 
nitrous oxide upon the living fydem, are analo- 
gous to thofe of difFufible iiimuK. Both in- 
creafe the force of circulation, produce plea- 
forable feeling, alter the condition of the organs 
of fenfation, and in their mod exteniive a<5lion 
deftroy life. 

In the mode of operation of nitrous oxide 
and diffufible (limuli, confiderable differences 
however, cxift. 

DifFufible fltmuli a<Jl immediately on the 
mufcular and nervous fibre. Nitrous oxide 
operates upon them only by producing peculiar 
changes in the compofition of the blood. 

DifFufible ftimuli afFed that part of the fyflem 






( 549 ) 

pjoft powerfully to ^hiqh they are applied^ and 
adl pn ;tbe whole only by means of its (ympathy 
with that partk ^ Nitrous oxide in combination 
with ith/e. blood, is un^verfal in its; .application- 
and a<^ion. 

We know very little of the nature of excite- 
ment ; as however, life depends immediately on 
certain changes effedled in the b]ck)d iq refpi- 
ration^ and ultimately on the fupply of certain, 
nutritive, matter by the lymphatics ; it is rea- 
fonabte to conclude^ th^t duripg the.adlion of 
Simulating fubfiances, from the increafed force 
of circulation > not only: more oxygene and 
perba{ps nitrogeb^milft be combined with tl)e 
bloqd in ( refpirdtiQU,!: but, likewife more. fluid 
nutritive matter fopplied. to it in circulation. 



• i ' .• I . ■ , • ■'it. 



* See Dr. Beddoes'ai Qmpderatipns, ^rt 1. page2,Q, RBs 
obfervations in the note in the laft fedion, will likewife 
apply here.— Is not healthy living adiion dependant upon 
a certain equilibrium between the principles fupplicd to the 
blood by the pulmonary. ypins from refpiration and by the 
lyinpbatics -. from abfoFp.tioa ? Does not fenlibility more^ 
ioimediately depend upon reoperation ? Deprive an animal 
under fiiniialatioD^ of air^, s^^d it inftantly dies , probably 



.-. •• 



By this <>zygene and iMlritke nntter encita- 
bility may be kept up: and exhauftion confe* 
queot to exeitemeni only ppoduccxl^ i» conlb- 
quence ofadefic^ncy of fomo of the nutritife 
principles^ which are fupplied by ablbrptioi^. 

When nitrons axide is breathed^ nitroeene 
(a principle ooder oommon ciroomikmceacbiefty 
carried into the blood by the abibrbentam fluid 
compounds) is fupplied m re^aUoo^ ; z greater 
quantity of oxygene is combined with the Udo4 
tban in common refpiration, whiift leis earlbome 
acid and probably lefa water are evolveid^ 

Hence a fmalter quantity of nutritive matter 
is probably required from tt;ie abfocbents di^ng 
Ike excitement from nitrous oxide, tban during 
the operation of fttmulants ; ^tld in coniequence^ 
exhauftion rom the expenditure of nutritive 
matter more feldom oceafioned. 



if abforption could be prevented, it would Hkewife'{))eedily 
die. It would be curious to tryr whether intoxieation from 
fermented liquors- cannot be prevented by breathing 
during their operatioa^ to atnaol|^ere depitved o# part of 
$ts oxjgene. 



{SSI) 

Since Refearch III. has be^n ptilfitisd^ I faaV6 
endeavoured to afcerfain the cjuanf H?c» Of n(trt)^ 
gene produced when nitrous oxide iis refpired 
for a confidieraftte time. In outer experiment, 
when I breathed iibout four quattai of gas m' tL 
gbft bell over impregnated tva,tier for near k 
minute, it i^asdimini(hed toabdut tWo quartd ; 
and thif refiduum extinguiflied flatnti. 

Now the experiments in Refearch ll. prove 
that when nitrous oxide is dccompofed by com- 
buflible bodies, the quantity of nitrogenp 
evolved is rather greater in volume than the 
pre-exifting nitrous oxide. Hence much of 
the riitrogene taken into the fyftem during the 
refpiration of nitrous oxide, muft be either 
carried into new combinations, or given out 
by the capillary veflels through the Ikin. 

It would be curious to afcertain whether the 
quantity of ammoniac in the falirie matters 
held in folution by the fecretcd fluids is 
increafed after the refpiration of nitrous oxide. 
.Experiments made upon the confumption of* 
nitrous oxide mingled with atmofpberic ,air 



( 562 ) 

by the ^mi^ller anloial^t wgnuI^^o far tp deter* 
ipine whether wy pitrogene . ia givea <>ut 
through the ikin. , [ . : . > 

The various efTefls of nitrpipa oxtde upoi:| 
different individuals and upon the fame indi- 
viduals at different times, prove that its powers 
are capable of bjcing. modified both by the pec^* 
liar condition of .organs,, and by :the*<Aate of 
general feeling, 

Reafoning from common phaenomena of fenfa- 
tion, particularly tbofe relating to heat, it is proba* 
blethatpleafurablefeelingisuniformlyconnedied 
with a moderate increafe of nervous acSlion ; and 
that this increafe when carried to certain limits, 
produces mixed emotion or fublime pleafure ; 
and beyond thofe limits occafions abfolute pain. 
Comparing the fadls in the lad divifion, it 
is likely that .individuals poflefled of high 
health and little fenfibility, will generally be 
lefs pleafurably afFeded by. nitrous oxide than 
fuch as have more fenfibility, in whom the 
emotions will fometimes fo far enter the limits 



(55?) 

* 

of pain aso tq- becpR*?^ iS^jliiae^l^i.ijrbii^ft.'the 
nervous a&wa ij^.^ii}acb.a.s.\isff^ exquifite : ienfi* 
biiity, will^ be fa ,fpj4ch iiw:rciafed /as often 
tp prod(Uce;^i(agreeable feeling, ; = 

Mpdific^Uc^rof the. powers of ipitrous oxide 
by mixture pf the. gas with oxygcnpor conoiOQn 
air, will prpbi^bly enable theijiDoi): delicately 
fenfible to refpire;it^without danger, and even 
with pleafurable effedls : heretofore it has been 
adipiniftered;to fucb.only in its pure form or 
mingled with fmall quantities of atmofpheric 
air, and in its pure form even the.mpA robull 
are unable to refpire it with fafety for more than 

five minutes.. 

. » . ■ • ■ ■■■-■./ 

The mufcular a(5lions-|- fometimes connected 

* Sublime emotion with regard to natural obieds, is 
generally produced by the connexion of the pleafure or 
beauty with the paffion of fear. 

f The immortal Hartley has demonflrated that all pur 
motions are originally automatic, and generally produced 
by the action of tangible things on the mufcular fibre^ 

The common a6tions of adults may be diflinguifhed into 
two kinds j voluntary a6iions, and mixed automatic adlions. 
The firft ai^e produced by ideas, or by. ideas con neded; with 
paffions. The fecpnd by impreffion^ or by pleafure and paio« 



( 554 ) 

with the ftelings produced By nitroM oxide, feem 
to depend in a great meafare upon* the par- 
ticular habits of the individual ; they Will ufually 
be of that kind which is produced ^ther by 
common pleafurable feelings or Arong emotions. 
Hyfterical afFe6)ion isoccafioned by nitrous ox- 
ide, probably only in confequence of the flrong 
emotion produced, which deftrbys the power of 
the will, and calls up feries ofautomatic motions 
formerly connected with a variety of Icfs powerful 
but fimilar feelings. 

The quicknefs of the operation of nitrous 
oxide, will probably render it ufeful in cafes of 
extreme debility produced by deficiency of 

In volunt;iry a^on, regular affociationa of ideas and 
tnufcular motions exift : as when acbemiA performs a pre- 
conceived experiment. 

In mixed aatoniatic adions^ the fimple daotions produced 
by impreflion are conneded with feries of motions formerly 
voluntary, but now produced without the interven^oo of 
ideas : as when a perfon accuftomed to play on the harpti- 
chord, from accidentally drlking a key, is induced to per- 
form theferies of motions which produced well-remembered 
tune. 

Evidently the muicular adHons produced bjr nitrous 
oxide are mixed automatic motions. 



. ( 555 ) 

oommon exditiSjg' powers. Pethips if nray ht y 
advahtageoufly^iipplftil mioglecl wirtr oxygead , 
or botnmon alJ"r, \b tHe rfeteosvery df J3elrf6fta ^ppa-' 
rthrty dead ftooi fuffoeation t^ drowing or 
baling. ' '■ ' 

The only difetffes 1b which nitifouid oxfrfe has^ 
been hi thefffei employed, affe thbfe ofdefficicnf • 
fti>fibility.-*-Ali account of its agency in para- 
lytic afFeflions, will be fpeedily pnbKflied by 
Dr, Beddoes. 

As by its ifruncdiafe operation the tone of the 
irrflable fibr^ is fncrcafed, and as exhauflion 
rarely foUows the violent mufcular motions 
fometimes produced by it, it is not unreafona- 
ble to expe<5l acirantagcs from it \\\ cafes of 
fimple mufcular debility. 

The apparent general tranfiency of its opera- 
tion in the piire form in fingle dofes has been 
confidered as offering arguments againft its' 
power of producing lading changes in the con- 
ilitution. It wHl, however, be eafy to keep up 
excitement of different degrees of intenfity for a 
great length of time^ eilber by adminittering 



( 556^ 

tbie unmingled gas in r^[ud,-fu^i;f;$ve dofes, . <>r. 
by preferving ^ permapeQfej,^tfppfpt)ere»^; conr. 
tainiDg difFerjept proportioi^fr of ;i^.trQus..pxjciA 
and common air^ by means ^( Si^nflf^ii^'ing chaipr: 
ber.* That (ingle dofes ncverthelefs^ are capable; 
q( producing permanent efTedls in,(bmecpnAi^ 
ti^tioi||^ is evident, ,as well froip^ (be byfterical 
caies a$ from fooiQ ,of the detailfir-rrparticularly 
th^t of Mr. JVT. . Wt- Coates. 

As nitrous oxide in its extenfive operation 
appears capable of dedroying phyfical paioj it 
may probably be ufed with advantage during 
furgical operations in vvhi9h no great efFufion 
of blood takes place. 

From the flrong inclination of thofc who have 
been pleafantly afFedled by the gas to refpire it 
^gain, it is evident, that the pleafure produced, 
is not loft, but that it mingles with the mafs of 
feelings, and becomes intelledlual pleafure, or 
hope. The defire of fome individuals acquainted 
with the pleafures of nitrous oxide for the gas 
has been often fo ftrong as to induce them to 

• Sec R. IV. Div. I. page 478. 



breathe with cagetAfjfs, the air retnaining in the 
bags after the refpiratiotl of others, . > -ji,.:] 
' M hydroc^rbonat^ a6h as a fedi3ti:Me,^)^4 
dinftiqiflies living adl^on as rapidly as .^itrpK^ 
oxide increaft^s it, on the common theory of 
excitability:}: it would follow, that by differently 
modifying theji^lmofphere by means of this gas 
and nitrous oxide, we fhould be in jpofleffion 
of a regular feriea of exciting and dq<>r©ffing* 
powers applicable to every deviation of the con^p 
flitution from health : but the common theory 

fR-IV. Div. I. page 467- 
X That of Brown modified by his difciples. 

, * Supppjfing the incrcafe or diipinution of living a6lion 
when produced by different agents, uniform, limilar and 
differing only in degree; it would follow, that certain 
mixtures of hydrocarbonate 3nd nitrous . oxide, or hydro- 
gene and nitrous oxide, ought to be capable of fupporting 
the life of animals for a much longer time than pure nitrous 
oxide. From the experiments in Ref. IIL' Div. Lit appears 
however, that this is not the cafe. 

It would feem^ that in life, a variety of different cor- 
pufculat changes are capable of prodacihg ph'aenomena 
apparently fimilar j fo that in the fcience of living aftion, 
we are incapable of reafoning concerning caufes from effeds* 



( &$« ) 

of ennt&bility is moft probabty jbdnded 6n k 
falfe generaliffition. The mojdificatbfis of diA 
Mfed a6lion may be infinite and (pecifle in 
dtflFeretit organs ; and b^i^e OCit^f the p6^er 
of agents operating on the whole vf the 
lyftem. 

Whenever we attempt to eoMibine our fcat- 
tercd phyfiological fads, we are flopped by the 
want of numerous intermediate analogies ; and 
fo loofely connci^ed or fo independant of each 
dther, are the different feries of phsDnomend, 
that wc are rarely able to make probable con- 
je£lures, much lefs certain prediflions concern- 
ing the refults of new experiments. 

An immenfemafsofpneumatological, chemi- 

cal, ^nd medical information mufl be collec^led, 
before we (hall be able to operate with certainty, 

on the human conititution. 

Pneumatic chemiilry in its application t6 

medicine, is an art in infancy, weak, alak>ft 

ufelefs, but apparently podefled of capabilities 

of improvement. To be rendered ilrong and 

mature, (he muft be nourifhed by fads. 



( 559 ) 

■ • 

flrengthened by exercife, and cautiouflydiredled 
jn the application of her powers by rational 
fcepticifm. 



i 



J 



pii-rfi 



11 



mi»mik^^i^m0matmm*mmm^ii^mm^ki^i^maAiimm^aiim^mmmmmimhmm^i^^^ 



* . *_ 



APPENDIX 



No. I. 



< » , 



Effeds of Nitrous Oxide on Pegetaiion^ 

i'N^ July J 799, I introduced twofmall plants 
of fpurge into nitrous oxide^ in contadl with a 
little water over mercury ; after 'Temaining in 
it tlvo days, they preferved their healthy ap- 
pearance, and I could not perceive that any gas 
had been abforbed. I was prevented by an 
accident^ from keeping them longer in .the 
gas. 

A fmall plant of mint introduced into nitrous 
oxide and expofed to light, in three days be- 
came dark olive and fpotted with brown ; and 
in about (ix days was quite dead.'^— Another 

fimilar plant, kept in the dark in nitrous oxide^ 

Mm 



if. 
-*r 



#• 



( 56a ) 

did not alter in color for five dajrs, and at the 
end of feven days, was only a little yellower 
than before. I could not afcertain whether any 
gas had been abforbed. 

I introduced into nitrous oxide through 
water^ a healthy budding rofe, thinking that 
its colors might be rendered brighter by the 
gas. I was difappointed, it very fpciedily faded 
and died ; polHbly injured by the folutron of 
nitrous oxide in water. 

Of two rows of peas juil appearing above 
ground ; I watered one with folutioo of nitrdus 
oxide in water, and the other with confimon 
water daily, for a fortnight. At the end of this 
time, I could perceive no difference in their 
i' growth, and afterwards they continued to grow 
equ^Iy fail. 

I introduced through water into fix phials, 
one of which coittained ^ydrogene, cme oxy- 
gene, one common air, one hydrocarbonate, 
one carbonic acid, and one nitrous oxide, fix 
fimilar plants of mint, their roots being in 



Tj- 






♦ 



% 



( 56d ) 

CDfitaA with wat^l" and tbeir I^VM expofed to 

Ughr. . 

S'be plant in carbonic acid begao to fade In 
h^ than two days, and in four was dead. 
That in hydrogene died in lefs than five days } 
that tn nitrous oxide did not fade mnch for the 
firft two days, but on the third, drooped veiy 
much, and was dead at the fame time as that in 
hydrogene. ' The plant in oxygene for the fiirft 
four days, looked flourifhing and was certaifil^ 
of a finefr greet) thaii before/ ^doally however^ 

its leaves became fpotted with black and drop<* 

•» 

ped off one by one, ^ill at the end often days 
they had all difappearad. At this time the 
plant in common air looked^^fickly and yellow^ 
wbilft that in hydrocarbonate was gi^ner and 
more flourifhing than ever. 

I have detailed thefe experiments not oti 
account of any important CQpclufions that may 
be drawn from theip ; but with a view of in* 
ducing others to repeat them, and to examine 
the changes effected in the gases. If it fhould 
be found by future experiments, thad faydfocar* 



(564) 

bonate generally increafed vegetation, it would 
throw fome light upoQ the ufe of manures, 
containing putrefying animal and vegeta)>le 
fubftances, fit>m which this gas is perpetually 
evolved. 

The cbemiiiry of vegetation though imme-r 
diately conne<Sied with agriculture, the art on 
which we depend for fubfiftence, has been but 
little inveftigated« The difooverias. of Frieftley 
and Ingenhouiz, feem to prove that it is within 
the reach of our inArumeiita of experiment. 



1 



No. II. 



•*, 



APPROXIMATIONS 

TO THE 

* Composition and Weight of the aeriform 

COMBINATIONS of NJTEOGENE. 
Jit temperature 550, and atmofpheric preflure 30. 






100 Cubic In. 



grains 



Nitrogene 



Oxygene 



Nitrogene 
Oxygene 



s 



g 

bo 

X 

o 



30.04 
35.06 



Atmofpher.air 
Nitrous oxide 
Nitrous gas 
Nitric acid 



bO 



o 

31.10)1* 

o 



a 

bO 

2 

'V 



Ammoniac 



I ^ 



50.20 
34.26 
76,00 



18.05 



c o 

CO 

.5 
S 

bO 



73.00 
63.30 
44.05 
29.50 






27,00 
36.70 
55^5 
70.50 



Nitrogenel Hy drogenel 



8 




■a, 



( »67 ) * 

No. m. 

* 

AddtUonal Obfervatlom. 

a. In Rcf. ift. Div. IV. Seft. III. in the ana- 
lyfis of nitrous gas by pyrophorus, as no abforp- 
'- tioo took place when the refidual nitrogene was 
expofed to water, I inferred that if any carbobic 
acid was formed it was in quantity fb minute, 
as to be unworthy of notice. A few days ago^ 
E compleatly decompofed a quantity of nitrous 
gas by pyrophorus, when the refidaal tiitrcgenfie 
was expofed to folution of ftrontian, the 'fluid 
became flightly clouded ; but no perceptible 
abfbrption took place. 

b. If there w^s the lead probability in any of 
Dr. Git%annier*« fpeculations on the con>pofition 
l^f Azote,* the experiments on the exhaufted 
Rapacity :|: of the lungs in Ref. III. might be 
(uppofed inconclufive. But there appears to 

* Annalcs de Chimie, 100 j and Mr. Tilloch's Phil. 
Magazine. '^, 

% 1 regret much that I could not procure Dr. Menzies's 
obfervations on Refpiration^ while I was making the ex- 
periments on the capacity of the lungs : they would proba- 
bly have faved me fome labor. 



( 567 ) . 

be no more reafon for fuppofinfg ttMit hjFdro- 
• gene is converted into nitrogene by refpiratipn^ 
than for fuppofing that it is converted into 
4vat6r^ carbonic acid or oxygene ; (of all thefc 
prodiJK^s are evolved when that gas is refpired. 
From the comparifon of Exp. 1 with Exp. 3, 
Ref. iii. Div. ii. Sec, 4, it is almoft denaonftra*^ 
ted that no alcertatnable change is ef]Fe<5led in 
bydrrtgenc by refpirafion. The experiment of the 
accurate Scheele in which hydrogenc after being 
• refpired thirty times io a bladder wholly loft its 
inflammability, mny beeafily accounted for froth 
its mixture with the relidual gafesof the lungs. 
About a fortnight ago^ I refpired, after forced 
voluntary exhau(!ion of my lungs, my noie 
being accurately elofed, three quarts of bydco* 
gene in a (ilk bag, at four intervals, for near 
five minutes. After this it was highly inflam* 
tnable, and burnt with a greenifh white flame 
io contadl with the atmofphere ; but v^as hot 
ib explofive as before.* ^ 

* If toofely Combined carbon eKifts in venous btood, 
bydrogene may probably diffolve a portion of it whiefrt 



(568) 

<• From what we have lately heard of the ourtous 
experiments of Mr. Volta aad Mr. Carlifley it is. 
very probable that the converiion of nitrous gas 
into nitrous oxide when expofed to wetted ^ioc, 
copper and tin, in contadl with mercury, as 
defcrihed in Ref. L Div. V. may in (pme mea*- 
fare depend on the aiSiion of the galvanic fluid. 
Whilft I was engaged io the experiments on this 
converfion> Dr. Beddoes* mentioned to me 
fome curious fadls noticed by Humboldt and 
Ritter, relating to the oxydation of metals by 
the decompofition of water, which induced me 



refpired and become ilightly carbonated. At leaft there 
is as much probability in the fuppofition that carbon in 
loofe affinity may combine with hydrogene at 98^ as that 
it may combine with oxygene. * 

* Dr. Bbddobs has iince favoured me with the following 
account of thefe fa6b. 

" Mr, Humboldt (ueber die gereizte Fafcr I. 473, 1797) 

quotes part of a letter from Dr. Afh, in which it is faid 

that if two finely poltflied plates of homogeneous zinc he mots- 

iened and laid together ^ little effeSt fallinvs — hut if %inc ftmt 

JUver he tried in the fame ivay, the nvhole furface of the 

Jiher %uill he covered ivith oxydated zinc. Lead and quick- 

JUver a^ as fvwetfyUy on each other, and fo^ do iron and 



to rexamine the phaDnomena with more atten* 
tion than I (hould have otherwife done.— I re- 
coUedl obfcrving that fome of the wetted zinc 

coffer.^Mr, Hunlioldt (p. 474) fays that, in repeating tlxis 
experiment, he faw air-bubbles afcend, which he fuppofet 
to have been hydrogen© gas from the decompoiition of 
water — ^When he placed zinc fimply on moift glafs, the 
fame phaenomena took place, but more (lowly and later« 
The quantity of oxyd of zinc upon the glafs alone was m 
20 hours to that on the iilver as one to three. 

In a very ingrnious but obfcurely written traA 
by Mr. Ritter, entitled, Evidence that the gahank 
adion ^xtfts in organic nature^ Svo. Jena, 1800 — ^Tbc 
author obferves, that the care of Dr. Aih and Mr. Hum- 
boldt that the metals fhould touch each other in ai 
many points as poiiible was fuperfluous, even if we could 
grant that two metallic plates miglit be made by po1i(hia^ 
to touch in a number of points. To (hew that it was fuffi- 
cient if by touching in one point only they (hould form a 
compleat galvaoip circle, he dropped a (ingle dropof diiUHed 
water upon the buft of a largQ lilver coin. A piece of pure 
zinc was placed with its one end^on the edge of the coin, 
while the other was fupported by a bif of glafs. The drop 
of water was neither in contact with the glafs nor with the 
point at which the metals touched. The materials were 
left in this fituation for four hours at the • temperature of 
680. On taking them apart, the water had become quite 
milky and had half di fa ppea red ; and Mr. Ritter a^nally 

_ • * • 

feparated a quastity of white oxide that had been prtjducrd 
in the experiment. 

The pieces of metal were cleaned and laid together in 



( 570 ) 

filings in nitrous gas on tbe fide o( tbe jar not 
in contact with tbe furface of merouiy, were 
very flowly oxydated. Wbilft on tbe furface 
of the mercury where fmall globules of that 
fubflance were mingled with thefilings of zittc, 
the decompofition went on much more rapidly i 



the fame manner, only that now a piece of paper was put 
between the metals at their former point of con tad. In 
four hours firfl, and afterwards in ten, a faint ring of oxide 
only bad been produced of which the quantity could net 
be eflimated, nor could it befeparated. In this cafe, the 
sine had fcarce loft any thing of its. fplendoar^ in the 
former it had been corroded. In many repetitiotis of tbe 
experiment, he found that far more oxide was formed wii«n 
tbe metals touched, than when they were feparated to the 
flighted diflance by an infolating body, even air. 

On expofing thefe apparatufes with fomewhat more wa- 
ter to a confiderable heat for four minutes, the water in the 
interrupted circle continued quite clear, while that in tbe 
other had become milk-white. 

Tbe fame phaenomena were prefented by other pairs of 
metals in a degree proportional to their galvanic aSdvity s 
viz. by zinc and molybdaena, zinc and bifmuth, zinc and 
copper, as alfo with tin and iilver, tin and molybdsena, 
and lead and iilver. The experiment with tin was parti- 
cularly decifive, for when in con tad with no other metal 
it was fcarcely at all oxydated by water, though oxydatiou 
took place when tiu was brought into contdd with fiLver> 



■k'lf 



( 571 ) 

poflibly thrODgh the^uicdium ^f Ibe moiftorc, 
a feries df galvanic circtes were fofmed. 

d. In Rer. 11. Dtv. I. it is (laledi that nilrcms 
oxfdedurtngits ibiutionby conimon wat^r^expeh 
about ^ of 'atmoTpheric air tbe volume of the 
water being unity. 






and both were conneded at the other end by a drop of 
water — What therefore took phce in Dr. Afh's experi- 
ment, arofe from an aggregation of galvanic circles of 
difitsrent forms. 

£/ the foregoing experiments, conclude! Mr. Ritter^ 
which though capable of the moft various modificdttom* 
unlforihly coincide in thdur main refult^ it is abundantly 
proved ^^2X gaJtfonk circles can he fitrmed of merely inorgeimc 
bodies, by tvbofe completion there is produced an action ^tMcb 
eeafes nvhen tbe circle is opened. The manner in which this 
has been (hewn, proves alfo that this a^ign can effe^hi- 
atefenfible modifications in organic bodies ; and the procefs 
by which thefe modifications have been efFeded, made 
it evident that they ivere not confequences of a momentary 
oBion of the circle^ but of an adion that is kept up ivhile the 
circle remains entire', for the procefs which brought this 
adtion under the cognizance of the fenfes went on, while 
the circle was unbroken, and its figure not brought back 
to that of a line. 

It is fcarce neceflary to obferve that the experiments 
here quoted, are far from being the -only ^nes on which 
the above conciufions reft.'* T. B. 



( 572) 

From the delicate experiments of Dr. Pear< 
£bn, on the pailage of tbe elei^ric fjiark tbroagh 

water^ it appears however probable, that much 
more than -^ of atmofpheric air is fometioies 
held in folution by that fluid,* poflibly tbe 
whole of the air is not expelled by nitrous oxide, 
owiijg to fome unknown law of faturation by 
which an equilibrium of affinity is produced, 
forming a triple compound. 

* Poffibly a ratio exists between the folubility of gafes 
in water^ and tbe folability of water in gafes. It is proba- 
ble from Mr. Win. Henrj's carioos experiments on the 
mariatic acid, that the abfolote quantity of water in ffutny 
gafes, may be afcertained by means of its decompofition by 
the eledtric fpark. 



( 573 ) 



No. IV. 



BESCBSmON OF A. "^ 



MERCURIAL AIR.HOLDER, * 

Suggefied by an infpedion of Mn Watt's Machioe for 
% containing Saditious Atrs^ 

By Wlf^IAM CLAYFIELD. 

i3lEV£RAL modes of countera6ling tbeprefltire: 
of a decreafing column of mercury baviog been' 
thought of in conjun£iion witb Mr. W. Cox^ the 
following was at laft adopted as the molL 
fimple and efibiSual. 

.Plate 1 Fig. 1, reprefents a fedtion of t^ 
machine, which confi As of a^firopg glals cylinr 
der A cemented to one of the fame kind B, 
fitted to tbe.folid block C, into which the glaft 
tube D is cemented for conveying air into the- 
moveable receiver £. 

The brafs axis F, Fig. 2, having a double 
bearing at a, a, i& terminated^at one end by the 
wheel 6, the circumference of which is equal 
to the depth of the receiver^ fo that it may be 
drawn to the furface of the mercury by the cord: 
h in one revolution ; to the other end is iStted 



the wheel H, over which the balance cord c rane 
in an oppofite direction in the fpiral groove e^ 
a front view^ofthe wheel H is (hewn at Fig. 3. 

Having loaded the receiver with the weight 
I, fomethtng heavier than may be neceflarj 
to force it through the nJercunuKjt is balanced 
by the fmall weight K, which iJangs from that 
part of the fpiral where the radius is equal to tbit 
of the wheel 6^ from this point the radius ^f the 
ipiral muft be increafed in fuch proportioat that 
in every part of its circuit, the weight K may 
be an exa6l counterpoife to the air^holder. Iq 
ibis way, to little fri^lion will be prodocedt 
that merely. plunging the lower orifiqe of the 
tube D under mercury contained m the foall 
wilel L, will be fufficient to overcome every 
refinance, and to force the gas difcharged from 
the beak of a retort into the receiver, where 
whatever may be its quantity, it will be fubjec^ed 
to a prefTure exaiSy correfponding to that of 
the atmofphere. The edge of the wbeel H bein^f 
graduated, the balance cord c may be made to 
indicate its volume. 

Should it at any time be ncceflaiy to reduce 



^ 



( 575 ) 

the prefTare to the medium iiandard of the 
barorneter, it may eafily be done by graduating ^ 
the lower end of the tube D^ and adding to the 
weights I or K, as nwy be found neoeflary ; the 
furface of the meroary in the tixbe pointing out 
the increafe or diminution. 

The concavity at the top of the internal 
cylinder is intended to contain any liquid U 
may be thought proper to expofe to the adion 
of the gas. 

The upper orifice /i with its ground-ftoppcr, 
is particularly ufeful in conveying air from the 
retort g^ with its curved neck, into the receiver^ 
without its pafiing through the tube D. In all 
cafes whbrea rapid extrication of gas is expected 
the retort j^, ihould be firmly luted to the ori^ 
fice, and the weight I, removed from the -top 
of. the receiver, this by diminifhing the prcf* 
fure, will admit the gas to expand freely in the 
air- holder at the inftant of its formation, and 
prevent an explofion of the veflels. The fame 
caution mud be obferved whenever any inf^amr 
mation of gas is produced by the eledric fparfc. 

The air may be readily transferred through 
water or even mercury by the tube b^ Fig. K 



« • 



(570) 

To prevent an abfbrption of mcrcnry in cafe 
of a condenfation taking place in the retort 
made ufe of for generating air, Mr. Davy has 
applied the flop-cock i, to which the neck is 
firmly luted. This ftop-cock is like wife of great 
fervice in faturating water with acid or alkaline 
gafes, which may be efFe6ied by luting one 
end of the tube k (o the ilop-cock, and plung-» 
ing the other into the fluid in the fmall vefTel /, 
cemented at top, and terminating in the bent 
funnel tn — ^the tube b having been previoufly 
removed, and the lower orifice of the tube D 
either funk to a coniiderable depth in mercary, 
or clofed with a ground fiopper* The bend of 
the funnel w, may be accurately clofed by the 
introduction of a few lines of mercury. 

The application of the flop-cock n, has 
enabled Mr. Davy to perform fbme experimenta 
on refpiration with confiderable accuracy. 

Nou. This apparatus was firft defcribed in the third part • 
of Dr. Beddoes*s Confiderations -, its relation to Mr. Davy's 
experiments with the improvements it has lately received, 
may probabl)^ be deemed fufficient to excufe the re-printiog 
it<-«-The weight I. Fig. 2> having been omitted in the 
plate^ the reader must fupply the deficiency, 

■ w.c. 



ttttali*mttm*a 



PROPOSAL 

THE PRESERVATION 

OF 

ACCIDENTAL OBSERVATIONS 

IN 

MEDICINE. 



IN times beyond the reach of hiftorjr, the medifinal 
application of fubi^ances could have* arifen from no 
other fource than accident. Among articles of the ma- 
teria medica of known origin^ we are indebted to acci-< 
dent for fome of the cnofl precious. 

Accident is every day prefenting to different individuals 
the fpe6tacle of phaenomena, arifing from uncommon 
i)uantities of drugs on the one hand^ and on the other^ 
from uncommon conditions of the fyflem^ where ordinary 
powers only have been knowingly or recently applied, 
w hat is faid of drugs may be extended to natural agen^ 
and mental affedions. 

From converlation with a variety both of medical prac- 
titioners and unprofeifional obfervers, the authpr of this 
propofal is perfuaded that fuch authentic occurreacei 
only^ as have prefented themfelves to perfons now living 
woqId> if they couldL be brought together, compofe a body 
of fa6t^ fo indrudtive to the philofopher^ and ufeful to tho 
phyiician^ that be defpairs of finding a term worthy Ip 
charad^rize it. 

Nn 



( 378 ) 

In (bme ct^es, the iafltteoce of unfuipeded pow^n would 
be deteded. In others^ rcfources available to the parpofe 
of redoring health in defperate fituations would be 
diredly prefented, or could be deteded by a (hort and eafy 

t m 

Y^rocefs of reafoning. Some anomalous obfervations, hj 
ihewing the abfence or agency of contefled cauies, wpuld 
perform the office o^ exfcrlmenta cruch — Unufual affe^ions 
occur of which an exa6t account would be among the noeans 
of removing from phydc its opprobrious unctirtaioty: for this 
uncertainty frequently depends upon our inabilitv to didin- 
gui(h the fubtler differences in cafes which refemble each 
other in their grolfer features. 

No tlriking fadk can be accurately flated, in conjunftion 
with its antecedent and concomitant circuniilances, without 
improving our acquaintance udth human nature. Our 
aequifitiohs in this mod important branch of knowledge^ 
may be compared to a ntimber of broken feries, of which 
we have not always more than one or two members. Bat 
every new accefiion bids fair to fill up foooe deficiencj -, 
and a large fupply would contribute towards connediDg 
feries apparently independent, aod working op the whole 
into one grand all-comprehending chain. 

There are complaints, and thofe by far too frequect, 
^ere no known procefs has a claim to the title of renuSal, 
Here the whole chance of prefervation dqiends on the phy- 
llcian*s capacity for bringing together fads that hare 
heretofore t^ood remote. But no power of combiDatioa 
can avail where there are no ideas to combine; 

Every new obfervation therefore, may be coofidered m a 
llandard trunk, fending forth analogies as ii^ manj branches 
crowned with blofibms, fome of which cannot £ul to be 
lucceeded by falutary fhtits. And were it not abford to 
extend the illaflratioQ of fo plain a point, it imght be added. 



(570) 

that when by the continual interpofition of new trunkd, 
the branches arc brought near together, the produce of each 
will be ennobled by the action of their refpedive principles 
of fecundation. 

Whenever the author has been able to obtain certaip 
information concernipg any unufual appearance in animal 
;>ature, it has been his cufton^ tp preferve it $ and among 
his papers he has 'memorandqiDs which prove that to 
our prefent circumfcribed ideas concerning the dofe 
of medicines may be fometimes imputed failures in 
pradiqe -, that certain iigns are not to be taken in the 
received iigni;fication ; and that many meafures are adopted 
or omitted to the detriment of invalids, becaufent is affuraed 
that circumdances are nece^anly connefted which may 
exift feparately, or that one given natural operation is incoyi- 
ftflent with another, to which it may really be fynchronous 
or next in order. 

AiBduous obfervation of the daily ftates of the hu- 
man microcofm will be the unfailing confequence of atten» 
tion to its finking phaenomena. Such is the progrefs of 
curiofity. Such the origin of all the fciences. The more 
uniformly clear the iky under which they tended their 
flocks^ thp lefs likely were the fhepherds of Chaldaea, to 
found the fcience of the ftars. And however the difpoiition 
to ftudy aflronomy might have been (Irengthened by the 
coincidence between the heliacal rifing of Sirius and the 
overflowing of the Nile, it muft, 1 conceive, have been 
awakened by the afpedt of mpteors and eclipfes. 

Whatever minute and authentic infornjation this im- 
perfed datement may produce, as foon as it (hall amount 
to a certain mafs, the author will prefent it to the public 
arranged. He flatters himfelf that no correfpondent will eke 
out by fuppoijtion the dcfc€t of genuine obfervation, without 



speedily will be Puhlisbed, 
OBSERVATIONS od tke External and latemal Ufe of 

NITROUS ACID. 

Demonflrating its PEftMANENT EFFICACY in 

VENEREAL COMPLAINTS ; 

And extending its ufe to other dangerous and painfal 

Diieaies. 

COMMUNICATBO 

By various Practitioners in Europe and Asia, 

TO 

THOMAS BEDDOES, M. D. 



Of tbe Puhlisber may be body price is. 6dl 

NOTICE of OBSERVATIONS 

AT THE PNEUMATIC INSTITUTION, 
By THOMAS BEDDOES, M, D. 

This Notice contains feme trials of nitrous Oixide by healthy peribns, 
not in the prefeot work, and fome cafies of palfy fucceisfiilly treated 

by that gas. 



Printed by Biggs and Cottle, St, Auguttme^t Back*