,transcriber's ,notes3      ,underscores
 80 before and after a word or phrase   
indicate italics      in the original   
text4    ,small capitals have been      
converted to ,,solid capitals4          
,illustrations have been moved so they  
do not break up paragraphs4             
,antiquated spellings have been         
preserved4    ,typographical and        
punctuation errors have been silently   
corrected4    ,the text usually uses a  
comma to designate a decimal point1     
although a       period is used in some 
instances4    ,the changes mentioned in 
the ,,errata have been applied to the   
text4                                   
,,researches1                ,,chemical 
,,and ,,philosophical2                  
,,chiefly ,,concerning                  
,,nitrous ,,oxide1                      
,,or               ,,dephlogisticated   
,,nitrous ,,air1                        
,,and ,,its                             
,,respiration4                       ,by
 ,,humphry ,,davy1                      

,,superintendent ,,of ,,the ,,medical   
,,pneumatic                             
,,institution4                          
,,london3        ,,printed ,,for ,j4    
,,johnson1 ,,st4 ,,paul',s              
,,church-,,yard1               ,,by     
,,biggs ,,and ,,cottle1 ,,bristol1      
#ahjj4          ,,contents4             
,,introduction1                         
xi4                                     
,,research ,i4      ,into the analysis  
of ,,nitric ,,acid and ,,nitrous ,,gas1 
and the production of ,,nitrous ,,oxide4
                                        
,,division ,i4      ,,experiments and   
,,observations on the composition       
of ,,nitric ,,acid1 and on its          
combinations with         ,,water and   
,,nitrous ,,gas4         #a4            
,preliminaries                          
#a       #b4 ,production of ariform     
,nitrous ,acid               #c         
#c4 ,specific gravity of ,gases         
#f       #d4 ,experiment on the         
formation of ,nitrous ,acid      #aa    

#e4 ,conclusions                        
#ag       #f4 ,experiments on the       
combination of ,nitrous ,gas            
with ,nitric ,acid                      
#ag       #g4 ,additional ,experiments  
#bc       #h4 ,conclusions              
#bi       #i4 ,mr4 ,,thomson',s ,theory 
of the difference          between      
,nitric and ,nitrous ,acid              
#cj      #aj4 ,composition of the       
different ,nitrous ,acids       #cf     
#aa4 ,combination of ,nitric ,acid with 
,water            #ch      #ab4 ,of     
,nitrous ,vapor                         
#db      #ac4 ,comparison of the results
 with those of          ,cavendish and  
,lavoisier                          #dc 
,,division ,,ii4      ,,experiments and 
,,observations on the composition       
of ,,ammoniac and on its combinations   
with ,,water         and ,,nitric       
,,acid4        #a4 ,analysis of         
,ammoniac                               
#ef      #b4 ,specific gravity of       
,ammoniac                      #fb      

#c4 ,of the quantities of true ,ammoniac
 in         ,ammoniacal ,solutions      
#fe      #d4 ,composition of ,nitrate of
 ,ammoniac                #ga      #e4  
,decomposition of ,carbonate of         
,ammoniac1         by ,nitrous ,acid    
#ge      #f4 ,decomposition of ,sulphate
 of ,ammoniac by ,nitre    #gg      #g4 
,non-existence of ,ammoniacal ,nitrites 
#gi      #h4 ,sources of error in       
,analysis                      #hj      
#i4 ,loss in ,solutions of ,nitrate of  
,ammoniac         during evaporation    
#hc                                     
,,division ,,iii4      ,,decomposition  
of ,,nitrate of ,,ammoniac--,preparation
         of ,,respirable ,,nitrous      
,,oxide4         #a4 ,of the heat       
required for the decomposition of       
,nitrate of ,ammoniac                   
#hd       #b4 ,decomposition of ,nitrate
 of ,ammoniac--,production          of  
respirable ,nitrous ,oxide--its         
properties       #hf       #c4 ,of the  
,gas remaining after the absorption of  

,nitrous ,oxide by ,water               
#hi       #d4 ,specific ,gravity of     
,nitrous ,oxide                #id      
#e4 ,analysis of ,nitrous ,oxide        
#ie       #f4 ,minute examination of the
 decomposition          of ,nitrate of  
,ammoniac                          #aja 
#g4 ,of the heat produced during the    
decomposition          of ,nitrate of   
,ammoniac                          #ajh 
#h4 ,decomposition of ,nitrate of       
,ammoniac at          high temperatures 
#aji       #i4 ,speculations on the     
decompositions of ,nitrate          of  
,ammoniac                               
#aac      #aj4 ,of the preparation of   
,nitrous ,oxide for          experiments
 on respiration                         
#aag                                    
,,division ,,iv4      ,,experiments and 
,,observations on the composition of    
,,nitrous ,,gas1 and on its absorption  
by different         bodies4         #a4
 ,preliminaries                         
#abb       #b4 ,analysis of ,nitrous    

,gas by ,charcoal             #abf      
#c4 ,analysis of ,nitrous ,gas by       
,pyrophorus           #acb       #d4    
,additional observations on the         
composition of          ,nitrous ,gas   
#acd       #e4 ,absorption of ,nitrous  
,gas by ,water              #adj        
#f4 ,absorption of ,nitrous ,gas by     
,water of          different kinds      
#adg       #g4 ,absorption of ,nitrous  
,gas by solution of          pale green 
,sulphate of ,iron                      
#aeb       #h4 ,absorption of ,nitrous  
,gas by solution of          green      
muriate of ,iron                        
#agi       #i4 ,by ,solution of ,nitrate
 of ,iron                  #ahg         
#aj4 ,by other metallic ,solutions      
#ahi      #aa4 ,action of sulphurated   
,hydrogene on solution          of green
 sulphate of iron impregnated with      
,nitrous ,gas                           
#aia      #ab4 ,additional ,observations
                         #aic           
,,division ,v4      ,,experiments and   

,,observations on the production of     
,,nitrous ,,oxide from ,,nitrous ,,gas  
and ,,nitric ,,acid         in different
 modes4         #a4 ,preliminaries      
#aig       #b4 ,conversion of ,nitrous  
,gas into ,nitrous ,oxide          by   
alkaline sulphites                      
#aii       #c4 ,by ,muriate of ,tin     
#bjb       #d4 ,by ,sulphurated         
,hydrogene                        #bjc  
#e4 ,decomposition of ,nitrous ,gas by  
,nascent          ,hydrogene            
#bjf       #f4 ,miscellaneous           
,observations                      #bji 
#g4 ,recapitulation                     
#baa       #h4 ,production of ,nitrous  
,oxide from ,metallic                   
,solutions                              
#bac       #i4 ,additional ,observations
 relating to the          production of 
,nitrous ,oxide                     #bai
      #aj4 ,decomposition of ,aqua regia
 by platina1          and evolution of a
 gas analogous to oxygenated            
muriatic acid1 and nitrogene            

#bbb      #aa4 ,action of the electric  
spark on a mixture          of          
,nitrogene and ,nitrous gas             
#bbi      #ab4 ,general remarks on the  
production          of ,nitrous ,oxide  
#bca                                    
,,research ,,ii4                 ,into  
the combinations of ,,nitrous ,,oxide1  
and its decomposition4                  
,,division ,i4      ,,experiments and   
,,observations on the combinations      
of ,,nitrous ,,oxide4         #a4       
,combination of ,water with ,nitrous    
,oxide         #bce       #b4 ---- of   
,nitrous ,oxide with fluid inflammable  
bodies                                  
#bdj       #c4 ,action of fluid ,acids  
on ,nitrous ,oxide          #bdd        
#d4 ---- of ,saline ,solutions          
#bde       #e4 ---- of ,gases           
#bdh       #f4 ,action of ariform       
,nitrous ,oxide on the                  
alkalies--,history of the discovery of  
the          combinations of ,nitrous   
,oxide1 with the          alkalies      

#bed       #g4 ,combination of ,nitrous 
,oxide with ,potash        #bfb         
#h4 ,combination of ,nitrous ,oxide with
 ,soda          #bfh       #i4 ---- ----
 ---- with ,ammoniac                    
#bfi      #aj4 ,probability of forming  
compounds of          ,nitrous ,oxide   
and the alkaline earths           #bgc  
#aa4 ,additional ,observations          
#bgd      #ab4 ,the properties of       
,nitrous oxide resemble          those  
of ,acids                               
#bgf                                    
,,division ,,ii4      ,decomposition of 
,,nitrous ,,oxide by combustible        
,bodies4        #a4 ,preliminaries      
#bgh      #b4 ,conversion of ,nitrous   
,oxide into ,nitrous ,acid         and a
 gas analogous to ,atmospheric ,air     
by ignition                             
#bgi      #c4 ,decomposition of ,nitrous
 ,oxide by ,hydrogene      #bhf      #d4
 ---- ---- ---- by ,phosphorus          
#bic      #e4 ---- ---- by ,phosphorated
 ,hydrogene                  #cjj       

#f4 ---- ---- by ,sulphur               
#cjc      #g4 ---- ---- by ,sulphurated 
,hydrogene                   #cjf       
#h4 ---- ---- by ,charcoal              
#caa      #i4 ---- ---- by              
,hydrocarbonate                         
#cac      #aj4 ,combustion of ,iron in  
,nitrous ,oxide             #caf        
#aa4 ---- of ,pyrophorus                
#cah      #ab4 ---- of the ,taper       
#cai      #ac4 ---- of different        
,compound ,bodies                 #cba  
#ad4 ,general ,conclusions relating to  
the          decomposition of ,nitrous  
,oxide1 and          to its analysis    
#cbb      #ae4 ,observations on the     
combinations of ,oxygene          and   
,nitrogene                              
#cbe                                    
,,research ,,iii4             ,relating 
to the ,,respiration of ,,nitrous       
,,oxide                            and  
,,other ,,gases4                        
,,division ,i4      ,,experiments and   
,,observations on the effects produced  

upon ,animals by the respiration of     
,,nitrous ,,oxide4        #a4           
,preliminaries                          
#ccc      #b4 ,on the respiration of    
,nitrous ,oxide by         warm-blooded 
,animals                                
#ccf      #c4 ,effects of the           
respiration of ,nitrous ,oxide          
upon ,animals1 as compared with those   
produced         by their immersion in  
,hydrogene and ,water        #cdc       
#d4 ,of the changes effected in the     
organisation of         warm-blooded    
,animals1 by the respiration of         
,nitrous ,oxide                         
#cdg      #e4 ,of the respiration of    
mixtures of ,nitrous ,oxide         and 
other ,gases1 by warm-blooded ,animals  
#ceh      #f4 ,recapitulation of facts  
relating to the         respiration of  
,nitrous ,oxide1 by warm-blooded        
,animals                                
#cfj      #g4 ,of the respiration of    
,nitrous ,oxide1         by amphibious  
,animals                            #cfb

      #h4 ,effects of ,solution of      
,nitrous ,oxide on ,fishes   #cff       
#i4 ,effects of ,nitrous ,oxide on      
,insects              #cgj              
,,division ,,ii4      ,of the changes   
effected in ,,nitrous ,,oxide           
and other ,gases1 by the ,respiration of
 ,animals4        #a4 ,preliminaries    
#cgc      #b4 ,absorption of ,nitrous   
,oxide by ,venous ,blood      #cgd      
#c4 ,of the changes effected in ,nitrous
 ,oxide         by ,respiration         
#chh      #d4 ,respiration of ,hydrogene
                         #djj      #e4  
,additional ,observations and           
,experiments on the         ,respiration
 of ,nitrous ,oxide                     
#daa      #f4 ,of the ,respiration of   
,atmospheric ,air            #dbi       
#g4 ,respiration of ,oxygene            
#dci      #h4 ,observations on the      
changes effected in the         blood by
 ,atmospheric ,air and ,oxygene         
#dde      #i4 ,observations on the      
,respiration of ,nitrous ,oxide #ddi    

,,research ,,iv4                        
,relating to the ,,effects produced by  
the                      ,,respiration  
of ,,nitrous ,,oxide                    
upon different ,,individuals4           
,,division ,i4      ,,history of the    
,discovery4--,,effects produced         
by the ,respiration of different        
,,gases4         #a4 ,respirability of  
,nitrous ,oxide                  #def   
#b4 ,effects of ,nitrous ,oxide         
#deh       #c4 ,general ,effects of     
,nitrous ,oxide on the ,health  #dfd    
#d4 ,respiration of ,hydrogene          
#dff       #e4 ----  of ,nitrogene      
#dfg       #f4 ,effects of              
,hydrocarbonate                         
#dfh       #g4 ---- of ,carbonic ,acid  
#dgb       #h4 ---- of ,oxygene         
#dgc       #i4 ---- of ,nitrous ,gas    
#dge      #aj4 ,most extensive action of
 ,nitrous ,oxide          produces no   
debility                            #dhe
                                        
,,division ,,ii4      ,,details of the  

,effects produced by the  ,respiration  
of ,,nitrous ,,oxide upon different     
,individuals1        furnished by       
,themselves4         #a4 ,detail of ,mr4
 ,j4 ,w4 ,tobin                         
#dig       #b4 ---- of ,mr4 ,w4         
,clayfield                          #ejb
       #c4 ,letter from ,dr4 ,kinglake  
#ejc       #d4 ,detail of ,mr4 ,southey 
#ejg       #e4 ,letter from ,dr4 ,roget 
#eji       #f4 ,letter from ,mr4 ,james 
,thomson                   #eab         
#g4 ,detail of ,mr4 ,coleridge          
#eaf       #h4 ---- of ,mr4 ,wedgwood   
#eah       #i4 ---- of ,mr4 ,g4 ,burnet 
#ebj      #aj4 ---- of ,mr4 ,t4 ,pople  
#eba      #aa4 ---- of ,mr4 ,hammick    
#ebb      #ab4 ---- of ,dr4 ,blake      
#ebd      #ac4 ---- of ,mr4 ,wanfey     
#ebe      #ad4 ---- of ,mr4 ,rickman    
#ebf      #ae4 ---- of ,mr4 ,lovell     
,edgworth                       #ebg    
#af4 ---- of ,mr4 ,g4 ,bedford          
#ebh      #ag4 ---- of ,miss ,ryland    
#ecj      #ah4 ,letter from ,mr4 ,m4 ,m4

 ,coates                    #ecj        
,,division ,,iii4      ,abstracts from  
additional ,details--,observations on   
the effects of ,,nitrous ,,oxide1       
by ,dr4 ,,beddoes--,conclusion4         
#a4 ,abstracts from additional details  
#ecc      #b4 ,of the effects of        
,nitrous ,oxide on         delicate     
females                                 
#ecg      #c4 ,observations on the      
effects of ,nitrous ,oxide         by   
,dr4 ,,beddoes                          
#eda      #d4 ,conclusion               
#edh                                    
,,appendix4      ,no4 ,i4   ,of the     
effects of ,nitrous ,oxide              
on ,vegetables                          
#efa      ,no4 ,,ii4  ,table of the     
,weight and ,composition                
of the combinations of ,nitrogene       
#eff      ,no4 ,,iii4 ,additional       
,observations      #efg      ,no4 ,,iv4 
,description of a ,mercurial ,airholder1
               and ,breathing ,machine1 
by ,mr4 ,w4 ,,clayfield4                

#egc      ,no4 ,v4   ,proposals for the 
,preservation of                        
,accidental ,observations in ,medicine4 
,by ,dr4 ,,beddoes4                     
#egg          ,,introduction4      ,in  
consequence of the discovery of the     
respirability and extraordinary  effects
 of nitrous oxide1 or the               
dephlogisticated nitrous gas of ,dr4    
,priestley1 made in ,april #agii1 in a  
manner to be particularly described     
hereafter1#a ,i was induced to carry on 
the following investigation  concerning 
its composition1 properties1            
combinations1 and mode of  operation on 
living beings4    #a ,a short account of
 this discovery has been given in ,dr4  
,beddoes's  ,notice of some             
,observations made at the ,pneumatic    
,institution1 and in  ,mr4 ,nicholson's 
,phil4 ,journal for ,may and ,december  
#agii4    ,in the course of this        
investigation1 ,i have met with many    
difficulties2  some arising from the    
novel and obscure nature of the subject1

 and  others from a want of coincidence 
in the observations of different        
experimentalists on the properties and  
mode of production of the gas4  ,by     
extending my researches to the different
 substances connected  with nitrous     
oxide2 nitrous acid1 nitrous gas and    
ammoniac2 and by  multiplying the       
comparisons of facts1 ,i have succeeded 
in removing the  greater number of those
 difficulties1 and have been enabled to 
give a  tolerably clear history of the  
combinations of oxygene and nitrogene4  
,by employing both analysis and         
synthesis whenever these methods were   
equally applicable1 and comparing       
experiments made under different        
circumstances1 ,i have endeavoured to   
guard against sources of error2  but ,i 
cannot flatter myself that ,i have      
altogether avoided them4 ,the  physical 
sciences are almost wholly dependant on 
the minute observation  and comparison  
of properties of things not immediately 
obvious to the  senses2 and from the    

difficulty of discovering every possible
 mode of  examination1 and from the     
modification of perceptions by the state
  of feeling1 it appears nearly         
impossible that all the relations of  a 
series of phnomena can be discovered by 
a single investigation1  particularly   
when these relations are complicated1   
and many of the  agents unknown4        
,fortunately for the active and         
progressive nature  of the human mind1  
even experimental research is only a    
method of  approximation to truth4      
,in the arrangement of facts1 ,i have   
been guided as much as possible by      
obvious and simple analogies only4      
,hence ,i have seldom entered into      
theoretical discussions1 particularly   
concerning light1 heat1 and other       
agents1 which are known only by isolated
 effects4    ,early experience has      
taught me the folly of hasty            
generalisation4 ,we  are ignorant of the
 laws of corpuscular motion2 and an     
immense mass of  minute observations    

concerning the more complicated chemical
 changes  must be collected1 probably   
before we shall be able to ascertain    
even  whether we are capable of         
discovering them4 ,chemistry in its     
present  state1 is simply a partial     
history of phnomena1 consisting of many 
series more or less extensive of        
accurately connected facts4    ,with the
 most important of these series1 the    
arrangement of the  combinations of     
oxygene or the antiphlogistic theory    
discovered by  ,lavoisier1 the chemical 
details in this work are capable of     
being  connected4    ,in the present    
state of science1 it will be unnecessary
 to enter into  discussions concerning  
the importance of investigations        
relating to  the properties of          
physiological agents1 and the changes   
effected in  them during their          
operation4 ,by means of such            
investigations1 we arrive  nearer       
towards that point from which we shall  
be able to view what is  within the     

reach of discovery1 and what must for   
ever remain unknown to  us1 in the      
phnomena of organic life4 ,they are of  
immediate utility1 by  enabling us to   
extend our analogies so as to           
investigate the properties  of untried  
substances1 with greater accuracy and   
probability of  success4    ,the first  
,research in this work chiefly relates  
to the production  of nitrous oxide and 
the analysis of nitrous gas and nitrous 
acid4  ,in this there is little that can
 be properly called mine2 and if by     
repeating the experiments of other      
chemists1 ,i have sometimes been able   
to make more minute observations        
concerning phnomena1 and to draw        
different conclusions1 it is wholly     
owing to the use ,i have made of  the   
instruments of investigation discovered 
by the illustrious fathers  of chemical 
philosophy1#b and so successfully       
applied by them to the  discovery of    
truth4    #b ,cavendish1 ,priestley1    
,black1 ,lavoisier1 ,scheele1 ,kirwan1  

,guyton1  ,berthollet1 c4    ,in the    
second ,research the combinations and   
composition of nitrous  oxide are       
investigated1 and an account given of   
its decomposition by  most of the       
combustible bodies4    ,the third       
,research contains observations on the  
action of nitrous  oxide upon animals1  
and an investigation of the changes     
effected in it  by respiration4    ,in  
the fourth ,research the history of the 
respirability and  extraordinary effects
 of nitrous oxide is given1 with details
 of  experiments on its powers made by  
different individuals4    ,i cannot     
close this introduction1 without        
acknowledging my obligations  to ,dr4   
,beddoes4 ,in the conception of many of 
the following experiments1  ,i have been
 aided by his conversation and advice4  
,they were executed  in an ,institution 
which owes its existence to his         
benevolent and  philosophic exertions4  
,dowry-,square1 ,hotwells1 ,bristol4    
,june #beth1 #ahjj4                     

,,research ,i4        ,,concerning ,,the
 ,,analysis ,,of      ,,nitric ,,acid   
,,and ,,nitrous ,,gas         ,,and     
,,the ,,production ,,of                 
,,nitrous ,,oxide4    ,illustration3    
,pl4 ,i4 ,,mercurial ,,airholder and    
,,breathing ,,machine4    ,lowry sculp4 
,,research ,i4    ,,into ,,the          
,,production ,,and ,,analysis ,,of      
,,nitrous ,,oxide1 ,,and ,,the          
,a,,riform  ,,fluids ,,related ,,to     
,,it4      ,,division ,i4               
,,experiments and ,,observations on the 
composition         of ,,nitric ,,acid1 
and on its combinations         with    
,,water and ,,nitrous ,,gas4    ,i4     
,though since the commencement of       
,pneumatic ,chemistry1 no substance  has
 been more the subject of experiment    
than ,nitrous ,acid2 yet still  the     
greatest uncertainty exists with regard 
to the quantities of the  principles    
entering into its composition4    ,in   
comparing the experiments of the        
illustrious ,cavendish on the  synthesis

 of nitrous acid1 with those of         
,lavoisier on the decomposition  of     
nitre by charcoal1 we find a much       
greater difference in the results  than 
can be accounted for by supposing the   
acid formed1 and that  decomposed1 of   
different degrees of oxygenation4    ,in
 the most accurate experiment of        
,cavendish1 when the nitrous acid       
appeared to be in a state of            
deoxygenation1 #a of nitrogene combined 
with about #b1cdf of oxygene4#c ,in an  
earlier experiment1 when the  acid was  
probably fully oxygenated1 the nitrogene
 employed was to the  oxygene nearly as 
#a to #b1ib4d    ,lavoisier1 from his   
experiments on the decomposition of     
nitre1 and  combination of nitrous gas  
and oxygene1 concludes1 that the        
perfectly  oxygenated1 or what he calls 
nitric acid1 is composed of nearly #a   
nitrogene1 with #c1i of oxygene2 and the
 acid in the last state of              
deoxygenation1 or nitrous acid1 of about
 #c oxygene with #a nitrogene4#e    #c  

,phil4 ,trans4 v4 #gh1 p4 #bgj4    #d   
,phil4 ,trans4 v4 #ge p4 #cha4    #e    
,elem4 ,kerr's ,trans4 page #gf1 and    
#baf1 and ,mem4 des ,sav4 ,etrang4  tom4
 #g1 page #fbi4    ,great as the        
difference is between the estimations of
 these  philosophers1 we find           
differences still greater in the        
accounts of the  quantities of nitrous  
gas necessary to saturate a given       
quantity of  oxygene1 as laid down by   
very accurate experimentalists4 ,on the 
one  hand1 ,priestley found #a of       
oxygene condensed by #b of nitrous gas1 
and  ,lavoisier by #a4 ,on the other1   
,ingenhouz1 ,scherer1 and ,de la        
,metherie1  state the quantity necessary
 to be from #c to #e4f ,humbolt1 who has
  lately investigated ,eudiometry with  
great ingenuity1 considers the mean     
quantity of nitrous gas necessary to    
saturate #a of oxygene1 as about        
#b1ee4g    #f ,ingenhouz sur les        
,vegetaux1 pag4 #bje4 ,de la ,metherie4 
,essai sur  differens ,airs1 pag4 #beb4 

#g ,annales de ,chimie1 tome #bh1 p4    
#afh4    ,,ii4 ,to reconcile these      
different results is impossible1 and the
  immediate connection of the subject   
with the production of nitrous  oxide1  
as well as its general importance1      
obliged me to search for  means of      
accurately determining the composition  
of nitrous acid in its  different       
degrees of oxygenation4    ,the first   
desideratum was to ascertain the nature 
and composition of a  fluid acid1 which 
by being deprived of1 or combined with  
nitrous gas1  might become a standard of
 comparison for all other acids4    ,to 
obtain this acid ,i should have         
preferred the immediate combination  of 
oxygene and nitrogene over water by the 
electric spark1 had it  been possible to
 obtain in this way by a common         
apparatus sufficient  for extensive     
examination2 but on carefully perusing  
the laborious  experiments of           
,cavendish1 ,i gave up all thoughts of  
attempting it4    ,my first experiments 

were made on the decomposition of nitre1
  formed from a known quantity of pale  
nitrous acid of known specific  gravity1
 by phosphorus1 tin1 and charcoal3 but  
in those processes1  unascertainable    
quantities of nitrous acid1 with excess 
of nitrous  gas1 always escaped         
undecompounded1 and from the            
non-coincidence  of results1 where      
different quantities of combustible     
substances  were employed1 ,i had       
reasons for believing that water was    
generally  decomposed4    ,before these 
experiments were attempted1 ,i had      
analized nitrous gas  and nitrous oxide1
 in a manner to be particularly         
described hereafter2  so that a         
knowledge of the quantities of nitrous  
gas and oxygene  entering into the      
composition of any acid1 enabled me to  
determine the  proportions of nitrogene 
and oxygene it contained4 ,in           
consequence of  which ,i attempted to   
combine together oxygene and nitrous    
gas1 in such  a manner as to absorb the 

nitrous acid formed by water1 in an     
apparatus  by which the quantities of   
the gases employed1 and the increase of 
weight of the water1 might be           
ascertained2 but this process likewise  
failed4 ,it was impossible to procure   
the gases perfectly free from           
nitrogene1 and during their combination1
 this nitrogene made to pass  into a    
pneumatic apparatus communicating with a
 vessel containing the  water carried   
over with it1 much nitrous acid vapor1  
of different  composition from the acid 
absorbed4    ,after many unsuccessful   
trials1 ,dr4 ,priestley's experiments on
 nitrous  vapor#h induced me to suppose 
that oxygene and nitrous gas1 made to   
combine out of the contact of bodies    
having affinity for oxygene1 would      
remain permanently ariform1 and on      
throwing them separately into an        
exhausted glass balloon1 ,i found that  
this was actually the case2  increase of
 temperature was produced1 and orange   
colored nitrous acid  gas formed1 which 

after remaining for many days in the    
globe1 at a  temperature below #ef1 did 
not in the slightest degree condense4   
#h ,experiments and ,observations1 ,vol4
 iii4 last edition1 page #aje1 c4       
,this fact afforded me the means not    
only of forming a standard acid1  but   
likewise of ascertaining the specific   
gravity of nitrous acid in  its ariform 
state4    ,,iii4 ,previous to the       
experiment1 for the purpose of          
correcting  incidental errors1 ,i was   
induced to ascertain the specific       
gravity of  the gases employed1         
particularly as ,i was unacquainted with
 any process  by which the weight of    
nitrous gas had been accurately         
determined4 ,mr4  ,kirwan's estimation1 
which is generally adopted1 being       
founded upon  the comparison of the loss
 of weight of a solution of copper in   
dilute  nitrous acid1 with the quantity 
of gas produced4#i    ,the instruments  
that ,i made use of for containing and  
measuring my  gases1 were two mercurial 

airholders graduated to the cubic inch  
of  ,everard1 and furnished with        
stop-cocks4#aj    #i ,when copper is    
dissolved in dilute nitrous acid1       
certain quantities  of nitrogene are    
generally produced1 likewise the nitrous
 gas carries  off in solution some      
nitrous acid4    #aj ,this airholder1   
considered as a pneumatic instrument1 is
 of  greater importance1 and capable of 
a more extensive application than  any  
other4 ,it was invented by ,mr4 ,w4     
,,clayfield1 and in its form is         
analogous to ,mr4 ,,watt',s hydraulic   
bellows1 consisting of a glass bell     
playing under the pressure of the       
atmosphere1 in a space between two      
cylinders filled with mercury4 ,a       
particular account of it will be given  
in the appendix4    ,they were weighed  
in a glass globe1 of the capacity of    
#ajh cubic  inches1 which with the small
 glass stop-cock affixed to it1 was     
equal1  when filled with atmospheric    
air1 to #agee grains4 ,the balance that 

,i  employed1 when loaded with a pound1 
turned with less than one eighth of  a  
grain4    ,into a mercurial airholder1  
of the capacity of #bjj cubic inches1   
#afj  cubic inches of nitrous gas were  
thrown from a solution of mercury in    
nitrous acid4    #gj measures of this   
were agitated for some minutes in a     
solution of  sulphate of iron1#aa till  
the diminution was complete4 ,the       
nitrogene  remaining hardly filled a    
measure2 and if we suppose with         
,humbolt#ab  that a very small portion  
of it was absorbed with the nitrous gas1
 the  whole quantity it contained may be
 estimated at #j1jadb1 or _/4    #aa    
,this absorption will be hereafter      
particularly treated of4    #ab ,annales
 de ,chimie4 ,tome xviii4 page #aci4    
#ge cubic inches received from the      
airholder into an exhausted balloon1    
increased it in weight #be1e grains2    
thermometer being #ef1 and  barometer   
#cj1i4 ,and allowing for the small      
quantity of nitrogene in the  gas1 #ajj 

cubic inches of it will weigh #cd4c     
grains4    ,one hundred and thirty cubic
 inches of oxygene were procured from   
oxide  of manganese and sulphuric acid1 
by heat1 and received in another        
mercurial airholder4    #aj measures of 
it1 mingled with #bf of the nitrous gas1
 gave1 after  the residuum was exposed  
to solution of sulphate of iron1 rather 
more  than one measure4 ,hence we may   
conclude that it contained about #j1a   
nitrogene4    #fj cubic inches of it    
weighed #bj1ge grains2 and accounting   
for the  nitrogene contained in these1  
#ajj grains of pure oxygene will weigh  
#ce1ji grains4    ,atmospherical air was
 decomposed by nitrous gas in excess2   
and the  residuum washed with solution  
of sulphate of iron till the ,nitrogene 
remained pure2 #hg cubic inches of it   
weighed #bf1e grains1 thermometer  being
 #dh1 barometer #cj1a2 #ajj will        
consequently weigh #cj1de4    #ij cubic 
inches of the air of the laboratory not 
deprived of its  carbonic acid1 weighed 

#bh1ge grains2 thermometer #ec1         
barometer #cj3 #ajj  cubic inches will  
consequently weigh #ca1i4ac #af measures
 of this air1  with #af nitrous gas1 of 
known composition1 diminished to #ai4   
,hence it  contained about1#bf          
oxygene4#ad    ,in comparing my results 
with those of ,lavoisier and ,kirwan1   
the  estimation of the weights of       
nitrogene and oxygene is very little    
different1 the corrections for          
temperature and pressure being made1    
from that of those celebrated           
philosophers4 ,the first makes oxygene  
to  weigh#ae #cd1ba1 and nitrogene      
#cj1jfd per cent2 and the last1 oxygene 
#cd1af and nitrogene #cj1e4    #ac ,a   
table of the specific gravities of these
 gases1 and other gases1  hereafter to  
be mentioned1 reduced to a barometrical 
and thermometrical  standard1 will be   
given in the appendix4    #ad #dj       
measures1 exposed to solution of potash1
 gave an absorption of  not quite a     
quarter of a measure3 hence it contained

 an inconsiderable  quantity of carbonic
 acid4    #ae ,trait ,elementaire4      
#af ,essai sur le phlogistique1 page    
#cj4    ,the specific gravity of nitrous
 gas1 according to ,kirwan1 is to that  
of  common air as #aaid to #ajjj4 ,hence
 it should weigh about #cg grains per   
cent4 ,this difference from my          
estimation is not nearly so great as ,i 
expected to have found it4#ag           
,,iv4#ah ,the thermometer in the        
laboratory standing at #ee1 and the     
barometer at #cj1a1 ,i now proceeded to 
my experiment4 ,the oxygene that  ,i    
employed was of the same composition as 
that which ,i had previously  weighed4  
,the nitrous gas contained1#jaff        
nitrogene4    ,for the purpose of       
combining the gases1 a glass balloon was
 procured1  of the capacity of #adh     
cubic inches1 with a glass stop-cock    
adapted to  it1 having its upper orifice
 tubulated and graduated for the purpose
 of  containing and measuring a fluid4  
,the whole weight of this globe and  its

 appendages1 when filled with common    
air1 was #bjff1e grains4    #ag ,the    
diminution of the specific gravity of   
the gas from the  quantity of nitrogene 
evolved in his experiment1 probably     
destroyed1 in  some measure1 the source 
of error from the nitrous acid carried  
over4    #ah ,experiment ,i4    ,it was 
partially exhausted by the air-pump1 and
 lost in weight just  #cb grains4 ,from 
whence we may conclude that about #ae   
grains of air  remained in it4    ,in   
this state of exhaustion it was         
immediately cemented to the  stop-cock  
of the mercurial airholder1 and the     
communication being made  with great    
caution1 #hb cubic inches of nitrous gas
 rushed into the  globe1 on the outside 
of which a slight increase of           
temperature was  perceived1 while the   
gases on the inside appeared of a deep  
orange4    ,before the common           
temperature was restored1 the           
communication was  stopped1 and the     
globe removed4 ,the increase of weight  

was #bi1be  grains2 whence it appeared  
that #a1ad grains of common air1 part of
  which had been contained in the       
stop-cocks1 had entered with the        
nitrous gas4    ,whilst it was cooling1 
from the accidental loosening of the    
stopper of  the cock1 #c grains more of 
common air entered4#ai    #ai ,that no  
greater contraction took place depended 
on the solution  of the nitrous acid    
formed in the nitrous gas2 a phnomenon  
to be  explained hereafter4    ,the     
communication was now made between the  
globe and the mercurial  airholder      
containing oxygene4 #fd cubic inches    
were slowly pressed in1  when the       
outside of the globe became warmer1 and 
the color on the  inside changed to a   
very dark orange4 ,as it cooled1 #f     
cubic inches more  slowly entered2 but  
no new increase of temperature1 or      
change of color  took place4    ,the    
globe being now completely cold1 was    
stopped1 removed1 and  weighed2 it had  
gained #bd1e grains1 from whence it     

appears that #j1d  grains of common air 
contained in the stop-cocks1 had entered
 with the  oxygene4#bj    #bj ,i judged 
it expedient always to ascertain the    
quantity of air in  the stop-cocks by   
weight1 as it was impossible to join    
them so as to  have always an equal     
capacity4 ,the upper tubes of the two   
stop-cocks  not joined1 contained nearly
 an inch and half4    ,to absorb the    
nitrous acid gas1 #da grains of water   
were introduced by  the tube of the     
stop-cock1 which though closed as       
rapidly as possible1  must have suffered
 nearly1#e grains of air to enter at the
 same time1 as  the increase of weight  
was #da1e grains4 ,the dark orange of   
the globe  diminished rapidly2 it became
 warm at the bottom1 and moist on the   
sides4 ,after a few minutes the color   
had almost wholly disappeared4    ,to   
ascertain the quantity of ariform fluid 
absorbed1 the globe was  again attached 
to the mercurial air apparatus1         
containing #adj cubic  inches of common 

air4 ,when the communication was made1  
#ea cubic inches  rushed in1 and it     
gained in weight #af1e grains4    ,a    
quantity of fluid equal to #ed grains   
was now taken out of the globe4  ,on    
examination it proved to be slightly    
tinged with green1 and occupied  a space
 equal to that filled by #da1e grains of
 water4 ,its specific  gravity was      
consequently #a1cja4    ,to ascertain if
 any unabsorbed ariform nitrous acid    
remained in the  globe1 #ac grains of   
solution of ammonia were introduced in  
the same  manner as the water1 and after
 some minutes1 when the white vapor  had
 condensed1 the communication was again 
made with the mercurial  airholder      
containing common air4 ,a minute        
quantity entered1 which could  not be   
estimated at more than three fourths of 
an inch1 and the globe  was increased in
 weight about #ac1be grains4#ba         
,common air was now thrown into the     
globe till the residual gases of  the   
experiment were judged to be displaced2 

it weighed #bajf1e grains1  that is1 #dj
 grains more than it had weighed when   
filled with common air  before the      
experiment4#bb    #ba ,that is1 by the  
solution of ammonia1 and air4    #bb    
,the following is an account of the     
increase and diminution of  weight of   
the globe1 as it was noted in the       
journal4        ,globe filled with      
common air                      gr4     
#bjff1e      ,after exhaustion          
#bjcd1e      ,after introduction of     
nitrous gas1 #hb cubic inches           
#bjfd1be      ,after the accidental     
admission of common air                 
#bjfg1be      ,after the admission of   
oxygene                        #bjia1ge 
----    ----   #da grains of water      
#bacc1be      ----    ----   #ea cubic  
inches of air                           
#badi1ge      ,taken out #ed grains of  
solution                       #bjie1ge 
,introduced #ac grains of ammoniacal    
solution           #baji1be      ,after 
introduction of common air              

#bajf1e      ,and if from those #dj     
grains we take #ac for the solution of  
ammonia  introduced1 the remainder1 #bg1
 will be the quantity of solution of    
nitrous acid in water remaining in the  
globe1 which added to #ed1 equals  #ha  
grains1 the whole quantity formed2 but  
if from this be taken #da  grains1 the  
quantity of water1 the remainder #dj    
grains1 will be the  quantity of nitrous
 acid gas absorbed in the solution4     
,to find the absolute quantity of       
nitrous acid formed1 we must find  the  
specific gravity of that absorbed2 but  
as during1 and after its  absorption1   
#ag grains of air1 equal to #ec1b cubic 
inches entered1 it  evidently filled    
such a space4 #ec1b cubic inches of it  
consequently  weigh #dj grains1 and #ajj
 cubic inches #ge1ag grains4 ,then1#ge  
cubic  inches weigh1#ef grains1 and this
 added to #dj1 makes #dj1ef grains1     
equal  to #ec1ie cubic inches1 the whole
 quantity of ariform nitrous acid       
produced4    ,but the quantity of       

nitrous gas entering into this1 allowing
 for the  nitrogene it contained1 is    
#bg1f grains1 equal to about #hj1e cubic
  inches2 and the oxygene is #dj1ef-bg1f
  to #ab1if grains1 or #cf1i cubic      
inches4    ,v4 ,there could exist in    
this experiment no circumstance         
connected with  inaccuracy1 except the  
impossibility of very minutely          
determining  the quantities of common   
air which entered with the gases from   
the  stop-cocks4 ,but if errors have    
arisen from this source1 they must be   
very inconsiderable2 as will appear from
 a calculation of the specific  gravity 
of the nitrous acid gas1 founded on the 
volume of the gases  that entered the   
globe4        ,the air that remained in 
the globe             after exhaustion  
was #ae grains        #dgbc cub4 in4    
,the nitrous gas introduced was         
#hb      ,common air                    
#ac      ,oxygene                       
#gj      ,common air                    
#a                                      

----      ,whole quantity of air thrown 
into the globe  #bac      ,from which   
subtract its capacity             #adh  
----      ,the remainder is             
#fe    #bc ,decimals are omitted1       
because the excess of the two first     
numbers  is exactly corrected by the    
deficiency of the last4    ,and this    
remainder taken from #hj1e nitrous gas  
#cf1i oxygene1 leaves  #eb1d cubic      
inches1 which is the space occupied by  
the nitrous acid gas1  and which differs
 from #ec1ie only by #a1ee cubic inches4
    ,i ought to have observed1 that     
before this conclusive experiment1 two  
similar ones had been made4 ,in         
comparing the results of one of them1   
performed with the assistance of my     
friend1 ,mr4 ,,joseph ,,priestley1 ,dr4 
,,priestley',s eldest son1 and chiefly  
detailed by him in the journal1 ,i  find
 a coincidence greater than could be    
even well expected1 where the  processes
 are so complex4 ,according to that     
experiment1 #da1e grains  of nitrous    

acid gas fill a space equal to #ec cubic
 inches1 and are  composed of nearly #bi
 nitrous gas1 and #ab1e oxygene4    ,we 
may then conclude1 ,first1 that #ajj    
cubic inches of nitrous acid1  such as  
exists in the#bd ariform state saturated
 with oxygene1 at  temperature #ee1 and 
atmospheric pressure #cj1a weigh #ge1ag 
grains4    #bd ,as is evident from the  
superabundant quantity of oxygene thrown
  into the globe4    ,secondly1 that    
#ajj grains of it are composed of #fh1jf
 nitrous gas1 and  #ca1id oxygene4 ,or  
assuming what will be hereafter proved1 
that #ajj  parts of nitrous gas consist 
of #ee1ie oxygene1 and #dd1je nitrogene1
 of  #bi1i nitrogene1 and #gj1a oxygene2
 or taking away decimals1 of #cj of the 
one to #gj of the other4    ,thirdly1   
that #ajj grains of pale green solution 
of nitrous acid in  water1 of specific  
gravity #a1cja1 are composed of #ej1fb  
water1 and #di1ch  acid of the above    
composition4    ,,vi4 ,having thus      
ascertained the composition of a        

standard acid1 my next  object was to   
obtain it in a more condensed state1 as 
it was otherwise  impossible to saturate
 it to its full extent with nitrous gas4
 ,but this  ,i could effect in no other 
way than by comparing mixtures of known 
quantities of water1 and acids of       
different specific gravities and        
colors1 with the acid of #a1cja4    ,for
 the purpose of combining my acids with 
water1 ,i made use of a  cylinder about 
#h inches long1 and1#c inches in        
diameter1 accurately  graduated to grain
 measures1 and furnished with a very    
tight stopper4    ,the concentrated acid
 was first slowly poured into it1 and   
the water  gradually added till the     
required specific gravity was           
produced2#be  the cylinder being closed 
and agitated after each addition1 so as 
to  produce combination without any     
liberation of elastic fluid4    #be ,the
 weight of the acid poured into the     
cylinder being known1 its  specific     
gravity was known from the space it     

occupied in the phial4  ,the weight of  
water being likewise known1 the specific
 gravity of the  solution1 when the     
common temperature was produced1 was    
given by the  condensation4    ,after   
making a number of experiments with     
acids of different colors  in this      
advantageous way1 ,i at length found    
that #ij grains of a deep  yellow acid1 
of specific gravity #a1e1 became1 when  
mingled at #dj with  #gg1e grains of    
water1 of specific gravity #a1cjb1 and  
of a light green  tinge1 as nearly as   
possible resembling that of the standard
 acid4    ,supposing1 then1 that these  
acids contain nearly the same relative  
proportions of oxygene and nitrogene1   
#ajj grains of the deep yellow  acid of 
#a1e1 are composed of #ia1i grains true 
nitrous acid1#bf and #h1a  grains of    
water4    #bf ,that is1 such as it      
exists in the ariform state at #ee4     
,from the  strong affinity of nitrous   
acid for water1 we may suppose that this
  acid gas contains a larger proportion 

of it than the other gases4    ,to      
ascertain the difference between the    
composition of this acid1  and that of  
the pale1 or nitric acid1 of the same   
specific gravity1  ,i inserted #aej     
grains of it into a small cylindrical   
mattrass of the  capacity of1#e cubic   
inches1 accurately graduated to grain   
measures1  and connected by a curved    
tube with the water apparatus4 ,after   
heat had  been applied to the bottom of 
the mattrass for a few minutes1 the     
color  of the fluid gradually changed to
 a deep red1 whilst the globules of  gas
 formed at the bottom of the acid1 were 
almost wholly absorbed in  passing      
through it4 ,in a short time deep red   
vapour began to fill the  tube1 and     
being condensed by the water in the     
apparatus1 was converted  into a bright 
green fluid1 at the same time that      
minute globules of  gas were given out4 
,as the heat applied became more        
intense1 a very  singular phnomenon     
presented itself2 the condensed vapor1  

increased  in quantity1 at length filled
 the curvature of the tube1 and when    
expelled1 formed itself into dark green 
spherules1 which sunk to the  bottom of 
the water1 rested for a moment1 and then
 resolved themselves  into nitrous      
gas4#bg    #bg ,this appearance will be 
explained hereafter4    ,when the acid  
was become completely pale1 it was      
suffered to cool1  and weighed4 ,it had 
lost near #ae grains1 and was of        
specific gravity  #a1dia4 #b cubic      
inches and quarter of nitrous gas only  
were collected4    ,from this experiment
 evidently no conclusions could be      
drawn1 as the  nitrous gas had carried  
over with it much nitrous acid 7in the  
form of  what ,dr4 ,priestley calls     
nitrous vapor7 and was partially        
dissolved  with it in the water4#bh     
#bh ,this phnomenon will be particularly
 explained hereafter4    ,to ascertain1 
then1 the difference between the pale   
and yellow acids1 ,i  was obliged to    
make use of synthesis1 compared with    

analysis1 carried  on in a different    
mode1 by means of the following         
apparatus4    ,,vii4 ,to the stop-cock  
of the upper cylinder of the mercurial  
airholder1  a capillary tube was        
adapted1 bent so as to be capable of    
introduction  into an orifice in the    
stopper of a graduated phial similar to 
that  employed for mingling acids with  
water1 and sufficiently long to reach   
the bottom4 ,with another orifice in the
 stopper of the phial was  connected a  
similar tube curved1 for the purpose of 
containing a fluid1  and of increased   
diameter at the extremity4#bi    #ej    
cubic inches of pure nitrous gas#cj were
 thrown into the mercurial  apparatus4  
,the graduated phial1 containing #ij    
grains of nitric acid1 of  specific     
gravity #a1e1 was placed on the top of  
the airholding cylinder1  and made to   
communicate with it by means of the     
stop-cock and first  tube4 ,into the    
second tube a small quantity of solution
 of potash was  placed4 ,when all the   

junctures were carefully cemented1 by   
pressing on  the airholder1 the nitrous 
gas was slowly passed into the phial1   
and  absorbed by the nitrous acid it    
contained2 whilst the small quantities  
of nitrogene evolved1 slowly drove      
forward the solution in the curved      
tube2 from the height of which1 as      
compared with that of the mercury in    
the conducing tube1 the pressure on the 
air in the cylinder was known4    ,in   
proportion as the nitrous gas was       
absorbed1 the phial became warm1  and   
the acid changed color2 it first became 
straw-colored1 then pale  yellow1 and   
when about #g cubic inches had been     
combined with it1  bright yellow4 ,it   
had gained in weight nearly #c grains1  
and was become  of specific gravity     
#a1dif4    #bi ,the outline only of this
 apparatus is given here1 as far as was 
necessary to make the experiment        
intelligible2 a detailed account of  it1
 and of its general application1 will be
 given in the appendix4    #cj ,that is1

 from nitrous acid and mercury4    ,this
 experiment afforded me an approximation
 to the real difference  between nitric 
and yellow nitrous acid2 and learning   
from it that  nitric acid was diminished
 in specific gravity by combination with
  nitrous gas1 ,i procured a pale acid  
of specific gravity #a1ejd4ca  ,after   
this acid had been combined in the same 
manner as before1 with  about #h cubic  
inches of nitrous gas1#cb it became     
nearly of specific  gravity #a1e1 and   
had gained in weight about #c grains4   
#ca ,a pale acid of #a4eb1 by being     
converted into yellow acid1 became      
nearly of specific gravity #ae1a4    #cb
 ,it is impossible to ascertain the     
quantity of gas absorbed to more  than a
 quarter of a cubic inch1 as the first  
portions of nitrous gas  thrown into the
 graduated cylinder are combined with   
the oxygene of the  common air in it1 to
 form nitrous acid1 and hence the slight
 excess of  weight4    ,assuming the    
accuracy of this experiment as a        

foundation for  calculation1 ,i         
endeavoured in the same manner to       
ascertain the  differences in the       
composition of the orange colored acids1
 and the  acids containing still larger 
proportions of nitrous gas4    #ic      
grains of the bright yellow acid of #a1e
 became1 when #f cubic inches  of gas   
had been passed through it1 orange      
colored and fuming1 whilst  the         
undissolved gas increased in quantity so
 much as to render it  impossible to    
confine it by the solution of potash4   
,when #i cubic inches  had passed       
through1 it became dark orange4 ,it had 
gained in weight  #b1ge grains1 and was 
become of specific gravity #a1dh nearly4
 ,hence it  was evident that much       
nitrous gas had passed through it       
undissolved4  #be cubic inches more of  
nitrous gas were now slowly sent through
 it3  it first became of a light olive1 
then of a dark olive1 then of a  muddy  
green1 then of a bright green1 and      
lastly of a blue green4 ,after  its     

assumption of this color1 the gas       
appeared to pass through it  unaltered1 
and large globules of fluid1 of a darker
 green than the  rest1 remained at the  
bottom of the cylinder1 and when        
agitated1 did  not combine with it4 ,the
 increase of weight was only #a grain1  
and the  acid was of specific gravity   
#a1dgd nearly4    ,in this experiment it
 was evident that the unabsorbed nitrous
 gas  had carried over with it a        
considerable quantity of nitrous acid4  
,i  endeavoured to correct the errors   
resulting from this circumstance1  by   
connecting the curved tube first with a 
small water apparatus1 and  afterwards  
with a mercurial apparatus2 but when the
 water apparatus  was used1 the greater 
part of the unabsorbed gas was dissolved
 with  the nitrous acid it held in      
solution1 by the water2 and when mercury
  was employed1 the nitrous acid that   
came over was decomposed1 and the       
quantity of nitrous gas evolved1 in     
consequence increased4    ,as it was    

possible that a small deficiency of     
weight might arise from  the red vapor  
given out during the processes of       
weighing and examining  the acid in the 
last experiment1 #ce cubic inches of    
nitrous gas were  very slowly passed    
through #ij grains of pale nitrous acid1
 of specific  gravity #a1e3 it became of
 similar appearance to that just        
described1  had gained in weight #f1ge  
grains1 and was become of specific      
gravity  #a1dge4    ,these experiments  
did not afford approximations           
sufficiently accurate  towards the      
composition of deoxygenated acids1      
containing more nitrous  gas than the   
dark orange colored4 ,to obtain them1 a 
solution consisting  of #id1be grains of
 blue green1 or perfectly nitrated acid1
 7if we  may be allowed to employ the   
term71 of specific gravity #a1dge1 was  
inserted into a graduated phial1 and    
connected by a curved tube1 with  the   
mercurial airholder2 in the conductor of
 which a small quantity of  water was   

inserted to absorb the nitrous acid     
which might be carried  over by the gas4
 ,heat was slowly applied to the phial1 
and nitrous gas  given out with great   
rapidity4 ,when #d cubic inches were    
collected1  the acid became dark olive1 
when #i dark red1 when #ac bright       
orange1  and when #ah pale4 ,it had lost
 #ca grains1 and when completely cool1  
was of specific gravity #a1ejb nearly4  
,the water in the apparatus was  tinged 
of a light blue2 from whence we may     
conclude that some of the  nitrous gas  
was absorbed by it with the nitrous     
acid3 but it will be  hereafter proved  
that the orange colored acid is the most
 nitrated acid  capable of combining    
undecompounded with water1 and that the 
color it  communicates to a large       
quantity of water1 is light blue4 ,if   
then we  take #f1a grains1 the quantity 
of gas collected1 from #ca the loss1 the
  remainder is #bd1i1 which reasoning   
from the synthetical experiment1  may be
 supposed to contain nearly #c cubic    

inches of nitrous gas4  ,consequently1  
#id1be grains of dark green acid1 of    
specific gravity  #a1dge1 are composed  
of nearly #ba cubic inches1 or #g1b     
grains of nitrous  gas1 and #hg1je      
grains of pale nitrous acid1 of #a1ejd4 
,,viii4 ,comparing the different        
synthetical and analytical experiments1 
we may conclude with tolerable accuracy1
 that #ib1ge grains of bright  yellow1  
or standard acid of #a1e1 are composed  
of #b1ge grains of nitrous  gas1 and #ij
 grains of nitric acid of #a1ejd2 but   
#ib1ge grains of  standard acid contain 
#he1bc grains of nitrous acid1 composed 
of about  #bg1bc of oxygene1 and #eh1   
nitrous gas3 now from #eh1 take #b1ge1  
and the  remainder #ee1be1 is the       
quantity of nitrous gas contained in #ij
 grains  of nitric acid of #a1ejd2      
consequently1 #ajj grains of it are     
composed  of #h1de water1 and #ia1ee    
true acid1 containing #fa1cb nitrous    
gas1 and  #cj1bc oxygene2 or #bg1ja     
nitrogene1 and #fd1ed oxygene3 and the  

nitrogene  in nitric acid1 is to the    
oxygene as #a to #b1chi4    ,,ix4 ,my   
ingenious friend1 ,mr4 ,,james          
,,thomson1 has communicated to me some  
observations relating to the composition
 of nitrous acid 7that is1 the  orange  
colored acid71 from which he draws a    
conclusion which is1 in my  opinion1    
countenanced by all the facts we are in 
possession of1 namely1  8that it ought  
not to be considered as a distinct and  
less oxygenated  state of acid1 but     
simply as nitric or pale acid1 holding  
in solution1  that is1 loosely combined 
with1 nitrous gas40#cc    #cc ,in a     
letter to me1 dated ,oct4 #bh1 #agii1   
after giving an account  of some        
experiments on the phlogistication of   
nitric acid by heat and  light1 he says1
 8,it was from an attentive examination 
of the manner in  which the nitric acid 
was phlogisticated in these experiments1
 that  ,i was confirmed in the suspicion
 ,i had long before entertained1 of  the
 real difference between the nitrous and

 nitric acids4 ,it is  not enough to    
shew that in the nitrous acid1 7that is1
 the nitric  holding nitrous gas in     
solution71 the proportion of oxygene in 
the  whole compound is less than that   
entering into the composition of the    
nitric acid1 and that it is therefore   
less oxygenated4 ,by the same  mode of  
reasoning we might prove that water1 by 
absorbing carbonic  acid gas1 became    
less oxygenated1 which is absurd4       
,should any one  attempt to prove 7which
 will be necessary to substantiate the  
generally  received doctrine7 that the  
oxygene of the nitrous gas combines with
  the oxygene of the acid1 and the      
nitrogene1 in like manner1 so that  the 
resulting acid1 when nitrous gas is     
absorbed by nitric acid1 is a  binary   
combination of oxygene and nitrogene1 he
 would find it somewhat  more difficult 
than he at first imagined2 it appears to
 me impossible4  ,it is much more       
consonant with experiment to suppose    
that nitrous acid  is nothing more than 

nitric acid holding nitrous gas in      
solution1 which  might in conformity to 
the principles of the ,french           
nomenclature1 be  called nitrate of     
nitrogene4 ,the difficulty1 and in some 
cases the  impossibility1 of forming    
nitrites1 arises from the weak affinity 
which nitrous gas has for nitric acid1  
compared with that of other  substances2
 and the decomposition of nitrous acid  
7that is1 nitrate of  nitrogene7 by an  
alkaline or metallic substance1 is      
perfectly analogous  to the             
decomposition of any other nitrate1 the 
nitrous gas being  displaced by the     
superior affinity of the alkali for the 
acid4    8,agreeable to this theory1 the
 salts denominated nitrites are in fact 
triple salts1 or ternary combinations of
 nitric acid1 nitrous gas1 and          
salifiable bases40    ,this theory is   
perfectly new to me4 ,other ,chemists to
 whom ,i have  mentioned it1 have       
likewise considered it as new4 ,yet in a
 subsequent  letter ,mr4 ,thomson       

mentions that he had been told of the   
belief of a  similar opinion among the  
,french ,chemists4    ,it is impossible 
to call any substance a simple acid that
 is incapable  of entering              
undecompounded into combination with the
 alkalies1 c2 but  it will appear       
hereafter that the salts called in the  
new nomenclature  nitrites1 cannot be   
directly formed4 ,if1 indeed1 it could  
be proved1  that the heat produced by   
the combination of nitrous acid with    
salifiable bases1 was the only cause of 
the partial decomposition of  it1 and   
that when this process was effected in  
such a way as to prevent  increase of   
temperature1 no nitrous gas was         
liberated1 the common  theory might have
 some foundation2 but though dilute     
phlogisticated  nitrous acid combines#cd
 with alkaline solutions without        
decomposition1 yet no excess of nitrous 
gas is found in the solid salt3  it is  
either disengaged in proportion as the  
water is evaporated1 or it  absorbs     

oxygene from the atmosphere1 and becomes
 nitric acid4    #cd ,in some           
experiments made on the nitrites of     
potash1 and of  ammoniac1 before ,i was 
well acquainted with the composition of 
nitric  acid1 ,i found that a light     
olive-colored acid of #a1bh1 was capable
  of being saturated by weak solutions  
of potash and ammoniac1 without  losing 
any nitrous gas2 but after the          
evaporation of the neutralised          
solution1 at very low temperatures1 the 
salts in all their properties  resembled
 nitrates4    ,in proportion as the     
nitrous acids contain more nitrous gas1 
so in  proportion do they more readily  
give it out4 ,from the blue green acid  
it is liberated slowly at the           
temperature of #ej1 and from the green  
likewise on agitation4 ,the orange      
coloured and yellow acids do not        
require a heat above #bjj to free them  
of their nitrous gas2 and all  the      
colored acids1 when exposed to the      
atmosphere absorb oxygene1 and  become  

by degrees pale4    ,if the nitrous     
vapour1 i4 e4 such as is disengaged     
during the  denitration of the colored  
acids1 was capable of combining with the
  alkalies1 it might be supposed a      
distinct acid1 and called nitrous  acid2
 and the acids of different colors might
 be considered simply as  compounds of  
this acid with nitric acid2 but it      
appears to be nothing  more than a      
solution of nitric acid in nitrous gas1 
incapable of  condensation1             
undecompounded1 and when decompounded   
and condensed1  constituting the dark   
green acid1 which is immiscible with    
water1#ce  and uncombinable with the    
alkalies4#cf    #ce ,as is evident from 
the curious appearance of the dark green
  spherules1 repulsive both to water1   
and light green acid4    #cf ,that is1  
undecompounded4    ,it seems therefore  
reasonable1 till we are in possession of
 new lights  on the subject1 to         
consider1 with ,mr4 ,thomson1 the       
deoxygenated or  nitrous acids simply as

 solutions of nitrous gas composed of   
sulphuric  acid1 metallic oxides1 and   
nitrous gas4#cg    #cg ,the existence of
 these bodies will be hereafter proved4 
,supposing the truth of these principles
 according to the logic of the  ,french 
nomenclature1 there is no acid to which 
the term nitrous acid  ought to be      
applied2 but as it has been used to     
signify the acids  holding in solution  
nitrous gas1 it is perhaps better still 
to apply it  to those substances1 than  
to invent for them new names4 ,a        
nomenclature1  accurately expressing    
their constituent parts1 would be too   
complex1  and like all other            
nomenclatures founded upon theory1      
liable to  perpetual alterations4 ,their
 composition is known from their        
specific  gravity and their colors2     
hence it is better to denote it by those
  physical properties3 thus orange      
nitrous acid1 of specific gravity       
#a1dhj1 will signify a solution of      
nitrous gas in nitric acid1 in which    

the nitric acid is to the nitrous gas1  
nearly as #hg to #e1 and to the  water  
as #aa to #a4    ,x4 ,the estimation of 
the composition of the yellow and orange
 colored  nitrous acids given in the    
following table1 may be considered as   
tolerably accurate1 being deduced from  
the synthetical experiments  in the     
sixth section1 compared with the        
analytical ones4 ,but as  in the        
synthetical experiment1 when the acid   
became green1 it was  impossible to     
ascertain the quantity of nitrous gas   
that passed through  it unabsorbed1 and 
as in the analysis the quantity of      
nitrous gas  dissolved by the water at  
different periods of the experiment     
could not  be ascertained1 the accounts 
of the composition of the green acids   
must  be considered only as very        
imperfect approximations to truth4      
,,table ,i4        ,containing          
,approximations to the quantities       
of ,,nitric ,,acid1 ,,nitrous ,,gas1 and
 ,,water in         ,,nitrous ,,acids1  

of different colors and specific        
gravities4                              
----------------------------------------
------------------           #ajj       
,specific     ,nitric  ,water  ,nitrous 
,parts             ,gravity       ,acid 
gas                                     
----------------------------------------
------------------      ,sol4 ,nitric   
,acid       #a1ejd    c   #ia1ee   #h1de
    -- --         ,yellow ,nitrous#ch   
#a1ejb    o   #ij1e    #h1c     #a1b    
,bright ,yellow      o   #a1ejj    n    
#hh1id   #h1aj    #b1if        ,dark    
,orange        f   #a1dhj    t   #hf1hd 
#g1f     #e1ef        ,light ,olive     
#a1dgi    a   #hf1jj   #g1ee    #f1de   
,dark ,olive            #a1dgh    i     
#he1d    #g1e     #g1a         ,bright  
,green          #a1dgf    n   #hd1h     
#g1dd    #g1gf        ,blue ,green#ci   
#a1dge        #hd1f    #g1d     #h1jj   
----------------------------------------
------------------           8,,footnote
 #ch0    #ch ,the blue green acid is not

 homogeneal in its composition1 it is   
composed of the blue green spherules and
 the bright green acid4 ,the  blue green
 spherules are of greater specific      
gravity than the dark  green acid1      
probably because they contain little or 
no water4    #ci ,the composition of the
 acids thus marked1 is given from       
calculations4      ,,table ,,ii4        
,binary ,proportions of ,,oxygene and   
,,nitrogene in         ,,nitric and     
,,nitrous ,,acids4#dj                   
----------------------------------------
--------------------         #ajj ,parts
      ,oxygene ,nitro-                  
,nitro-,oxygene                         
gene                gene                
----------------------------------------
--------------------      ,nitric ,acid 
c  #gj1ej  #bi1ej                  #a   
#b1chi       --------------- o          
---------------                         
--------------      ,bright yellow   n  
#gj1aj  #bi1ij                  #a      
#b1cdd           ,nitrous     t         

,proportions4                           
--------------- a ---------------       
,nitrogene4  --------------      ,orange
 coloured i  #fi1fc  #cj1cg     ,unity4 
#a    #b1bib       --------------- n    
---------------                         
--------------      ,dark ,green        
#fi1jh  #cj1ib                  #a      
#b1bcj                                  
----------------------------------------
--------------------    #dj ,nitrous gas
 contains #dd1je ,nitrogene1 and #ee1ie 
,oxygene1 as has  been said before4     
,,xi4 ,i have before mentioned that     
dilute nitric acids are incapable of    
dissolving so much nitrous gas in       
proportion to their quantities of  true 
acid1 as concentrated ones4 ,during     
their absorption of it1 they  go through
 similar changes of color2 #ccj grains  
of nitric acid1 of  specific gravity    
#a1cf1 after #ej cubic inches of gas had
 been passed  through it1 became blue   
green1 and of specific gravity #a1cea4  
,it had  gained in weight but #c grains2

 and when the nitrous gas was driven    
from it by heat into a water apparatus1 
but #g cubic inches were  collected4#da 
,from the diminution of specific gravity
 of nitric acid by combination  with    
nitrous gas1 and from the smaller       
attraction of nitric acid for  nitrous  
gas1 in proportion as it is diluted1 it 
is probable that the  nitrated acids1 in
 their combinations with water1 do not  
contract so  much as#db nitric acids of 
the same specific gravities4 ,the       
affinities  resulting from the small    
attraction of nitrous gas for water1 and
 its  greater attraction for nitric     
acid1 must be such as to lessen the     
affinity of nitric acid and water for   
each other4    #da ,a great portion of  
it1 of course1 dissolved in the water   
with the  nitrous acid carried over4    
#db ,their changes of volume1           
corresponding to changes of temperature1
  most probably1 are likewise different4
    ,hence it would require an infinite 
number of experiments to ascertain  the 

real quantities of acid1 nitrous gas1   
and water1 contained in  the different  
diluted nitrous acids2 and after these  
quantities were  determined1 they would 
probably have no important connection   
with the  chemical arrangement4 ,as yet1
 our instruments of experiment are not  
sufficiently exact to afford us the     
means of ascertaining the ratio in      
which the attraction of nitric acid#dc  
for water diminishes in its  progress   
towards saturation4    #dc ,probably in 
the ratio of the square of the quantity 
of water  united to it4    ,the         
estimations in the following table1 of  
the real quantities of  nitric acid in  
solutions of different specific         
gravities1 were deduced  from           
experiments made in the manner described
 in section ,,vi1 except  that the phial
 employed was longer1 narrower1 and     
graduated to half  grains4 ,the         
temperature1 at the time of combination1
 was from #dj to  #df4      ,,table     
,,iii4        ,of the ,quantities of    

,true ,,nitric ,,acid in solutions      
of different ,,specific ,,gravities4    
----------------------------------------
-      #ajj ,parts ,nitric     ,true    
,acid#dd ,water       ,acid of specific 
gravity                                 
----------------                        
--------------------           #a1ejdj  
c      #ia1ee       #h1de               
#a1ddge      o      #hj1ci      #ai1fa  
#a1dbhe      n      #ga1fe      #bh1ce  
#a1cijf      t      #fb1if      #cg1jd  
#a1ceea      a      #ef1hh      #dc1ab  
#a1cahf      i      #eb1jc      #dg1ig  
#a1cjdb      n      #di1jd      #ej1if  
#a1bhca             #df1jc      #ec1ig  
#a1bjij             #de1bg      #ed1gc  
----------------------------------------
-      #dd ,the quantities of ,oxygene  
and ,nitrogene in any solution1 may be  
thus found---- ,let ,a  the true acid1  
,x the oxygene1 and ,y the nitrogene4   
,then            #bch ,a            ,a  
,x  ------------ and ,y  --------       
#bci            #bci      ,,xii4 ,the   

blue green spherules mentioned in       
section ,v4 produced by  the            
condensation of nitrous vapor1 and by   
the combination of nitric  acid with    
nitrous gas1 may be considered as       
saturated solutions of  nitrous gas in  
nitric acid4 ,the combinations of nitric
 acid and nitrous  gas containing a     
larger proportion of nitrous gas1 are   
incapable of  existing in the fluid     
state at common temperatures2 and1 as   
appears  from the first experiment1 an  
increase of volume takes place during   
their formation4 ,they consequently     
ought to be looked upon as solutions  of
 nitric acid in nitrous gas1 identical  
with the nitrous vapor of  ,priestley4  
,from the researches of this great      
discoverer1 we learn that nitrous  vapor
 is decomposable1 both by water and     
mercury4 ,hence it is almost  impossible
 accurately to ascertain its            
composition4 ,in one of his             
experiments1#de when more than #acj     
grains of strong nitrous acid were      

exposed for two days to nearly #bdg     
cubic inches of nitrous gas1 over       
water3 about half of the acid was       
dissolved1 and deposited with the gas   
in the water4#df    #de ,experiments and
 ,observations2 last edition1 vol4 #a1  
page #chd4    #df ,nitrous gas1 holding 
in solution nitrous acid1 is more       
readily  absorbed by water than when in 
its pure form1 from being presented to  
it in a more condensed state in the     
green acid1 formed by the contact  of   
water and nitrous vapor4    ,,xiii4 ,in 
comparing the results of my fundamental 
experiment on the  composition of       
nitrous acid1 with those of ,cavendish1 
the great  coincidence between them gave
 me very high satisfaction1 as affording
  additional proofs of accuracy4 ,if the
 acid formed in the last  experiment of 
this illustrious philosopher be supposed
 analogous to the  light green acid     
formed in my first experiment1 our      
estimations will be  almost identical4  
,lavoisier's account of the composition 

of the nitric and nitrous  acids1 has   
been generally adopted4 ,according to   
his estimation1 these  substances       
contain a much larger quantity of       
oxygene than ,i have  assigned to them4 
,the fundamental experiments of this    
great philosopher were made at an  early
 period of pneumatic chemistry1#dg on   
the decomposition of nitre  by charcoal2
 and he considered the nitrogene        
evolved1 and the oxygene  of the        
carbonic acid produced in this process1 
as the component parts  of the nitric   
acid contained in the nitre4    #dg     
,mem4 des ,savans ,etrangers1 v4 xi4    
#bbf4 ,vide ,kirwan sur le  phlogistique
 pag4 #aaj4    ,i have before mentioned 
the liberation of nitrous acid1 in the  
decomposition of nitre by combustible   
bodies2 and ,i had reasons for          
suspecting that this circumstance was   
not the only source of inaccuracy4      
,that my suspicions were well founded1  
will appear from the following          
experiments3    ,,experiment a4 ,i      

introduced into a strong glass tube1 #c 
inches long1  and nearly1#c wide1 a     
mixture of #aj grains of pulverised1    
well burnt  charcoal1 and #fj grains of 
nitre4 ,it was fired by means of        
touch-paper1  and the tube instantly    
plunged under a jar filled with dry     
mercury4  ,a quantity of gas1 clouded   
with dense white vapor was collected4   
,when this vapor was precipitated1 so   
that the surface of the mercury  could  
be seen1 it appeared white1 as if acted 
on by nitrous acid4 ,on  introducing a  
little oxygene into the jar1 copious red
 fumes appeared4    ,,exp4 b4 ,a similar
 mixture was fired#dh under the jar1 the
 top of  the mercury being covered with 
a small quantity of red cabbage juice1  
rendered green by an alkali4 ,this      
juice1 examined when the vapor  was     
precipitated1 was become red1 and on    
introducing to it a little  carbonate of
 potash1 a slight effervescence took    
place4    #dh ,in this experiment1 as   
well as in the last1 some of the mixture

  was thrown into the jar               
undecompounded4    ,,exp4 c4 ,five      
grains of charcoal1 and #bj of nitre1   
were now fired in  the same manner as   
before1 the mercury being covered with a
 stratum  of water4 ,after the          
precipitation of the vapor on the       
introduction of  oxygene1 no red fumes  
were perceived4    ,,exp4 d4 #cj grains 
of nitre1 #e of charcoal1 and five of   
silicious  earth1#di were now mingled   
and fired4 ,the gas received under      
mercury  was composed of #ah carbonic   
acid1 and nearly #ab nitrogene4#ej ,a   
little muriatic acid was poured on the  
residuum in the tube2 a slight          
effervescence took place4    #di ,to    
detach the potash from the carbonic     
acid4    #ej ,this nitrogene contained a
 little nitrous gas1 as it gave red     
fumes when exposed to the air4 ,the free
 nitrous acid was decomposed by  the    
mercury1 as it was not covered with     
water4    ,,exp4 e4 ,the top of the     
mercury in the jar was now covered with 

a  little diluted muriatic acid1 and a  
small glass tube filled with a  mixture 
of #c grains of charcoal1 and #bj nitre4
 ,after the deflagration1  the tube     
itself with the residuum it contained1  
were thrown into the  jar4 ,the carbonic
 acid was quickly detached from them by 
the muriatic  acid1 and the whole       
quantity of gas generated in the        
process1 obtained2  it measured #ae     
cubic inches4    #d cubic inches of it  
exposed to solution of potash1          
diminished to  #a_/2 #g of the          
remainder1 with #h of oxygene1 gave only
 #ab4    ,,exp4 f4 #fj grains of nitre1 
and #i of charcoal were fired1 the  top 
of the mercury in the jar being covered 
with water4 ,after the  deflagration1   
the tube that had contained them was    
introduced1 and  the carbonic acid      
contained by the carbonate of potash1   
disengaged by  muriatic acid4 #cj       
measures of the gases evolved were      
exposed to caustic  potash2 #bj exactly 
were absorbed1 the #aj remaining1 with  

#aj of oxygene1  diminished to #ag4     
,,exp4 g4 ,a mixture of nitre and       
charcoal were deflagrated over a  little
 water in the mercurial jar3 after the  
precipitation of the  vapor1 the water  
was absorbed by filtrating paper4 ,this 
filtrating  paper1 heated in a solution 
of potash1 gave a faint smell of        
ammoniac4    ,,exp4 h4 ,water           
impregnated with the vapor produced in  
the  deflagration1 was heated with      
quicklime1 and presented separately to  
three persons accustomed to chemical    
odors4 ,two of them instantly           
recognised the ammoniacal smell1 the    
other could not ascertain it4  ,paper   
reddened with cabbage juice was quickly 
turned green by the vapor4    ,these    
experiments are sufficient to shew that 
the decomposition of  nitre by charcoal 
is a very complex process1 and that the 
intense  degree of heat produced may    
effect changes in the substances        
employed1  which we are unable to       
estimate4    ,the products1 instead of  

being simply carbonic acid1 and         
nitrogene1 are  carbonic acid1          
nitrogene1 nitrous acid1 probably       
ammonia1 and sometimes  nitrous gas4    
,the nitrous acid is disengaged from the
 base by the  intense heat4 ,concerning 
the formation of the ammonia1 it is     
useless to  reason till we have obtained
 unequivocal testimonies of its         
existence2  it may be produced either by
 the decomposition of the water         
contained  in the nitre1 by the         
combination of its oxygene with the     
charcoal1 and  of its nascent hydrogene 
with the nitrogene of the nitric acid2  
or from  some unknown decomposition of  
the potash4    ,as neither ,lavoisier   
nor ,berthollet found nitrous gas       
produced in  the decomposition of nitre 
by charcoal1 when a water apparatus was 
employed2 and as it was not uniformly   
evolved in my experiments1 the  most    
probable supposition is1 that it arises 
from the decomposition of  a portion of 
the free nitrous acid intensely heated1 

by the mercury4    ,in none of my       
experiments was the whole of the nitre  
and charcoal  decomposed1 some of it was
 uniformly thrown with the gases into   
the  mercurial apparatus4 ,the nitrogene
 evolved1 as far as ,i could ascertain  
by the common tests1 was mingled with no
 inflammable gas4    ,if we consider    
experiment f as accurate1 with regard to
 the relative  quantities of carbonic   
acid and nitrogene produced1 they are to
 each  other nearly as #bj to #h2 that  
is1 allowing #b for the nitrous gas1 and
  consequently1 reasoning in the same   
manner as ,lavoisier1 concerning the    
composition of nitric acid1 it should be
 composed of #a nitrogene to  #c1ch     
oxygene4 ,but though the quantity of    
oxygene in this estimation is  far short
 of that given in his1 yet still it is  
too much4 ,from whatever  source the    
errors arise1 whether from the evolution
 of phlogisticated  nitrous acid1 or the
 decomposition of water1 or the         
production of  nitrous gas1 they all    

tend to increase the proportion of the  
carbonic  acid to the nitrogene4    ,i  
am unacquainted with any experiment from
 which accurate opinions  concerning the
 different relative proportions of      
oxygene and nitrogene  in the nitric and
 nitrous acids could be deduced4        
,lavoisier's  calculation is founded on 
his fundamental experiment1 and on the  
combination of nitrous gas and oxygene4 
,dr4 ,priestley's experiment mentioned  
in section #ab1 on the absorption  of   
nitrous gas by nitrous acid1 from which 
,kirwan#ea deduces the  composition of  
the differently colored nitrous acids1  
was made over  water1 by which1 as is   
evident from a minute examination of the
  facts#eb1 the greater portion of the  
nitrous gas employed was absorbed4      
#ea ,essay on phlogiston4    #eb ,dr4   
,priestley says1 8,having filled a phial
 containing exactly  the quantity of    
four pennyweights of water1 with strong1
 pale1 yellow  spirit of nitre1 with its
 mouth quite close to the top of a large

  receiver standing in water1 ,i        
carefully drew out almost all the common
  air1 and then filled it with nitrous  
air2 and as this was absorbed1  ,i kept 
putting in more and more1 till in less  
than two days it had  completely        
absorbed #acj ounce measures4 ,presently
 after this process  began1 the surface 
of the acid assumed a deep orange color1
 and when #bj  or #cj ounce measures of 
air were absorbed1 it became green at   
the top3  this green descended lower and
 lower1 till it reached the bottom of   
the  phial4 ,towards the end of the     
process1 the evaporation was perceived  
to  be very great1 and when ,i took it  
out1 the quantity was found to have     
diminished to one half4 ,also it had    
become1 by means of this process1  and  
the evaporation together1 exceeding     
weak1 and was rather blue than  green40 
,experiments and ,observations1 vol4 #a1
 p4 #chd4 ,last edition4 ,,xiv4  ,the   
opinions heretofore adopted respecting  
the quantities of real or  true acid in 

solutions of nitrous acid of different  
specific gravities1  have been founded  
on experiments made on the nitro-neutral
 salts1  the most accurate of which are 
those of ,kirwan1 ,bergman1 and ,wenzel4
  ,the great difference in the results  
of these celebrated men1 proves  the    
difficulty of the investigation1 and the
 existence of sources of  error4#ec     
,kirwan deduces the composition of the  
solutions of nitrous  acid in water1    
from an experiment on the formation of  
nitrated soda4  ,in this experiment1    
#cf1je grains of soda were saturated by 
#ade grains  of nitrous acid1 of        
specific gravity #a1bged4 ,by a test    
experiment1 he  found the quantity of   
salt formed to be #he1adb grains4#ed    
,hence he  concludes that #ajj parts of 
nitrous acid1 of specific gravity       
#a1eedc1  contain #gc1ed of the         
strongest1 or most concentrated acid4   
#ec ,see ,mr4 ,keir's excellent         
observations on this subject4 ,chem4    
,dict4  ,art4 ,acid4    #ed ,irish      

,transactions1 vol4 #d1 p4 #cd4         
,supposing his estimation perfectly     
true1 #ajj parts of the ariform acid  of
 #ee would be composed of #gd1ed of his 
real acid1 and #be1df water4  ,in       
examining1 however1 one of his later    
experiments1#ee we shall find  reasons  
for concluding1 that the acid in        
nitrated soda cannot contain  much less 
water than the ariform acid4 ,a solution
 of carbonated soda1  containing #abe   
grains of real alkali1 was saturated by 
#cjf1b grains of  nitrous acid1 of      
specific gravity #a1daf4 ,the           
evaporation was carried  on in a        
temperature not exceeding #abj1 and the 
residuum exposed to a  heat of #djj for 
six hours1 at the end of which time it  
weighed #cjh  grains4 ,now according to 
my estimation1 #cjf grains of nitric    
acid1 of  #a1daf1 should contain #bae   
true acid2 and we can hardly suppose1   
but  that during the evaporation and    
consequent long exposure to heat1 some  
of the nitrated soda was lost with the  

water4    #ee ,addit4 ,obs4 pag4 #gd4   
,bergman estimates the quantity of water
 in this salt at #be1 and the  acid at  
#dc per cent2 but his real acid was not 
so concentrated as  ,kirwan's1          
consequently the nitric acid in nitrated
 soda should contain  more water than my
 true acid4    ,wenzel1 from an         
experiment on the composition of        
nitrated soda1  concludes that it       
contains #cg1dh of alkali1 and #fb1eb of
 nitrous acid2  and #ajjj of this acid1 
from ,kirwan's calculation1 contain     
#hab1f of his  real acid2 consequently1 
#ajj parts of my ariform acid should    
contain  #ic1bh of ,wenzel's acid1 and  
#f1gb of water4    ,i saturated with    
potash #ed grains of solution of nitric 
acid1 of  specific gravity #a1cja4      
,evaporated at about #bab1 it produced  
#ff grains  of nitre4 ,this nitre       
exposed to a higher temperature1 and    
kept in  fusion for some time1 was      
reduced to #fj grains4    ,now from the 
table1 #ed of #a1cja1 should contain    

#bf1e of true acid4 ,but  according to  
,kirwan's estimation1 #ajj parts of dry 
nitre contain #ddef  of his real acid1  
with #d water2 consequently #fj should  
contain #bf1d4    #ef ,additional       
,observations1 page #gj4    ,again1 #ij 
grains of acid1 of specific gravity     
#a1ejd1 saturated with  potash1 and     
treated in the same manner1 gave #agc   
grains of dry nitre4  ,consequently1    
#ajj parts of it should contain #dg1c   
grains of true acid4    ,now            
,lavoisier#eg allows about #ea of dry   
acid to #ajj grains of nitre1  and      
,wenzel #eb4    ,from ,berthollet's#eh  
experiments1 #ajj grains of nitre1 in   
their  decomposition by heat1 give out  
nearly #di grains of gas4#ei    ,hence  
it appears that the ariform acid1 that  
is1 the true acid of my  table1 contains
 rather less water than the acid        
supposed to exist in  nitre4    #eg     
,elements1 pag4 #ajc1 ,kerr's           
,translation4    #eh ,mem4 ,acad4 #aghg4
    #ei ,as well as oxygene and         

nitrogene1 ,mr4 ,watt's experiments     
prove  that much phlogisticated nitrous 
acid is produced4      ,,division ,,ii4 
,,experiments and ,,observations on the 
composition of         ,,ammoniac and on
 its combinations with ,,water and      
,,nitric ,,acid4      ,i4 ,analysis of  
,,ammoniac or ,,volatile ,,alkali4      
,the formation and decomposition of     
volatile alkali in many processes1  was 
observed by ,priestley1 ,scheele1       
,bergman1 ,kirwan1 and ,higgins2 but  to
 ,berthollet we owe the discovery of its
 constituent parts1 and their           
proportions to each other4 ,these       
proportions this excellent philosopher  
deduced from an experiment on the       
decomposition of ariform ammoniac by    
the electric spark3#fj a process in     
which no apparent source of error       
exists4    #fj ,journal de ,physique1   
#aghf4 ,tom4 #b1 pag4 #agf4    ,since1  
however1 his estimations have been made1
 the proportions of  oxygene and        
hydrogene in water have been more       

accurately determined4  ,this           
circumstance1 as well as the conviction 
of the impossibility  of too minutely   
scrutinizing facts1 fundamental to a    
great mass of  reasoning1 induced me to 
make the following experiments4    ,a   
porcelain tube was provided1 open at    
both ends1 and well glazed  inside and  
outside1 its diameter being about1#e    
inches4 ,to one end of  this1 a glass   
tube was affixed1 curved for the purpose
 of communicating  with the water       
apparatus4 ,with the other end a glass  
retort was  accurately connected1       
containing a mixture of perfectly       
caustic slacked  lime1 and muriate of   
ammoniac4    ,the water in the apparatus
 for receiving the gases had been       
previously  boiled1 to expel the air it 
might contain1 and during the experiment
  was yet warm4    ,when the tube had   
been reddened in a furnace adapted to   
the purpose1  the flame of a spirit lamp
 was applied to the bottom of the       
retort4 ,a  great quantity of gas was   

collected in the water apparatus2 of    
this the  first portions were rejected1 
and the last transferred to the         
mercurial  trough4    ,a small quantity 
examined1 did not at all diminish with  
nitrous gas1  and burnt with a lambent  
white flame1 in contact with common air4
    #b of this gas1 equal to #aaj grain 
measures1 were fired with #b1 equal  to 
#hj1 of oxygene1 in a detonating tube1  
by the electric spark4 ,they  were      
reduced to #b1 or #ij4 ,on introducing  
to the remainder a solution  of         
strontian1 it became slightly clouded on
 the top1 and an absorption  of some    
grain measures took place4    ,it was   
evident1 then1 that in this experiment1 
charcoal#fa had been  somehow present in
 the tube2 which being dissolved by the 
nascent  hydrogene1 had rendered it     
slightly carbonated1 and in consequence 
made  the results inconclusive4    #fa  
,though the tube had never been used1   
and was apparently clean and  dry on the
 inside1 it must have contained         

something in the form of  dust1 capable 
of furnishing either hydrocarbonate1 or 
charcoal4    ,a tube of thick green     
glass carefully made clean1 was now     
employed1  inclosed in the porcelain    
tube4 ,every other precaution was taken 
to  prevent the existence of sources of 
error1 and the experiment conducted  as 
before4    #adj grain measures of the   
gas produced1 fired with #abj of        
oxygene1  left1 in two experiments1     
nearly #aaj4 ,solution of strontian     
placed in  contact with the residuum1   
did not become clouded1 and no          
absorption  was perceived4    ,now #aej 
measures of gas were destroyed1 and if  
we take ,lavoisier's  and ,meusnier's   
estimation of the composition of water1 
and suppose  the weight of oxygene to be
 #ce grains1 and that of hydrogene #b1f 
the  hundred cubic inches2 the oxygene  
employed will be to the hydrogene as    
#bdc to #egf4 ,put x for the oxygene1   
and y for the hydrogene4        ,then   
x  y  #aej                x 3 y 33 #bdc 

3 #egf                             #bdcy
                    x   ------------    
#egf                   #haiy  #hfdjj    
y  #aje    x  #de        ,and     #adj -
 #aje  #ce    ,consequently1 the        
nitrogene in ammoniac is to the         
hydrogene as #ce3 #aje  in volume3 and  
#ac1c grains of ammoniac are composed of
 #aj1f nitrogene1  7supposing that #ajj 
cubic inches weigh #cj1de grains7 and   
#b1g hydrogene4    ,according to        
,berthollet1 the weight of the nitrogene
 in ammoniac is to  that of the         
hydrogene as #aba to #bi4fb ,the        
difference between this  estimation and 
mine is so small as to be almost        
unworthy of notice1 and  arises most    
probably from the slight difference     
between the accounts  of ,lavoisier and 
,monge1 of the composition of water1 and
 the different  weights assigned to the 
gases employed4    #fb ,journal de      
,physique1 #aghf1 t4 #b1 #agg4    ,we   
may then conclude1 that #ajj grains of  
ammoniac are composed of about  #hj     

nitrogene1 and #bj hydrogene4    ,the   
decomposition of ammoniac by heat1 as   
well as by the electric  spark1 was     
first discovered by ,priestley4 ,in an  
experiment#fc when  ariform ammoniac was
 sent through a heated tube from a      
caustic  solution of ammoniac in water1 
this great discoverer observed that an  
inflammable gas was produced1 though in 
no great quantity1 and that a  fluid    
blackened by matter1 probably           
carbonaceous1 likewise came over4    #fc
 ,phil4 ,trans4 vol4 #gi1 page #bid4    
,in my experiments the whole of the     
ammoniac appeared to be decomposed2  the
 quantity of gas generated was immense1 
and not clouded1 as is  usually the case
 with gases generated at high           
temperatures4 ,it is  possible1 that the
 larger quantity of water carried over  
in his  experiment1 by its strong       
attraction for ammoniac in the ariform  
state1 might have1 in some measure1     
retarded the decomposition4 ,it  is     
however1 more probable to suppose1 that 

a fissure existed in the  earthen tube  
he employed1 through which a certain    
quantity of gas  escaped1 and coaly     
matter entered4    ,priestley found that
 the metallic oxides when strongly      
heated1  decomposed ammoniac1 the metal 
being revivified and water and nitrogene
  produced4#fd ,the estimations of the  
composition of ammoniac that may  be    
deduced from his experiments on the     
oxide of lead1 differ very  little from 
those already detailed4    #fd ,vol4 #b1
 page #cih4      ,,ii4 ,specific gravity
 of ,ammoniac4    ,from the great       
solubility of ammoniac in water1 it is  
difficult to  ascertain its specific    
gravity in the same manner as that of a 
gas  combinable to no great extent with 
that fluid4 ,it is impossible to        
prevent the existence of a small        
quantity of solution of ammoniac  in the
 mercurial airholder1#fe or apparatus   
containing the gas2  and during the     
diminution of the pressure of the       
atmosphere on this  solution1#ff a      

certain quantity of gas is liberated    
from it1 and hence  a source of error4  
#fe ,ammoniac generated at a temperature
 above that of the atmosphere1  always  
deposits ammoniacal solution during its 
reduction to the common  temperature4   
#ff ,by the introduction of ariform     
ammoniac into the exhausted globe4      
,to ascertain1 then1 the weight of      
ammoniac1 ,i employed an apparatus      
similar to that used for the absorption 
of nitrous gas by nitric acid4    #ej   
cubic inches of gas were collected in   
the mercurial airholder1 from  the      
decomposition of muriate of ammoniac by 
lime2 thermometer being  #eh1 and       
barometer #bi1f4    #ajj grains of      
diluted sulphuric acid were introduced  
into the small  graduated cylinder1     
which after being carefully weighed1 was
 made to  communicate with the          
airholder1 the curved tube containing a 
small  quantity of water4 ,the gas was  
slowly passed into the fluid1 and the   
globules wholly absorbed before they    

reached the top2 much increase of       
temperature being consequent4 ,when the 
absorption was compleat1 the  phial was 
increased in weight exactly #i grains4  
,this experiment was repeated three     
times4 ,the difference of weight1  which
 was probably connected with alterations
 of temperature and  pressure1 never    
amounted to more than one sixth of a    
grain4    ,we may then conclude1 that at
 temperature #eh1 and atmospheric       
pressure  #bi1f1 #ajj cubic inches of   
ammoniac weigh #ah grains4    ,according
 to ,kirwan1 #ajj cubic inches of       
alkaline air#fg weigh #ah1af  grains2   
barometer #cj1 thermometer #fa4 ,the    
difference between these  estimations1  
the corrections for temperature and     
pressure being made1  is trifling4      
#fg ,additional ,observations1 page     
#ajg4      ,,iii4 ,of the quantities of 
true ,ammoniac in ,aqueous ,ammoniacal  
,solutions1 of different specific       
gravities4    ,to ascertain the         
quantities of ammoniac1 such as exists  

in the ariform  state1 saturated with   
moisture1 in solutions of different     
specific  gravities1 ,i employed the    
apparatus for absorption so often       
mentioned4  ,thermometer being #eb1 the 
mercurial airholder was filled with     
ammoniacal gas1 and the graduated phial1
 containing #ej grains of pure  water1  
connected with it4 ,during the          
absorption of the gas1 the phial  became
 warm4 ,when about #cj cubic inches had 
been passed through1 it was  suffered to
 cool1 and weighed3 it had gained #e1be 
grains1 and the fluid  filled a space   
equal to that occupied by #egfh grains  
of water4    #fh ,it is necessary in    
these experiments1 that the greatest    
care be  observed in the introduction   
and extraction of the capillary tube4   
,if  it is introduced dry1 there will be
 a source of error from the moisture    
adhering to it when taken out4 ,i       
therefore always wetted it before its   
introduction1 and took care that no more
 fluid adhered to it after the          

experiment1 than before4                
,consequently1 #ajj grains of solution  
of ammoniac in water of specific        
gravity1#ifhd contain #i1ejb grains of  
ammoniac4    ,the apparatus being       
adjusted as before1 #ej grains of pure  
water were  now perfectly saturated with
 ammoniac4 ,they gained in weight #ag   
grains1 and when perfectly cool1 filled 
a space equal to #gd of water4          
,consequently #ajj grains of aqueous    
ammonial solution of specific           
gravity1#ijed contain #be1cg grams of   
ammoniac4    ,the two solutions were    
mingled together2 but no alteration of  
temperature took place4 ,consequently   
the resulting specific gravity  might   
have been found by calculation4    ,on  
mingling a large quantity of caustic    
solution of ammoniac with  of  its      
weight of water1 of exactly the same    
temperature1 no alteration  of it was   
perceptible by a sensible               
thermometer4--,hence the two            
experiments#fi being assumed as data1   

the intermediate estimations in  the    
following table1 were found by          
calculation4    #fi ,previous to those  
experiments1 ,i had made a number of    
others on  the combination of ammoniac  
with water4--,my design was1 to         
ascertain  the diminution of specific   
gravity for every three grains of       
ammoniac  absorbed2 but this ,i found   
impossible4 ,the capillary tube1 when   
taken out of the phial1 always carried  
with it a minute portion of  the        
solution1 which partially evaporated    
before it could be again  introduced2   
and thus the sources of error increased 
in proportion to  the number of         
examinations4      ,,table ,,iv4        
,of approximations to the quantities of 
,,ammoniac1         such as exists in   
the ariform state1 saturated with       
water at #eb1 in ,,aqueous ,,ammoniacal 
,,solutions of         different        
specific gravities4                     
---------------------------------       
#ajj         ,ammoniac4 ,water4         

,specific                               
,gravity4                               
----------     ------------------       
#ijed          #be1cg    #gd1fc         
#iaff          #bb1jg    #gg1ic         
#ibee          #ai1ed    #hj1df         
#icbf     c    #ag1eb    #hb1dh         
#iche     o    #ae1hh    #hd1ab         
#idce     n    #ad1ec    #he1dg         
#idgf     t    #ac1df    #hf1ed         
#ieac     a    #ab1dj    #hg1fj         
#iede     i    #aa1ef    #hh1dd         
#iegc     n    #aj1hb    #hi1ah         
#ieig          #aj1ag    #hi1hc         
#ifai           #i1fj    #ij1dj         
#ifhd           #i1ej    #ij1ej         
#ifci           #i1ji    #ij1ia         
#igac           #g1ag    #ib1hc         
---------------------------------       
,as yet no mode has been discovered for 
obtaining      gases in a state of      
absolute dryness2 consequently      we  
are ignorant of the different quantities
      of water they hold in solution at 
different      temperatures4 ,as far as 

we are acquainted with      the         
combinations of ammoniac1 there is no   
state      in which it exists so free   
from moisture1 as when      ariform1 at 
low temperatures4    ,that no           
considerable source of error existed in 
the two experiments1  is evident from   
the trifling difference between the     
estimations of the  quantities of real  
ammoniac1 in the solution of1#ifhd1 as  
found in the  first experiment1 and as  
given by calculation from the last4     
,the quantity of ammoniac in a solution 
of specific gravity not in the  table1  
may be thus determined--find the        
difference between the two  specific    
gravities nearest to it in the table2 d1
 and the difference  between their      
quantities of alkali1 b2 likewise the   
difference  between the given specific  
gravity and that nearest to it1 c4      
then    d 3 b 33 c 3 x                  
bc      and x  ----------               
d    ,which1 added to the quantity of   
the lower specific gravity1 is the      

alkali sought4    ,the differences in   
specific gravity of the solutions of    
ammoniac at  temperatures between #d,o  
and #fegj are so trifling as to be      
hardly  ascertainable1 by our imperfect 
instruments1 and consequently are       
unworthy of notice4    #gj ,the         
expansion from increase of temperature  
is probably great in  proportion to the 
quantity of ammoniac in the solution4   
,it is possible at very low temperatures
 to obtain ammoniacal solutions  of less
 specific gravity than1#i1 but they are 
incapable of being kept  for any length 
of time under the common pressure of the
 atmosphere4      ,,iv4 ,combinations of
 ,ammoniac with ,nitric ,acid1          
,composition of ,nitrate  of ,ammoniac1 
c4    #bjj grains of ammoniacal         
solution1 of specific gravity1#ijef1    
were  saturated by #che1e grains of     
nitric acid1 of specific gravity #a1cjf4
  ,the combination was effected in a    
long phial1 the nitrous acid added  very
 slowly1 and the phial closed after     

every addition1 to prevent any          
evaporation in consequence of the great 
increase of temperature4#ga  ,the       
specific gravity of the solution1 when  
reduced to the common  temperature1 was 
#a1ae4 ,evaporated at a heat of #bab1gb 
it gave #bed  grains of salt of fibrous 
crystalization4 ,this salt was dissolved
 in  #cca grains of water2 the specific 
gravity of the solution was #a1adh      
nearly4    #ga ,from the combination4   
#gb ,i had before proved that at this   
temperature the salt neither  decomposed
 nor sublimed4    ,hence it was evident 
that some of the salt had been lost     
during the  evaporation4    ,to find the
 quantity lost1 fibrous nitrate of      
ammoniac was dissolved  in small        
quantities in the solution1 the specific
 gravity of which was  examined after   
every addition of #c grains4 ,when #af  
grains had been  added to it1 it became 
of #a1ae4    ,consequently1 the solution
 composed of #bjj grains of ammoniacal1 
and  of #che1e of nitric acid solution1 

contained #bfb grains of salt of        
fibrous crystalization1 and of this salt
 #h grains were lost during the         
evaporation4    ,but the alkali in #bjj 
grains of ammoniacal solution of1#ijef  
#ej1e  grains4 ,and the true nitric acid
 in #che1e grains of solution of #a1cjf 
#aij grains4    ,then #bfb-bdj1e  #ba1e1
 the quantity of water4    ,and #bfb    
grains of fibrous crystalized nitrate of
 ammoniac1 contain #aij  grains true    
acid1 #ej1e ammoniac1 and #ba1e water4  
,and #ajj parts contain  #gb1e acid4    
#ai1c ammoniac1 and #h1b water4    ,in  
proportion as the temperature employed  
for the evaporation of  nitro-ammoniacal
 solutions1 is above or below #bab1 so  
in proportion  does the salt produced   
contain more or less water than the     
fibrous  nitrate4 ,but whatever may have
 been the temperature of evaporation1   
the  acid and alkali appear always to be
 in the same proportions to each  other4
    ,of the salts containing different  
quantities of water1 two varieties  must

 be particularly noticed4 ,the prismatic
 nitrate of ammoniac1  produced at the  
common temperatures of the atmosphere1  
and containing  its full quantity of    
water of crystalisation2 and the compact
 nitrate  of ammoniac1 either amorphous1
 or composed of delicately needled      
crystals1 formed at #cjj1 and containing
 but little more water than  exists in  
nitric acid and ammoniac4    ,to        
discover the composition of the         
prismatic nitrate of ammoniac1 #bjj     
grains of fibrous salt were dissolved in
 the smallest possible quantity  of     
water1 and evaporated in a temperature  
not exceeding #gj4 ,the  greater part of
 the salt was composed of perfectly     
formed tetrahdral  prisms1 terminated by
 tetrahdral pyramids4 ,it had gained in 
weight  about #h1e grains4              
,consequently #ajj grains of prismatic  
nitrate of ammoniac may be  supposed to 
contain #fi1e acid1 #ah1d ammoniac1 and 
#ab1a water4    ,to ascertain the       
composition of the compact nitrate of   

ammoniac1 ,i  exposed in a deep         
porcelain cup1 #djj grains of the       
fibrous salt1 in a  temperature below   
#cjj4 ,it quickly became fluid1 and     
slowly gave out  its water without any  
ebullition1 or liberation of gas4 ,when 
it was  become perfectly dry1 it had    
lost #cc grains4 ,i suspected1 that in  
this  experiment some of the salt had   
been carried off with the water2 to     
determine this1 ,i introduced into a    
small glass retort1 #dfj grains of      
fibrous salt2 it was kept at a heat     
below #cbj1 in communication with a     
mercurial apparatus1 in a regulated     
air-furnace1 till it was perfectly  dry3
 it had lost #bc grains4 ,no gas1 except
 the common air of the retort  came     
over1 and the fluid collected had but a 
faint taste of nitrate of  ammoniac4    
,though in this experiment ,i had       
removed all the fluid retained in the   
neck of the retort1 still a few drops   
remained in the head1 and on  the sides1
 which ,i could not obtain4 ,it was of  

importance to me to be  accurately      
acquainted with the composition of the  
compact salt1 and for  that reason ,i   
compared these analytical experiments   
with a synthetical  one4    ,i saturated
 #bjj grains of solution of ammoniac1   
of1#ijef with acid1  ascertained the    
specific gravity of the solution1       
evaporated it at  #bab1 and fused and   
dried it at about #cjj-bfj4 ,it gave    
#bdf grains  of salt1 and a solution    
made of the same specific gravity as    
that  evaporated1 indicated a loss of #i
 grains4 ,consequently1 #bee grains of  
this salt contain #ej1e grains alkali1  
#ajj grains acid1 and #ad1e grains      
water4    ,we may then conclude1 that   
#ajj parts of compact nitrate of        
ammoniac  contain #gd1e acid1 #ai1h     
alkali1 and #e1g water4      ,v4        
,decomposition of ,carbonate of         
,ammoniac by ,nitric ,acid4    ,in my   
first experiments on the production of  
nitrate of ammoniac1 ,i  endeavoured to 
ascertain its composition by            

decompounding carbonate  of ammoniac by 
nitric acid2 and in making for this     
purpose1 the  analysis of carbonate of  
ammoniac1 ,i discovered that there      
existed  many varieties of this salt1   
containing very different proportions of
  carbonic acid1 alkali1 and water2 the 
carbonic acid and water being           
superabundant in it1 in proportion as   
the temperature of its formation  was   
low1 and the alkali in proportion as it 
was high3 and not only  that a different
 salt was formed at every different     
temperature1 but  likewise that the     
difference in them was so great1 that   
the carbonate  of ammoniac formed at    
#cjj contained more than #ej per cent   
alkali1  whilst that produced at #fj    
contained only #bj4gc    ,i found #baj  
grains of carbonate of ammoniac1 which  
from comparison with  other salts       
previously analised1 ,i suspected to    
contain about #bj or  #ba per cent      
alkali1 saturated by #bjj grains of     
nitric acid of #a1ejd4  ,but though the 

carbonate was dissolved in much water1  
still1 from the  smell of the carbonic  
acid generated1 ,i suspect that a small 
portion  of the nitric acid was         
dissolved1 and carried off by it4 ,the  
solution1  evaporated at about #bjj1 and
 afterwards exposed to a temperature    
below  #cjj1 gave #bcb grains of compact
 salt4 ,but reasoning from the quantity 
of acid in #bjj grains of nitric acid of
 #a1ejd1 it ought to have given  #bde4  
,consequently #ac were lost by          
evaporation2 and this loss agrees  with 
that in the other experiments4    #gc ,a
 particular account of the experiments  
from which these facts  were deduced1   
was printed in ,september1 and will     
appear in the first  volume of the      
,researches4      ,,vi4 ,decomposition  
of ,sulphate of ,ammoniac by ,nitre4    
,as a cheap mode of obtaining nitrate of
 ammoniac1 ,dr4 ,,beddoes proposed  to  
decompose nitre by sulphate of ammoniac1
 which is a well known  article of      
commerce4 ,from synthesis of sulphate of

 ammoniac1 compared  with analysis made 
in ,august #agii1gd ,i concluded that   
#ajj grains of  prismatic salt were     
composed of about #ah grains ammoniac1  
#dd acid1 and  #ch water2 and supposing 
#ajj grains of nitre to contain #ej     
acid1 #ajj  grains of sulphate of       
ammoniac will require for their         
decomposition #acd  grains of nitre1 and
 form #ij1i grains of compact nitrate of
 ammoniac4    #gd ,and which will be    
published1 with an account of its       
perfect  decomposition at a high        
temperature1 in the ,researches4    ,to 
ascertain if the sulphate of potash and 
nitrate of ammoniac could be  easily    
separated1 ,i added to a heated         
saturated solution of sulphate of       
ammoniac1 pulverised nitre1 till the    
decomposition was complete4 ,after  this
 decomposition1 the solution contained a
 slight excess of sulphuric  acid1 which
 was combined with lime1 and the whole  
set to evaporate at  a temperature below
 #bej4 ,as soon as the sulphate of      

potash began to  crystalise1 the        
solution was suffered to cool1 and then 
poured off from  the crystalised salt1  
which appeared to contain no nitrate of 
ammoniac4  ,after a second evaporation  
and crystalisation1 almost the whole of 
the sulphate appeared to be deposited1  
and the solution of nitrate of  ammoniac
 was obtained nearly pure3 it was       
evaporated at #bab1 and gave  fibrous   
crystals4      ,,vii4 ,non-existence of 
,ammoniacal ,nitrites4    ,i attempted  
in different modes to combine nitrous   
acids with  ammoniac1 so as to form the 
salts which have been supposed to exist1
  and called nitrites of ammoniac2 but  
without success4    ,i first decomposed 
a solution of carbonate of ammoniac by  
dilute olive  colored acid2 but in this 
process1 though no heat was generated1  
yet all the nitrous gas appeared to be  
liberated with the carbonic  acid4#ge ,i
 then combined a small quantity of      
nitrous gas1 with a  solution of nitrate
 of ammoniac4 ,but after evaporating    

this solution  at #gj-hj1 ,i could not  
detect the existence of nitrous gas in  
the  solid salt2 it was given out during
 the evaporation and crystalisation1    
and formed into nitrous acid by the     
oxygene of the atmosphere4 ,i  likewise 
heated nitrate of ammoniac to different 
degrees1 and partially  decomposed it1  
to ascertain if in any case the acid was
 phlogisticated  by heat3 but in no     
experiment could ,i detect the existence
 of  nitrous acid in the heated salt1   
when it had been previously  perfectly  
neutralised4    #ge ,when nitrous gas   
exists in neutro-saline solutions1 they 
are  always colored more or less        
intensely1 from yellow to olive1 in     
proportion to the quantity combined with
 them4    ,when nitrate of ammoniac1    
indeed1 with excess of nitric acid1 is  
exposed to heat1 the superabundant      
nitric acid becomes phlogisticated1  and
 is then liberated from the salt1 which 
remains neutral4#gf    #gf ,hence a     
nitrate of ammoniac with excess of acid1

 when exposed to  heat1 first becomes   
yellow1 and then white4    ,we may      
therefore conclude that nitrous gas has 
little or no affinity  for solid nitrate
 of ammoniac1 and that no substance     
exists to which  the name nitrite of    
ammoniac can with propriety be applied4 
,,viii4 ,of the sources of error in     
,analysis4    ,to compare my synthesis  
of nitrate of ammoniac with analysis1 ,i
  endeavoured to separate the ammoniac  
and nitric acid from each other1        
without decomposition4 ,but in going    
through the analytical process1 ,i  soon
 discovered that it was impossible to   
make it accurate1 without  many         
collateral laborious experiments on the 
quantities of ammoniac  soluble in water
 at different temperatures4    ,at a    
temperature above #bab1 ,i decomposed1  
by caustic slacked lime1 #ej  grains of 
compact nitrate of ammoniac in a retort 
communicating with  the mercurial       
airholder1 the moisture in which had    
been previously  saturated with         

ammoniac4 #bb cubic inches of gas were  
collected at #ch1  and from the loss of 
weight of the retort1 it appeared that  
#ac grains  of solution of ammoniac in  
water1 had been deposited by the gas4   
,now evidently1 this solution must have 
contained much more alkali in           
proportion to its water than that of    
#ee1 otherwise the quantity of  ammoniac
 in #ej grains of salt would hardly     
equal #h grains4#gg    #gg ,the accounts
 given by different chemists of the     
composition of  nitrate of ammoniac1 are
 extremely discordant2 they have been   
chiefly  deduced from decompositions of 
carbonate of ammoniac 7the varieties of 
which have been heretofore unknown7 by  
nitrous acids of unknown degrees  of    
nitration4 ,hence they are particularly 
erroneous with regard to the  alkaline  
part4 ,wenzel supposes it to be #cb per 
cent1 and ,kirwan #bd4  ,addit4 ,observ4
 pag4 #abj4      ,,ix4 ,of the loss of  
,solutions of ,nitrate of ,ammoniac     
during  evaporation4    ,the most       

concentrated solution of nitrate of     
ammoniac capable of  existing at #fj1 is
 of specific gravity #a1cjd1 and        
contains #cc water1  and #fg fibrous    
salt1 per cent4 ,when this solution is  
evaporated at  temperatures between #fj 
and #ajj1 the salt is increased in      
weight by  the addition of water of     
crystalisation1 and no portion of it is 
lost4    ,during the evaporation of     
solutions of specific gravity #a1adf and
 #a1ae1  at temperatures below #abj1 ,i 
have never detected any loss of salt4   
,when the temperature of evaporation is 
#bab1 the loss is generally from  #c to 
#d grains per cent2 and when from #bcj  
to the standard of their  ebullition1   
from #d to #f grains4    ,in proportion 
as solutions are more diluted1 their    
loss in evaporation  at equal           
temperatures is greater4      ,,division
 ,,iii4        ,decomposition of        
,,nitrate of ,,ammoniac3 preparation of 
,,respirable ,,nitrous ,,oxide2 its     
,,analysis4      ,i4 ,of the heat       

required for the decomposition of       
,,nitrate of ,,ammoniac4    ,the        
decomposition of nitrate of ammoniac has
 been supposed by  ,cornette#gh to take 
place at temperatures below #bab1 and   
its  sublimation at #bcd4    ,kirwan1   
from the non-coincidence in the accounts
 of its composition1  has imagined that 
it is partially decomposable1 even by a 
heat of  #hj4gi    #gh ,mem4 ,par4      
#aghc4 ,see ,irish ,trans4 vol4 #d4     
#gi ,addit4 ,obs4 pag4 #abj4    ,to     
ascertain the changes effected by       
increase of temperature in this  salt1 a
 glass retort was provided1 tubulated   
for the purpose of  introducing the bulb
 of a thermometer4 ,after it had been   
made to  communicate with the mercurial 
airholder1 and placed in a furnace1  the
 heat of which could be easily          
regulated1 the thermometer was          
introduced1 and the retort filled with  
the salt1 and carefully luted2  so that 
the appearances produced by different   
temperatures could be  accurately       

observed1 and the products evolved      
obtained4    ,from a number of          
experiments made in this manner on      
different salts1  the following         
conclusions were drawn4    #ast4        
,compact1 or dry nitrate of ammoniac1   
undergoes little or no change  at       
temperatures below #bfj4    #b;dly4 ,at 
temperatures between #bge and #cjj1 it  
slowly sublimes1  without decomposition1
 or without becoming fluid4    #c;dly4  
,at #cbj it becomes fluid1 decomposes1  
and still slowly sublimes2  it neither  
assuming1 or continuing in1 the fluid   
state1 without  decomposition4          
#dthly4 ,at temperatures between #cdj   
and #dhj1 it decomposes rapidly4        
#ethly4 ,the prismatic and fibrous      
nitrates of ammoniac become fluid at    
temperatures below #cjj1 and undergo    
ebullition at temperatures between  #cfj
 and #djj1 without decomposition4       
#fthly4 ,they are capable of being      
heated to #dcj without decomposition1   
or sublimation1 till a certain quantity 

of their water is evaporated4    #gthly4
 ,at temperatures above #dej they       
undergo decomposition1 without          
previously losing their water of        
crystalisation4      ,,ii4              
,decomposition of ,nitrate of ,ammoniac2
 production of respirable  ,nitrous     
,oxide2 its properties4    #bjj grains  
of compact nitrate of ammoniac were     
introduced into a  glass retort1 and    
decomposed slowly by the heat of a      
spirit lamp4  ,the first portions of the
 gas that came over were rejected1 and  
the  last received in jars containing   
mercury4 ,no luminous appearance was    
perceived in the retort during the      
process1 and almost the whole of the    
salt was resolved into fluid and gas4   
,the fluid had a faint acid taste1  and 
contained some undecompounded nitrate4  
,the gas collected exhibited  the       
following properties4--    a4 ,a candle 
burnt in it with a brilliant flame1 and 
crackling noise4  ,before its           
extinction1 the white inner flame became

 surrounded with an  exterior blue one4 
b4 ,phosphorus introduced into it in a  
state of inflammation1 burnt  with      
infinitely greater vividness than       
before4    c4 ,sulphur introduced into  
it when burning with a feeble blue      
flame1  was instantly extinguished2 but 
when in a state of active inflammation  
7that is1 forming sulphuric acid7 it    
burnt with a beautiful and vivid        
rose-colored flame4    d4 ,inflamed     
charcoal1 deprived of hydrogene1        
introduced into it1  burnt with much    
greater vividness than in the           
atmosphere4    e4 ,to some fine twisted 
iron wire a small piece of cork was     
affixed3  this was inflamed1 and the    
whole introduced into a jar of the air4 
,the  iron burned with great vividness1 
and threw out bright sparks as in       
oxygene4    f4 #cj measures of it       
exposed to water previously boiled1 was 
rapidly  absorbed2 when the diminution  
was complete1 rather more than a measure
  remained4    g4 ,pure water saturated 

with it1 gave it out again on           
ebullition1 and  the gas thus produced  
retained all its former properties4     
h4 ,it was absorbed by red cabbage      
juice2 but no alteration of color  took 
place4    i4 ,its taste was distinctly  
sweet1 and its odor slight1 but         
agreeable4    j4 ,it underwent no       
diminution when mingled with oxygene or 
nitrous  gas4    ,such were the obvious 
properties of the ,,nitrous ,,oxide1 or 
the gas  produced by the decomposition  
of nitrate of ammoniac in a temperature 
not exceeding #ddj4 ,other properties of
 it will be hereafter  demonstrated1 and
 its affinities fully investigated4     
,,iii4 ,of the gas remaining after the  
absorption of ,nitrous ,oxide by        
,water4    ,in exposing nitrous oxide at
 different times to rain or spring      
water1  and water that had been lately  
boiled1 ,i found that the gas remaining 
after the absorption was always least   
when boiled water was employed1  though 
from the mode of production of the      

nitrous oxide1 ,i had reason  to believe
 that its composition was generally the 
same4    ,this circumstance induced me  
to suppose that some of the residuum    
might be gas previously contained in the
 water1 and liberated from  it in       
consequence of the stronger affinity of 
that fluid for nitrous  oxide4 ,but the 
greater part of it1 ,i conjectured to   
consist of  nitrogene produced in       
consequence of a complete decomposition 
of part  of the acid1 by the hydrogene4 
,it was in endeavoring to ascertain the 
relative purity of nitrous oxide        
produced at different periods of the    
process of the decomposition of nitrate 
of ammoniac1 that ,i discovered  the    
true reason of the appearance of        
residual gas4    ,i decomposed some pure
 nitrate of ammoniac in a small glass   
retort2  and after suffering the first  
portions to escape with the common air1 
,i caught the remainder in three        
separate vessels standing in the same   
trough1 filled with water that had been 

long boiled1 and which at  the time of  
the experiment was so warm that ,i could
 scarcely bear my  hands in it4 ,the    
different quantities collected gave the 
same intense  brilliancy to the flame of
 a taper4    #bf measures of each of    
them were separately inserted into #c   
graduated  cylinders1 of nearly the same
 capacity1 over the same boiled water4  
,as the water cooled1 the gas was       
absorbed by agitation4 ,when the        
diminution was complete1 the residuum in
 each cylinder filled1 as  nearly as    
possible1 the same space2 about two     
thirds of a measure4    ,to each of the 
residuums ,i added two measures of      
nitrous gas2 they gave  copious red     
vapor1 and after the condensation filled
 a space rather  less than two measures4
    ,hence the residual gas contained   
more oxygene than common air4    ,i now 
introduced #bf measures of gas from one 
of the vessels into a  cylinder filled  
with unboiled spring water of the same  
kind4#hj ,after  the absorption was     

complete1 near two measures remained4   
,these added to  two measures of nitrous
 air1 diminished to #b1e nearly4    #hj 
,two measures of air dispelled from this
 water by boiling1 mingled  with #b of  
nitrous gas1 diminished to #b1d nearly4 
,these experiments induced me to believe
 that the residual gas was not  produced
 in the decomposition of nitrate of     
ammoniac1 but that it was  wholly       
liberated from the water4    ,to        
ascertain this point with precision1 ,i 
distilled a small quantity  of the same 
kind of water1 which had been near an   
hour in ebullition1  into a graduated   
cylinder containing mercury4 ,to this ,i
 introduced  about one third of its     
bulk1 i4 e4 #ab measures of nitrous     
oxide1 which  had been carefully        
generated in the mercurial apparatus4   
,after the  absorption1 a small globule 
of gas only remained1 which could hardly
  have equalled one fourth of a measure4
 ,on admitting to this globule a  minute
 quantity of nitrous gas1 an evident    

diminution took place4    ,though this  
experiment proved that in proportion as 
the water was free  from air1 the       
residuum was less1 and though there was 
no reason to  suppose that the          
ebullition and distillation had freed   
the water from  the whole of the air it 
had held in solution1 still ,i          
considered a  decisive experiment       
wanting to determine whether nitrous    
oxide was the  only gas produced in the 
slow decomposition of nitrate of        
ammoniac1 or  whether a minute quantity 
of oxygene was not likewise evolved4    
,i received the middle part of the      
product of a decomposition of nitrate   
of ammoniac1 under a cylinder filled    
with dry mercury1 and introduced  to it 
some strong solution of ammoniac4 ,after
 the white cloud produced  by the       
combination of the ammoniacal vapor with
 the nitric acid  suspended in the      
nitrous oxide1 had been completely      
precipitated1 ,i  introduced a small    
quantity of nitrous gas4 ,no white vapor

 was produced4    ,now if any gas       
combinable with nitrous gas had existed 
in the cylinder1  the quantity of       
nitrous acid produced1 however small1   
would have  been rendered perceptible by
 the ammoniacal fumes2 for when a minute
  globule of common air was admitted    
into the cylinder1 white clouds were    
instantly perceptible4    ,it seems     
therefore reasonable to conclude1    #a4
 ,that the residual gas of nitrous      
oxide1 is air previously contained  in  
the water1 7which in no case can be     
perfectly freed from it by  ebullition71
 and liberated by the stronger          
attraction of that fluid for  nitrous   
oxide4    #b4 ,that nitrate of ammoniac1
 at temperatures below #ddj1 is         
decompounded into pure nitrous oxide1   
and fluid4    #c4 ,that in ascertaining 
the purity of nitrous oxide from its    
absorption  by water1 corrections ought 
to be made for the quantity of gas      
dispelled from the water4 ,this quantity
 in common water distilled  under       

mercury being about _/2 in water simply 
boiled1 and used when  hot1 about _/2   
and in common spring water1 _/4         
,,iv4 ,specific gravity of ,nitrous     
,oxide4    ,to understand accurately the
 changes taking place during the        
decomposition of nitrate of ammoniac1 we
 must be acquainted with the  specific  
gravity and composition of nitrous      
oxide4    #ij cubic inches of it1       
containing about _/ common air1         
introduced  from the mercurial airholder
 into an exhausted globe1 increased it  
in  weight #dd1ge grains2 thermometer   
being #ea1 and atmospheric pressure     
#cj1g4    #ajf cubic inches1 of similar 
composition1 weighed in like manner1    
gave at the same temperature and        
pressure nearly #eb1be grains2 and in   
another experiment1 when the thermometer
 was #da1 #ec grains4    ,so that       
accounting for the small quantity of    
common air contained in  the gases      
weighed1 we may conclude1 that #ajj     
cubic inches of pure  nitrous oxide     

weigh #ej1a grains at temperature #ej1  
and atmospheric  pressure #cj1g4    ,i  
was a little surprised at this great    
specific gravity1 particularly  as ,i   
had expected1 from ,dr4 ,priestley's    
observations1 to find it less  heavy    
than atmospherical air4 ,this           
philosopher supposed1 from some         
appearances produced by the mixture of  
it with ariform ammoniac1 that  it was  
even of less specific gravity than that 
gas4#ha    #ha ,experiments and         
,observations1 vol4 #b1 pag4 #hi4 ,last 
,edition4      ,v4 ,analysis of ,nitrous
 ,oxide4    ,the nitrous oxide may be   
analised1 either by charcoal or         
hydrogene2  during the combustion of    
other bodies in it1 small portions of   
nitrous  acid are generally formed1 as  
will be fully explained hereafter4      
,the gas that ,i employed was generated 
from compact nitrate of ammoniac1  and  
was in its highest state of purity1 as  
it left a residuum of _/  only1 when    
absorbed by boiled water4    #aj cubic  

inches of it were inserted into a jar   
graduated to1#a cubic  inches1          
containing dry mercury4 ,through this   
mercury a piece of  charcoal which had  
been deprived of its hydrogene by long  
exposure  to heat1 weighing about a     
grain1 was introduced1 while yet warm4  
,no  perceptible absorption of the gas  
took place4#hb    #hb ,a minute         
quantity1 however1 must have been       
absorbed1 and given out  again when the 
charcoal was heated4    ,thermometer    
being #df1 the focus of a lens was      
thrown on the charcoal1  which instantly
 took fire1 and burnt vividly for about 
a minute1 the  gas being increased in   
volume4 ,after the vivid combustion had 
ceased1  the focus was again thrown on  
the charcoal2 it continued to burn for  
near ten minutes1 when the process      
stopped4    ,the gas1 when the original 
pressure and temperature were restored1 
filled a space equal to #ab1e cubic     
inches4    ,on introducing to it a small
 quantity of strong solution of         

ammoniac#hc1 white vapor was instantly  
perceived1 and after a short  time the  
reduction was to about #aj1a cubic      
inches2 so that apparently1  #b1d cubic 
inches of carbonic acid had been formed4
 ,the #aj1a cubic  inches of gas        
remaining were exposed to water which   
had been long in  ebullition1 and which 
was introduced whilst boiling1 under    
mercury4  ,after the absorption of the  
nitrous oxide by the water1 the gas     
remaining was equal to #e1c4    #hc     
,strong solution of ammoniac has no     
attraction for nitrous oxide4    ,but on
 combining a cubic inch of pure nitrous 
oxide with some of the  same water1     
which had been received under mercury in
 a separate vessel1  nearly _/ remained4
 ,consequently we may conclude1 that    
#e1a of a gas  unabsorbable by water1   
was produced in the combustion4    ,this
 gas extinguished flame1 gave no        
diminution with oxygene1 and the        
slightest possible with nitrous gas4    
,when an electric spark was passed      

through it1 mingled with oxygene2 no    
inflammation1 or perceptible  diminution
 took place4#hd ,we may consequently    
conclude that it was  nitrogene1 mingled
 with a minute portion of common air1   
expelled from  the water4    #hd ,the   
gas was examined by those tests in order
 to prove that no  water had been       
decomposed4    ,the charcoal was        
diminished in bulk to one half nearly1  
but the loss of  weight could not be    
ascertained1 as its pores were filled   
with mercury4    ,now #e cubic inches of
 nitrous oxide were absorbed by the     
water1  consequently #e were            
decompounded by the charcoal2 and these 
produced  #e1a cubic inches of          
nitrogene2 and by giving their oxygene  
to the  charcoal1 apparently #b1d of    
carbonic acid4    ,but #e cubic inches  
of nitrous oxide weigh #b1e grains1 and 
#e1a cubic  inches of nitrogene #a1ee2  
then #b1e-a1ee 1#ie4    ,so that        
reasoning from the relative specific    
gravities of nitrogene and  nitrous     

oxide1 #b1e grains of the last are      
composed of #a1ee nitrogene1  and1#ie   
oxygene4    ,but from many experiments  
made on the specific gravity of carbonic
  acid1 in ,august1 #agii1 ,i concluded 
that #ajj cubic inches of it weighed    
#dg1e grains1 thermometer being #fj1a1  
and barometer #bi1e4 ,consequently1     
making the necessary corrections1 #b1d  
cubic inches of it weigh  #a1ad grains2 
and on ,lavoisier's and ,guyton's#he    
estimation of its  composition1 these   
#a1ac grains contain #h1b of oxygene4   
#he ,see the curious paper of this      
excellent philosopher1 on the           
combustion of the diamond1 in which he  
proves that charcoal is1 in  fact1 oxide
 of diamond4 ,annales de ,chimie1 xxxi4 
,so that1 drawing conclusions from the  
quantity of carbonic acid formed  in    
this experiment1 #b1e grains of nitrous 
oxide will be composed of1#hb  oxygene1 
and #a1fh nitrogene4    ,the difference 
between these estimations is            
considerable1 and yet not  more than    

might have been expected1 if we consider
 the probable sources  of error in the  
experiment4    #a4 ,it is likely that   
variable minute quantities of hydrogene 
remain  combined with charcoal1 even    
after it has been long exposed to a red 
heat4    #b4 ,it is probable that the   
nitrogene and carbonic acid produced    
were  capable of dissolving more water  
than that held in solution by the       
nitrous oxide2 and if so1 they were more
 condensed than if saturated  with      
moisture1 and hence the quantity of     
carbonic acid under-rated4    ,we may   
consequently suppose the estimation     
founded on the quantity of  nitrogene   
evolved1 most correct2 and making a     
small allowance for the  difference1    
conclude1 that #ajj grains of nitrous   
oxide are composed of  about #cg        
oxygene1 and #fc nitrogene2 existing in 
a much more condensed  state than when  
in their simple forms4    ,the tolerable
 accuracy of this statement will be     
hereafter demonstrated  by a number of  

experiments on the combustion of        
different bodies in  nitrous oxide1     
detailed in ,research ,,ii4      ,,vi4  
,minute examination of the decomposition
 of ,nitrate of ,ammoniac4    ,into a   
retort weighing #dac1ge grains1 and of  
the capacity of #g1e  cubic inches1 #ajj
 grains of pulverised compact nitrate of
 ammoniac  were introduced4 ,to the neck
 of this retort was adapted a recipient1
  weighing #gaa grains1 tubulated for   
the purpose of communicating with  the  
mercurial airholder1 and of the capacity
 of #h1c cubic inches4    ,temperature  
being #ej and atmospheric pressure      
#cj1f1 the recipient  was inserted into 
a vessel of cold water1 and made to     
communicate  with the airholder4 ,the   
heat of a spirit lamp was then slowly   
applied  to the retort3 the salt quickly
 began to decompose1 and to liquify4    
,the temperature was so regulated1 as to
 keep up an equable and slow            
decomposition4    ,during this          
decomposition1 no luminous appearance   

was perceived in the  retort2 the gas   
that came into the airholder was very   
little clouded1  and much water         
condensed in the receiver4    ,after the
 process was finished1 the communication
 between the mercurial  airholder and   
the recipient was preserved till the    
common temperature  was restored to the 
retort4    ,the volume of the gas in the
 cylinder was #he1e cubic inches4 ,the  
absolute quantity of nitrous oxide in   
those #he1e cubic inches1 it was        
difficult to ascertain with great       
nicety1 on account of the common air    
previously contained in the vessels4    
#de measures of it1 exposed to well     
boiled water1 diminished by  agitation  
to #h measures4 ,so that reasoning from 
the quantity of air1  which should have 
been expelled from the water by the     
nitrous oxide1 we  may conclude that the
 #he1e cubic inches were nearly pure4   
,the retort now weighed #dai1be grains1 
consequently #e1e grains of salt        
remained in it4 ,this salt was chiefly  

collected about the lower part  of the  
neck1 and contained rather more water   
than the compact nitrate1  as in some   
places it was crystalised4    ,the      
recipient with the fluid it contained1  
weighed #gei grains4 ,it had            
consequently gained in weight #dh       
grains4    ,now the #he1e cubic inches  
of nitrous oxide produced1 weigh about  
#db1e  grains2 and this added to #dh and
 #e1e1  #if grains2 so that about #d    
grains of salt and fluid were lost1     
probably by being carried over and      
deposited by the gas4#hf    #hf ,this   
was actually the case2 for on examining 
the conducting tube  the day after the  
experiment1 some minute crystals of     
prismatic nitrate  of ammoniac were     
perceived in it4    ,as much of the     
fluid as could be taken out of the      
recipient1 weighed  #df grains1 and held
 in solution much nitrate of ammoniac   
with  superabundance of acid4 ,this acid
 required for its saturation1 #c of     
carbonate of ammoniac 7containing1 as   

well as ,i could guess71 about #bj  per 
cent alkali4    ,the whole solution     
evaporated1 gave #ah grains of compact  
nitrate of  ammoniac4 ,but reasoning    
from the quantity of carbonate of       
ammoniac  employed1 the free nitric acid
 was equal to #b1ge grains1 and this    
must  have formed #c1ef grains of salt4 
,consequently the salt pre-existing in  
the solution was about #ad1dd grains4   
,but besides the fluid taken out of the 
recipient1 #b grains remained in  it3   
let us suppose this1 and the #d grains  
lost1 to contain #b of salt1  and1#f of 
free acid4    ,then the undecompounded  
salt is   #e1e   #ad1d  #b   #ba1i      
,the free acid #b1ge    1#f        #c1ce
      ,gas                              
#db1e      ,water                       
#cb1be                                  
------------                            
#ajj    ,now about #gh1a grains of salt 
were decompounded1 and formed into #db1e
  grains of gas1 #c1ce grains acid1 and 
#cb1be grains water4    ,but there is   

every reason to suppose1 that in this   
process1 when the  hydrogene of the     
ammoniac combines with a portion of the 
oxygene of  the nitric acid to form     
water1 and the nitrogene enters into    
union  with the nitrogene and remaining 
oxygene of the nitric acid1 to form     
nitrous oxide2 that water pre-existing  
in nitric acid and ammoniac1  such as   
they existed in the ariform state1 is   
deposited with the water  produced by   
the new arrangement1 and not wholly     
combined with the  nitrous oxide formed4
 ,hence it is impossible to determine   
with great  exactness1 the quantity of  
water which was absolutely formed in    
this  experiment4    #gh1a grains of    
salt are composed of #ae1d alkali1 #eh  
acid1 and #d1g water4    ,and reasoning 
from the different affinities of water  
for nitric acid1  ammoniac1 and nitrous 
oxide1 it is probable that ammoniac1 in 
its  decomposition1 divides its water in
 such a ratio1 between the nitrogene    
furnished to the nitrous oxide1 and the 

hydrogene entering into union  with the 
oxygene of the nitric acid1 as to enable
 us to assume1 that  the hydrogene      
requires for its saturation nearly the  
same quantity of  oxygene as when in the
 ariform state2 or that it certainly    
cannot  require less4    ,but #ae1d     
alkali contain #c1jh hydrogene1 and     
#ab1cb nitrogene2#hg and  #c1jh         
hydrogene require #ag1d of oxygene to   
form #bj1dh of water4    #hg ,owing part
 of their weight to an unknown quantity 
of water4    ,now #cb1e grains of water 
existed before the experiment2 #d1g     
grains of  water were contained by the  
salt decomposed1 and #cb1e-d1g  #bg1h3  
and  #bg1h-bj1dh1 the quantity          
generated1  #g1eb1 the quantity existing
 in  the nitric acid4    ,but the nitric
 acid decomposed is #eh-c1ce  to #ed1g2 
and #ed1g-g1e   #dg1b1 which entered    
into new combinations4 ,these #dg1b     
consist of  #cc1b oxygene1 and #ad1     
nitrogene4 ,and #cc1b-ag1d1 the quantity
 employed  to form the water1  #ae1h1   

which combined with #ad1j1 nitrogene of 
the nitric acid1 and #ab1cb of that of  
the ammoniac1 to form #db1ab of  nitrous
 oxide4 ,and on this estimation1 #ajj   
parts of nitrous oxide  would contain   
#cg1f oxygene1 and #fb1d nitrogene2 a   
computation much  nearer the results of 
the analysis than could have been       
expected1  particularly as so many      
unavoidable sources of error existed in 
the  process4    ,the experiment that ,i
 have detailed is the most accurate of  
four1 made  on the same quantity of     
salt4 ,the others were carried on at    
rather  higher temperatures1 in         
consequence of which1 more water and    
salt were  sublimed with the gas4    ,to
 ,berthollet1 we owe the discovery of   
the products evolved during the  slow   
decomposition of nitrate of ammoniac2   
but as this philosopher  in his         
examination of this process1 chiefly    
designed to prove the  existence of     
hydrogene in ammoniac1 he did not       
ascertain the quantity  of gas produced1

 or minutely examine its properties2    
from two of  them1 its absorption by    
water and its capability of supporting  
the  vivid combustion of a taper1 he    
inferred its identity with the          
dephlogisticated nitrous gas of         
,priestley1 and concluded that it was   
nitrous gas with excess of pure air4#hh 
#hh ,mem4 de ,paris4 #aghe1 and ,journal
 de ,physique1 #aghf1 page #age4        
,,vii4 ,of the heat produced during the 
decomposition of nitrate of  ammoniac4  
,to ascertain whether the temperature of
 nitrate of ammoniac was  increased or  
diminished after it had been raised to  
the point essential  to its             
decomposition1 during the evolution of  
nitrous oxide and water2  that is1 in   
common language1 whether heat was       
generated or absorbed  in the process2  
,i introduced a thermometer into about  
#aejj grains of  fibrous nitrate of     
ammoniac1 rendered liquid in a deep     
porcelain cup4  ,during the whole of the
 evaporation1 the temperature was about 

#chj1  the fire being carefully         
regulated4    ,as soon as the           
decomposition took place1 the           
thermometer began to rise2  in less than
 a quarter of a minute it was #daj1 in  
two minutes it was  #dfj4    ,the cup   
was removed from the fire2 the          
decomposition still went on  rapidly1   
and for about a minute the thermometer  
was stationary4 ,it  then gradually and 
slowly fell2 in three minutes it was    
#ddj1 in  five minutes #dbj1 in seven   
minutes #dje in nine minutes #cfj and in
  thirteen minutes #cjg1 when the       
decomposition had nearly ceased1 and    
the salt began to solidify4    ,from    
this experiment1 it is evident that an  
increase of temperature  is produced by 
the decomposition of nitrate of         
ammoniac3 though the  capacity of water 
and nitrous oxide for heat1 supposing   
the truth of  the common doctrine1 and  
reasoning from analogy1 must be         
considerably  greater than that of the  
salt4      ,,viii4 ,of the decomposition

 of ,nitrate of ,ammoniac at high       
temperatures1 and production of ,nitrous
 gas1 ,nitrogene1 ,nitrous ,acid1  and  
,water4    ,at an early period of my    
investigation relating to the nitrous   
oxide1  ,i discovered that when a heat  
above #fjj was applied to nitrate of    
ammoniac1 so that a vivid luminous      
appearance was produced in the  retort1 
certain portions of nitrous gas1 and    
nitrogene1 were evolved  with the       
nitrous oxide4 ,but ,i was for some time
 ignorant of the  precise nature of this
 decomposition1 and doubtful with regard
 to  the possibility of effecting it in 
such a manner as to prevent the         
production of nitrous oxide altogether4 
,i first attempted to decompose nitrate 
of ammoniac at high  temperatures1 by   
introducing it into a well coated green 
glass retort1  having a wide neck1      
communicating with the pneumatic        
apparatus1 and  strongly heated in an   
air-furnace4 ,but though in this process
 a  detonation always took place1 and   

much light was produced1 yet still  the 
greater portion of the gas generated was
 nitrous oxide2 the nitrous  gas and    
nitrogene never amounting to more than  
one third of the whole4    ,after       
breaking many retorts by explosions1    
without gaining any accurate  results1  
,i employed a porcelain tube1 curved so 
as to be capable of  introduction into  
the pneumatic apparatus1 and closed at  
one end4    ,the closed end was heated  
red1 nitrate of ammoniac introduced into
 it1  and all the latter portions of gas
 produced in the explosion1 received  in
 the pneumatic apparatus1 filled with   
warm water4    ,three explosions were   
required to fill a jar of the capacity  
of #bj  cubic inches4 ,the gas produced 
in the first1 when it came over1 was    
transparent and dark orange1 similar in 
its appearance to the nitrous  acid gas 
produced in the first experiment2 but it
 speedily became white  and clouded1    
whilst a slight diminution of volume    
took place4    ,when the second portion 

was generated and mingled with the      
clouded  gas1 it again became           
transparent and yellow for a short time1
 and then  assumed the same appearance  
as before4    ,the water in the trough1 
after this experiment1 had an acid      
taste1 and  quickly reddened cabbage    
juice rendered green by an alkali4    #f
 cubic inches of the gas produced were  
exposed to boiled water1 but  little or 
no absorption took place4 ,hence1       
evidently1 it contained no  nitrous     
oxide4    ,they were then exposed to    
solution of sulphate of iron3 the       
solution  quickly became dark colored1  
and an absorption of #a1f took place on 
agitation4#hi    #hi ,the absorption of 
nitrous gas by sulphate of iron1 c4 will
 be  treated of in the next division4   
,the gas remaining instantly            
extinguished the taper1 and was         
consequently nitrogene4    ,this        
experiment was repeated1 with nearly the
 same results4    ,we may then conclude1
 that at high temperatures1 nitrate of  

ammoniac is  wholly resolved into water1
 nitrous acid1 nitrous gas1 and         
nitrogene2  whilst a vivid luminous     
appearance is produced4    ,the         
transparency and orange color produced  
in the gas that had been  clouded1 by   
new portions of it1 doubtless arose from
 the solution of  the nitric acid and   
water forming the cloud1 in the heated  
nitrous  vapor produced1 so as to       
constitute an ariform triple compound2  
whilst the cloudiness and absorption    
subsequent were produced by the         
diminished temperature1 which destroyed 
the ternary combination1 and  separated 
the nitrous acid and water from the     
nitrous gas4    ,from the rapidity with 
which the deflagration of nitrate of    
ammoniac  proceeds1 and from the immense
 quantity of light produced1 it is      
reasonable to suppose that a very great 
increase of temperature takes  place4   
,the tube in which the decomposition has
 been effected1 is always  ignited after
 the process4      ,,ix4 ,speculations  

on the decompositions of ,nitrate of    
,ammoniac4    ,all the phnomena of      
chemistry concur in proving1 that the   
affinity of  one body1 ,a1 for another1 
,b1 is not destroyed by its combination 
with a  third1 ,c1 but only modified2   
either by condensation1 or expansion1 or
  by the attraction of ,c for ,b4    ,on
 this principle1 the attraction of      
compound bodies for each other  must be 
resolved into the reciprocal attractions
 of their constituents1  and            
consequently the changes produced in    
them by variations of  temperature      
explained1 from the alterations produced
 in the attractions  of those           
constituents4    ,thus in nitrate of    
ammoniac1 four affinities may be        
supposed to exist3        #a4 ,that of  
hydrogene for nitrogene1 producing      
ammoniac4        #b4 ,that of oxygene   
for nitrous gas1 producing nitric acid4 
#c4 ,that of the hydrogene of ammoniac  
for the oxygene         of nitric acid4 
#d4 ,that of the nitrogene of ammoniac  

for the nitrous gas         of nitric   
acid4    ,at temperatures below #cjj1   
the salt1 from the equilibrium between  
these affinities1 preserves its         
existence4    ,now when its temperature 
is raised to #djj1 the attractions of   
hydrogene for nitrogene1#ij and of      
nitrous gas for oxygene1#ia are         
diminished2 whilst the attraction of    
hydrogene for oxygene#ib is  increased2 
and perhaps that of nitrogene for       
nitrous gas4    #ij ,as is evident from 
the decomposition of ammoniac by heat4  
#ia ,nitric acid is phlogisticated by   
heat1 as appears from ,dr4  ,priestley's
 experiments4 ,vol4 #c1 p4 #bf4    #ib  
,as is evident from the increase of     
temperature required for the  formation 
of water4    ,hence the former          
equilibrium of affinity is destroyed1   
and a new one  produced4    ,the        
hydrogene of the ammoniac combines with 
the oxygene of the nitric  acid to      
generate water2 and the nitrogene of the
 ammoniac enters into  combination with 

the nitrous gas to form nitrous oxide3  
and the water  and nitrous oxide        
produced1 most probably exist in binary 
combination  in the ariform state1 at   
the temperature of the decomposition4   
,but when a heat above #hjj is applied  
to nitrate of ammoniac1 the  attractions
 of nitrogene and hydrogene for each    
other1 and of  oxygene for nitrous      
gas1#ic are still more diminished2      
whilst that  of nitrogene for nitrous   
gas is destroyed1 and that of hydrogene 
for oxygene increased to a great extent3
 likewise a new attraction  takes place2
 that of nitrous gas for nitric acid1 to
 form nitrous  vapor4#id ,hence a new   
arrangement of principles is rapidly    
produced2  the nitrogene of ammoniac    
having no affinity for any of the single
  principles at this temperature1 enters
 into no binary compound3 the  oxygene  
of the nitric acid forms water with the 
hydrogene1 and the  nitrous gas combines
 with the nitric acid to form nitrous   
vapor4 ,all  these substances most      

probably exist in combination at the    
temperature  of their production2 and at
 a lower temperature1 assume the forms  
of  nitrous acid1 nitrous gas1          
nitrogene1 and water4    #ic ,for       
ammoniac and nitrous oxide are both     
decomposed at the red  heat1 and oxygene
 given out from nitric acid when it is  
passed through  a heated tube4    #id   
,whenever nitrous acid is produced at   
high temperatures1 it is  always highly 
phlogisticated1 provided it has not been
 long in contact  with oxygene4 ,when   
,dr4 ,priestley passed nitric acid      
through a tube  heated red1 he procured 
much oxygene1 and phlogisticated acid2  
and the  water in the apparatus employed
 was fully impregnated with nitrous air4
  ,hence it would appear1 that heat     
diminishes the attraction between       
oxygene and nitrous gas1 and increases  
the affinity of nitrous gas for  nitrous
 acid4 ,mr4 ,,james ,,thomson1 whose    
theory of the ,nitrous ,acid ,i  have   
already mentioned1 from some experiments

 on the phlogistication  of ,nitric     
,acid by heat1 which he has communicated
 to me1 concludes  with great justness1 
that a portion of the acid is always    
completely  decomposed in this process3 
the oxygene liberated1 and the nitrous  
gas  combined with the remaining acid4  
,i have avoided entering into any       
discussions concerning the light  and   
heat produced in this process2 because  
these phnomena cannot be  reasoned upon 
as isolated facts1 and their relation to
 general theory  will be treated of     
hereafter4      ,x4 ,on the preparation 
of ,nitrous ,oxide for experiments on   
,respiration4    ,when compact nitrate  
of ammoniac is slowly decomposed1 the   
nitrous  oxide produced is almost       
immediately fit for respiration2 but as 
one  part of the salt begins to         
decompose before the other is rendered  
fluid1 a considerable loss is produced  
by sublimation4    ,for the production  
of large quantities of nitrous oxide1   
fibrous  nitrate of ammoniac should be  

employed4 ,this salt undergoes no       
decomposition till the greater part of  
its water is evaporated1 and in         
consequence at the commencement of that 
process1 is uniformly heated4    ,the   
gas produced from fibrous nitrate1 must 
be suffered to rest at  least for an    
hour after its generation4 ,at the end  
of this time it is  generally fit for   
respiration4 ,if examined before1 it    
will be found  to contain more or less  
of a white vapor1 which has a           
disagreeable  acidulous taste1 and      
strongly irritates the fauces and lungs4
 ,this  vapor1 most probably1 consists  
of acid nitrate of ammoniac and water1  
which were dissolved by the gas at the  
temperature of its production1  and     
afterwards slowly precipitated4    ,it  
is found in less quantity when compact  
nitrate is employed1  because more salt 
is sublimed in this process1 which being
 rapidly  precipitated1 carries with it 
the acid and water4    ,whatever salt is
 employed1 the last portions of gas     

produced1 generally  contain less vapor1
 and may in consequence be respired     
sooner than the  first4    ,the nitrate 
of ammoniac should never be decomposed  
in a metallic  vessel1#ie nor the gas   
produced suffered to come in contact    
with  any metallic surface2 for in this 
case the free nitric acid will be       
decomposed1 and in consequence1 a       
certain quantity of nitrous gas         
produced4    #ie ,except it be gold or  
platina4    ,the apparatus that has been
 generally employed in the medical      
pneumatic  institution1 for the         
production of nitrous oxide1 consists   
#a4 ,of a glass retort1 of the capacity 
of two or three quarts1         orificed
 at the top1 and furnished with a ground
 stopper4        #b4 ,of a glass tube1  
conical for the purpose of receiving the
         neck of the retort2 about 1#d  
inches wide in the narrowest            
part1 #d feet long1 curved at the       
extremity1 so as to be         capable  
of introduction into an airholder1 and  

inclosed by         tin plate to        
preserve it from injury4        #c4 ,of 
airholders of ,mr4 ,watt's invention1   
filled with water         saturated with
 nitrous oxide4        #d4 ,of a common 
air-furnace1 provided with dampers for  
the         regulation of the heat4     
,the retort1 after the insertion of the 
salt1 is connected with the  tube1      
carefully luted1 and exposed to the heat
 of the furnace1 on a  convenient stand4
 ,the temperature is never suffered to  
be above #ejj4  ,after the decomposition
 has proceeded for about a minute1 so   
that the  gas evolved from the tube     
enlarges the flame of a taper1 the      
curved end  is inserted into the        
airholder1 and the nitrous oxide        
preserved4    ,the water thrown out of  
the airholders in consequence of the    
introduction of the gas1 is preserved in
 a vessel adapted for the  purpose1 and 
employed to fill them again2 for if     
common water was to  be employed in     
every experiment1 a great loss of gas   

would be produced  from absorption4     
,a pound of fibrous nitrate of ammoniac1
 decomposed at a heat not above  #ejj1  
produces nearly #e cubic feet of gas2   
whilst from a pound of  compact nitrate 
of ammoniac1 rarely more than #d1be     
cubic feet can be  collected4    ,for   
the production of nitrous oxide in      
quantities not exceeding #bj  quarts1 a 
mode still more simple than that ,i have
 just described may be  employed4 ,the  
salt may be decomposed by the heat of an
 argands lamp1 or  a common fire1 in a  
tubulated glass retort1 of #bj or #cj   
cubic inches in  capacity1 furnished    
with a long neck1 curved at the         
extremity2 and the  gas received in     
small airholders4    ,thus1 if the      
pleasurable effects1 or medical         
properties of the nitrous  oxide1 should
 ever make it an article of general     
request1 it may be  procured with much  
less time1 labor1 and expence1#if than  
most of the  luxuries1 or even          
necessaries1 of life4    #if ,a pound of

 nitrate of ammoniac costs about #es4   
#aj;d4 ,this pound1  properly           
decomposed1 produces rather more than   
#cd moderate doses of  air2 so that the 
expence of a dose is about #b;d4 ,what  
fluid stimulus can  be procured at so   
cheap a rate8      ,,division ,,iv4     
,,experiments and ,,observations on the 
,,composition of         ,,nitrous      
,,gas1 and on its ,,absorption by       
different         bodies4      ,i4      
,preliminaries4    ,in my account of the
 composition of nitric acid1 in         
,division ,i4 ,i gave  an estimation of 
the quantities of oxygene and nitrogene 
combined  in nitrous gas3 ,i shall now  
detail the experiments on which that    
estimation is founded4    ,at an early  
period of my researches relating to     
nitrous oxide1 from  the observation of 
the phnomena taking place during the    
production of  this substance1 ,i had   
concluded1 that the common opinion with 
regard  to the composition of nitrous   
gas1 was very distant from the truth4   

,i had indeed analysed nitrous gas1 by  
converting it into nitrous  oxide1      
before ,i attempted to ascertain its    
composition by immediately  separating  
the constituent principles from each    
other3 and my first  hopes of the       
possibility of effecting this1 were     
derived from ,dr4  ,priestley's         
experiments on the combustion of        
pyrophorus in nitrous gas1  and on the  
changes effected in it1 by heated iron  
and charcoal4    ,this great philosopher
 found1 that pyrophorus placed in       
contact with  nitrous gas1 burnt with   
great vividness1 whilst the gas was     
diminished  in volume to about one half1
 which generally consisted of nitrogene 
and nitrous oxide4 ,he likewise found1  
iron heated by a lens in nitrous  gas1  
increased in weight1 whilst the gas was 
diminished about 1 and  converted into  
nitrogene4#ig    ,he heated common      
charcoal1 and charcoal of copper1#ih in 
nitrous gas  by a lens4 ,when common    
charcoal was employed1 the gas was      

neither  increased or diminished in     
bulk1 but wholly converted into         
nitrogene2  when charcoal of copper was 
used1 the volume was a little increased1
  and the gas remaining consisted of _/ 
nitrogene1 and _/ carbonic acid4    #ig 
,experiments and ,observations1 vol4    
,,ii4 pag4 #ej4 ,last ,edition4    #ih  
,that is1 charcoal produced by the      
decomposition of spirits of  wine4 ,vol4
 ,,ii4 pag4 #ci4    ,in his experiments 
on the iron and pyrophyrus1 the nitrous 
gas  was evidently decomposed4 ,from the
 great quantity of nitrogene  produced  
in those on the charcoal1 it seems      
likely that both the  common            
charcoal1#ii and the charcoal of copper 
employed contained  atmospherical air1  
which being dispelled by the heat of the
 lens1  was decomposed by the nitrous   
gas3 indeed1 till ,i made the following 
experiment1 ,i suspected that the       
carbonic acid produced1 when the        
charcoal of copper was employed1 arose  
from a decomposition of the  nitrous    

acid1 formed in this way4    #ii ,dr4   
,priestley says1 8having heated iron in 
nitrous air1 ,i  proceeded to heat in   
the same air1 a piece of charcoal not   
long after  it had been subjected to a  
strong heat covered with sand4 ,the sun 
not shining immediately1 after the      
charcoal was introduced into the  vessel
 of air1 through the mercury by which it
 was confined1 part  of the air was     
absorbed2 but on heating the charcoal1  
the quantity  was increased4 ,having    
continued the progress as long as ,i    
thought  necessary1 ,i examined the air 
and found it to be about as much as  the
 original quantity of nitrous air2 but  
it was all phlogisticated  air          
extinguishing a candle and having no    
mixture of fixed air in                 
it40--,experiments and ,observations1   
,vol4 ,,ii1 page #ci4    ,i introduced a
 piece of well-burnt charcoal1 which    
could hardly have  weighed the eighth of
 a grain1 whilst red hot1 under a       
cylinder filled  with mercury1 and      

admitted to it half a cubic inch of     
nitrous gas4 ,a  slight absorption took 
place4    ,the sun being very bright1 ,i
 kept the charcoal in the focus of a    
small lens for near a quarter of an     
hour4 ,at the end of this time  the gas 
occupied a space nearly as before the   
experiment1 and a very  minute portion  
of the charcoal had been consumed4 ,on  
introducing  into the cylinder a small  
quantity of solution of strontian1 a    
white  precipitation was perceived1 and 
the gas slowly diminished to about      
three tenths of a cubic inch4 ,to these 
three tenths a little common air  was   
admitted1 when very slight red fumes    
were perceived4    ,this experiment     
convinced me1 that the attraction of    
charcoal for the  oxygene of nitrous    
gas1 at high temperatures1 was          
sufficiently strong  to effect a slow   
decomposition of it4    ,to be more     
accurately acquainted with this         
decomposition1 and to learn  the        
quantities of carbonic acid and         

nitrogene produced from a known         
quantity of nitrous gas1 ,i proceeded in
 the following manner4      ,,ii4       
,analysis of ,nitrous ,gas by ,charcoal4
    ,a quantity of nitrous gas was      
procured in a water apparatus1 from  the
 decomposition of nitrous acid by       
mercury4 ,a portion of it was           
transferred to the mercurial trough4    
,after the mercury and the jar  had been
 dried by bibulous paper1 #dj measures  
of this portion were  agitated in a     
solution of sulphate of iron4 ,the gas  
remaining after  the absorption was     
complete1 filled about a measure and    
half2 so that  the nitrous gas contained
 nearly _/ nitrogene4    ,thermometer   
being #ec1 a small piece of well-burnt  
charcoal1 the  weight of which could    
hardly have equalled a quarter of a     
grain1  was introduced ignited1 into a  
small cylinder filled with mercury1     
graduated to1#aj grain measures2 to     
this1 #af measures1 equal to #afj  grain
 m4 of nitrous gas1 were admitted4 ,an  

absorption of about one  measure and    
half took place4 ,when the focus of a   
lens was thrown on the  charcoal1 a     
slight increase of the gas was produced1
 from the emission  of that which had   
been absorbed4    ,after the process had
 been carried on for about a half an    
hour1 the  charcoal evidently began to  
fume1 and to consume very slowly1 though
 no  alteration in the volume of the gas
 was observed4    ,the sun not          
constantly shining1 the progress of the 
experiment was now  and then stopped3   
but taking the whole time1 the focus    
could not have  been applied to it for  
less than four hours4 ,when the process 
was  finished1 the gas was increased in 
bulk nearly three quarters of a         
measure4    ,a drop of water was        
introduced into the cylinder1 by means  
of a small  glass tube1 on the          
supposition that the carbonic acid1 and 
nitrogene1  might be capable of holding 
in solution1 more water than that       
contained  in the nitrous gas           

decomposed2 but no alteration of volume 
took place4    ,when #bj grain measures 
of solution of pale green#ajj sulphate  
of iron  were introduced into the       
cylinder1 they became rather yellower   
than  before1 but not dark at the edges1
 as is always the case when nitrous  gas
 is present4 ,on agitation1 a diminution
 of nearly half a measure was  produced1
 doubtless from the absorption of some  
of the carbonic acid by  the solution4  
#ajj ,that is1 sulphate of iron         
containing oxide of iron1 in the first  
degree of oxygenation4    ,a small      
quantity of caustic potash1 much more   
than was sufficient to  decompose the   
sulphate of iron1 was now introduced4 ,a
 rapid diminution  took place1 and the  
gas remaining filled about #h measures4 
,this gas was  agitated for some time   
over water1 but no absorption took      
place4 ,two  measures of it were then   
transferred into a detonating cylinder  
with  two measures of oxygene4 ,the     
electric spark was puffed through them1 

but no diminution was produced4 ,hence  
it was nitrogene1 mingled with no       
ascertainable quantity of hydrogene3    
consequently little or no water  could  
have been decomposed in the process4    
,now supposing1 for the greater ease of 
calculation1 each of the  measures      
employed1 cubic inches4    #af of       
nitrous gas--_/  #ae1d were decomposed1 
and these weigh1 making  the necessary  
corrections1 #e1b2 but #g1d nitrogene   
were produced1 and  these weigh about   
#b1b4 ,so that reasoning from the       
relative specific  gravities of nitrous 
gas and nitrogene1 #e1b grains of       
nitrous gas will  be composed of #c     
oxygene1 and #b1b nitrogene4    ,but    
#h1g of carbonic acid were produced1    
which weigh #d1a grains1 and  consist of
 #b1i oxygene1 and #a1b charcoal4#aja   
,consequently1 drawing  conclusions from
 the quantity of carbonic acid formed1  
#e1b grains of  nitrous gas will consist
 of #b1i oxygene1 and #b1c nitrogene4   
#aja ,that is1 carbon1 or oxide of      

diamond4    ,the difference in these    
estimations is much less than could have
 been  expected2 and taking the mean    
proportions1 it would be inferred from  
them1 that #ajj grains of nitrous gas1  
contain #ef1e oxygene1 and #dc1e        
nitrogene4    ,i repeated this          
experiment with results not very        
different1 except that  the increase of 
volume was rather greater1 and that more
 unabsorbable  gas remained2 which      
probably depended on the decomposition  
of a minute  quantity of water1 that had
 adhered to the charcoal in passing     
through  the mercury4    ,as nitrous gas
 is decomposable into nitrous acid1 and 
nitrogene1 by the  electric spark2 it   
occurred to me1 that a certain quantity 
of nitrous  acid might have been        
possibly produced1 in the experiments on
 the  decomposition of nitrous gas1 by  
the intensely ignited charcoal4 ,to     
ascertain this circumstance1 ,i         
introduced into #ab measures of nitrous 
gas1 a small piece of charcoal which had

 been just reddened4 ,the sun  being    
very bright1 the focus of the lens was  
kept on it for rather more  than an hour
 and quarter4 ,in the middle of the     
process it began to fume  and to        
sparkle1 as if in combustion4 ,in three 
quarters of an hour1 the  gas was       
increased rather more than half a       
measure2 but no alteration of  volume   
took place afterwards4    ,the mercury  
was not white on the top as is usually  
the case when  nitrous acid is produced4
 ,on introducing into the cylinder a    
little  pale green sulphate of iron1 and
 then adding prussiate of potash1 a     
white precipitate only was produced4    
,now1 if the minutest quantity  of      
nitric acid had been formed1 it would   
have been decomposed by the  pale green 
oxide of iron1 and hence1 a visible     
quantity of prussian  blue#ajb produced1
 as will be fully explained hereafter4  
#ajb ,that is1 blue prussiate of iron4  
,,iii4 ,analysis of ,nitrous ,gas by    
,pyrophorus4    ,i placed some newly    

made pyrophorus1 about as much as would 
fill  a quarter of a cubic inch1 in a   
jar filled with dry mercury1 and        
introduced to it1 four cubic inches of  
nitrous gas1 procured from  mercury and 
nitric acid4    ,it instantly took fire 
and burnt with great vividness for some 
moments4    ,after the combustion had   
ceased1 the gas was diminished about    
three  quarters of a cubic inch4 ,the   
remainder was not examined2 for the     
diminution appeared to go on for some   
time1 after2 in an half hour1  when it  
was compleat1 it was to #b cubic inches4
 ,a taper1 introduced  into these1 burnt
 with an enlarged flame1 blue at the    
edges2 from  whence it appeared1 that   
they were composed of nitrogene and     
nitrous  oxide4    ,i now introduced    
about half a cubic inch of pyrophorus to
 two cubic  inches of nitrous gas2 the  
combustion took place1 and the gas was  
rapidly diminished to one half2 and on  
suffering it to remain five  minutes to 
one third nearly2 which extinguished    

flame4    ,suspecting that this great   
diminution was owing to the absorption  
of  some of the nitrogene formed1 by the
 charcoal of the pyrophorus1 ,i         
carefully made a quantity of pyrophorus2
 employing more than two thirds  of     
alumn1 to one third of sugar4    ,to    
rather more than half of a cubic inch of
 this1 two cubic inches of  nitrous gas1
 which contained about _/ nitrogene1    
were admitted4 ,after  the combustion1  
the gas remaining1 apparently filled a  
space equal  to #a1b cubic inches2 but1 
as on account of the burnt pyrophyrus in
 the  jar1 it was impossible to         
ascertain the volume with nicety1 it was
  carefully and wholly transferred into 
another jar4 ,it filled a space  equal  
to #a1ae cubic inches nearly4    ,when  
water was admitted to this gas no       
absorption took place4 ,it  underwent no
 diminution with nitrous gas1 and a     
taper plunged into it  was instantly    
extinguished4 ,we may consequently      
conclude that it was  nitrogene4    ,now

 #b cubic inches of nitrous gas         
weigh1#fhf grains1 and #a1a of          
nitrogene--1#je1 the quantity previously
 contained in the gas  to #a1je1  #c1ai4
 ,hence1#fhf of nitrous gas would be    
composed of1#cfg oxygene1 and  1#cai    
nitrogene2 and #ajj grains would contain
 #ec1d oxygene1 and #df1f  nitrogene4   
,,iv4 ,additional observations on the   
combustion of bodies in ,nitrous  ,gas1 
and on its ,composition4    ,though     
phosphorus may be fused1 and even       
sublimed1 in nitrous gas1  without      
producing the slightest luminous        
appearance1#ajc yet when it  is         
introduced into it in a state of active 
inflammation1 it burns  with almost as  
much vividness as in oxygene4#ajd ,hence
 it is evident1  that at the heat of    
ignition1 phosphorus is capable of      
attracting the  oxygene from the        
nitrogene of nitrous gas4    #ajc ,no   
luminous appearance is produced when    
phosphorus is introduced  into pure     
nitrous gas4 ,it has been often         

observed1 that phosphorus is  luminous  
in nitrous gas1 that has not been long  
in contact with water  after its        
production4 ,this phnomenon1 ,i suspect1
 depends either on the  decomposition of
 the nitric acid held in solution by the
 nitrous gas2  or on the combination of 
the phosphorus with oxygene loosely     
adhering  to the binary ariform compound
 of nitric acid and nitrous gas4 ,i have
  not yet examined if nitrous gas can be
 converted into nitrous oxide by  long  
exposure to heated phosphorus3 it       
appears1 however1 very probable4    #ajd
 ,perhaps this fact has been noticed    
before2 ,i have not1 however1  met with 
it in any chemical work4    ,i attempted
 to analise nitrous gas1 by introducing 
into a known  quantity of it1 confined  
by mercury1 phosphorus1 in a vessel     
containing  a minute quantity of        
oxygene4#aje ,the phosphorus was        
inflamed with  an ignited iron wire1 by 
which1 at the moment of the combustion1 
the  vessel containing it was raised    

from the mercury into the nitrous gas4  
,but after making in this way1 five of  
six unsuccessful experiments1 ,i        
desisted4 ,when the communication       
between the vessels was made before  the
 oxygene was nearly combined with the   
phosphorus1 nitrous acid  was formed1   
which instantly destroyed the           
combustion2 when1 on the  contrary1 the 
phosphorus was suffered to consume      
almost the whole  of the oxygene1 it was
 not sufficiently ignited when          
introduced1 to  decompose the nitrous   
gas4    #aje ,this mode of inflaming    
bodies in gases1 not capable of         
supporting  combustion at low           
temperatures1 will be particularly      
described  hereafter4    ,in one        
experiment1 indeed1 the phosphorus burnt
 for a moment in the  nitrous gas2 the  
diminution however was slight1 and not  
more than  of  it was decomposed4       
,sulphur1 introduced in a state of vivid
 inflammation1 into nitrous gas1  was   
instantly extinguished4    ,i passed a  

strong electric shock through equal     
parts of hydrogene  and nitrous gas1    
confined by mercury in a detonating     
tube2 but no  inflammation1 or          
perceptible diminution1 was produced4   
#ai1b grain measures of hydrogene were  
fired by the electric shock1  with #aj  
of nitrous oxide1 and #f of nitrous gas2
 the diminution was  to #ag2 and pale   
green sulphate of iron admitted to the  
residuum1 was  not discolored4          
,consequently the nitrous gas was       
decomposed by the  hydrogene1 and as    
will be hereafter more clearly          
understood1 nearly as  much nitrogene   
furnished by it1 as would have been     
produced from half  the quantity of     
nitrous oxide4    ,suspecting that      
phosphorated hydrogene might inflame    
with nitrous  gas1 ,i passed the        
electric spark through #a measure of    
phosphorated  hydrogene1 and #d of      
nitrous gas2 but no diminution was      
perceptible4 ,i  likewise passed the    
electric spark through #a of nitrous    

gas1 with #b of  phosphorated hydrogene1
 without inflammation4    ,perhaps if ,i
 had tried many other different         
proportions of the gases1 ,i  should    
have at last discovered one1 in which   
they would have inflamed2  for1 as will 
be seen hereafter1 nitrous oxide cannot 
be decomposed by  the compound          
combustible gases1 except definite      
quantities are employed4    ,from ,dr4  
,priestley's experiments on iron and    
pyrophorus1 and from the  experiments ,i
 have detailed1 on charcoal1 phosphorus1
 and hydrogene1  it appears that at     
certain temperatures1 nitrous gas is    
decomposable  by most of the combustible
 bodies3 even the extinction of sulphur1
 when  introduced into it in a state of 
inflammation1 depends perhaps1 on the   
smaller quantity of heat produced by the
 combustion of this body1 than  that of 
most others4    ,the analysis of nitrous
 gas by charcoal1 as affording data for 
determining immediately the quantities  
of oxygene and nitrogene1  ought to be  

considered as most accurate2 and        
correcting it by mean  calculations     
derived from the decomposition of       
nitrous gas by  pyrophorus and          
hydrogene1 and its conversion into      
nitrous oxide1 a  process to be         
described hereafter1 we may conclude1   
that #ajj grains  of nitrous gas are    
composed of #ee1ie oxygene1 and #dd1je  
nitrogene2 or  taking away decimals1 of 
#ef oxygene1 and #dd nitrogene4    ,this
 estimation will agree very well with   
the mean proportions that  would be     
given from ,dr4 ,priestley's experiments
 on the decomposition  of nitrous gas by
 iron2 but as he never ascertained the  
purity of his  nitrous gas1#ajf and     
probably employed different kinds in    
different  experiments1 it is impossible
 to fix on any one1 from which accurate 
conclusions can be drawn4               
,lavoisier's estimation of the          
quantities of oxygene and nitrogene     
entering into the composition of nitrous
 gas1 has been generally  adopted4 ,he  

supposes #fd parts of nitrous gas to be 
composed of #dc of  oxygene1 and #bj of 
nitrogene4#ajg    #ajf ,elements        
,english ,trans4 edit4 i4 pag4 #baf4    
#ajg ,experiments and ,observations1    
,vol4 ,,ii4 pag4 #dj1 #b;d4 ,ed4    ,the
 difference between this account and    
mine is very great indeed2  but ,i have 
already1 in ,division #ast1 pointed out 
sources of error in  the experiments of 
this great man1 on the decomposition of 
nitre by  charcoal2 which experiments   
were fundamental1 both to his accounts  
of  the constitution of nitrous acid1   
and nitrous gas4      ,v4 ,of the       
absorption of ,nitrous ,gas by ,water4  
,amongst the properties of nitrous gas  
noticed by its great discoverer1  is    
that of absorbability by water4    ,in  
exposing nitrous air to distilled water1
 ,dr4 ,priestley found a  diminution of 
the volume of gas1 nearly equal to one  
tenth of the bulk  of the water2 and by 
boiling the water thus impregnated1 he  
procured  again a certain portion of the

 nitrous gas4    ,humbolt1 in his paper 
on eudiometry1 mentions the diminution  
of  nitrous gas by water4 ,this         
diminution1 he supposes to arise from   
the  decomposition of a portion of the  
nitrous gas1 by the water1 and the      
consequent formation of nitrate of      
ammoniac4#ajh    #ajh ,he says1 8,on a  
observ1 7depuis qu'on travaille sur le  
puret de  l'air7 que le gaz nitreux1    
secou avec l'eau1 en souffre une        
diminution  de volume4 ,quelques        
physiciens attribuent ce changement  une
 vraie  absorption1  une dissolution du 
gaz nitreux dans l'eau2 d'autres   l'air
 contenu dans les interstices de tous   
les fluides4 ,le cit4  ,vanbreda1       
,delft1 a fait des recherches           
trs-exactes sur l'influence  des eaux de
 pluie et de puit1 sur les nombres      
eudiomtriques2 et les  belles expriences
 du cit4 ,hassenfratz1 sur l'abondance  
d'oxygne1  contenue dans les eaux de    
neige et de pluie1 sont supposer que    
l'air  des interstices de l'eau joue un 

rle important dans l'absorption  du gaz 
nitreux4 ,en comparant ces effets avec  
les phnomnes observ  dans la            
decomposition du sulfate de fer1 nous   
supposmes1 le cit4  ,tassaert et moi1   
que le simple contact du gaz nitreux    
avec l'eau  distille pourroit bien      
causer une dcomposition de ce dernier4  
,nous  examinmes soigneusement une      
petite quantit d'eau distille1 secoue   
avec beaucoup de gas nitreux trs-pur1 et
 nous trouvmes1 au moyen de  la terre   
calcaire1 et l'acide muriatique1 qu'il  
s'y forme du nitrate  d'ammoniaque4     
,l'eau se dcompose en cette opration1   
par un double  affinit de l'oxygene pour
 le gaz nitreux1 et de l'hydrogne pour  
l'azote2 il se forme de l'acide nitrique
 et de l'ammoniaque2 et1  quoique la    
quantit du dernier paroisse trop petite 
pour en valuer  exactment la quantit1   
son existence cependant se manifeste1 7 
ne pas  sans douter7 par le dgagement   
des vapeurs1 qui blanchissent dans la   
proximit de l'acide muriatique4 ,voil un

 fait bien frappant que la  composition 
d'une substance alcaline par le contact 
d'une acide1 et de  l'eau40             
,annales de ,chimie1 t4 xxviii4 pag4    
#aec4      ,i confess1 that even before 
the following experiments were made1 ,i 
was but little inclined to adopt this   
opinion3 the small diminution  of       
nitrous gas by water1 and the uniform   
limits of this diminution1  rendered it 
extremely improbable4    a4 ,to         
ascertain the quantity of nitrous gas   
absorbable by pure water1  and the      
limits of absorption1 ,i introduced into
 a glass retort about #e  ounces of     
water1 which had been previously boiled 
for some hours4 ,the  neck of the retort
 was inverted in mercury1 and the water 
made to boil4  ,after a third of it had 
been distilled1 so that no air could    
possibly  remain in the retort1 the     
remainder was driven over1 and condensed
 in  an inverted jar filled with        
mercury4 ,to three cubic inches of this 
water1#aji confined in a cylinder       

graduated to1#je cubic inches1 #e  cubic
 inches of nitrous gas1 containing      
nearly one thirtieth nitrogene1  were   
introduced4    #aji ,which was certainly
 as free from air as it ever can be     
obtained4    ,after agitation for near  
an hour1 rather more than _/ of a cubic 
inch  appeared to be absorbed2 but      
though the process was continued for    
near  two hours longer1 no further      
diminution took place4    ,the remaining
 gas was introduced into a tube         
graduated to1#jb cubic  inches4 ,it     
measured _/2 hence _/ had been absorbed4
    ,consequently1 #ajj cubic inches of 
pure water are capable of absorbing     
#aa1h of nitrous gas4 ,in the water thus
 impregnated with nitrous gas ,i  could 
distinguish no peculiar taste2#aaj it   
did not at all alter the  color of blue 
cabbage juice4    #aaj ,dr4 ,priestley  
found distilled water1 saturated with   
nitrous air1  to acquire an astringent  
taste and pungent smell4 ,in some       
unboiled  impregnated pump water1 ,i    

once thought that ,i perceived a subacid
  taste2 but it was extremely slight1   
and probably owing to nitrous acid      
formed by the union of the oxygene of   
the common air in the water1 with  some 
of the nitrous gas4    b4 ,to determine 
if the absorption of nitrous gas was    
owing1 to a  decomposition of it by the 
water1 as ,humbolt has supposed1 or to a
  simple solution2 ,i procured some     
nitrous gas from nitrous acid and       
mercury1 containing about one seventieth
 nitrogene4 1#e cubic inches  of it1    
mingled with 1#be1 of oxygene1 from     
sulphuric acid and manganese  left a    
residuum of1#jc4 #e cubic inches more   
were introduced to #c of  water1        
procured in the same manner as in the   
last experiment1 in the  same cylinder4 
,after the diminution was complete1 the 
cylinder was  transferred in a small    
vessel containing mercury1 into a water 
bath1  and nearly covered by the water4 
,as the bath was heated1 small globules 
of gas were given out from the          

impregnated water1 and when it began to 
boil1 the production of gas was  still  
more rapid4 ,after an hour's ebullition1
 the volume of heated gas  was equal to 
#a1d cubic inches nearly4    ,the       
cylinder was now taken out of the bath1 
and quickly rendered cool  by being     
placed in a water apparatus4 ,at the    
common temperature the gas  occupied1 as
 nearly as possible1 the space of1#e    
cubic inches3 these1#e  mingled with1#be
 of oxygene1 of the same kind as that   
employed before1  left a residuum nearly
 equal to1#jc4    ,from this experiment1
 which was repeated with nearly the same
 results1  it is evident1        #a4    
,that nitrous gas is not decomposable by
 pure water4        #b4 ,that the       
diminution of volume of nitrous gas     
placed         in contact with water1 is
 owing to a simple solution         of  
it in that fluid4        #c4 ,that at   
the temperature of #bab1 nitrous gas is 
incapable of remaining in combination   
with water4    ,humbolt's opinion       

relating to the decomposition of nitrous
 gas by  water1 is founded upon the     
disengagement of vapor from distilled   
water  impregnated with nitrous gas1 by 
means of lime1 which became white in    
the proximity of the muriatic acid4 ,but
 this is a very imperfect1 and          
fallacious test1 of the presence of     
ammoniac4 ,i have this day1 ,april  #b1 
#ahjj1 heated #d cubic inches of        
distilled water1 impregnated with       
nitrous gas1 with caustic lime2 the     
vapor certainly became a little  whiter 
when held over a vessel containing      
muriatic acid2 but the vapor  of        
distilled water produced precisely the  
same appearance1#aaa which  was owing1  
most likely1 to the combination of the  
acid with the  aqueous vapor4 ,indeed1  
when ,i added a particle of nitrate of  
ammoniac1  which might have equalled one
 twentieth of a grain1 to the lime and  
impregnated water1 the increased        
whiteness of the vapor was but barely   
perceptible1 though this quantity of    

nitrate of ammoniac is much more        
considerable than that which could have 
been formed1 even supposing the  nitrous
 gas decomposed4    #aaa ,as carbonic   
acid and ammoniac are both products of  
animalisation1  is it not probable that 
our common waters particularly those in1
 and  near towns and cities1 contain    
carbonate of ammoniac8 ,if so1 this     
salt will always exist in them after    
distillation4 ,in the experiments  on   
carbonate of ammoniac1 to which ,i have 
often alluded1 ,i found1 in  distilling 
a solution of this salt in water1 that  
before half of the  water had passed    
into the recipient1 the carbonate of    
ammoniac had  sublimed2 so that the     
distilled solution was much stronger    
than before1  whilst the water remaining
 in the retort was tasteless4 ,will this
  supposition at all explain ,humbolt's 
mistake8      ,,vi4 ,of the absorption  
of ,nitrous ,gas by ,water of different 
kinds4    ,in agitating nitrous gas over
 spring water1 the diminution rarely    

amounts to more than one thirtieth1 the 
volume of water being taken as  unity4  
,i at first suspected that this great   
differcnce in the quantity  of gas      
absorbed by spring water1 and pure      
water1 depended on carbonic  acid       
contained in the last1 diminishing the  
attraction of it for  nitrous gas3 but  
by long boiling a quantity of spring    
water confined  by mercury1 ,i obtained 
from it about one twentieth of its bulk 
of air1  which gave nearly the same     
diminution with nitrous gas1 as         
atmospheric  air4    ,this fact induced 
me to refer the difference of diminution
 to the  decomposition of the           
atmospheric air held in solution by the 
water1  the oxygene of which ,i supposed
 to be converted into nitric acid1 by   
the nitrous gas1 whilst the nitrogene   
was liberated2 and hence the  increased 
residuum4    a4 ,i exposed to pure      
water1 that is1 water procured by       
distillation  under mercury1 nitrous    
gas1 containing a known quantity of     

nitrogene4  ,after the absorption was   
complete1 ,i found the same quantity of 
nitrogene in the residuum1 as was       
contained in a volume of gas equal to   
the whole quantity employed4    b4      
,spring water boiled for some hours1 and
 suffered to cool under  mercury1       
absorbed a quantity of nitrous gas equal
 to one thirteenth of  its bulk2 which  
is not much less than that absorbed by  
pure water4    c4 ,i exposed to spring  
water1 #aj measures of nitrous gas2 the 
composition of which had been accurately
 ascertained2 the diminution  was one   
twenty-eighth1 the volume of water being
 taken as unity4 ,on  placing the       
residuum in contact with solution of    
sulphate of iron1  the nitrogene        
remaining was nearly one twentieth more 
than had been  contained by the gas     
before its exposure to water4    d4     
,distilled water was saturated with     
common air1 by being agitated  for some 
time in the atmosphere4 ,nitrous gas    
placed in contact with  this water1     

underwent a diminution of _/2 the volume
 of water being  unity4 ,the gas        
remaining after the absorption contained
 about one  twenty-seventh nitrogene    
more than before4    e4 ,nitrous gas    
exposed to water combined with about one
 fourth of its  volume of carbonic acid1
 diminished to _/#aab nearly4 ,the      
remainder  contained little or no       
superabundant nitrogene4    #aab ,the   
water still being unity4    ,from these 
observations it appears1 that the       
different degrees of  diminution of     
nitrous gas by different kinds of water1
 may depend upon  various causes4    #a4
 ,less nitrous gas will be absorbed by  
water holding in solution  earthy salts1
 than by pure water2 and in this case   
the diminution of  the attraction of    
water for nitrous gas will probably be  
in the ratio  of the quantities of salt 
combined with it4 a4 b4    #b4 ,the     
apparent diminution of nitrous gas in   
water1 holding in solution  atmospheric 
air1 will be less than in pure water1   

though the absolute  diminution will be 
greater2 for the same portion will be   
absorbed1  whilst another portion is    
combined with the oxygene of the        
atmospheric  air contained in the water2
 and from the disengagement of the      
nitrogene  of this air1 arises an       
increased residuum4 c4 d4    #c4        
,probably in waters containing          
nitrogene1 hydrogene1 and other gases1  
absorbable only to a slight extent1 the 
apparent diminution will be  less1 on   
account of the disengagement of those   
gases from the water1 by  the stronger  
affinity of nitrous gas for that fluid4 
#d4 ,in water containing carbonic acid1 
and probably some other acid  gases1 the
 diminution will be small in proportion 
to the quantity of  gas contained in the
 water3 the affinity of this fluid for  
nitrous gas  being diminished by its    
greater affinity for the substance      
combined  with it4 e4    ,the different 
diminution of nitrous gas when agitated 
in different  kinds of water1 has been  

long observed by experimenters on the   
constituent parts of the atmosphere1 and
 various solutions have been  given of  
the phnomenon2 the most singular is that
 of ,humbolt4#aac ,he  supposes that the
 apparent diminution of nitrous gas is  
less in spring  water than distilled    
water1 on account of the decomposition  
of the  carbonate of lime contained in  
the spring water1 by the nitrous acid   
formed from the contact of nitrous gas  
with the water2 the carbonic  acid      
disengaged from this decomposition      
increasing the residuum4    #aac ,he    
says 8#ajj parties de gaz nitreux1 7    
#j4ad d'azote7 secoues  avec l'eau      
distille1 rcemment cuite1 diminuent en  
volume de #j4aa1 ou  #j4ab4 ,ce mme gaz1
 en contact avec l'eau de puits1 ne perd
 que #j4jb4 ,la  cause de cette         
diffrence de #j4i1 ou #j4aj1 ne doit pas
 tre attribue  ni  l'impurit de l'air   
atmosphrique1 contenu dans les          
interstices  de l'eau1 ni  la           
dcomposition de cette eau mme4 ,elle    

n'est  qu'apparente2 car l'acide        
nitrique1 qui se forme par le contact du
 gaz  nitreux avec l'eau de puits1 en   
dcompose le carbonate de chaux4 ,il se  
dgage de l'acide carbonique1 qui1 en    
augmentant le volume du residu1  rend   
l'absorption du gaz nitreux moins       
sensible4 ,pour dterminer la  quantit de
 cet acide carbonique1 je lavai le rsidu
 avec de l'eau de  chaux4 ,dans un grand
 nombre d'expriences1 le volume diminua 
de #j4ji1  ou #j4jg4 ,il faut en        
conduire que l'eau de puits absorbe     
rellement #i   #b1 ou #g  #b parties de 
gas nitreux1 c'est--dire1  peu-prs la   
mme  quantit que l'eau distille40       
,annales ,de ,chimie1 xxviii4 pag4 #aed4
      ,this opinion may be confuted     
without even reference to my            
observations4 ,it is1 indeed1 altogether
 unworthy of a philosopher1  generally  
acute and ingenious4 ,he seems to have  
forgotten that carbonic  acid is        
absorbable by water4      ,,vii4 ,of the
 absorption of ,nitrous ,gas1 by        

solution of pale green  ,sulphate of    
,iron4    a4 ,the discovery of the exact
 difference between the sulphates of    
iron1 is owing to ,proust4#aad          
,according to the ingenious researches  
of  this chemist1 there exist two       
varieties of sulphate of iron1 the green
  and the red4 ,the oxide in the green  
sulphate contains _/ oxygen4  ,this     
salt1 when pure1 is insoluble in spirit 
of wine2 its solution in  water is of a 
pale green color2 it is not altered by  
the gallic acid1  and affords a white   
precipitate with alkaline prussiates4   
#aad ,nicholson's ,phil4 ,jour4 ,no4 #a1
 p4 #dec4    ,the red sulphate of iron  
is soluble in alcohol and               
uncrystalizable2 its  oxide contains _/ 
oxygene4 ,it forms a black precipitate  
with the  gallic acid1 and with the     
alkaline prussiates1 a blue one4    ,the
 common sulphates of iron generally     
consist of combinations of these  two   
varieties in different proportions4     
,the green sulphate may be converted    

into the red by oxygenated muriatic     
acid or nitric acid4 ,the common        
sulphate may be converted into green    
sulphate1 by agitation in contact with  
sulphurated hydrogene4    ,the green    
sulphate has a strong affinity for      
oxygene1 it attracts it  from the       
atmosphere1 from oxygenated marine acid1
 and nitric acid4 ,the  alkalies        
precipitate from it a pale green oxide1 
which if exposed to  the atmosphere1    
rapidly becomes yellow red4    ,the red 
sulphate of iron has no affinity for    
oxygene1 and when  decomposed by the    
alkalies1 gives a red precipitate1 which
 undergoes no  alteration when exposed  
to the atmosphere4#aae    #aae ,i have  
been able to make these observations on 
the sulphates of  iron1 most of them    
after ,proust4    b4 ,the absorption of 
nitrous gas by a solution of sulphate of
 iron1  was long ago discovered by      
,priestley4 ,during this absorption1 he 
remarked a change of color in the       
solution1 analogous to that produced  by

 the mixture of it with nitric acid4    
,this chemical fact has been lately     
applied by ,humbolt1 to the discovery   
of the nitrogene generally mingled with 
nitrous gas4    ,vauquelin and ,humbolt 
have published a memoir1 on the causes  
of the  absorption#aaf of nitrous gas by
 solution of sulphate of iron4 ,they    
saturated an ounce and half of sulphate 
of iron in solution1 with #ahj  cubic   
inches of nitrous gas4    #aaf ,annales 
de ,chimie1 vol4 xxviii4 pag4 #ahb4     
,thus impregnated it strongly reddened  
tincture of turnsoyle2 when  mingled    
with sulphuric acid1 gave nitric acid   
vapor2 and saturated with  potash1      
ammoniacal vapor4    ,by analysis1 it   
produced as much ammoniac as that       
contained in #d grains  of ammoniacal   
muriate1 and a quantity of nitric acid  
equal to that  existing in #ag grains of
 nitre4 ,hence they concluded1 that the 
nitrous  gas and a portion of the water 
of the solution1 had mutually decomposed
  each other2 the oxygene of the water  

combining with the oxygene and a        
portion of the nitrogene of nitrous gas 
to form nitric acid2 and its  hydrogene 
uniting with the remaining nitrogene1 to
 generate ammoniac4    ,they have taken 
no notice of the nature of the sulphate 
of iron  employed1 which was most       
probably the common or mixed sulphate2  
nor of  the attraction of the oxide of  
iron in this substance for oxygene4     
c4 ,before ,i was acquainted with the   
observations of ,proust1 the  common    
facts relating to the oxygenation of    
vitriol of iron induced  me to suppose1 
that the attraction of this substance   
for oxygene was  in some way connected  
with the process of absorption4 ,the    
comparison  of the experiments of       
,humbolt and ,vauquelin1 with the       
observations of  ,proust1 enabled me to 
discover the true nature of the process4
    ,i procured a solution of red       
sulphate of iron1 by passing oxygenated 
muriatic acid through a solution of     
common sulphate of iron1 till it  gave  

only a red precipitate1 when mingled    
with caustic potash4 ,to  nitrous gas   
confined by mercury1 a small quantity of
 this solution was  introduced4 ,on     
agitation1 its color altered to muddy   
green2 but the  absorption that took    
place was extremely trifling3 in half an
 hour it  did not amount to1#b1 the     
volume of the solution being unity1 when
 it  had nearly regained the yellow     
color4    ,i now obtained a solution of 
green sulphate of iron1 by dissolving   
iron  filings in diluted sulphuric acid4
 ,the solution was agitated in contact  
with sulphurated hydrogene1 and         
afterwards boiled2 when it gave a white 
precipitate with prussiate of potash4   
,a small quantity of this solution      
agitated in nitrous gas1 quickly  became
 of an olive brown1 and the gas was     
diminished with great  rapidity2 in two 
minutes1 a quantity equal to four times 
the volume of  the solution1 had been   
absorbed4    ,these facts convinced me  
that the solubility of nitrous gas in   

common  sulphate of iron1 chiefly       
depended upon the pale green sulphate   
contained by it2 and that the attraction
 of one of the constituents of  this    
substance1 the green oxide of iron1 for 
oxygene1 was one of the  causes of the  
phnomenon4    d4 ,green sulphate of iron
 rapidly decomposes nitric acid4 ,it was
  consequently difficult to conceive how
 any affinities existing between        
nitrous gas1 water1 and green sulphate  
of iron1 could produce the  nitric acid 
found in the experiments of ,vauquelin  
and ,humbolt4    ,to ascertain if the   
presence of a great quantity of water   
destroyed the  power of green sulphate  
of iron to decompose nitric acid1 ,i    
introduced  into a cubic inch of        
solution of green sulphate of iron1 two 
drops of  concentrated nitric acid4     
,the solution assumed a very light olive
 color2 prussiate of potash  mingled    
with a little of it1 gave a dark green  
precipitate4 ,hence  the nitric acid had
 been evidently decomposed4 ,as no      

nitrous gas was  given out1 which is    
always the case when nitric acid is     
poured on  crystalised sulphate of iron1
 ,i suspected that a compleat           
decomposition  of the acid had taken    
place2 but when the solution was heated1
 a few  minute globules of gas were     
liberated1 and it gradually became      
slightly  clouded4    ,having often     
remarked that no precipitation is ever  
produced during the  conversion of green
 sulphate of iron into red1 by          
oxygenated muriatic  acid1 or           
concentrated nitric acid1 ,i could refer
 the cloudiness to no  other cause than 
to the formation of ammoniac4    ,to    
ascertain if this substance had been    
produced1 a quantity of slacked  caustic
 lime was thrown into the solution4 ,on 
the application of heat1  the ammoniacal
 smell was distinctly perceptible1 and  
the vapor held  over orange nitrous     
acid1 gave dense white fumes4    e4     
,when ,i considered this fact of the    
decomposition of nitric acid  and water 

by the solution of green sulphate of    
iron1 and the change  of color effected 
in it by the absorption of nitrous gas1 
exactly  analogous to that produced by  
the decomposition of nitric acid2 ,i    
was induced to believe that the nitric  
acid found in the analysis of           
,vauquelin and ,humbolt1 had been formed
 by the combination of some  of the     
nitrous gas thrown into the solution    
with the oxygene of the  atmosphere3 and
 that the absorbability of nitrous gas1 
by solution of  green sulphate of iron1 
was owing to a decomposition produced by
 the  combination of its oxygene with   
the green oxide of iron1 and of its     
nitrogene with the hydrogene disengaged 
from water1 decompounded at the  same   
time4    ,to ascertain this1 ,i procured
 a quantity of nitrous gas3 it was      
suffered to remain in contact with water
 for some hours after its  production4  
,transferred to the mercurial apparatus1
 it gave no  white vapor when placed in 
contact with solution of ammoniac2 and  

consequently held no nitric acid in     
solution4    ,into a graduated jar      
filled with mercury1 a cubic inch of    
concentrated  solution of pure green    
sulphate of iron was introduced1 and #g 
cubic  inches of nitrous gas admitted to
 it4 ,the solution immediately became   
dark olive at the edges1 and on         
agitation this color was diffused       
through it4 ,in #c minutes1 when near #e
 cubic inches had been absorbed1  the   
diminution ceased4 ,the solution was now
 of a bright olive brown1  and          
transparent at the edges4 ,after it had 
rested for a quarter of an  hour1 no    
farther absorption was observed2 the    
color was the same1 and  no             
precipitation could be perceived4 ,a    
little of it was thrown into a  small   
glass tube1 under the mercury1 and      
examined in the atmosphere4  ,its taste 
was rather more astringent than that of 
solution of green  sulphate2 it did not 
at all alter the color of red cabbage   
juice4 ,when  a little of it was poured 

on the mercury1 it soon lost its color1 
its  taste became acid1 and it quickly  
reddened cabbage juice1 even rendered   
green by an alkali4    ,to the solution 
remaining in the mercurial jar1 a small 
quantity of  prussiate of potash was    
introduced1 to ascertain if any red     
sulphate of  iron had been formed2 but  
instead of the production of either a   
blue1  or a white precipitate1 the whole
 of the solution became opaque1 and     
chocolate colored4    ,surprised at this
 appearance1 ,i was at first induced to 
suppose1  that the ammoniac formed by   
the nitrogene of the nitrous gas and the
  hydrogene of the water1 had been      
sufficient to precipitate from the      
sulphuric acid1 the red oxide of iron   
produced1 and that the color of  the    
mixture was owing to this precipitation4
 ,to dissolve any uncombined  oxide that
 might exist in the solution1 ,i added a
 very minute quantity  of diluted       
sulphuric acid2 but little alteration of
 color was produced4  ,hence1 evidently1

 no red oxide had been formed4    ,this 
unexpected result obliged me to theorise
 a second time1  by supposing that      
nitrate of ammoniac had been produced1  
which  by combining with the white      
prussiate of iron1 generated a new      
combination4 ,but on mingling together  
green sulphate of iron1 prussiate  of   
potash1 and nitrate of ammoniac in the  
atmosphere1 the mixture  remained       
perfectly white4    ,to ascertain if any
 nitric acid existed1 combined with any 
of the  bases1 in the impregnated       
solution1 ,i introduced into it an equal
 bulk  of diluted sulphuric acid3 it    
became rather paler2 but no green or    
blue  tinge was produced4    ,that the  
prussic acid had not been decomposed1   
was evident from the  bright green      
produced1 when less than a grain of     
dilute nitric acid was  admitted into   
the solution4    f4 ,from these         
experiments it was evident1 that no red 
sulphate of  iron1 or nitric acid1 and  
consequently no ammoniac1 had been      

produced  after the absorption of       
nitrous gas by green sulphate of iron4  
,and when  ,i compared them with the    
observations of ,priestley1 who had     
expelled  by heat a minute quantity of  
nitrous gas from an impregnated solution
  of common sulphate of iron1 and who   
found common air phlogisticated by      
standing in contact with it1 ,i began to
 suspect that nitrous gas was  simply   
dissolved in the solution1 without      
undergoing decomposition4    g4 ,to     
determine more accurately the nature of 
the process1 ,i  introduced into a      
mercurial cylinder #daj grains of       
solution of green  sulphate of iron1    
occupying a space nearly equal to a     
cubic inch and  quarter2 it was         
saturated with nitrous gas1 by absorbing
 #h cubic  inches4 ,this saturated      
solution exhibited the same appearance  
as  the last2 and after remaining near  
an hour untouched1 had evidently        
deposited no oxide of iron1 nor gained  
any acid properties4    ,into a small   

mattrass filled with mercury1 having a  
tight stopper  with a curved tube       
adapted to it1 the greater part of this 
solution  was introduced2 judging from  
the capacity of the mattrass1 about #ej 
grains of it might have been lost4 ,to  
prevent common air from coming in       
contact with the solution1 the stopper  
was introduced into the mattrass  under 
the mercury2 the curved tube connected  
with a graduated cylinder  filled with  
that substance2 and the mattrass brought
 over the side of  the mercurial trough4
 ,but in spite of these precautions a   
large globule  of common air got into   
the top of the mattrass1 from the       
curvature of  the tube4 ,when the heat  
of a spirit lamp was applied to the     
solution1  it gave out gas with great   
rapidity1 and gradually lost its color4 
,when #e cubic inches were collected it 
became perfectly pale green1  whilst a  
yellow red precipitate was deposited on 
the bottom of the  mattrass4    ,on     
pouring a little of the clear solution  

into prussiate of potash1 it  gave only 
white prussiate of iron4    ,but on     
introducing a particle of sulphuric acid
 into the solution1  sufficient to      
dissolve some of the red precipitate1   
and then pouring  a little of it into a 
solution of prussiate of potash1 it gave
 a fine  blue prussiate of iron4        
,hence the red precipitate was evidently
 red yellow oxide of iron4    ,i now    
examined the gas1 suspecting that it was
 nitrous oxide4 ,on  mingling a little  
of it with atmospheric air1 it gave red 
vapor1 and  diminished4 ,solution of    
sulphate of iron introduced to the      
remainder1  almost wholly absorbed it3  
the small residual globule of nitrogene 
could not equal one thirtieth of a cubic
 inch4    ,consequently it was nitrous  
gas1 nearly pure4    ,caustic potash was
 now introduced into the solution1 till 
all the oxide  of iron was precipitated4
 ,the solution1 when heated1 gave a     
strong  smell of ammoniac1 and dense    
white fumes when held over muriatic     

acid4  ,it was kept at the heat of      
ebullition till the evaporation had been
  nearly compleated4 ,sulphuric acid    
poured upon the residuum gave no  yellow
 fumes1 or nitric acid vapor in any way 
perceptible2 even when  heated and made 
to boil1 there was no indication of the 
production of  any vapor1 except that of
 the sulphuric acid4    h4 ,this        
experiment1 compared with the others1   
seemed almost to prove1  that nitrous   
gas combined with solution of pale green
 sulphate of  iron1 at the common       
temperature1 without decomposition2 and 
that when  the impregnated solution was 
heated1 the greater portion of gas was  
disengaged1 whilst the remainder was    
decompounded by the green oxide of      
iron2 which attracted at the same time  
oxygene from the water and the  nitrous 
gas2 whilst their other constituent     
principles1 hydrogene and  nitrogene1   
entered into union as ammoniac4         
,whilst1 however1 ,i was reasoning upon 
this singular chemical change1  as      

affording presumptive proofs in favor of
 the exertion of simple  affinities by  
the constituent parts of compound       
substances1 a doubt  concerning the     
decomposition of the nitrous gas        
occurred to me4 ,as  near as ,i could   
guess at the quantity of nitrous gas    
contained by  the impregnated solution1 
at least  of it must have been expelled 
undecompounded4    ,more than a quarter 
of a cubic inch of common air had been  
present in  the mattrass3 the oxygene of
 this common air must have combined with
  the nitrous gas1 to form nitric acid4 
,might not this nitric acid have  been  
decomposed1 and furnished oxygene to the
 red oxide of iron1 and  nitrogene to   
the small quantity of ammoniac found in 
the solution1 as  in d8    i4 ,i now    
introduced to a solution of green       
sulphate confined by  mercury1 nitrous  
gas1 perfectly free from nitric acid4   
,when the  solution was saturated1 a    
portion of it was introduced into a     
small  mattrass filled with dry mercury1

 in the mercurial trough4 ,the curved   
tube was closed by a small cork at the  
top1 and filled with nitrous  gas2 it   
was then adapted to the mattrass1 which 
was raised from the  trough1 and the    
solution thus effectually preserved from
 the contact of  the atmosphere4        
,when the heat of a spirit lamp was     
applied to the mattrass1 it began to    
give out gas with great rapidity4 ,after
 some time the solution lost its  dark  
color1 and became turbid4 ,when the     
production of nitrous gas had  ceased1  
it was suffered to cool4 ,a copious red 
precipitate had fallen  down2 which1    
examined by the same tests as in the    
last experiment1  proved to be red oxide
 of iron4    ,the solution treated with 
lime1 as before1 gave ammoniac2 but with
  sulphuric acid1 not the slightest     
indications of nitric acid4    k4       
,having thus procured full evidence of  
the decomposition of  nitrous gas in the
 heated solution1 in order to gain a    
more accurate  acquaintance with the    

affinities exerted1 ,i endeavoured to   
ascertain  the quantity of nitrous gas  
decomposed by a given solution1 under   
known  circumstances4    ,into a        
cylinder of the capacity of #bj cubic   
inches1 inverted in  mercury1 #aaej     
grains of solution of green sulphate of 
iron1 of specific  gravity #a1d1 were   
introduced4 ,nitrous gas was admitted to
 it1 and after  some time #ba cubic     
inches were absorbed4    ,the           
impregnated solution was thrown into a  
mattrass1 in the same manner  as in the 
last experiment1 and the same           
precautions taken to preserve  it from  
the contact of atmospheric air4 ,a      
quantity was lost during  the process of
 transferring1 which1 reasoning from the
 space occupied  in the mattrass by the 
remaining portion1 as determined by     
experiment  afterwards1 must have       
amounted nearly to #bdj grains4    ,the 
curved tube from the mattrass was now   
made to communicate with  the mercurial 
airholder4 ,by the application of heat  

#ab1e cubic inches  of nitrous gas were 
collected1 after the common temperature 
had been  restored to the mattrass2     
which was suffered to remain in         
communication  with the conducting tube4
    ,the solution was now pale green1   
that is1 of its natural color1 and a    
considerable quantity of red oxide of   
iron had been deposited4    ,solid      
caustic potash was introduced into it1  
till all the green oxide  of iron had   
been precipitated1 and till the solution
 rendered green1  red cabbage juice4    
,a tube was now accurately connected    
with the mattrass1 bent1 and  introduced
 into a small quantity of diluted       
sulphuric acid4 ,nearly half  of the    
fluid in it was slowly distilled into   
the sulphuric acid1 by  the heat of a   
spirit lamp4 ,the impregnated acid      
evaporated at a heat  above #bab1 and   
gave a small quantity of crystalised    
salt1 which barely  amounted to two     
grains and quarter3 it had every        
property of sulphate  of ammoniac4      

,sulphuric acid in excess was poured on 
the residuum1 and  the whole distilled  
by a heat not exceeding #cjj1 into a    
small quantity  of water4 ,this water1  
after the process1 tasted strongly of   
sulphuric  acid2 it had no peculiar     
odor4 ,tin thrown into it when heated1  
was not  perceptibly oxydated2 mingled  
with strontitic lime water1 it gave a   
copious white precipitate1 and after the
 precipitation became almost  tasteless4
 ,hence it evidently contained no nitric
 acid4    ,the #ab1e cubic inches of    
undecompounded gas that came over were  
examined2 and accounting for the small  
quantity of common air  previously      
contained in the airholder1 must have   
been almost pure4    l4 ,now supposing  
#ibg grains of the impregnated solution 
7including  the weight of the nitrous   
gas71 to have been operated upon1 this  
must  have contained about #af1g cubic  
inches of nitrous gas4 ,but #ab1e cubic 
inches escaped undecompounded3 hence    
#d1b were decomposed2 and these  weigh  

#a1dd grains1 and are composed of1#h    
oxygene1 and1#fd nitrogene4#aag         
,consequently1 the nitrous gas must have
 furnished1#h of oxygene to the  green  
oxide of iron4    ,but1#fd of nitrogene 
require1#ae of hydrogene to form1#gi of 
ammoniac3#aah consequently #a of water  
was decompounded1 and this              
furnished1#he of oxygene to the green   
oxide of iron4    #aag ,division ,,iv4  
,section #e4    #aah ,division ,,ii4    
,section #a4    ,the green oxide of iron
 contains _/ oxygene2 the red _/4 ,but  
the whole quantity of oxygene supplied  
from the water and nitrous  gas is #j1h 
#j1he  #a1fe2 and calculating on the    
difference of the  composition of the   
red and green oxide of iron1 #e1g grains
 of red oxide  must have been deposited1
 and consequently these would saturate  
as  much acid as1#gi grains of ammoniac1
 or #d1a grains of green oxide of       
iron4#aai    ,and supposing the ammoniac
 in sulphate of ammoniac to be to the   
acid  as #a is to #c1abj #c4b grains of 

sulphate of ammoniac must have been     
formed1 containing about #b1d grains    
acid2 and then #f1e grains of green     
sulphate of iron must have been         
decomposed4    #aai ,no precipitation   
takes place during the conversion of    
solution of  green sulphate into red2   
and the acid appears saturated4    #abj 
,division ,,ii1 ,section #f4    ,hence  
we gain the following equation3         
#f1e green s4     #b1da sul4 acid  #d1a 
gr4 ox4 iron4                           
#a1dd nit4 gas    1#fd nitrogene  1#h   
oxygene4                                
#a water          1#he oxygene1  1#ae   
hydrogene1                        equal 
#c1b sul4 am4     #b1da s4 acid  1#fd   
nit4  1#ae hyd4                         
#e1g r4 ox4 iron  #d1a gr4 ox4 iron     
#a1f oxyg4    ,though the estimation of 
the quantities in this equation must not
  be considered as strictly accurate1 on
 account of the degree of  uncertainty  
that remains concerning the exact       
numerical expression of  the quantities 

of the constituents of water1 ammoniac1 
and the other  compound bodies employed2
 yet as founded on a simple quantity1   
that is1  the nitrous gas decomposed1 it
 cannot be very distant from the truth4 
,the sulphate of ammoniac given by      
experiment1 is considerably less than   
that which was really produced2 much of 
it was probably carried off  during the 
evaporation of the superabundant acid4  
,the conclusions that may be drawn from 
this experiment1 afford a  striking     
instance of the importance of the       
application of the science  of quantity 
to the chemical changes3 for the data   
being one chemical  fact1 the           
decomposition of a given quantity of    
nitrous gas by known  agents2 the       
composition of nitrous gas1 of water1   
ammoniac1 the oxides  of iron1 and      
sulphate of ammoniac2 we are able not   
only to determine  the quantities of the
 simple constituents that have entered  
into new  arrangements1 but likewise the
 composition of two compound bodies1 the

  green and red sulphates of iron4#aba  
#aba ,according to the estimation in the
 equation1 #f4e of dry green  sulphate  
of iron contain #d4a green oxide of     
iron1 and #b4d of ,kirwan's  real       
sulphuric acid2 and #h4a red sulphate of
 iron1 contain #b4d acid1  and #e4g red 
oxide of iron4    m4 ,though from the   
experiments in e it appeared that no    
decomposition of nitrous gas had been   
produced during or even after its       
absorption by solution of sulphate of   
iron at the common temperature2  yet a  
suspicion that it might take place      
slowly1 and that indications  of it     
might be given by deposition1 induced me
 to examine minutely  two impregnated   
solutions1 one of which had been at     
rest1 confined by  mercury1 for #ai     
hours1 and the other for #bg4 ,in       
neither of them could ,i  discover any  
deposition1 or alteration of color1     
which might denote a  change4    ,two   
cubic inches of oxygene were admitted to
 half a cubic inch of one  of these     

solutions4 ,the oxygene was slowly      
absorbed1 and the solution  gradually   
lost its color4    ,to ascertain if     
during the conversion of the nitrous gas
 held in  solution by sulphate of iron1 
into nitric acid1 by the oxygene of the 
atmosphere at the common temperature1   
any water was decomposed2 ,i  suffered  
an impregnated solution1 weighing nearly
 two ounces1 to remain  in contact with 
the atmosphere at #eg-fb1 till it was   
become perfectly  pale4 ,it then had a  
strong acid taste1 effervesced with     
carbonate  of potash1 and gave a blue   
precipitate with prussiate of           
potash4--,it  was saturated with        
quicklime1 and heated3 slight           
indications of the  presence of ammoniac
 were perceived4    ,as in this         
experiment the nitric acid had been most
 probably decomposed  by the green oxide
 of iron1 as in f1 ,i sent oxygenated   
muriatic acid  through an impregnated   
solution1 till all the green oxide of   
iron was  converted into red1 and all   

the nitrous gas into nitric acid4       
,this solution saturated with potash1   
and heated1 gave no ammoniacal  smell4  
,from these experiments we may conclude1
    #ast4 ,that solution of red sulphate
 of iron has little or no affinity  for 
nitrous gas#abb2 and that solution of   
common sulphate absorbs  nitrous gas    
only in proportion as it contains green 
sulphate4    #abb ,the muddy green color
 produced in a solution of red sulphate 
of  iron agitated in nitrous gas1       
depended upon impurities in the mercury4
  ,i have since found1 that when the    
solution is completely oxygenated1  the 
diminution is barely perceptible4       
#b;dly4 ,that solutions of green        
sulphate of iron dissolve nitrous gas in
  quantities proportionable to their    
concentration1 without effecting  any   
decomposition of it at common           
temperatures4 ,and the solubility  of   
nitrous gas in solution of green        
sulphate1 may be supposed to  depend on 
an equilibrium of affinity1 produced by 

the following simple  attractions3      
#a4 ,that of green oxide of iron for the
 oxygene         of nitrous gas and     
water4        #b4 ,that of the hydrogene
 of the water         for the nitrogene 
of the nitrous gas4        #c4 ,that of 
the principles of the sulphuric         
acid1 for nitrogene and hydrogene4      
#c;dly4 ,that at high temperatures1 that
 is1 from #bjj to #cjj1 the  equilibrium
 of affinity producing the binary       
combination between  nitrous gas and    
solution of green sulphate of iron is   
destroyed2 the  attraction of the green 
oxide of iron for oxygene being         
increased2  whilst probably that of     
nitrogene for hydrogene is diminished4  
,hence the nitrous gas is either        
liberated1#abc in consequence of the    
affinity between oxygene and hydrogene1 
and oxygene and nitrogene not  following
 the same ratio of alteration on        
increased temperature2 or  decomposed1  
because at a certain temperature the    
green oxide exerts  such affinities upon

 water and nitrous gas1 as to attract   
oxygene from  both of them to form red  
oxide2 whilst the still existing        
affinity  between the hydrogene of the  
one1 and the nitrogene of the other1    
disposes them to combine to form        
ammoniac4    #abc ,perhaps the          
liberation of nitrous gas from the      
solution takes  place at a lower        
temperature than its decomposition4 ,i  
have always  observed that the quantity 
of yellow precipitate is greater when   
the  solution is rapidly made to boil4  
,were it possible to heat it to a       
certain temperature at once1 probably a 
compleat decomposition would  take      
place4    #dthly4 ,that the change of   
color produced by introducing nitric    
acid  to solution of common sulphate of 
iron1 exactly analogous to that         
occasioned in it by impregnation with   
nitrous gas1 is owing to the            
decomposition of the acid1 by the       
combination of its oxygene with the     
green oxide of iron1 and of its nitrous 

gas with the solution4    #ethly4 ,that 
nitrous gas in combination with solution
 of green sulphate  of iron1 is capable 
of exerting a strong affinity upon free 
or loosely  combined oxygene1 and of    
uniting with it to form nitric acid4    
n4 ,the products obtained from a        
solution of sulphate of iron  saturated 
with nitrous gas1 by ,vauquelin and     
,humbolt1 and their  consequent mistake 
with regard to the nature of the process
 of  absorption1#abd must have arisen   
from exposure of their impregnated      
solution to the atmosphere4    #abd     
,annales de ,chimie4 ,t4 #ch1 pag4 #ahg4
    ,indeed1 from the acidity of it1 on 
examination1 from the small portion  of 
ammoniac1 and the large quantity of     
nitric acid obtained1 it appears  most  
probable that the whole of the nitrous  
gas employed was converted  into nitric 
acid1 by combining with atmospheric     
oxygene2 for no nitric  acid could have 
been obtained in the mode in which they 
operated1  unless the green oxide of    

iron in the solution had been previously
  converted into red4      ,,viii4 ,on  
the absorption of ,nitrous ,gas by      
solution of green ,muriate of  ,iron4   
a4 ,the analogy between the affinities  
of the constituents of the  muriate and 
sulphate of iron1 induced me to         
conjecture that they  possessed similar 
powers of absorbing nitrous gas2 and ,i 
soon found  that this was actually the  
case2 for on agitating half a cubic inch
  of solution of muriated iron1 procured
 by dissolving iron filings  in muriatic
 acid1 in nitrous gas1 the gas was      
absorbed with great  rapidity1 whilst   
the solution assumed a deep and bright  
brown tinge4    b4 ,proust1#abe who as  
,i have before mentioned1 supposes the  
existence of two oxides of iron only1   
one containing _/ oxygene1  the other   
_/1 has assumed1 that the muriatic acid1
 and most other  acids as well as the   
sulphuric1 are capable of combining with
 these  oxides1 and of forming with each
 of them a distinct salt4 ,he has1      

however1 detailed no experiments on the 
muriates of iron4    #abe ,annales de   
,chimie1 xxiii4 pag4 #he2 or            
,nicholson's ,phil4 ,journal  vol4 i4   
pag4 #de4    ,as these salts are still  
more distinct from each other in their  
properties than the sulphates1 and as   
these properties are connected  with the
 phnomenon of the absorption and        
decomposition of nitrous gas1  ,i shall 
detail the observations ,i have been    
able to make upon them4    c4 ,when iron
 filings have been dissolved in pure    
muriatic acid1 and  the solution        
preserved from the contact of air1 it is
 of a pale green  color1 and gives a    
white precipitate with alkaline         
prussiates4 ,the  alkalies throw down   
from it a light green oxide of iron4    
,when evaporated1 it gives crystals     
almost white1 which are extremely       
soluble in water2 but insoluble in      
alcohol4    ,the solution of green      
muriate of iron has a great affinity for
 oxygene1  and attracts it from the     

atmosphere1 from nitric acid1 and       
probably  from oxygenated muriatic acid4
    ,when red oxide of iron is dissolved
 in muriatic acid1 or when nitric  acid 
is decomposed by solution of green      
muriate of iron2 the red  muriate of    
iron is produced4 ,the solution of this 
salt is of a deep  brown red1 its odor  
is peculiar1 and its taste1 even in a   
very diluted  state1 highly astringent4 
,it acts upon animal and vegetable      
matters in  a manner somewhat analogous 
to the oxygenated muriatic acid1        
rendering  them yellowish white1 or     
yellow4#abf    #abf ,probably by giving 
them oxygene2 whereas the green muriate 
and  sulphate blacken animal substances2
 most likely by abstracting from  them  
oxygene4    ,sulphuric acid poured upon 
it1 produces a smell resembling that of 
oxygenated muriatic acid4 ,evaporated at
 a low temperature1 it gives an         
uncrystalisable dark1 orange colored    
salt1 which is soluble in alcohol1  and 
when decomposed by the alkalies1 gives a

 red precipitate4 ,with  prussiate of   
potash it gives prussian blue4    ,the  
common muriate of iron consists of      
different proportions of these  two     
salts4 ,it may be converted into red    
muriate by concentrated nitric  acid1 or
 into green by sulphurated hydrogene4   
d4 ,to ascertain if solution of red     
muriate of iron was capable of          
absorbing nitrous gas1 ,i introduced    
into a jar filled with mercury1 a  cubic
 inch of nitrous gas1 and admitted to it
 nearly half a cubic inch  of solution  
of red muriate of iron4 ,no             
discoloration took place4 ,by  much     
agitation1 however1 an absorption of    
nearly1#b was produced1 and  the        
solution became of a muddy green4 ,but  
this change of color1 and  probably the 
absorption1 was in consequence of the   
oxydation of either  the mercury1 or    
some imperfect metals combined with it1 
by the oxygene  of the red muriate4 ,for
 ,i afterwards found1 that precisely the
 same  change of color was produced when

 a solution was agitated over mercury4  
e4 ,i introduced to a cubic inch of     
concentrated solution of green  muriate 
of iron1 #g cubic inches of nitrous gas1
 free from nitric acid2  the solution   
instantly became colored at the edges1  
and on agitation  absorbed the gas with 
much greater rapidity than even sulphate
 of iron2  in a minute1 only a quarter  
of a cubic inch remained4    ,the       
solution appeared of a very dark brown1 
but evidently no  precipitation had     
taken place in it1 and the edges1 when  
viewed against  the light1 were         
transparent and puce colored4    ,five  
cubic inches more of nitrous gas were   
now dissolved in the  solution4 ,the    
intensity of the color increased1 and   
after an hour no  deposition had taken  
place4 ,a little of it was then examined
 in the  atmosphere2 it had a much more 
astringent taste than the unimpregnated 
solution1 and effected no change in red 
cabbage juice4 ,when prussiate  of      
potash was introduced into it1 its color

 changed to olive brown4 ,a  few drops  
of the solution1 that had accidentally  
fallen on the mercury1  soon became     
colorless1 and then effervesced with    
carbonate of potash1  and tasted        
strongly acid4    ,the remainder of the 
impregnated solution1 which must have   
nearly  equalled1#ge cubic inches1 was  
introduced into a mattrass1 having a    
stopper and curved tube1 as in the      
experiments on the solution of  sulphate
 of iron2 great care being taken to     
preserve it from the  contact of air4   
,the mattrass was heated by a spirit    
lamp1 the curved tube being in          
communication with a mercurial cylinder4
 ,near #h cubic inches of nitrous  gas  
were collected1 when the solution became
 of a muddy yellow4 ,it was  suffered to
 cool1 and examined4 ,a small quantity  
of yellow precipitate  covered the      
bottom of the mattrass2 the fluid was   
pellucid1 and  light green4 ,a little of
 it thrown on prussiate of potash1 gave 
a  white precipitate1 colored by streaks

 of light blue4 ,when the yellow        
precipitate was partly dissolved by     
sulphuric acid1 a drop of the  solution1
 mingled with prussiate of potash1 gave 
a deep blue green4    ,hence1 evidently1
 the precipitate was red oxide of iron4 
,caustic potash in excess was introduced
 into the remainder of the  solution1   
and it was heated4 ,it gave an evident  
smell of ammoniac1 and  dense white     
fumes1 when held over strong            
phlogisticated nitrous acid4    ,when   
half of it was evaporated1 sulphuric    
acid in excess was poured on  the       
remainder2 muriatic acid was liberated1 
not perceptibly combined  with any      
nitric acid4    f4 ,in an experiment    
that ,i made to ascertain the quantity  
of nitrous  gas capable of combining    
with solution of green muriate of iron2 
,i  found that1#ge cubic inches of      
saturated solution absorbed about #ah   
of nitrous gas1 which is nearly double  
the quantity combinable with  an equal  
portion of the strongest solution of    

sulphate of iron4 ,a  part of this      
impregnated solution1 heated slowly1    
gave out more  gas in proportion to the 
quantity it contained1 than the last1   
and  consequently produced less         
precipitate2 so that ,i am inclined to  
suppose it probable1 that at a certain  
temperature1 all the dissolved  nitrous 
gas may be dispelled from a solution4   
,from these experiments we may conclude1
    #ast4 ,that the solution of green   
muriate of iron absorbs nitrous gas in  
consequence of nearly the same          
affinities as solution of green sulphate
  of iron2 its capability of absorbing  
larger quantities depending  most       
probably on its greater concentration   
7that is1 on the greater  solubility of 
the muriate of iron71 and perhaps1 in   
some measure1 on a  new combining       
affinity1 that of muriatic acid for     
oxygene4    #b;dly4 ,that at certain    
temperatures nitrous gas is either      
liberated from  solution of green       
muriate1 or decomposed1 by the          

combination of its  oxygene with green  
oxide of iron1 and of its nitrogene with
 hydrogene1  produced from water        
decompounded by the oxide at the same   
time4      ,,ix4 ,absorption of ,nitrous
 ,gas by ,solution of ,nitrate of ,iron4
    a4 ,as well as two sulphates and two
 muriates of iron1 there exist two      
nitrates4#abg ,when concentrated nitric 
acid is made to act upon iron1  nitrous 
gas is disengaged with great rapidity1  
and with great increase  of temperature3
 the solution assumes a yellowish tinge1
 and as the  process goes on1 a yellow  
red oxide is precipitated4    #abg ,the 
existence of green nitrate was not      
suspected by ,proust4    ,nitrate of    
iron made in this way1 gives a bright   
blue mingled with  prussiate of potash1 
and decomposed by the alkalies1 a red   
precipitate4  ,its solution has little  
or no affinity for nitrous gas4    b4   
,when very dilute nitric acid1 that is1 
such as of specific gravity  #a1af1 is  
made to oxydate iron1 without the       

assistance of heat1 the  solution gives 
out no gas for some time1 and becomes   
dark olive brown3  when neutralised it  
gives1 decomposed by the alkalies1 a    
light green  precipitate2 and mingled   
with prussiate of potash1 pale green    
prussiate  of iron4    ,it owes its     
color to the nitrous gas it holds in    
solution4 ,by exposure  to the          
atmosphere it becomes pale1 the nitrous 
gas combined with it  being converted   
into nitric acid4    ,it is then capable
 of absorbing nitrous gas1 and consists 
of pale  nitrate of iron1 mingled with  
red nitrate4    ,i have not yet obtained
 a nitrate of iron giving only a white  
precipitate with prussiate of potash1   
that is1 such as contains only  oxide of
 iron at its minimum of oxydation2 for  
when pure green oxide  of iron is       
dissolved by very dilute nitric acid1 a 
small quantity of  the acid is generally
 decomposed1 which is likewise the case 
in the  decomposition of nitre by green 
sulphate of iron4 ,the solutions of     

nitrate of iron1 however1 procured in   
both of these modes1 absorb  nitrous gas
 with rapidity1 and by sulphurated      
hydrogene might probably  be converted  
into pale nitrate4    ,as it is         
impossible to obtain concentrated       
solutions of pale nitrate of  iron1     
chiefly containing green oxide1 its     
powers of absorbing nitrous  gas cannot 
be compared with the muriatic and       
sulphuric solutions1  unless they are   
made of nearly the same specific        
gravity4    ,nitrous gas is disengaged  
by heat from the impregnated solution of
  nitrate of iron1 at the same time that
 much red oxide of iron is              
precipitated4 ,whether any nitrous gas  
is decomposed1 ,i have not yet          
ascertained2 for when unimpregnated pale
 nitrate of iron is heated1  a part of  
the acid1 and of the water of the       
solution1 is decomposed  by the green   
oxide of iron2#abh and in consequence   
ammoniac1 and red  nitrate of iron      
formed1 whilst red oxide is             

precipitated4    #abh ,in this process  
nitrous oxide is sometimes given out1 as
 will be  seen hereafter4      ,x4      
,absorption of ,nitrous ,gas by other   
,metallic ,solutions4    a4 ,white      
prussiate of iron in contact with water 
absorbs nitrous gas  to a great extent1 
and becomes dark chocolate4#abi    b4   
,concentrated solution of sulphate of   
tin1 probably at its  minimum of        
oxydation1 absorbs one eighth of its    
bulk of nitrous gas1  and becomes brown1
 without deposition4    c4 ,solution of 
sulphate of zinc absorbs about one tenth
 of its volume  of nitrous gas1 and     
becomes green4    d4 ,solution of       
muriate of zinc#acj absorbs nearly the  
same quantity1  and becomes orange      
brown4    #abi ,hence we learn why no   
nitrous gas is disengaged when          
impregnated  solution of sulphate of    
iron is decomposed by prussiate of      
potash1 as  in ,div4 ,,iv4 ,sec4 vii4   
#acj ,in both of these solutions the    
metal is at its minimum of  oxydation4  

,the absorption of a small quantity of  
nitrous gas by white  vitriol was       
observed by ,priestley4    e4 ,these are
 all the metallic substances on which ,i
 have  experimented4 ,it is more than   
probable that there exist others        
possessing similar powers of absorbing  
nitrous gas4    ,whenever the metals    
capable of decomposing water exist in   
solutions at  their minimum of          
oxydation1 the affinities exerted by    
them on nitrous  gas and water1 will be 
such as to produce combination4 ,the    
powers of  metallic solutions to combine
 with nitrous gas at common             
temperatures1  as well as to decompose  
it at higher temperatures1 will probably
 be  in the ratio of the affinity of the
 metallic oxides they contain1 for      
oxygene4      ,,xi4 ,the action of      
,sulphurated ,hydrogene on solution of  
,green ,sulphate  of ,iron1 impregnated 
with ,nitrous ,gas4    a4 ,in an        
experiment on the absorption of nitrous 
gas by solution of  green sulphate of   

iron1 ,i introduced an unboiled solution
 of common  sulphate1 deprived of red   
oxide of iron by sulphurated hydrogene1 
into  a jar filled with nitrous gas2 the
 absorption took place as usual1  and   
nearly six of gas entered into          
combination1 the volume of the  solution
 being unity4 ,on applying heat to a    
part of this impregnated  solution1 the 
whole of the nitrous gas it contained   
7as nearly as ,i  could guess71 was     
expelled undecompounded1 and no yellow  
precipitate  produced4 ,prussiate of    
potash poured into it gave only white   
prussiate  of iron2 and when it was     
heated with lime1 no ammoniacal smell   
was  perceptible4    ,i could refer this
 phnomenon to no other cause than to the
 existence  of a small quantity of      
sulphurated hydrogene in the solution4  
,that this  was the real cause ,i found 
from the following experiment4    b4    
,one part of a solution of green        
sulphate of iron1 formed by the         
agitation of common sulphate of iron in 

contact with sulphurated  hydrogene1 was
 boiled for some minutes to expel the   
small quantity of  gas retained by it   
undecompounded4 ,it had then no peculiar
 smell1 and  gave a white prussiate of  
iron with prussiate of potash2 the other
  part had a faint odor of sulphurated  
hydrogene1 and gave a dirty white       
precipitate with prussiate of potash4   
,nearly equal quantities of each  were  
saturated with nitrous gas1 and heated4 
,the unboiled impregnated  solution gave
 out all its nitrous gas undecompounded2
 whilst in the  boiled solution it was  
partly decomposed1 yellow precipitate   
and  ammoniac being formed4    c4 ,this 
singular phnomenon of the power of a    
minute quantity of  sulphurated         
hydrogene1 in preventing the            
decomposition of nitrous gas  and water1
 by green oxide of iron1 will most      
probably take place in  other           
impregnated solutions4 ,it seems to     
depend on the strong affinity  of the   
hydrogene of sulphurated hydrogene for  

oxygene4      ,,xii4 ,additional        
,observations4    a4 ,for separating    
nitrous gas from gases absorbable to no 
great  extent by water2 a well boiled   
solution of green muriate of iron       
should be employed4 ,nitrous gas        
agitated in this is rapidly absorbed1   
and it has no affinity for1 or action   
on1 nitrogene1 hydrogene1 or            
hydrocarbonate4    b4 ,nitrous gas      
carefully obtained from mercury and     
nitric acid1 when  received under       
mercury1 or boiled water1 and absorbed  
by solution of  green muriate1 or       
sulphate of iron1 rarely leaves a       
residuum of _/  of its volume3 preserved
 over common water1 and absorbed1 the   
remainder  is generally from _/ to _/1  
from the nitrogene disengaged by the    
decomposition of the common air         
contained in the water4    c4 ,the      
nitrous gas carefully obtained from the 
decomposition of  nitric acid of #a1bf1 
by copper1 ,i have hardly ever found to 
contain  more than from _/ to _/        

nitrogene1 when received through common 
water3 when boiled water is employed1   
the residuum is nearly the same  as that
 of nitrous gas obtained from mercury4  
d4 ,consequently the gas from those two 
solutions may be used in  common4 ,it is
 more than probable1 that the small     
quantities of  nitrogene generally      
mingled with nitrous gas from copper and
 mercury1  arise either from the common 
air of the vessels in which it was      
produced1 or that of the water over     
which it was received4 ,there is no     
reason for supposing that it is         
generated by a complete decomposition   
of a portion of the acid4#aca    #aca   
,humbolt1 who is the first philosopher  
that has applied the  solution of       
sulphate of iron to ascertain the purity
 of nitrous gas1  asserts that he       
uniformly found nitrous gas obtained    
from solution  of copper in nitrous     
acid1 to contain from six tenths to one 
tenth  nitrogene4        ,annales de    
,chimie1 vol4 xxviii4 pag4 #adg4      e4

 ,whenever nitrous oxide is mingled with
 nitrous gas and nitrogene1  it must be 
separated by well boiled water2 and     
after the corrections  are made for the 
quantity of air disengaged from the     
water1 the nitrous  gas absorbed by the 
muriatic solution4      ,,division ,v4  
,,experiments and ,,observations on the 
production of         ,,nitrous ,,oxide 
from ,,nitrous ,,gas and ,,nitric       
,,acid1 in         different modes4     
,i4 ,preliminaries4    a4 ,the opinions 
of ,priestley#acb and ,kirwan1#acc      
relating to the  causes of the          
conversion of nitrous gas into nitrous  
oxide1 were  founded on the theory of   
phlogiston4 ,the first of these         
philosophers  obtained nitrous oxide by 
placing nitrous gas in contact with     
moistened  iron filings1 or the alkaline
 sulphures4 ,the last by exposing it to 
sulphurated hydrogene4    #acb ,vol4 ii4
 pag4 #ee4    #acc ,phil4 ,trans4 vol4  
lxxvi4 pag4 #acc4    ,the ,dutch        
chemists1#acd the latest                

experimentalists on nitrous oxide1  have
 supposed that the production of this   
substance depends upon the  simple      
abstraction of a portion of the oxygene 
of nitrous gas4 ,they  obtained nitrous 
oxide by exposing nitrous gas to muriate
 of tin1 to  copper in solution of      
ammoniac1 and likewise by passing it    
over heated  sulphur4    #acd ,journal  
de ,physique1 tom4 xliii4 #cbc4    ,the 
diminution of volume sustained by       
nitrous gas during its conversion  into 
nitrous oxide1 has never been accurately
 ascertained2 it has  generally been    
supposed to be from two thirds to eight 
tenths4    b4 ,nitrous gas may be       
converted into nitrous oxide in two     
modes4    ,first1 by the simple         
abstraction of a portion of its oxygene1
 by bodies  possessing a strong affinity
 for that principle1 such as alkaline   
sulphites1 muriate of tin1 and dry      
sulphures4    ,second1 by the           
combination of a body with a portion    
both of its oxygene  and nitrogene1 such

 as hydrogene1 when either in a nascent 
form1 or a  peculiar state of           
combination4    c4 ,each of these modes 
will be distinctly treated of2 and to   
prevent  unnecessary repetitions1 ,i    
shall give an account of the general    
manner  in which the following          
experiments on the conversion of nitrous
 gas  into nitrous oxide1 have been     
conduced4    ,nitrous gas1 the purity of
 which has been accurately ascertained  
by  solution of muriate of iron1 is     
introduced into a graduated jar filled  
with dry mercury4 ,if a fluid substance 
is designed for the conversion  of the  
gas into nitrous oxide1 it is heated1 to
 expel any loosely  combined air which  
might be liberated during the process2  
and then  carefully introduced into the 
jar1 by means of a small phial4 ,after  
the process is finished1 and the        
diminution accurately noted1 the        
nitrous oxide formed is absorbed by pure
 water4 ,if any nitrous gas  remains1 it
 is condensed by solution of muriate of 

iron2 other residual  gases are examined
 by the common tests4 ,the quantity of  
nitrous oxide  dissolved by the fluid is
 determined by a comparative experiment2
 and  the corrections for temperature   
and pressure being guessed at1 the      
conclusions drawn4    ,if a solid       
substance is used1 rather more nitrous  
gas than that  designed for the         
conversion1 is introduced into the jar4 
,the substance  is brought in contact   
with the gas1 by being carried under the
 mercury2  and as a little common air   
generally adheres to it1 a small portion
  of the nitrous gas is transferred into
 a graduated tube1 after the  insertion1
 and its purity ascertained4 ,in other  
respects the process is  conducted as   
mentioned above4      ,,ii4 ,of the     
conversion of ,nitrous gas into ,nitrous
 ,oxide1 by ,alkaline  ,sulphites4      
,the alkaline sulphites1 particularly   
the sulphite of potash1 convert  nitrous
 gas into nitrous oxide1 with much      
greater rapidity than any  other bodies4

    ,at temperature #df1 #af cubic      
inches of nitrous gas were converted1 in
  less than an hour1 into #g1h of       
nitrous oxide1 by about #ajj grains of  
pulverised sulphite of potash1          
containing its water of crystalisation4 
,no sensible increase of temperature was
 produced during the process1  no water 
was decomposed1 and the quantity of     
nitrogene remaining after  the          
experiment1 was exactly equal to that   
previously contained in the  nitrous    
gas4    ,the nitrous oxide produced from
 nitrous gas by sulphite of potash1 has 
all the properties of that generated    
from the decomposition of nitrate  of   
ammoniac4 ,it gives1 as will be seen    
hereafter1 the same products by         
analysis4 ,phosphorus1 the taper1       
sulphur1 and charcoal1 burn in it with  
vivid light4 ,it is absorbable by water1
 and capable of expulsion from  it      
unaltered1 by heat4    ,nitrous gas is  
converted into nitrous oxide by the     
alkaline sulphites  with the same       

readiness1 whether exposed to the light1
 or deprived of  its influence4    ,the 
solid sulphites act upon nitrous gas    
much more readily than  their           
concentrated solutions2 they should     
however always be suffered  to retain   
their water of crystalisation1 or       
otherwise they attract  moisture from   
the gas1 and render it drier1 and in    
consequence more  condensed than it     
would otherwise be4 ,in case perfectly  
dry sulphites  are employed1 the gas    
should be always saturated with moisture
 after  the experiment1 by introducing  
into the cylinder a drop of water4      
,the sulphites1 after exposure to       
nitrous gas1 are either found wholly1   
or partially1 converted into sulphates4 
,consequently the conversion of  nitrous
 gas into nitrous oxide by these bodies1
 simply depends on the  abstraction of a
 portion of its oxygene2 the nitrogene  
and remaining  oxygene assuming a more  
condensed state of existence4    ,if we 
reason from the different specific      

gravities of nitrous oxide and  nitrous 
gas1 as compared with the diminution of 
volume of nitrous gas1  during its      
conversion into nitrous oxide1 #ajj     
parts of nitrous gas1  supposing the    
former estimation of the composition of 
nitrous oxide  given in ,division ,,iii1
 accurate1 would consist of #ed oxygene1
 and #df  nitrogene2 which is not far   
from the true estimation4 ,or assuming  
the  composition of nitrous gas1 as     
given in ,division ,,iv1 it would appear
  from the diminution1 that #ajj parts  
of nitrous oxide consisted of #ch       
oxygene1 and #fb nitrogene4      ,,iii4 
,conversion of ,nitrous ,gas into       
,nitrous ,oxide1 by ,muriate of ,tin1   
and dry ,sulphures4    a4 ,nitrous gas  
exposed to dry muriate of tin1 is slowly
 converted  into nitrous oxide3 during  
this process the apparent diminution is 
to about one half2 but if the products  
are nicely examined1 and the  necessary 
corrections made1 the real diminution of
 nitrous gas by  muriate of tin1 will be

 the same as by the sulphites2 that is1 
#ajj  parts of it will be converted into
 #dh of nitrous oxide4    ,during this  
conversion1 no water is decomposed1 and 
no nitrogene  evolved4 ,solution of     
muriate of tin converts nitrous gas into
 nitrous  oxide2 but with much less     
rapidity than the solid salt4    b4     
,nitrous gas exposed to dry and         
perfectly well made sulphures1          
particularly such as are produced from  
crystalised alumn#ace and  charcoal not 
sufficiently inflammable to burn in the 
atmosphere1 is  converted into nitrous  
oxide by the simple abstraction of a    
portion of  its oxygene1 and            
consequently undergoes a diminution of  
_/4    ,it is probable1 that all the    
bodies having strong affinity for       
oxygene  will1 at certain temperatures1 
convert nitrous gas into nitrous oxide4 
,priestley1 and the ,dutch chemists1    
effected the change by heated  sulphur4 
,perhaps nitrous gas sent through a tube
 heated1 but not  ignited1 with         

phosphorus1 would be converted into     
nitrous oxide4    #ace ,that is1 alumn  
containing sulphate of potash4          
,,iv4 ,decomposition of ,nitrous ,gas1  
by ,sulphurated ,hydrogene4    a4 ,when 
nitrous gas and sulphurated hydrogene   
are mingled together1  a decomposition  
of them slowly takes place4 ,the gases  
are diminished1  sulphur deposited1     
nitrous oxide formed1 and signs of the  
production of  ammoniac#acf and water   
perceived4    #acf ,the production of   
ammoniac in this process was observed by
 ,kirwan  and ,austin4    ,in this      
process no sulphuric1 or sulphureous    
acid is produced2  consequently none of 
the sulphur is oxydated1 and of course  
the changes  depend upon the combination
 of the hydrogene of the sulphurated    
hydrogene1 with different portions of   
the oxygene and nitrogene of the        
nitrous gas1 to form water and ammoniac1
 the remaining oxygene and  nitrogene   
assuming the form of nitrous oxide4     
,this singular exertion of attractions  

by a simple body1 appears  highly       
improbable a priori1 nor did ,i admit   
it1 till the formation of  ammoniac1 and
 the non-oxygenation of the sulphur1    
were made evident by  many experiments4 
,in those experiments1 the diminution of
 the nitrous gas was not  uniformly the 
same4 ,it varied from _/ to _/4 ,in the 
most accurate  of them1 #e cubic inches 
of nitrous gas were converted into #b4b 
of  nitrous oxide4 ,consequently the    
quantity of ammoniac formed was1#jdg    
grains4    ,in experiments on the       
conversion of nitrous gas into nitrous  
oxide1 by  sulphurated hydrogene1 the   
gases should be rendered as dry as      
possible4  ,the presence of water       
considerably retards the decomposition4 
b4 ,the sulphures#acg dissolved in water
 convert nitrous gas into  nitrous      
oxide4 ,this decomposition is not1      
however1 produced by the  simple        
abstraction of oxygene from the nitrous 
gas to form sulphuric  acid4 ,it depends
 as well on the decomposition of the    

sulphurated  hydrogene dissolved in the 
solution1 or liberated from it4 ,in this
  process sulphur is deposited on the   
surface of the fluid1 sulphuric  acid is
 formed1 and the diminution1 making the 
necessary corrections1  is nearly the   
same as when free sulphurated hydrogene 
is employed4    #acg ,solution of       
sulphure of strontian1 or barytes1      
should be used4  ,during the conversion 
of nitrous gas into nitrous oxide by    
those  bodies1 a thin film is deposited 
on the surface of the solution4  ,this  
film examined1 is found to consist of   
sulphur and sulphate4  ,possibly the    
nitrous gas is wholly decomposed by the 
hydrogene of the  sulphurated hydrogene 
in the solution1 whilst the sulphate is 
produced  from water decompounded by the
 sulphur to form more gas for the       
saturation of the hydro-sulphure4    ,it
 is extremely probable that sulphurated 
hydrogene1 in combination  with the     
alkalies1 as well as with water1 is     
capable of being slowly  decomposed by  

nitrous gas4      ,v4 ,decomposition of 
,nitrous ,gas by ,nascent ,hydrogene4   
a4 ,when nitrous gas1 is exposed to     
wetted iron filings1 a diminution  of   
its volume slowly takes place2 and after
 a certain time1 it is found  converted 
into nitrous oxide4    ,in this process 
ammoniac#ach is formed1 and the iron    
partially  oxydated4    #ach ,as was    
first observed by ,priestley and        
,austin1 and as ,i have  proved by many 
experiments4    ,the water in contact   
with the iron is decomposed by the      
combination of  its oxygene with that   
substance1 and of its hydrogene with a  
portion  of the oxygene and nitrogene of
 the nitrous gas1 to form water and     
ammoniac4    ,that the iron is not      
oxydated at the expence of the oxygene  
of the  nitrous gas1 appears very       
probable from the analogy between this  
process1 and the mutual decomposition of
 nitrous gas and sulphurated  hydrogene4
 ,besides1 dry iron filings effect no   
change whatever in  nitrous gas1 at     

common temperatures4    ,i have         
generally found about #ab of nitrous gas
 converted into #e of  nitrous oxide in 
this process2 which is not very         
different from the  diminution by       
sulphurated hydrogene4 ,it takes place  
equally well in  light and darkness2 but
 more rapidly in warm weather than in   
cold4    b4 ,nitrous gas exposed to a   
large surface of zinc1 in contact with  
water1 is slowly converted into nitrous 
oxide2 at the same time that  ammoniac  
is generated1 and white oxide of zinc   
formed4 ,this process  appears to       
depend1 like the last1 upon the         
decomposition of water by  the          
affinities of part of the oxygene and   
nitrogene of nitrous gas1  for its      
hydrogene1 to form ammoniac and water2  
and by that of zinc  for its oxygene4   
,zinc placed in contact with water1 and 
confined by  mercury1#aci decomposes it 
at the common temperature4 ,zinc1 when  
perfectly dry1 does not in the slightest
 degree act upon nitrous gas4    #aci   

,as ,i have found by experiment4    ,i  
have not been able to determine exactly 
the diminution of volume of  nitrous    
gas1 during its conversion into nitrous 
oxide by zinc4 ,in one  experiment #bj  
measures of nitrous gas1 containing     
about1#jc nitrogene1  were diminished to
 #i1 after an exposure of eight days to 
wetted zinc2  but from an accident1 ,i  
was not able to ascertain the exact     
quantity of  nitrous oxide formed4    c4
 ,it is probable that most of the       
imperfect metals will be found  capable 
of oxydation1 by the decomposition of   
water1 when its  hydrogene is attracted 
by the oxygene and nitrogene of nitrous 
gas4  ,i have this day 7,april #ad1     
#ahjj71 examined two portions of nitrous
  gas1 one of which had been exposed to 
copper filings1 and the other to  powder
 of tin1 for twenty-three days4    ,the 
gas that had been exposed to copper was 
diminished nearly two  fifths4 ,the     
taper burnt in it with an enlarged      
flame1 blue at the  edges4 ,hence it    

evidently contained nitrous oxide4      
,the nitrous gas in contact with tin had
 undergone a diminution of one  fourth  
only1 and did not support flame4        
,,vi4 ,miscellaneous ,observations on   
the conversion of ,nitrous ,gas into    
,nitrous ,oxide4    a4 ,dr4 ,priestley  
found nitrous gas exposed to a mixture  
of iron  filings and sulphur1 with      
water1 converted after a certain time1  
into  nitrous oxide4 ,sulphurated       
hydrogene is always produced during the 
combination of iron and sulphur1 when   
they are in contact with water2  and by 
the hydrogene of this in the nascent    
state1 the nitrous gas is  most probably
 decomposed4    b4 ,green oxide of iron 
moistened with water1 exposed to nitrous
 gas1  slowly gains an orange tinge1    
whilst the gas is diminished4 ,most     
likely  it is converted into nitrous    
oxide2 but this ,i have not ascertained4
    c4 ,i exposed nitrous gas1 to the   
following bodies over mercury  for many 
days1 without any diminution1 or        

apparent change in its  properties4     
,alcohol1 saccharine matter1            
hydrocarbonate1 sulphureous  acid1 and  
phosphorus4    d4 ,crystalised sulphate1
 and muriate of iron1 absorb a small    
quantity  of nitrous gas1 and become    
dark colored on the outside2 but after  
this  absorption1 7which probably       
depends on their water of               
crystalisation17  has taken place1 no   
change is effected in the gas remaining4
    e4 ,the power of iron to decompose  
water being much increased by  increase 
of temperature1 nitrous gas is converted
 into nitrous oxide  much more rapidly  
when placed in contact with a surface of
 heated  iron1 than when exposed to it  
at common temperatures4 ,during the     
decomposition of nitrous gas in this    
way1 ammoniac#adj is formed4    f4 ,the 
curious experiments of ,rouppe1#ada on  
the absorption of gases  by charcoal1   
compared with the phnomena noticed in   
this ,division1  render it probable that
 hydrogene in a state of loose          

combination with  charcoal1 will be     
found to convert nitrous gas into       
nitrous oxide4    #adj ,as was observed 
by ,milner4 ,nitrous gas passed over    
heated zinc1  or tin1 ,i doubt not will 
be found converted into nitrous oxide4  
#ada ,annales de ,chimie1 xxxii4 p4 #c4 
,,vii4 ,recapitulation of conclusions   
concerning the conversion of  ,nitrous  
,gas into ,nitrous ,oxide4    a4        
,certain bodies having a strong affinity
 for oxygene1 as the  sulphites1 dry    
sulphures1 muriate of tin1 c4 convert   
nitrous gas into  nitrous oxide1 by     
simply attracting a portion of its      
oxygene2 whilst  the remaining oxygene  
enters into combination with the        
nitrogene1 and  they assume a more      
condensed state of existence4    b4     
,nitrous gas is converted into nitrous  
oxide by hydrogene1 in a  peculiar state
 of existence1 as in sulphurated        
hydrogene2 and that by  a series of very
 complex affinities4 ,both oxygene and  
nitrogene are  attracted from the       

nitrous gas by the hydrogene1 in such   
proportions  as to form water and       
ammoniac1 whilst the remaining oxygene  
and  nitrogene#adb assume the form of   
nitrous oxide4    #adb ,the             
decomposition and recomposition of      
water1 in this process1  are analogous  
to some of the phnomena observed by the 
ingenious ,mrs4  ,fulhame4    c4        
,nitrous gas placed in contact with     
bodies1 such as iron and  zinc          
decomposing water1 is converted into    
nitrous oxide1 at the same  time that   
ammoniac is formed4 ,it is difficult to 
ascertain the exact  rationale of this  
process4 ,for either the nascent        
hydrogene produced by  the decomposition
 of the water by the metallic substance 
may combine  with portions of both the  
oxygene and nitrogene of the nitrous    
gas2 and  thus by forming water and     
ammoniac1 convert it into nitrous oxide4
 ,or  the metallic substance may attract
 at the same time oxygene from the      
water and nitrous gas1 whilst the       

nascent hydrogene of the water seizes   
upon a portion of the nitrogene of the  
nitrous gas to form ammoniac4    ,the   
degree of diminution1 and the analogy   
between this process and the            
decomposition of nitrous gas by         
sulphurated hydrogene1 render the first 
opinion most probable4      ,,viii4 ,the
 production of ,nitrous ,oxide during   
the oxydation of ,tin1  ,zinc1 and      
,iron1 in ,nitric ,acid4    a4 ,dr4     
,priestley discovered1 that during the  
solution of tin1 zinc1  and iron1 in    
nitric acid1 certain portions of nitrous
 oxide were  produced1 mingled with     
quantities of nitrous gas1 and          
nitrogene1  varying in proportion as the
 acid employed was more or less         
concentrated4    ,it has long been known
 that ammoniac is formed during the     
solution of  tin1 zinc1 and iron1 in    
diluted nitric acid4 ,consequently1 in  
these  processes water is decomposed4   
,i had designed to investigate minutely 
these phnomena1 so as to  ascertain the 

quantities of water and acid            
decompounded1 and of the new  products  
generated4 ,but after going through some
 experiments on the  oxydation of tin   
without gaining conclusive results1 the 
labor1 and  sacrifice of time they      
demanded1 obliged me to desist from     
pursuing the  subject1 till ,i had      
completed more important investigations4
    ,i shall detail the few observations
 which have occurred to me1 relating  to
 the production of nitrous oxide from   
metallic solutions4    b4 ,when tin is  
dissolved in concentrated nitric acid1  
such as of  #a4d1 nitrous oxide is      
produced1 mingled with generally more   
than twice  its bulk of nitrous gas4 ,in
 this process but little free nitrogene 
is  evolved1 and the tin is chiefly     
precipitated in the form of a white     
powder4 ,if the solution1 after the     
generation of these products1 is        
saturated with lime1 and heated1 the    
ammoniacal smell is distinct4    ,when  
nitric acid of specific gravity #a4bd1  

is made to act upon tin2  in the        
beginning of the process1 nearly equal  
parts of nitrous gas  and nitrous oxide 
are produced2 as it advances1 the       
proportion of  nitrous oxide to the     
nitrous gas increases3 the largest      
quantity of  nitrous oxide that ,i have 
found in the gas procured from tin is 1 
the  remainder being nitrous gas and    
nitrogene4    ,when tin is oxydated in  
an acid of less specific gravity than   
#a4ji1 the  quantities of gas disengaged
 are very small1 and consist of         
nitrogene1  mingled with minute portions
 of nitrous oxide1 and nitrous gas4     
,whenever ,i have saturated solutions of
 tin in nitric acid of different        
specific gravities1 with lime1 and      
afterwards heated them1 the  ammoniacal 
smell has been uniformly perceptible1   
and generally most  distinct when       
diluted acids have been employed4    c4 
,when zinc is dissolved in nitric acid1 
whatever is its specific  gravity1      
certain quantities of nitrous oxide are 

produced4    ,nitric acids of greater   
specific gravity than #a4b1 act upon    
zinc with  great rapidity1 and great    
increase of temperature4 ,the gases     
disengaged  from these solutions consist
 of nitrous gas1 nitrous oxide1 and     
nitrogene2 the nitrous oxide rarely     
equals one third of the whole4    ,when 
nitric acid of #a1ajd is made to        
dissolve zinc1 the gas obtained in  the 
middle of the process consists chiefly  
of nitrous oxide4 ,from such  a solution
 ,i obtained gas which gave a residuum  
of one sixth only when  absorbed by     
water4 ,the taper burnt in it with a    
brilliant flame1 and  sulphur with a    
vivid rose-colored light4    #ajj grains
 of granulated zinc1 during their       
solution in #cjj grains  of nitric acid1
 of #a1dc1 diluted with #ad times its   
weight of water1  produced #bf cubic    
inches of gas4 ,of this gas _/ were     
nitrous1 _/#cf  nitrous oxide1 and the  
remainder nitrogene4 ,the solution      
saturated with  lime and heated1 gave a 

distinct smell of ammoniac4    d4       
,during the solution of iron in         
concentrated nitric acid1 the gas  given
 out is chiefly nitrous2 it is however  
generally mingled with  minute          
quantities of nitrous oxide4 ,when very 
dilute nitric acids  are made to act    
upon iron1 by the assistance of heat1   
nitrous oxide  is produced in           
considerable quantities1 mingled with   
nitrous gas  and nitrogene2 the         
proportions of which are smaller as the 
process  advances4#adc ,the fluid       
remaining after the oxydation and       
solution of  iron in nitric acid1 always
 contains ammoniac4    #adc ,from one of
 ,dr4 ,priestley's experiments1 it      
appears that  hydrogene gas is sometimes
 disengaged during the solution of iron 
in  very dilute nitric acid by heat4    
,this phnomenon has never occurred to   
me4    e4 ,as during the solution of    
tin1 zinc1 and iron1 in nitric acid1 the
  quantity of acid is diminished in     
proportion as the process advances1  it 

is reasonable to suppose that the       
relative quantities of the gases        
evolved are perpetually varying4 ,in the
 beginning of a dissolution1  the       
nitrous gas generally predominates1 in  
the middle nitrous oxide1  and at the   
end nitrogene4    f4 ,during the        
generation of nitrous gas1 nitrous      
oxide1 and ammoniac1  from the          
decomposition of solution of nitric acid
 in water1 by tin1  zinc1 and iron1 very
 complex attractions must exist between 
the  constituents of the substances     
employed4 ,the acid and the water are   
decomposed at the same time1 and in     
proportions different as the  solution  
is more concentrated1 by the combination
 of their oxygene with  the metallic    
body4    ,the nitrous gas is produced by
 the combination of the metal with  _/  
of the oxygene of the acid4 ,the nitrous
 oxide is most probably  generated by   
the decomposition of a portion of the   
nitrous gas  disengaged1 by the nascent 
hydrogene of the water decompounded2    

some  of it may be possibly formed from 
a more complete decomposition of the    
acid4    ,the production of ammoniac may
 arise1 probably from two causes2 from  
the decomposition of the nitrous gas by 
the combination of the nascent          
hydrogene of the water1 with portions of
 its oxygene and nitrogene at  the same 
time2 and from the union of hydrogene   
with nascent nitrogene  liberated in    
consequence of a complete decomposition 
of part of the  acid4      ,,ix4        
,additional ,observations on the        
production of ,nitrous ,oxide4    a4    
,when nitric acid is combined with      
muriatic acid1 or sulphuric  acid1#add  
the quantities of nitrous oxide produced
 from its  decomposition by tin1 zinc1  
and iron1 are rather increased than     
diminished4 ,the nitrous oxide obtained 
from these solutions is1  however1 never
 sufficiently pure for physiological    
experiments4 ,it is  always mingled with
 either nitrous gas1 nitrogene1 or      
hydrogene1 and  sometimes with all of   

them4    #add ,as was discovered by     
,priestley1 and the ,dutch ,chemists4   
b4 ,from the solutions of bismuth1      
nickel1 lead1 and copper1 in  diluted   
nitric acid1 ,i have never obtained any 
perceptible quantity  of nitrous oxide3 
the gas produced is nitrous1 mingled    
with different  portions of nitrogene4  
,antimony and mercury1 during their     
solution in  aqua regia1 give out only  
nitrous gas4    ,probably none of the   
metallic bodies1 except those that      
decompose  water at temperatures below  
ignition1 will generate nitrous oxide   
from  nitric acid4 ,on cobalt and       
manganese ,i have never had an          
opportunity of  experimenting3 manganese
 will probably produce nitrous oxide4   
c4 ,during the solution of vegetable    
matters#ade in nitric acid1 by  heat1   
very minute portions of nitrous oxide   
are sometimes produced1  always however 
mingled with large quantities of nitrous
 gas1 and  carbonic acid4    #ade ,such 
as the leaves1 bark1 and wood1 of trees4

    ,when nitric acid is decompounded by
 ether1 fixed oils1 volatile oils1  or  
alcohol1 towards the end of the process 
small quantities of nitrous  oxide are  
produced1 and sometimes sufficiently    
pure to support the  flame of the       
taper4#adf    d4 ,when green oxide of   
iron is dissolved in nitric acid1       
nitrous  oxide is produced1 mingled with
 nitrogene and nitrous gas4    e4       
,during the conversion of green         
sulphate1 or green muriate of iron  into
 red1 by the decomposition of dilute    
nitric acid1 nitrous oxide is  formed1  
mingled with different proportions of   
nitrous gas and nitrogene4    f4 ,when  
solution of green nitrate of iron is    
heated1 a part of the  acid is          
decomposed1 red oxide is precipitated1  
red nitrate formed1 and  impure nitrous 
oxide evolved4    g4 ,when iron is      
introduced into a solution of nitrate of
 copper1 the  copper is precipitated in 
its metallic state1 whilst nitrous      
oxide1  mingled with small portions of  

nitrogene1 is produced4#adg    #adf ,as 
,i have observed after ,priestley4      
#adg ,as was discovered by ,priestly4   
,both zinc and tin precipitate copper in
 its metallic form from  solution in the
 nitric acid4 ,during these             
precipitations1 certain  quantities of  
nitrous oxide are generated1 mingled    
however with larger  quantities of      
nitrogene than that produced from       
decomposition by iron4  ,in all these   
processes ammoniac is formed1 and water 
consequently  decomposed4    ,the       
decomposition of water and nitric acid1 
during the precipitation  of copper from
 solution of nitrate of copper1 by tin1 
zinc1 and iron1  depends upon the strong
 affinity of those metals for oxygene1  
and their  powers of combining with a   
larger quantity of it than copper4      
,x4 ,decomposition of ,aqua ,regia by   
,platina1 and evolution of a ,gas       
analogous to ,oxygenated ,muriatic      
,acid1 and ,nitrogene4    a4 ,de la     
,metherie1 in his essay on different    

airs1 has asserted that  the gas        
produced by the solution of platina in  
nitro-muriatic acid1 is  identical with 
the dephlogisticated nitrous gas of     
,priestly4 ,he calls  it nitrous gas    
with excess of pure air1 and affirms    
that it diminishes1  both with nitrous  
gas and common air4    b4 ,i introduced 
into a vessel containing #cj grains of  
platina1  #bjej grains of aqua regia1   
composed of equal parts1 by weight1 of  
concentrated nitric acid of #a1dc1 and  
muriatic acid of #a1af4 ,at the  common 
temperature1 that is1 #di1 no action    
between the acid and  platina appeared  
to take place4 ,on the application of   
the heat of a  spirit lamp1 the solution
 gradually became yellow red1 and gas   
was  given out with rapidity4 ,some of  
this gas received in a jar filled  with 
warm water1 appeared of a bright yellow 
color4 ,on agitation1  the greater part 
of it was absorbed by the water1 and the
 remainder  extinguished flame4 ,when it
 was received over mercury1 it acted    

upon it  with great rapidity1 and formed
 on the surface a white crust4    ,as   
the process of solution advanced1 the   
color of the acid changed  to dark red1 
at the same time that the production of 
gas was much  increased2 more than #dj  
cubic inches were soon collected in the 
water  apparatus4    ,different portions
 of the gas were examined1 it exhibited 
the following  properties3        #a4   
,its color was orange red1#adh and its  
smell exactly         resembled that of 
oxygenated muriatic acid4        #b4    
,when agitated in boiled water1 it was  
rapidly absorbed1         leaving a     
residuum of rather more than one        
twelfth4        #c4 ,the taper burnt in 
it with increased brilliancy1           
the flame being long1 and deep red at   
the edges4        #d4 ,iron introduced  
into it ignited1 burnt with a dull      
red light4        #e4 ,green vegetables 
exposed to it were instantly            
rendered white4        #f4 ,it underwent
 no diminution1 mingled with            

atmospheric air4        #g4 ,when       
mingled with nitrous gas1 it gave dense 
red         vapor1 and rapid diminution4
    #adh ,this deep color depended1 in  
some measure1 upon the  nitro-muriatic  
vapor suspended in it4 ,i have since    
observed that it is  more intense in    
proportion as the heat employed for the 
production of  the gas has been         
stronger4 ,the natural color of the     
peculiar gas is  deep yellow4    c4     
,from the exhibition of these           
properties1 it was evident that the  gas
 produced during the solution of platina
 in aqua regia1 chiefly  consisted of   
oxygenated muriatic acid1 or of a gas   
highly analogous to  it4 ,it was1       
however1 difficult to conceive how a    
body1 by combining  with a portion of   
the oxygene of nitro-muriatic acid1     
could produce  from it oxygenated       
muriatic acid1 apparently mingled with  
very small  portions of any other gas4  
d4 ,to ascertain whether any permanent  
gas was produced during the  ebullition 

of aqua regia1 of the same composition  
as that used for the  solution of the   
platina2 ,i kept a large quantity of it 
boiling for some  time1 in communication
 with the water apparatus2 the gas      
generated  appeared to be wholly        
nitro-muriatic1 and was absorbed as fast
 as  produced1 by the water4    e4 ,to  
determine whether any nitrous oxide was 
mingled with the  peculiar gas1 as well 
as the nature and quantity of the       
unabsorbable  gas1 nitrous gas was      
gradually added to #ba cubic inches of  
the gas  produced from a new solution1  
till the diminution was complete3 the   
gas  remaining equalled #b1c cubic      
inches2 it was unabsorbable by water1   
and  extinguished flame4    ,in another 
experiment1 when the last portions of   
gas from a solution  were carefully     
received in water previously boiled1 #ab
 cubic inches  agitated in water left a 
residuum of #a4c2 whilst the same       
quantity  decomposed by nitrous gas1    
containing1#jb nitrogene1 left about    

#a4e4    ,hence it appeared that the    
ariform products of the solution        
consisted  of the peculiar gas analogous
 to oxygenated muriatic acid1 and of a  
small quantity of nitrogene4    f4      
,consequently a portion of the nitric   
acid of the aqua regia had  been        
decomposed2 but if it had given oxygene 
both to the platina and  muriatic acid1 
the quantity of nitrogene evolved ought 
to have been  much more considerable4   
g4 ,to ascertain if any water had been  
decomposed1 and the nitrogene  condensed
 in the solution by its hydrogene1 to   
form ammoniac1 ,i  saturated a solution 
with lime1 and heated it1 but no        
ammoniacal smell  was perceived4    h4  
,to determine if any nitrogene had      
entered into chemical  combination with 
muriatic acid and oxygene1 so as to form
 an ariform  triple compound1 analogous 
in its properties to oxygenated muriatic
  acid1 ,i exposed some of the gas to   
mercury1 expecting that this  substance1
 by combining with its oxygene1 would   

effect a complete  decomposition2 and   
this was actually the case3 for the gas 
was at  first rapidly diminished1 and   
the mercury became oxydated2 its volume1
  however1 soon increased2 and the      
residual gas appeared to be nitrous1    
mingled with much nitrogene4 ,the exact 
proportions of each1 from an  accident1 
,i could not determine4    ,this        
experiment was inconclusive1 because the
 nitro-muriatic acid  suspended in the  
peculiar gas1 from which it can probably
 be never  perfectly freed1 acted in    
common with it upon the mercury1 and    
produced  nitrous gas3 and this nitrous 
gas1 at the moment of its production1   
formed nitrous acid by combining with   
the oxygene of the peculiar  gas2 and   
the nitrous acid generated#adi was again
 decomposed by the  mercury2 and hence  
nitrous gas evolved1 and possibly some  
nitrogene4    #adi ,the decomposition of
 ariform nitrous acid by mercury1 was   
first  noted by ,priestley2 vol4 iii4   
pag4 #aja4 ,this decomposition ,i have  

often  had occasion to observe4 ,in     
reading ,humbolt's paper on eudiometry1 
,annales de ,chimie1 xxviii1 pag4 #aej1 
,i was not a little surprised to  find  
that he takes no notice of this fact4   
,he seems to suppose that  nitrous acid 
can remain ariform1 and even be         
condensed1 in contact  with mercury1    
without alteration4 ,he says1 8,in      
mingling #ajj parts of  atmospheric air 
with #ajj of nitrous air1 the air       
immediately became  red1 but all the    
acid produced remained ariform2 and     
after eighteen  hours some drops only of
 acid were formed1 which swam upon the  
mercury40    i4 ,peculiar circumstances 
prevented me at this time from          
completely  investigating the subject4  
,it remains doubtful whether the gas    
consists  simply of highly oxygenated   
muriatic acid and nitrogene1#aej        
produced  by the decomposition of nitric
 acid from the coalescing affinities of 
platina and muriatic acid for oxygene2  
or whether it is composed of a  peculiar

 gas1 analogous to oxygenated muriatic  
acid1 and nitrogene1  generated from    
some unknown affinities4#aea    #aej    
,lavoisier has said concerning aqua     
regia1 8,in solutions of metals  in this
 acid1 as in all other acids1 the metals
 are first oxydated1  by attracting a   
part of the oxygene from the compound   
radical4 ,this  occasions the           
disengagement of a particular species of
 gas not hitherto  described1 which may 
be called nitro-muriatic gas4 ,it has a 
very  disagreeable smell1 and is fatal  
to animal life when respired2 it        
attacks iron1 and causes it to rust2 it 
is absorbed in considerable  quantities 
by water40 ,elem4 ,eng4 #bcg4    #aea ,i
 have no doubt but that the gas procured
 from the solution of  gold in aqua     
regia1 is analogous to that produced    
from platina4    ,some very uncommon    
circumstances are attendant on the      
solution of  platina3    #ast4 ,the     
immense quantity of acid required for   
the solution of a minute  quantity of   

platina4    #b;d4 ,the great quantity of
 gas produced during the solution of    
this  minute quantity4    #c;d4 ,the    
intense red color of the solution1 and  
its perfectly acid  properties after it 
ceases to act upon the metal4      ,,xi4
 ,on the action of the ,electric ,spark 
on a mixture of ,nitrogene and  ,nitrous
 ,gas4    ,thinking it possible that    
nitrous gas and nitrogene might be made 
to  combine by the action of the        
electric spark1 so as to form nitrous   
oxide1 ,i introduced #bj grain measures 
of each of them into a small  detonating
 tube1 graduated to grains1 standing    
over mercury1 and  containing a very    
small quantity of cabbage juice rendered
 green by an  alkali4 ,after electric   
sparks had been passed through the gases
 for an  hour and half1 they were       
diminished to about #cb1 and the cabbage
 juice  was slightly reddened4 ,on      
introducing about #aj measures of       
hydrogene1  and passing the electric    
spark through the whole1 no inflammation

 or  diminution was perceptible4 ,hence 
the condensation most probably arose    
wholly from the formation of nitrous    
acid1#aeb by the more intimate  union of
 the oxygene of nitrous gas with some of
 its nitrogene1 as in  the experiments  
of ,priestley4    #aeb ,for if nitrous  
oxide had been formed1 it would have    
been  decomposed by the hydrogene4      
,as the nascent nitrogene1 in the       
decomposition of nitrate of ammoniac1   
combines with a portion of oxygene and  
nitrogene1 to form nitrous  oxide2 it is
 probable that nitrous oxide may be     
produced during the  passage of nitrous 
gas and ammoniac through a heated tube4 
,,xii4 ,general ,remarks4    ,there are 
no reasons for supposing that nitrous   
oxide is formed in any  of the processes
 of nature2 and the nice equilibrium of 
affinity by  which it is constituted1   
forbids us to hope for the power of     
composing  it from its simple           
principles4 ,we must be content to      
produce it1 either  directly or         

indirectly1 from the decomposition of   
nitric acid4 ,and as  in the            
decomposition of nitrate of ammoniac1   
not only all the nitrogene  of the      
nitric acid enters into the composition 
of the nitrous oxide  produced1 but     
likewise that of the ammoniac1 this     
process is by far  the cheapest1 as well
 as the most expeditious4 ,a mode of    
producing  ammoniac at little expence1  
has been proposed by ,mr4 ,watt4        
,condensed  in the sulphuric acid1 it   
can be easily made to combine with      
nitric  acid1 from the decomposition of 
nitre by double affinity4 ,and thus1  if
 the hopes which the experiments at the 
end of those researches  induce us to   
indulge1 do not prove fallacious1 a     
substance which has  been heretofore    
almost exclusively appropriated to the  
destruction of  mankind1 may become1 in 
the hands of philosophy1 a means of     
producing  health and pleasurable       
sensation4          ,,research ,,ii4    
,,into ,,the ,,combinations ,,of        

,,nitrous ,,oxide1 ,,and ,,its          
,,decomposition ,,by  ,,combustible     
,,bodies4      ,,division ,i4           
,,experiments and ,,observations on the 
,,combinations of ,,nitrous ,,oxide4    
,i4 ,combination of ,water with ,nitrous
 ,oxide4    a4 ,the discoverer of       
nitrous oxide first observed its        
solubility in  water2 and it has since  
been noticed by different               
experimentalists4    ,dr4 ,priestley    
found that water dissolved about one    
half of its bulk  of nitrous oxide1 and 
that at the temperature of ebullition1  
this  substance was incapable of        
remaining in combination with it4#aec   
#aec ,experiments and observations1 vol4
 ii4 pag4 #ha4    b4 ,i introduced to #i
 cubic inches of pure water1 i4 e4 water
  distilled under mercury1 #g cubic     
inches of nitrous oxide1 which  had been
 obtained over mercury1 from the        
decomposition of nitrate  of ammoniac1  
and in consequence was perfectly pure4  
,after they had  remained together for  

#aa hours1 temperature being #df1 during
 which  time they were frequently       
agitated1 the gas remaining was #b1c2   
consequently #d1g cubic inches had been 
absorbed4 ,and then1 #ajj cubic  inches1
  #becjj grains of water1 will absorb   
#ed cubic inches1  #bg  grains1 of      
nitrous oxide4    c4 ,the taste of water
 impregnated with nitrous oxide1 is     
distinctly  sweetish2 it is softer than 
common water1 and1 in my opinion1 much  
more  agreeable to the palate4 ,it      
produces no alteration in vegetable     
blues1  and effects no change of color  
in metallic solutions4    d4 ,thinking  
that water impregnated with nitrous     
oxide might probably  produce some      
effects when taken into the stomach1 by 
giving out  its gas1 ,i drank1 in ,june1
 #agii1 about #c ounces of it1 but      
without  perceiving any effects4    ,a  
few days ago1 considering this quantity 
as inadequate1 ,i took at two  draughts 
nearly a pint1 fully saturated2 and at  
this time ,mr4 ,joseph  ,priestley drank

 the same quantity4    ,we neither of us
 perceived any remarkable effects4      
,since that time ,i have drank near     
three pints of it in the course of a    
day4 ,in this instance it appeared to   
act as a diuretic1 and ,i imagined  that
 it expedited digestion4 ,as a matter of
 taste1 ,i should always  prefer it to  
common water4    e4 ,two cubic inches of
 pure water1 that had been made to      
absorb  about #a1a cubic inches of      
nitrous oxide2 when kept for some time  
in  ebullition1 and then rapidly cooled1
 produced nearly #a of gas4 ,sulphur    
burnt in this gas with a vivid          
rose-colored flame4    ,in another      
experiment1 in which the gas was        
expelled by heat from  impregnated      
water1 and absorbed again after much    
agitation on cooling2  the residuum was 
hardly perceptible1 and most likely     
depended upon some  gas which had       
adhered to the mercury1 and was         
liberated during the  ebullition4 ,hence
 it appears that nitrous oxide is       

expelled unaltered  from its aqueous    
solution by heat4    f4 ,i have before  
mentioned1 ,division ,,iii1 that nitrous
 oxide1 during  its combination with    
spring water1 expels the common air     
dissolved in  it4 ,this common air      
generally amounts to one sixteenth1 the 
volume of  the water being unity4 ,a    
correction on account of this           
circumstance  must be made for the      
apparent deficiency of diminution1 and  
for the  common air mingled in          
consequence1 with nitrous oxide during  
its  absorption by common water4    g4  
,water impregnated with nitrous gas     
absorbed nitrous oxide2 but the         
residual gas was much greater than that 
of common water1 and gave red  fumes    
with atmospheric air4 ,nitrous gas      
agitated for a long while over  water   
highly impregnated with nitrous oxide1  
was not in the slightest  degree        
diminished1 in one experiment indeed it 
was rather increased2  doubtless from   
the liberation of some nitrous oxide    

from the water by  the agitation4    h4 
,nitrous oxide kept in contact with     
aqueous solution of sulphurated         
hydrogene and often agitated1 was not in
 the slightest degree  diminished4      
,sulphurated hydrogene1 introduced into 
a solution of nitrous oxide1 was        
rapidly absorbed1 and as the process    
advanced1 the nitrous oxide was  given  
out4    i4 ,water impregnated with      
carbonic acid1 possessed no action upon 
nitrous oxide1 and did not in the       
slightest degree absorb it4 ,when       
carbonic acid was introduced to an      
aqueous solution of nitrous oxide2  the 
ariform acid was absorbed1 and the      
nitrous oxide liberated4    k4 ,from    
these observations it appears that      
nitrous oxide has less  affinity for    
water1 than even the weaker acids1      
sulphurated hydrogene  and carbonic     
acid2 as indeed one might have          
conjectured a priori from  its degree of
 solubility3 likewise that it has a     
stronger attraction  for water than the 

gases not possessed of acid or alkaline 
properties2  it expelling from water    
nitrous gas1 oxygene1 and common air2   
probably  hydrocarbonate1 hydrogene1 and
 nitrogene4      ,,ii4 ,combinations of 
,nitrous ,oxide with ,fluid ,inflammable
 ,bodies4    a4 ,vitriolic ether absorbs
 nitrous oxide in much larger quantities
  than water4    ,a cubic inch of ether1
 at temperature #eb1 combined with a    
cubic inch  and seven tenths of nitrous 
oxide4    ,ether thus impregnated was   
not at all altered in its appearance2   
its  smell was precisely the same1 but  
the taste appeared less pungent1 and    
more agreeable4 ,nitrous oxide is       
liberated unaltered from ether at a     
very low temperature1 that is1 at about 
the boiling point of this fluid4    ,for
 expelling nitrous oxide from           
impregnated ether1 and for  ascertaining
 in general the quantity of gases       
combined with fluids1 ,i  have lately   
made use of a very simple method1 which 
it may not be amiss  to describe4       

,the impregnated fluid is introduced    
into a small thin tube1 graduated       
to1#je cubic inches1 through mercury4   
,the quantity of fluid should never     
equal more than a fifth or sixth of the 
capacity of the tube4    ,the lower part
 of the tube is adapted to an orifice in
 the shelf of  the mercurial apparatus1 
so as to make an angle of about #dj with
 the  surface of the mercury4    ,the   
flame of a small spirit lamp is then    
applied to that part of the  tube       
containing the fluid2 and after the     
expulsion of the gas from it1  the heat 
is raised so as to drive out the fluid  
through the orifice of  the tube4 ,thus 
the liberated gas is preserved in a     
state proper for  accurate examination4 
,impregnated ether1 during its          
combination with water1 gives out the   
greater part of its nitrous oxide4      
,during the liberation of nitrous  oxide
 from ether1 by its combination with    
water1 a very curious  phnomenon takes  
place4    ,if the water employed is     

colored1 so that it may be seen in a    
stratum  distinct from the impregnated  
ether1 at the point of contact a number 
of small spherules of fluid will be     
perceived1 apparently repulsive  both to
 water and ether2 these spherules become
 gradually covered  with minute globules
 of gas1 and as this gas is liberated   
from their  surfaces1 they gradually    
disappear4    b4 ,alcohol dissolves     
considerable quantities of nitrous      
oxide4    #b cubic inches of alcohol1 at
 #eb1 combined with #b1d cubic inches of
  nitrous oxide4 ,the alcohol thus      
impregnated had a taste rather sweeter  
than before1 but in other physical      
properties was not perceptibly  altered4
    ,nitrous oxide is incapable of      
remaining in combination with this fluid
  at the temperature of ebullition2 it  
is liberated from it unaltered by  heat4
    ,impregnated alcohol1 during its    
combination with water1 gives out  the  
greater part of its combined nitrous    
oxide3 on mingling the two  fluids      

together1 at the point of contact the   
alcohol becomes covered  with an        
infinite number of small globules of    
gas1 which continue to be  generated    
during the whole of the combination1 and
 in passing through  the fluid render it
 almost opaque4    c4 ,the essential    
oils absorb nitrous oxide to a greater  
extent than  either alcohol or ether4   
1#e cubic inches of oil of carui        
combined with #a1b cubic inches of      
nitrous oxide at #ea4 ,the color of the 
oil thus impregnated was rather  paler  
than before4    ,nitrous oxide is       
expelled unaltered from impregnated oil 
of carui1 by  heat4    #a of oil of     
turpentine absorbed nearly #b of nitrous
 oxide1 at #eg4 ,its  properties were   
not sensibly altered from this          
combination1 and the gas  was expelled  
from it undecompounded1 by heat4    d4  
,as well as the essential oils1 the     
fixed oils dissolve nitrous  oxide at   
low temperatures1 whilst at high        
temperatures they do not  remain in     

combination4    #a of olive oil         
absorbed1 at #fa1 #a1b of nitrous oxide1
 but without  undergoing any apparent   
physical change4      ,,iii4 ,action of 
,fluid ,acids on ,nitrous ,oxide4    a4 
,nitrous oxide exposed to concentrated  
sulphuric acid1 undergoes no  change1   
and suffers no diminution1 that may not 
be accounted for from  the abstraction  
of a portion of its water by the acid4  
b4 ,nitrous oxide is scarcely at all    
soluble in nitrous acid1 and  exposed to
 that substance1 undergoes no           
alteration4    c4 ,muriatic acid1 of    
specific gravity #a1ad absorbs about a  
third  of its bulk of nitrous oxide4 ,it
 suffers no apparent change in its      
properties from being thus impregnated1 
and the gas is again given out  from it 
on the application of heat4    d4       
,acetic acid absorbs nearly one third of
 its bulk of nitrous oxide4    e4 ,aqua 
regia1 that is1 the nitro-muriatic acid1
 absorbs a very  minute portion of      
nitrous oxide4    f4 ,nitrous oxide was 

exposed to a new compound acid1         
consisting of  oxygenated muriatic acid1
 and sulphuric acid1 which ,i discovered
 in  ,july1 #agii1 and of which an      
account will be shortly published2 but  
it  was neither absorbed or altered4    
,i have before mentioned that the       
aqueous solutions of sulphurated        
hydrogene and carbonic acid1 neither    
dissolve or alter nitrous oxide4        
,,iv4 ,action of ,saline ,solutions1 and
 other ,substances1 on ,nitrous  ,oxide4
    a4 ,nitrous oxide exposed to        
concentrated solution of green sulphate 
of iron1 at #eh1 underwent no           
perceptible diminution2 not even after  
it  had been suffered to remain in      
contact with it for half an hour4    b4 
,it underwent diminution of nearly1#b   
when agitated in contact with  a        
solution of red sulphate of iron1 the   
volume of the solution being  unity4    
c4 ,solution of green sulphate of iron1 
fully impregnated with nitrous  gas1 did
 not in the slightest degree absorb     

nitrous oxide1 and appeared  to have no 
action upon it4    d4 ,solution of green
 muriate of iron1 whether impregnated   
with  nitrous gas1 or unimpregnated1 has
 no affinity for1 or action upon1       
nitrous oxide4    e4 ,solution of red   
muriate of iron in alcohol1 absorbed    
nearly one  fifth of its bulk1 of       
nitrous oxide4    f4 ,solution of       
prussiate of potash absorbed nearly one 
third of its  volume1 of nitrous oxide1 
which was again expelled from it by     
heat4    g4 ,solution of nitrate of     
copper appeared to have no affinity for 
nitrous oxide4    h4 ,concentrated      
solution of nitrate of ammoniac1 at #eh1
 absorbed one  eighth of its bulk of    
nitrous oxide4    i4 ,solutions of      
alkaline sulphures absorb nitrous oxide 
in quantities  proportionable to the    
water they contain2 it is expelled from 
them  unaltered by heat4 ,none of the   
hydro-sulphures dissolve more than half 
their bulk of nitrous oxide4    k4      
,concentrated solutions of the sulphites

 possess little or  no action on nitrous
 oxide2 diluted solutions absorb it in  
small  quantities4    l4 ,concentrated  
solution of muriate of tin absorbs about
 one eighth  of nitrous oxide2 more     
dilute solutions absorb larger          
quantities4    ,from these observations 
we learn1 that neutro-saline solutions  
in  general1 have very feeble           
attractions for nitrous oxide2 and as   
solutions of green muriate1 and sulphate
 of iron1 whether free from  nitrous    
gas1 or impregnated with it1 possess no 
action upon nitrous  oxide1 nitrous gas 
may be separated from this substance by 
those  solutions with greater facility  
than nitrous oxide can be separated     
from nitrous gas1 by water or alcohol4  
,charcoal absorbs nitrous oxide as well 
as all other gases2 and it is           
disengaged from it by heat4    ,i have  
as yet found no other solid body1 not   
possessed of alkaline  properties1      
capable of absorbing nitrous oxide in   
any state of  existence4    ,the bodies 

possessing the strongest affinity for   
oxygene1 the dry  sulphites1 muriate of 
tin1 the common sulphures1 white        
prussiate of  potash1 and green oxide of
 iron1 do not in the slightest degree   
act on  nitrous oxide at common         
temperatures4      ,v4 ,action of       
different ,gases on ,nitrous ,oxide4    
a4 #ab measures of muriatic acid gas    
were mingled with #g measures  of       
nitrous oxide at #ef4 ,after remaining  
together for a minute1 they  filled a   
space equal to #ai measures4 ,when water
 was introduced to  them1 the muriatic  
acid was absorbed much more slowly than 
if it had  been unmingled4    ,in       
another experiment1 when the gases were 
saturated with water1 #i  measures of   
each of them1 when mingled and suffered 
to remain in  contact for a quarter of  
an hour1 filled a space nearly equal to 
#ai2  and after the muriatic acid had   
been absorbed by potash1 the nitrous    
oxide remained unaltered in its         
properties4    ,from the expansion1 it  

appears most probable that ariform      
muriatic  acid1 and nitrous oxide1 have 
a certain affinity for each other1 and  
that they combine when mingled together2
 for in the last experiment1  the       
increase of volume cannot be accounted  
for by supposing that  nitrous oxide    
undergoes less change of volume than    
muriatic acid1  by ariform combination  
with water1 and that the expansion      
depended  upon the solution of some of  
its combined water by the muriatic acid4
  ,that muriatic acid and nitrous oxide 
have a slight affinity for each  other1 
likewise appears from the absorption of 
nitrous oxide by aqueous  solution of   
muriatic acid4    ,thinking that nitrous
 oxide might attract muriatic acid from 
its  solution in water1 ,i exposed a    
minute quantity of fluid muriatic acid  
to nitrous oxide2 but no alteration of  
volume took place in the gas4    b4 #f  
measures of nitrous oxide were mingled  
with #aa measures of  sulphureous acid1 
saturated with water2 after remaining at

 rest for six  minutes1 they filled a   
space nearly equal to #ah measures4     
,exposed to  water1 the sulphureous acid
 was absorbed1 but not nearly so rapidly
 as  when in a free state4 ,sulphur     
burnt with a vivid flame in the residual
  nitrous oxide4 #g measures of         
sulphureous acid were now mingled with  
#h of nitrous oxide4 ,they filled a     
space nearly equal to #ae1 and no       
farther expansion took place afterwards4
    ,from these experiments it appears  
probable that sulphureous acid1 and     
nitrous oxide1 have some affinity for   
each other4    c4 #aa measures of       
carbonic acid were mingled with #h of   
nitrous  oxide2 they filled a space     
nearly equal to #ai measures4 ,on       
exposing  the mixture to caustic potash1
 the carbonic acid was absorbed1 and the
  nitrous oxide remained pure4 ,hence it
 appears that carbonic acid and  nitrous
 oxide do not combine with each other4  
d4 ,oxygenated muriatic acid1 and       
nitrous oxide1 were mingled in a  water 

apparatus3 there was a slight appearance
 of condensation2 but  this was most    
probably owing to absorption by the     
water2 on agitation1  the oxygenated    
muriatic acid was absorbed1 and the     
greater part of the  nitrous oxide      
remained unaltered4    e4 ,sulphurated  
hydrogene and nitrous oxide1 mingled    
together1 neither  expanded or          
contracted2 exposed to solution of      
potash1 the acid#aed  only was absorbed4
    #aed ,the experiments of ,berthollet
 have clearly proved the perfect        
acidity of this substance4    f4 #aj    
measures of nitrous gas were admitted to
 #ab of nitrous oxide at  #ei4 ,they    
filled a space equal to #bb1 and after  
remaining together for  an hour1 had    
undergone no change4 ,solution of       
muriate of iron absorbed  the nitrous   
gas without affecting the nitrous oxide4
    g4 ,nitrous oxide was successively  
mingled with oxygene1 atmospheric  air1 
hydrocarbonate1 phosphorated hydrogene1 
hydrogene1 and nitrogene1  at #eg2 it   

appeared to possess no action on any of 
them1 and was  separated by water1 the  
gases remaining unaltered4    h4 ,as    
nitrous oxide was soluble in ether1     
alcohol1 and the other  inflammable     
fluids1 it was reasonable to suppose    
that its affinity for  those bodies     
would enable them to unite with it in   
the ariform state4  ,at the suggestion  
of ,dr4 ,beddoes ,i made the following  
experiment3    ,to #ab measures of      
nitrous oxide1 at #ed1 ,i introduced a  
single drop of  ether2 the gas          
immediately began to expand1 and in four
 minutes filled  a space equal to       
sixteen measures and a quarter4 ,when an
 inflamed taper  was plunged into the   
gas thus holding ether in solution1 a   
light blue  flame slowly passed through 
it4    ,a considerable diminution of    
temperature is most probably produced1  
from the great expansion of nitrous     
oxide during its combination with       
ether4    ,a drop of alcohol was        
admitted to #ad measures of nitrous     

oxide4 ,in five  minutes1 the gas filled
 a space equal to fifteen and a third2  
but no  farther diminution took place   
afterwards4    ,a minute quantity of oil
 of turpentine was introduced to #ad    
measures  of nitrous oxide2 it filled1  
in #d minutes1 a space rather less than 
#ad2 and no farther change took place   
afterwards4 ,most likely this           
contraction arose from the precipitation
 of the water dissolved in the  gas by  
the stronger affinity of the oil for    
nitrous oxide4 ,to ascertain  with      
certainty if any oil had been dissolved 
by the gas1 ,i introduced  into it a    
small quantity of ammoniac4 ,it         
immediately became slightly  clouded1   
most probably from the formation of     
soap1 by the combination  of the        
dissolved oil with the ammoniac4        
,from these experiments we learn1 that  
when nitrous oxide is mingled  with     
either carbonic acid1 oxygene1 common   
air1 hydrocarbonate1  sulphurated       
hydrogene1 hydrogene1 or nitrogene1 they

 may be separated  from each other      
without making any allowance for        
contraction or  expansion2 but if a     
mixture of either muriatic acid1 or     
sulphureous  acid gas1 with nitrous     
oxide1 is experimented upon2 in the     
absorption  of the acid by alkalies1 the
 apparent volume of gas condensed will  
be  less than the real one1 by a        
quantity equal to the sum of expansion  
from combination4 ,consequently a       
correction must be made on account of   
this circumstance4    ,though alcohol1  
ether1 essential oils1 and the fluid    
inflammable  bodies in general1 dissolve
 nitrous oxide with much greater        
rapidity  than water1 yet as we are not 
perfectly acquainted with their action  
on  unabsorbable gases1 it is better to 
employ water for separating nitrous     
oxide from these substances2            
particularly as that fluid is more or   
less  combined with all gases1 and as we
 are acquainted with the extent of  its 
action upon them4    ,by pursuing the   

subject of the solution of essential    
oils in gases1  we may probably discover
 a mode of obtaining them in a state of 
absolute dryness4 ,for if other gases as
 well as nitrous oxide1 have a  stronger
 affinity for oils than for water1 water
 most probably will  be precipitated    
from them during their solution of oils2
 and after  their saturation with oil1  
it is likely that they are capable of   
being  deprived of that substance by    
ammoniac4      ,,vi4 ,action of ariform 
,nitrous ,oxide in the ,alkalies4       
,history of the  discovery of the       
combinations of ,nitrous ,oxide with the
 ,alkalies4    a4 ,when nitrous oxide in
 a free state is exposed to the solid   
caustic  alkalies and alkaline earths1  
at common temperatures1 it is neither   
absorbed nor acted upon2 when it is     
placed in contact with solutions  of    
them in water1 a small quantity is      
dissolved2 but this combination  appears
 to depend on the water of the solution1
 for the gas can be  expelled unaltered1

 at the temperature of ebullition4    b4
 ,caustic potash was exposed to nitrous 
oxide for #ac hours3 the  diminution was
 not to one fiftieth1 and this slight   
condensation most  probably depended    
upon its combination with the water of  
the gas4    ,concentrated solution of   
potash absorbed a fourth of its bulk of 
nitrous oxide4 ,when the impregnated    
solution was heated1 globules of  gas   
were given out from it rapidly2 but the 
quantity collected was too  small to    
examine4    ,soda1 whether solid or in  
solution1 exhibited exactly the same    
phnomena with nitrous oxide4 ,the       
solution of soda absorbed near a        
quarter of its bulk of gas4    c4 #aa   
measures of ammoniacal gas were mingled 
with #h measures of  nitrous oxide over 
dry mercury1 both of the gases being    
saturated with  water4 ,no change of    
appearance was produced by the mixture1 
and they  filled1 after two minutes1 a  
space equal to #ai4 ,on the introduction
  of a little water1 the ammoniac was   

absorbed1 and the nitrous oxide         
remained unaltered1 for it was dissolved
 by water as rapidly as if it  had never
 been mingled with ammoniac4#aee    #aee
 ,the ,dutch chemists have asserted1    
that mixture with ammoniac  prevents the
 absorption of nitrous oxide by water1  
either wholly or  partially4 ,journal de
 ,physique1 t4 xliii4 part ii4 pag4     
#cbg4 ,it is  difficult to account for  
their mistake4    #g measures of nitrous
 oxide1 exposed to #f measures of       
solution of  ammoniac in water1 was in  
an hour diminished to #d nearly4 ,when  
the  solution was heated over mercury1  
permanent gas was produced1 which  was  
unabsorbable by a minute quantity of    
water1 and soluble in a large  quantity2
 consequently it was nitrous oxide4     
d4 ,nitrous oxide was exposed to dry    
caustic strontian2 it underwent a       
diminution of nearly one fortieth1 which
 most likely was owing to the           
combination of the strontian with its   
water4    #aa measures of nitrous oxide 

were agitated in contact with #h of     
strontian lime water3 nearly #d measures
 were absorbed4 ,the impregnated        
solution exposed to heat1 rapidly gave  
out its gas2 #c measures were  soon     
collected1 which mingled with a small   
quantity of hydrogene1 and  inflamed by 
the taper1 gave a smart detonation4     
e4 ,nitrous oxide exposed to lime and   
argil1 both wet and dry1 was not  in the
 slightest degree acted upon4    ,from  
these experiments it is evident that    
nitrous oxide in the ariform  state     
cannot be combined either with the      
alkalies1 or the alkaline  earths4 ,that
 a combination may be effected between  
nitrous oxide and  these substances1 it 
must be presented to them1 in the       
nascent state4    ,the salts composed of
 the alkalies and nitrous oxide1 are not
  analogous to any other compound       
substances1 being possessed of very     
singular properties4 ,before these      
properties are detailed1 it may not  be 
amiss to give an account of the         

accidental way in which ,i discovered   
the mode of combination4    ,in         
,december1 #agii1 designing to make a   
very delicate experiment1 with  a view  
to ascertain if any water was decomposed
 during the conversion  of nitrous gas  
into nitrous oxide1 by sulphite of      
potash1 ,i exposed  #bjj grains of      
crystalised sulphite of potash1         
containing great  superabundance of     
alkali1 to #ad cubic inches of nitrous  
gas1 containing  one eighteenth         
nitrogene4 ,the alkali was employed to  
preserve any  ammoniac that might be    
formed1 in the free state1 as it would  
otherwise  combine with sulphureous     
acid4#aef    #aef ,sulphureous acid     
saturates more potash than sulphuric    
acid1 so  that most probably during the 
conversion of sulphite of potash into   
sulphate1 portions of sulphureous acid  
are disengaged4    ,the volume of gas   
diminished with great rapidity2 in two  
hours and  ten minutes it was reduced to
 #f_/1 which ,i considered as the limit 

of diminution4 ,accidentally1 however1  
suffering it to remain for three  hours 
longer1 ,i was much surprised by finding
 that not quite #b cubic  inches        
remained1 which consisted of nitrous    
oxide1 mingled with the  nitrogene that 
existed before the experiment4    ,in   
accounting theoretically for this       
phnomenon1 different suppositions       
necessarily presented themselves4       
#ast1 ,it was possible1 that though     
sulphite of potash1 and potash1         
separately possessed no action on free  
nitrous oxide1 yet in  combination they 
might exert such affinities upon it as  
either to  absorb it1 or make it enter  
into new combinations4    #b;dly4 ,it   
was more probable that the caustic      
potash1 though incapable  of condensing 
ariform nitrous oxide1 was yet possessed
 of a strong  affinity for it when in   
the nascent state1 and that the nitrous 
oxide  condensed in the experiment had  
been combined in this state with the    
free alkali4    ,to ascertain if the    

compound of potash and sulphite of      
potash with  sulphate1 was capable of   
acting upon nitrous oxide1 ,i suffered a
  quantity of this substance to remain  
in contact with the gas for near a  day3
 no change whatever took place4    ,to  
determine whether the diminution of     
nitrous oxide depended upon its         
absorption in the nascent state1 by the 
peculiar compound of potash and         
sulphite of potash1 or if it was simply 
owing to the alkali4    ,i mingled a    
solution of sulphite of potash with     
caustic soda2 the  salt1 after being    
evaporated at a low temperature1 was    
exposed to  nitrous gas4 ,the nitrous   
oxide formed was absorbed1 but in rather
 less  quantities than when alkaline    
sulphite of potash was employed4        
,hence it was evident that the alkali   
was the agent that had condensed  the   
nitrous oxide in those experiments1 for 
soda is incapable of  combining either  
with sulphate1 or sulphite of potash4   
,to ascertain whether any change in the 

constitution of the nitrous  oxide had  
been produced by the condensation1 ,i   
introduced a small  quantity of sulphite
 of potash1 with excess of alkali1 that 
had  absorbed nitrous oxide1 into a long
 and thin cylindrical tube filled  with 
mercury2 and inclining it at an angle of
 #ce with the plane of the  mercury1    
applied the heat of a spirit lamp to    
that part of the tube  containing the   
salts2 when the glass became very hot1  
gas was given out  with rapidity2 in    
less than a minute the tube was full4   
,this gas was  transfered into another  
tube1 and examined2 it proved to be     
nitrous  oxide in its highest state of  
purity2#aeg for a portion of it absorbed
  by common water1 left no more than a  
residuum of _/1 and sulphur  burnt in it
 with a vivid rose-colored flame4       
#aeg ,hence we learn that sulphite of   
potash1 when strongly heated1  does not 
decompose nitrous oxide1 even in the    
nascent state4    ,being now satisfied  
that the alkalies were capable of       

combining with  nitrous oxide2 to       
investigate with precision the nature of
 these new  compounds1 ,i proceeded in  
the following manner4      ,,vii4       
,combination of ,nitrous ,oxide with    
,potash4    a4 ,into a solution of      
sulphite of potash1 which had been made 
by  passing sulphureous acid gas from a 
mercurial airholder into caustic  potash
 dissolved in water1 ,i introduced #ag  
grains of dry potash4 ,the  whole       
evaporated at a low temperature1 gave   
#adc grains of salt4 ,this  salt was not
 wholly composed of sulphite of potash  
and potash2 it  contained as well1 a    
minute quantity of carbonate1 and       
sulphate of  potash1 formed during the  
evaporation4#aeh    #aeh ,see the       
excellent memoir of ,fourcroy and       
,vauquelin on the  sulphureous acid1 and
 its combinations4 ,annales de ,chimie1 
ii1 #ed4 ,or  ,nicholson's ,phil4       
,journal1 vol4 i1 pag4 #cac4    #abj    
grains of it finely pulverised1 and     
retaining the water of  crystalisation1 

were exposed to #ae cubic inches of     
nitrous gas1 over  mercury4 ,the nitrous
 gas diminished with great rapidity1 and
 in three  hours a cubic inch and nine  
tenths only remained1 which consisted of
  nearly one third nitrous oxide1 and   
two thirds nitrogene that had           
pre-existed in the nitrous gas4 ,the    
increase of weight of the salt  could   
not be determined1 as some of it was    
lost by adhering to the  vessel in which
 the combination was effected1 and to   
the mercury4 ,it  presented no distinct 
series of crystalisations1 even when    
examined  by the magnifier2 rendered    
green vegetable blues1 and its taste was
  very different from that of the       
remaining quantity of salt that had     
been exposed to the atmosphere4 ,a      
portion of it strongly heated over      
mercury1 gave out gas with great        
rapidity1 which had all the properties  
of the purest nitrous oxide4    ,when   
water was poured upon some of it1 no gas
 was given out1 and the  whole was      

equably and gradually dissolved4        
,alcohol1 as well as ether1  appeared   
incapable of dissolving any part of it4 
,when muriatic acid was introduced into 
it1 confined by mercury1 a rapid        
effervescence took place4 ,part of the  
gas disengaged was sulphureous  acid1   
and carbonic acid2 the remainder was    
nitrous oxide4    b4 ,i made a number of
 experiments upon salts procured in the 
manner  ,i have just described1 with a  
view to obtain the compound of nitrous  
oxide and potash1 free from admixture of
 other salts4    ,when the mixed salt   
was boiled in alcohol or ether1 no part 
of it  appeared to be dissolved4        
,finding that little or no gas was given
 out  during the ebullition of          
concentrated solutions of the mixed     
salts1  ,i attempted to separate the    
sulphate1 sulphite1 and carbonate of    
potash1 from the combination of nitrous 
oxide and potash1 by successive         
evaporations and crystalisations4 ,but  
though in this way it was nearly  freed 

from sulphate of potash1 yet the extreme
 and nearly equal  solubility of the    
other salts1 prevented me from          
completely separating  them from each   
other4    ,by exposing1 however1 very   
finely pulverised sulphite of potash1   
mingled with alkali1 for a great length 
of time to nitrous gas1 it was  almost  
wholly converted into sulphate2 and     
after the separation of  this solution1 
evaporation1 and crystalisation1 at a   
low temperature1  ,i obtained the new   
combination1 mingled with very little   
carbonate of  potash1 and still less of 
sulphite4    ,the minute quantity of    
sulphite chiefly appeared in very small 
crystals2 distinct from the mass of     
salt1 which possessed no regular        
crystalisation1 and was almost wholly   
composed of the new compound1  intimated
 mingled with a little carbonate4 ,the  
new compound1 as nearly  as ,i could    
estimate from the quantity of nitrous   
oxide absorbed1  consisted of about #c  
alkali1 to #a of nitrous oxide1 by      

weight4    ,it exhibited the following  
properties3    #a4 ,its taste was       
caustic1 and possessed of a pungency    
different from  either potash or        
carbonate of potash4    #b4 ,it rendered
 vegetable blues green1 which might     
possibly depend upon  the carbonate of  
potash mixed with it4    #c4 ,pulverised
 charcoal mingled with a few grains of  
it1 and inflamed1  burnt with flight    
scintillations4 ,projected into zinc in 
a state of  fusion1 a slight            
inflammation was produced4    #d4 ,when 
either sulphuric1 muriatic1 or nitric   
acid was introduced to  it under        
mercury1 it gave out nitrous oxide1     
mingled with a little  carbonic acid4   
#e4 ,thrown into a solution of          
sulphurated hydrogene1 gas was          
disengaged  from it1 but in quantities  
too minute to be examined4    #f4 ,when 
carbonic acid was thrown into a solution
 of it in water1 gas  was disengaged2 on
 examination it proved to be nitrous    
oxide4    #g4 ,a concentrated solution  

of it kept in ebullition in a cylinder1 
confined by mercury1 gave out a few     
globules of gas1 which were too  minute 
to be examined1 and probably consisted  
of common air previously  contained in  
the water4    c4 ,in the experiments    
made to ascertain these properties all  
the salt  was expended1 otherwise ,i    
should have endeavoured to ascertain    
what  quantity of gas would have been   
liberated by heat from a given weight2  
and likewise what would have been the   
effects of admixture of it with  oil4   
,when some of the mixed salt was mingled
 with oil of turpentine1  part of it was
 dissolved1 and the fluid became white2 
but no gas was  given out4 ,on this     
coarse experiment1 however1 ,i cannot   
place much  dependance4 ,if the         
combination of nitrous oxide and potash 
is capable  of combining with oil       
without decomposition1 barytes and      
strontian#aei  will probably separate   
the oil from it1 and thus it may        
possibly be  obtained in a state of     

purity4    #aei ,unless the sum of      
affinity of the potash1 oil1 nitrous    
oxide1 and  earths1 should be inch as to
 enable the nitrous oxide to combine    
with  the earth1 whilst the oil and     
alkali remained in combination1  c4     
,in a rough experiment made on the      
conversion of nitrous gas into  nitrous 
oxide1 by concentrated solution of      
sulphite of potash with  excess of      
alkali1 very little of the nitrous oxide
 was absorbed4 ,hence  it is probable   
that water lessens the affinity of      
potash for nascent  nitrous oxide4      
,,viii4 ,combination of ,nitrous ,oxide 
with ,soda4    ,the union of nitrous    
oxide with soda is effected in the same 
manner  as with potash4 ,the alkali1    
mingled by solution and evaporation1    
with  either sulphite of soda1 or of    
potash1 is exposed to nitrous gas2 the  
nitrous oxide is condensed by it at the 
moment of generation1 and the           
combination effected4    ,as far as ,i  
have been able to observe1 nitrous oxide

 is not absorbed to  so great an extent 
by soda1 as potash4    ,i have not yet  
been able to obtain the combination of  
nitrous  oxide with soda in its pure    
state4 ,to the attainment of this end1  
difficulties identical with those       
noticed in the last section present     
themselves4 ,it is extremely difficult  
to procure the soda perfectly  free from
 carbonic acid1 and though by using     
sulphite of potash the  sulphate formed 
is easily separated1 yet still          
evaporation and  crystalisation will not
 disengage the sulphite and carbonate   
from the  new compound4    ,the compound
 of soda and nitrous oxide1 mingled with
 a little sulphite  and carbonate of    
soda1 was rapidly soluble1 both in warm 
and cold  water1 without effervescence4 
,its solution1 heated to ebullition1    
gave  out no gas4 ,the taste of the     
solid salt was caustic1 and more acrid  
than that of the mixture of carbonate   
and sulphite of soda4 ,when cast  upon  
zinc in fusion1 it burnt with a white   

flame4 ,when heated to #djj  or #ejj1 it
 gave out nitrous oxide with rapidity4  
,nitrous oxide was  expelled from it by 
the sulphuric1 muriatic1 and carbonic   
acids1 ,i  believe1 by sulphurated      
hydrogene4#afj    #afj ,for when a      
little of the mixed salt was introduced 
into a  solution of sulphurated         
hydrogene1 globules of gas were given   
out  during the solution4      ,,ix4    
,combination of ,nitrous ,oxide with    
,ammoniac4    ,i attempted to effect    
this combination by converting nitrous  
gas into  nitrous oxide1 by sulphite of 
ammoniac1 wetted with strong solution of
  caustic ammoniac2 but without success2
 for the whole of the nitrous  oxide    
produced remained in a free state4      
,when ,i exposed sulphite of potash1    
mingled by solution and evaporation     
with highly alkaline carbonate of       
ammoniac1#afa to nitrous gas1 the       
diminution was nearly one fourth more   
than if pure sulphite of potash  had    
been employed4 ,hence it appears most   

likely that ammoniac is  capable of     
combination with nitrous oxide in the   
nascent state4    #afa ,carbonate of    
ammoniac formed at a high temperature1  
containing  near #fj per cent alkali1   
and capable of combining with small     
quantities  of acids without giving out 
its carbonic acid4 ,of this salt a      
particular account will be given in the 
experiments on the ammoniacal  salts1   
which ,i have often mentioned in the    
course of this work4    ,in the         
experiments on the conversion of nitrous
 gas into nitrous oxide1  by nascent    
hydrogene1 and by sulphurated hydrogene1
 ,res4 ,i4 ,divis4  ,v4 probably the    
water formed at the same time with the  
ammoniac  and nitrous oxide1 prevented  
them from entering into combination2    
possibly the peculiar compound was      
formed1 but in quantities so  minute as 
not to be distinguished from simple     
ammoniac2#afb for even  the existence of
 ammoniac in these processes1 is but    
barely perceptible4    ,if it should be 

proved by future experiments1 that in   
the decomposition  of nitrous gas by    
nascent hydrogene1 a peculiar compound  
of nitrous  oxide1 water and ammoniac1  
is formed1 it will afford proofs in     
favor of  the doctrine of predisposing  
affinity2#afc for then this             
decomposition  might be supposed to     
depend upon the disposition of oxygene1 
hydrogene  and nitrogene to assume the  
states of combination in which they     
might  form a triple compound1 of water1
 nitrous oxide1 and ammoniac4    #afb   
,it may not be amiss to mention some    
appearances taking place in  the        
decomposition of nitrous gas by         
sulphurated hydrogene1 though it  is    
useless to theorise concerning them4    
,the sulphur deposited is at  first     
yellow2 as the process proceeds1 it     
becomes white1 and in some  instances ,i
 have suspected a diminution of it4     
#afc ,predisposing affinity1 the        
existence of which at first             
consideration it is difficult to admit1 

may be easily accounted for  by         
supposing the attractions of the simple 
principles of compound  substances4 ,and
 this doctrine will apply in all        
instances where the  constitution of    
bodies is known4 ,predisposing affinity 
ought not to be  considered as the      
affinity of non-existing bodies for each
 other2 but  as the mutual affinity of  
their simple principles1 disposing them 
to  assume new arrangements4    ,nitrous
 oxide might probably be made to combine
 with ammoniac by  exposing a mixture of
 nitrous gas and ariform ammoniac1 to   
the  sulphites4    ,it is probable that 
nitrous oxide may be combined with      
ammoniac1  by means of double affinity4 
,perhaps sulphate of ammoniac and the   
combination of potash with nitrous oxide
 mingled together in solution1  would be
 converted into sulphate of potash and  
the compound of nitrous  oxide1 and     
ammoniac4      ,x4 ,probability of      
forming ,compounds of ,nitrous ,oxide   
and the ,alkaline  ,earths4    ,i       

attempted to combine nitrous oxide with 
lime and strontian1 by  exposing        
sulphites of lime and strontian with    
excess of earth1 to  nitrous gas2 but   
this process did not succeed3 the       
diminution took  place so slowly as to  
destroy all hopes of gaining any results
 in  a definite time4 ,sulphite of      
potash is decomposable by barytes1      
strontian1 and lime2#afd consequently it
 was impossible to employ this          
substance to effect the combination4    
,as the dry sulphures1 when well made1  
convert nitrous gas into nitrous  oxide1
 it is probable that the union of the   
earths with nascent nitrous  oxide may  
be effected by exposing nitrous gas to  
their sulphures1  containing an excess  
of earth4    #afd ,see the above        
mentioned elaborate memoir of ,fourcroy 
and  ,vauquelin4    ,perhaps the        
combination of nitrous oxide with       
strontian may be effected  by           
introducing the combination of potash   
and nitrous oxide into  strontian lime  

water4    ,it is probable that nitrous  
oxide may be combined with clay and     
magnesia1 by exposing these bodies1     
mingled with sulphite of potash or      
soda1 to nitrous gas4      ,,xi4        
,additional ,observations on the        
combinations of ,nitrous ,oxide with    
the ,alkalies4    ,a desire to complete 
physiological investigations relating to
 nitrous  oxide1 has hitherto prevented 
me from pursuing to a greater extent1   
the  experiments on the combination of  
this substance with the alkalies1 c4    
,as soon as an opportunity occurs1 ,i   
purpose to resume the subject4    ,the  
observations detailed in the foregoing  
sections are sufficient to  show that   
nitrous oxide is capable of entering    
into intimate union  with the fixed     
alkalies3 and as the compounds formed by
 this union  are insoluble in alcohol1  
decomposable by the acids1 and heat1 and
  possessed of peculiar properties1 they
 ought to be considered as a new  class 
of saline substances4    ,if it is      

thought proper1 on a farther            
investigation of their  properties1 to  
signify them by specific names1 they    
may1 according to  the usually adopted  
fashion of nomenclature1 be called      
nitroxis3  thus the nitroxi of potash   
would signify the salt formed by the    
combination of nitrous oxide with       
potash4    ,future experiments must     
determine the different affinities of   
nitrous  oxide for the alkalies1 and    
alkaline earths4    ,with regard to the 
uses of these new compounds it is       
difficult to  form a guess4 ,when they  
are obtained pure1 and fully saturated  
with  nitrous oxide1 on account of the  
low temperature at which their gas is   
liberated1 they will probably constitute
 detonating compounds4 ,from  their     
facility of decomposition by the weaker 
acids1 they may possibly  be used       
medicinally1 if ever the evolution of   
nitrous oxide in the  stomach should be 
found beneficial in diseases4           
,,xii4 ,the properties of ,nitrous      

,oxide resemble those of ,acids4    ,if 
we were inclined to generalise1 and to  
place nitrous oxide among  a known class
 of bodies1 its properties would        
certainly induce us  to consider it as  
more analogous to the acids than to any 
other  substances2 for it is capable of 
uniting with water and the alkalies1    
and is insoluble in most of the acids4  
,it differs1 however1 from the  stronger
 acids1 in not possessing the sour      
taste1#afe and the power  of reddening  
vegetable blues3 and from both the      
stronger and weaker  acids1 in not being
 combinable when in a perfectly free    
state1 at  common temperatures1 with the
 alkalies4 ,if it should be proved by   
future experiments1 that condensation by
 cold gave it the capability of         
immediately forming neutro-saline       
compounds with the alkalies2 it ought   
to be considered as the weakest of the  
acids4 ,till those experiments  are     
made1 its extraordinary chemical and    
physiological properties are  sufficient

 to induce us to consider it as a body  
sui generis4    #afe ,the different     
persons who have respired nitrous oxide 
have1 as  will be seen hereafter1 given 
different accounts of the taste2 the    
greater number have called it sweet1    
some metallic4 ,one of my friends1  in a
 letter to me dated ,nov4 #ac1 #agii1   
containing a detail of some  experiments
 made on the respiration of nitrous     
oxide1 at ,birmingham1  denotes the     
taste of it by the term 8sweetish       
faintly acidulous40 ,to  me the taste   
both of the gas and of its solution in  
water1 has always  appeared faintly     
sweetish4    ,it is a singular fact that
 nitrous gas1 which contains in its     
composition a quantity of oxygene so    
much greater than nitrous oxide1  should
 nevertheless possess no acid           
properties4 ,it is uncombinable with    
alkalies1 very little soluble in water1 
and absorbable by the acids4            
,,division ,,ii4        ,on the         
,,decomposition of ,,nitrous ,,oxide by 

,,combustible         ,,bodies4 ,its    
,,analysis4 ,,observations on the       
different         combinations of       
,,oxygene and ,,nitrogene4      ,i4     
,preliminaries4    ,from the phnomena   
mentioned in ,res4 ,i4 ,divis4          
,,iii4#aff it appears  that the         
combustible bodies burn in nitrous oxide
 at certain  temperatures4 ,the         
experiments in this ,division were      
instituted for the  purpose of          
investigating the precise nature of     
these combustions1 with  a view of      
ascertaining exactly the composition of 
nitrous oxide4    #aff ,section #b4     
,it will be seen hereafter that very    
high temperatures are required for  the 
decomposition of nitrous oxide1 by most 
of the combustible bodies1  and that in 
this process heat and light are produced
 to a very great  extent4 ,these agents 
alone are possessed of a considerable   
power of  action on nitrous oxide2 of   
which it is necessary to give an        
account1  that we may be able to        

understand the phnomena in the following
  sections4      ,,ii4 ,conversion of   
,nitrous ,oxide into ,nitrous ,acid1 and
 a ,gas analogous  to ,atmospheric ,air1
 by ,ignition4    a4 ,dr4 ,priestley    
asserts1 that nitrous oxide exposed for 
a certain  time to the action of the    
electric spark1 is rendered immiscible  
with  water1 and capable of diminution  
with nitrous gas1 without suffering  any
 alteration of volume2 and likewise that
 the same changes are  effected in it by
 exposure to ignited incombustible      
bodies4#afg    #afg ,vol4 ii4 pag4 #ia4 
,the ,dutch chemists state1 that the    
electric spark passed through  nitrous  
oxide1 occasions a small diminution of  
its volume1 and that the  gas remaining 
is analogous to common air4#afh ,they   
conclude that this  change depends on   
the separation of its constituent parts1
 oxygene and  nitrogene1 from each      
other4    #afh ,journal de ,physique1   
tom4 xliii1 part ii4 pag4 #ccj4 ,they   
effected  the same change by passing it 

through a heated tube4 ,dr4 ,priestley  
had  published an account of similar    
experiments more than two years before4 
,none of these chemists have suspected  
the production of nitrous acid in  this 
process4    b4 ,nitrous oxide undergoes 
no change whatever from the simple      
action  of light4 ,i exposed some of it1
 confined by mercury1 for many days to  
this agent1 often passing through it    
concentrated rays by means of a  small  
lens4 ,when examined it appeared1 as    
well as ,i could estimate1 of  the same 
degree of purity as at the beginning of 
the experiment4    c4 ,a temperature    
below that of ignition effects no       
alteration in the  constitution of      
nitrous oxide4 ,i passed nitrous oxide  
from a retort  containing decomposing   
nitrate of ammoniac1 through a green    
glass  tube1 strongly heated in an      
air-furnace1 but not suffered to undergo
  ignition4 ,the gas1 received in a     
water apparatus exhibited the same      
properties as the purest nitrous oxide2 

some of it absorbed by water1  left a   
residuum of not quite one thirteenth4   
d4 ,the action of the electric spark for
 a long while continued1  converts      
nitrous oxide into a gas analogous to   
atmospheric air1 and  nitrous acid4     
,i passed about #aej strong shocks from 
a small ,leyden phial1 through #g  ten  
grain measures of pure nitrous oxide4   
,after this it filled a space  rather   
less than six measures3 the mercury was 
rendered white on the  top1 as if it had
 been acted on by nitric acid4 ,six     
measures of nitrous  gas mingled with   
the residual gas of the experiment1 over
 mercury  covered by a little water1    
gave red fumes1 and rapid diminution4   
,in  five minutes the volume of the     
gases nearly equalled ten4 ,thermometer 
in this experiment was #eh4    ,electric
 sparks were passed for an hour and half
 through #g ten grain  measures of      
nitrous oxide over mercury covered with 
a little red  cabbage juice1 previously 
saturated with nitrous oxide1 and       

rendered  green by an alkali4 ,after the
 process the gas filled a space equal   
to rather more than six measures and    
half1 and the juice was become  of a    
pale red4 ,the gas was introduced into a
 small tube filled with  pure water1 and
 agitated2 no absorption was            
perceptible3 #g measures  of nitrous gas
 added to it gave red fumes1 and after  
six minutes a  diminution to #i nearly4 
#f measures of common air from the      
garden1  with #g of nitrous gas1 gave   
exactly #i4    ,in this experiment it   
was evident that nitrous oxide was      
converted into  a gas analogous to      
atmospheric air1 at the same time that  
an acid was  formed4 ,there could be    
little doubt but that this was the      
nitrous acid4  ,to ascertain it1        
however1 with greater certainty1 the    
electric spark  was passed through #f   
measures of nitrous oxide1 over a little
 solution  of green sulphate of iron1   
confined by mercury4 ,as the process    
went on1  the color of the solution     

became rather darker4 ,when the         
diminution  was complete1 a little      
prussiate of iron was added to the      
solution4 ,a  precipitate of pale blue  
prussiate of potash was produced4    c4 
,nitrous oxide was passed from          
decomposing nitrate of ammoniac1        
through a porcelain tube well glazed    
inside and outside1 strongly  ignited in
 an air-furnace1 and communicating with 
the water apparatus4  ,the gas collected
 was rendered opaque by dense red vapor4
 ,it appeared  wholly unabsorbable by   
water4 ,after the precipitation of its  
vapor1 a  candle burnt in it with nearly
 the same brilliancy as in atmospheric  
air4 #bj measures of it that had been   
agitated in water immediately  after its
 production1 mingled with #dj measures  
of nitrous gas1  diminished to about    
#dg4e2 whereas #bj measures that had    
remained  unagitated for some time after
 their generation1 introduced to the    
same  quantity of nitrous gas1 gave     
nearly #di4 #bj measures of atmospheric 

air1 with #dj of the same nitrous gas1  
were condensed to #df4    ,the water    
with which the gas had been in contact1 
was strongly acid4 ,a  little of it     
poured into a solution of green sulphate
 of iron1 and then  mingled with        
prussian alkali1 produced a green       
precipitate4 ,hence the  acid it        
contained was evidently nitrous4        
,that no source of error could have     
existed in this experiment from  fissure
 in the tube1 ,i proved1 by sending     
water through it whilst  ignited1 after 
the process1 from the same retort in    
which the nitrate  of ammoniac had been 
decomposed2 a few globules of air only  
were  produced1 not equal to one tenth  
of the volume of the water boiled1 and  
which were doubtless previously         
contained in it4    ,i have repeated    
this experiment two or three times1 with
 similar  results2 whenever the air was 
agitated in water immediately after its 
production1 it gave almost the same     
diminution with nitrous gas as  common  

air2 when1 on the contrary1 it has been 
suffered to remain for  some time in    
contact with the phlogisticated nitrous 
acid suspended  in it1 the condensation 
has been less with nitrous gas by five  
or  six hundred parts4 ,hence ,i am     
inclined to believe1 that if it were    
possible to condense all the nitrous    
acid formed1 immediately after  its     
generation1 so as to prevent it from    
absorbing oxygene from the  permanent   
gas1 this gas would be found identical  
with the air of the  atmosphere4    ,the
 changes effected by fire on nitrous    
oxide are not analogous to  those       
produced by it in other bodies2 for the 
power of this agent  seems generally    
uniform1 either in wholly separating the
 constituent  principles of bodies from 
each other1 or in making them enter into
 more  intimate union4#afi    #afi ,on  
the one hand1 it decomposes ammoniac    
into hydrogene and  nitrogene1 whilst on
 the other1 it converts free oxygene and
 nitrogene  into nitrous acid4 ,it      

likewise converts nitrous gas into      
nitrous acid  and nitrogene4 ,till we   
are more accurately acquainted with the 
nature  of heat1 light1 and electricity1
 we shall probably be unable to explain 
these phnomena4    ,it is a singular    
phnomenon1 that whilst it condenses one 
part of the  oxygene and nitrogene of   
nitrous oxide1 in the form of nitrous   
acid2  it should cause the remainder to 
expand1 in the state of atmospheric     
air4 ,does not this fact afford an      
inference in favor of the chemical      
composition of atmospheric air8         
,,iii4 ,decomposition of ,nitrous ,oxide
 by ,hydrogene1 at the temperature  of  
,ignition4    ,in the following         
experiments on the decomposition of     
nitrous oxide  by hydrogene1 the gases  
were carefully generated in the         
mercurial  apparatus1 and their purity  
ascertained by the tests mentioned in   
,research ,i4 ,they were measured in    
small tubes graduated to grains1 and    
then transferred into the detonating    

tube1 which was eight tenths of an  inch
 in diameter1 and graduated to ten grain
 measures4    ,the space occupied by the
 gases being noted after the            
inflammation by  the electric shock1    
green muriate of iron1 and prussiate of 
potash1  were successively introduced1  
to ascertain if any nitrous acid had    
been formed4 ,the absorption1 if any    
took place1 was marked1 and the  gases  
transferred into a narrow grain measure 
tube1 and their bulk and  composition   
accurately ascertained4    b4 ,the      
hydrogene employed was procured from    
water by means of zinc  and sulphuric   
acid4 #ej grain measures of it fired by 
the electric  spark1 with #cj grain     
measures of oxygene containing one      
eleventh  nitrogene1 gave a residuum of 
about #d4 ,nitrous gas mingled with     
those  #d1 indicated the presence of    
rather less than #a of unconsumed       
oxygene4  ,in another experiment #bc of 
it1 with #bj of the same oxygene left   
rather  more than #f residuum4    ,the  

nitrous oxide was apparently pure1 for  
it left a remainder of about  1#je only1
 when absorbed by common water4    c4   
#cj of hydrogene were fired with #dj of 
nitrous oxide2 the  concussion was very 
great1 and the light given out bright   
red2 no  perceptible quantity of nitrous
 acid was formed2 the residual gas      
filled a space equal to #eb4 ,no part of
 it was absorbable by water1 it  gave no
 diminution with nitrous gas1 when it   
was mingled with a little  oxygene1 and 
again acted on by the electric spark1 an
 inflammation and  slight diminution was
 produced4    d4 #cc of hydrogene were  
fired with #ce of nitrous oxide3 nitrous
 acid  was produced in very minute      
quantity2 the gas that remained was not 
absorbable by water1 and filled a space 
equal to #cg grains4 ,nitrous gas       
mingled with these1 underwent a very    
slight diminution4    e4 #df hydrogene  
were fired with #df nitrous oxide4 ,the 
quantity of  nitrous acid formed was    
just sufficient to tinge the white      

prussiate  of potash4 ,the gases filled 
a space equal to #di1 gave no           
perceptible  diminution with nitrous    
gas1 and did not inflame with oxygene4  
f4 #dj hydrogene were fired with #ci    
nitrous oxide2 no perceptible  quantity 
of nitrous acid was formed4 ,the        
residual gas filled a space  equal to   
#da2 was unabsorbable by water1         
underwent no diminution when  mingled   
with nitrous gas2 or when acted on by   
the electric spark in  contact with     
oxygene4    g4 #bj hydrogene were fired 
with #fd nitrous oxide2 after detonation
  the expansion of the gases was greater
 in this experiment than any of  the    
preceding ones2 dense white fumes were  
observed in the cylinder1  and a slow   
contraction of volume took place4 ,after
 a little green  muriate of iron had    
been admitted1 the gases filled a space 
equal  to #gc3 prussiate of potash      
mingled with the muriate1 gave a deeper 
blue than in any of the preceding       
experiments4 ,the residual gas was      

unabsorbable by water3 #fe of it1       
mingled with #fe of nitrous gas1        
diminished to #ic2 whilst #fe of common 
air1 with #fe of nitrous gas1 gave  #hd4
    h4 #h of hydrogene were fired with  
#ed of nitrous oxide2 the same  phnomena
 as were observed in the last experiment
 took place2 nitrous  acid was formed2  
after the absorption of which the       
residual gas filled  a space equal to   
#ee4 #ej of this1 with an equal quantity
 of nitrous gas1  diminished to #gf4 ,in
 these processes the temperatures were  
from #ef to  #fa4    ,these experiments 
are selected as the most accurate of    
nearly fifty1  made on the inflammation 
of different quantities of nitrous oxide
 and  hydrogene4    ,as ,mr4 ,keir found
 muriatic acid in the fluid1 produced by
 the  inflammation of oxygene and       
hydrogene in closed vessels1 in ,dr4    
,priestley's experiments1 ,i preserved  
the residual gas of about #c cubic      
inches of nitrous oxide1 that had been  
detonated at different times  with less 

than a cubic inch and half of hydrogene2
 but solution of  nitrate of silver was 
not clouded when agitated in this gas1  
nor when  introduced into the detonating
 tube in which the inflammation had been
  made4    ,from these experiments we   
learn that nitrous oxide is decomposable
 at  the heat of ignition1 by hydrogene1
 in a variety of proportions4    ,when  
the quantity of hydrogene very little   
exceeds that of the nitrous  oxide1 both
 of the gates disappear1 water is       
produced1 no nitrous acid  is formed1   
and the volume of nitrogene evolved is  
rather greater than  that of the nitrous
 oxide decomposed4    ,when the quantity
 of hydrogene is less than that of the  
nitrous oxide1  water1 nitrous acid1    
oxygene and nitrogene1 are generated in 
different  proportions2 one part of the 
nitrous oxide is most probably wholly   
decomposed by the hydrogene1 and the    
other part converted into nitrous  acid 
and atmospheric air1 in consequence of  
the ignition4    ,from experiments c1 d1

 and e1 the composition of nitrous oxide
  may be deduced4 ,in experiment d1 #ci 
of nitrous oxide were decomposed  by #dj
 of hydrogene1 and converted into #da of
 nitrogene4    ,now from b it appears   
that #dj of hydrogene require for their 
condensation about #bj4h of oxygene in  
volume2 so that founding the  estimation
 upon the quantity of hydrogene         
consumed1 #ajj parts of  nitrous oxide  
would consist nearly of #fc4a of        
nitrogene1 and #cf4i of  oxygene4 ,but  
#da of nitrogene weigh #ab4d1 ,res4 ,i4 
,div4 ,i4 ,consequently1  deducing the  
composition of nitrous oxide from the   
quantity of  nitrogene evolved1 #ajj    
parts of it would consist of #fc4e      
nitrogene1 and  #cf4e oxygene4    ,these
 estimations are very little different  
from those which may be  deduced from   
the other experiments1 and the          
coincidence is in favor of  their       
accuracy4    ,from the following        
experiment it appears that the          
temperature required  for the           

decomposition of nitrous oxide by       
hydrogene must be higher  than that     
which is necessary to produce the       
inflammation of hydrogene  with oxygene4
 ,i introduced into small tubes filled  
with equal parts of  nitrous oxide and  
hydrogene1 standing on a surface of     
mercury1 iron  wires ignited to         
different degrees1 from the dull red to 
the vivid  white heat4 ,the gases were  
always inflamed by the white and vivid  
red heats2 but never by the dull red    
heat1 though the last uniformly         
inflamed mixtures of oxygene and        
hydrogene1 and atmospheric air and      
hydrogene4    ,dr4 ,priestley#agj first 
detonated together nitrous oxide and    
hydrogene2 his experiment was repeated  
by the ,dutch chemists1 who found  that 
when a small quantity of hydrogene was  
employed1 the nitrous  oxide was        
partially converted into a gas analogous
 to common air4 ,their  estimation of   
its composition1 which is not far       
removed from the truth1  was founded on 

this phnomenon4#aga    #agj ,vol4 ii4   
pag4 #hc4    #aga ,journal de ,physique1
 tom4 xliii4 part #b1 pag4 #cca4 ,they  
supposed  it to consist of about #cg1e  
oxygene1 and #fb1e nitrogene4 ,the      
nearness  of this account to the truth  
is singular1 when we consider that they 
were neither acquainted with the        
specific gravity of nitrous oxide1 nor  
with the production of nitrous acid in  
this experiment4      ,,iv4             
,decomposition of ,nitrous ,oxide by    
,phosphorus4    a4 ,phosphorus          
introduced into pure nitrous oxide at   
common  temperatures1 is not at all     
luminous4 ,it is capable of being fused1
  and even sublimed in it1 without      
undergoing acidification1 and without   
effecting any alteration in its         
composition4    ,about #b grains of     
phosphorus were fused1 and gradually    
sublimed1 in #b  cubic inches of pure   
nitrous oxide1 over mercury1 by the heat
 of a  burning lens4 ,no alteration was 
produced in the volume of gas1 and a    

portion of it absorbed by water1 left a 
residuum of one twelfth only4           
,phosphorus was sublimed in pure nitrous
 oxide over mercury1 in a  dark room1 by
 an iron heated nearly to ignition2 but 
no luminous  appearance was perceptible1
 nor was any gas decomposed4    b4      
,phosphorus decomposes nitrous oxide at 
the temperature of  ignition1 with      
greater or less rapidity1 according to  
the degree of  heat4 ,we have already   
seen1 that when phosphorus in active    
inflammation  is introduced into nitrous
 oxide1 it burns with intensely vivid   
light4    ,phosphorus was sublimed by a 
heated wire in a jar filled with nitrous
  oxide1 standing over warm mercury4 ,in
 this state of sublimation an iron      
heated dull red was introduced to it by 
being rapidly passed through  the       
mercury2 a light blue flame surrounded  
the wire1 and disappeared as  soon as it
 ceased to be red4    ,to phosphorus    
sublimed as before1 in nitrous oxide1   
over warm mercury1  a thick wire ignited

 to whiteness was introduced2 a terrible
 detonation  took place1 and the jar was
 shattered in pieces4    ,by employing  
thick conical jars1#agb containing only 
a small quantity  of nitrous oxide1 ,i  
effected the detonation several times   
with safety2  but on account of the     
great expansion of the elastic products1
 the jar  was generally either raised   
from the mercury1 or portions of gas    
were  thrown out of it4 ,hence ,i was   
unable to ascertain the exact changes   
produced by this mode of decomposition4 
#agb ,experiments on the detonation of  
nitrous oxide with phosphorus  in this  
way require great attention4 ,the       
detonating jar should be very  conical2 
the nitrous oxide employed should never 
equal more than one  eighth of the      
capacity of the jar4 ,the wire for the  
inflammation must  be very thick1 and   
curved so as to be easily introduced    
into the jar4  ,when ignited1 it must be
 instantaneously passed through the     
heated  mercury into the jar4           

,perhaps the electric spark might be    
advantageously applied for  detonating  
phosphoric vapor with nitrous oxide4    
c4 ,as my first attempts to ascertain   
the constitution of nitrous  oxide were 
made on its decomposition by phosphorus1
 ,i employed many  different modes of   
partially igniting this substance in it 
over  mercury1 so as to produce a       
combustion without explosion4    ,the   
first method adopted was inflammation by
 means of oxygenated  muriate of potash4
 ,a small particle of oxygenated muriate
 of potash was  inserted into the       
phosphorus to be burnt4 ,on the         
application of a wire1  moderately hot1 
to the point of insertion1 the salt was 
decomposed by  the phosphorus1 and      
sufficient fire generated and partially 
applied  by the slight explosion1 to    
produce the combustion of the           
phosphorus1  without the previous       
sublimation of any part of it4    ,the  
second way employed was the ignition of 
a part of the phosphorus1  by means of  

the combustion of a small portion of    
tinder of cotton1#agc  or paper1 in     
contact with it1 by the burning glass4  
#agc ,it will be seen hereafter that    
these bodies are easily inflamed  in    
nitrous oxide4    ,the third1 and most  
successful mode1 was by introducing into
 the  graduated jar containing the      
nitrous oxide1 the phosphorus in a small
  tube containing oxygene1 so balanced  
as to swim on the surface of the        
mercury1 without communicating with the 
nitrous oxide4 ,the phosphorus  was     
fired in the oxygene with an ignited    
iron wire1 by which at the  moment of   
combustion1 the tube containing it was  
raised into the  nitrous oxide1 and thus
 the inflammation continued4    d4 ,in  
different experiments1 made with        
accuracy1 ,i found that the  whole of a 
quantity of nitrous oxide was never     
decomposable by ignited  phosphorus2 the
 combustion always stopped when the     
nitrous oxide  remaining was to the     
nitrogene evolved as about #a to #e2    

likewise that  the volume of nitrogene  
produced was rather less than that of   
the  nitrous oxide decomposed1 and that 
this deficiency arose from the          
formation of nitrous acid by the intense
 ignition produced during the  process4 
,of one experiment ,i shall give a      
detail4    ,temperature being #dh1 two  
cubic inches of pure nitrous oxide1     
which  had been generated over mercury1 
were introduced into a jar of the       
capacity of #i cubic inches1 graduated  
to1#a cubic inches1 and much  enlarged  
at the base4 ,a grain of phosphorus was 
inserted into a small  vessel about one 
third of an inch long1 and half an inch 
in diameter1  containing about #ae grain
 measures of very pure oxygene2 this    
vessel1  which swam on the surface of   
the mercury1 was carefully introduced   
into the jar containing the nitrous     
oxide4 ,the phosphorus was fired by     
means of a heated wire1 and before the  
oxygene was wholly consumed1 the  vessel
 containing it elevated into the nitrous

 oxide4 ,the combustion  was extremely  
vivid and rapid4 ,after the atmospheric 
temperature was  restored1 the gas was  
rendered opaque by dense white vapor4   
,when this  had been precipitated1 and  
the small vessel removed from the jar1  
the  gas filled a space nearly equal to 
#a4i cubic inches4 ,on introducing to   
it a little solution of green muriate of
 iron1 and prussiate of potash1  green  
prussiate of iron was produced3 hence1  
evidently1 nitrous acid  had been       
formed4    ,on the admission of pure    
water1 an absorption of rather more     
than1#c  took place4    ,the #af        
measures remaining underwent no         
perceptible diminution with  nitrous    
gas2 the taper plunged into them was    
instantly extinguished4    ,to ascertain
 if the phosphoric acid produced in the 
experiments made  under mercury did not 
in some measure prevent the             
decomposition of  the whole of the      
nitrous oxide by the phosphorus1 ,i     
introduced into a  mixture of #e        

nitrogene and #a nitrous oxide1 ignited 
phosphorus3 but it  was immediately     
extinguished4#agd    ,the ,dutch        
,chemists found that phosphorus might be
 fused in nitrous  oxide without being  
luminous4 ,they assert that phosphorus  
in a state of  inflammation1 introduced 
into this gas1 was immediately          
extinguished2  though when taken out    
into the atmosphere1 it again burnt of  
its own  accord4#age ,it is difficult to
 account for their mistake4    #agd     
,phosphorus burnt feebly with a white   
flame in a mixture of #d  nitrogene and 
#a nitrous oxide4    #age ,journal de   
,physique1 xliii4 #cbh4      ,v4        
,decomposition of ,nitrous ,oxide by    
,phosphorated ,hydrogene4    a4 ,it has 
been mentioned in ,res4 ,,ii4 ,div4 ,i4 
that phosphorated  hydrogene and nitrous
 oxide posses no action on each other1  
at  atmospheric temperatures4           
,phosphorated hydrogene mingled with    
nitrous oxide1 is capable of being      
inflamed by the electric spark1 or by   

ignition4    b4 ,e4 #a4 #aj grain       
measures of phosphorated hydrogene1     
carefully  produced by means of         
phosphorus and solution of caustic      
alkali1 were  mingled with #eb measures 
of nitrous oxide4 ,the electric spark   
passed  through them1 produced a vivid  
inflammation4 ,the elastic products were
  clouded with dense white vapor1 and   
after some minutes filled a space       
nearly equal to #fj4 ,on the            
introduction of water1 no absorption    
took  place4 ,when #dc of nitrous gas   
were admitted1 the whole diminished to  
#gj4    ,e4 #b4 #be of nitrous oxide    
were fired with #aj of phosphorated     
hydrogene1 by the electric spark4 ,after
 detonation#agf they filled  a space    
exactly equal to #be4 ,on the admission 
of solution of green  sulphate of iron1 
and prussiate of potash1 no blue or     
green precipitate  was produced4 ,on the
 introduction of water1 no diminution   
was  perceived4 #be of nitrous gas      
mingled with them1 gave exactly #ej4    

#agf ,in this experiment1 as in the     
last1 dense white vapor was  produced4  
,e4 #c4 #aj of nitrous oxide1 mingled   
with #bj of phosphorated hydrogene1     
could not be inflamed4    #be of nitrous
 oxide1 with #bj phosphorated hydrogene1
 inflamed4 ,the  gas after detonation1  
was rendered opaque by dense white      
vapor1 and  filled a space nearly equal 
to #de4 ,no absorption took place when  
water was introduced4 ,on admitting a   
little oxygene no white fumes1  or      
diminution1 was perceived4 ,the electric
 spark passed through the  mixture1     
produced an explosion1 with great       
diminution4    c4 ,from ,e4 #a it       
appears1 that when a small quantity of  
phosphorated hydrogene is inflamed with 
nitrous oxide1 both the  phosphorus and 
hydrogene are consumed2 whilst the      
superabundant  nitrous oxide1 is        
converted into nitrous acid and         
atmospheric air1  by the ignition2 or a 
certain quantity is partially decomposed
 into  atmospheric air by the           

combination of a portion of its oxygene 
with the  combustible gas4    ,from ,e4 
#b we learn1 that when the phosphorated 
hydrogene and nitrous  oxide are to each
 other as #be to #aj nearly1 they both  
disappear1 whilst  nitrogene is evolved1
 and water and phosphoric acid produced4
 ,reasoning  concerning the composition 
of nitrous oxide from this experiment1  
we should conclude that it was composed 
of about #ch oxygene1 and #fb           
nitrogene4    ,the result of ,e4 #c is  
interesting2 we are taught from it that 
the  affinity of phosphorus for the     
oxygene of nitrous oxide is stronger    
than that of hydrogene1 at the          
temperature of ignition2 so that when   
phosphorated hydrogene is mingled with a
 quantity of nitrous oxide1 not         
containing sufficient oxygene to burn   
both its constituent parts1 the         
phosphorus only is consumed1 whilst the 
hydrogene is liberated4    ,in repeating
 the experiments with phosphorated      
hydrogene that had  remained for some   

hours in the mercurial apparatus1 ,i did
 not gain  exactly the same results2 for
 a larger quantity of it was required to
  decompose the nitrous oxide1 than in  
the former experiments2 doubtless  from 
its having deposited a portion of its   
phosphorus4 ,they confirm1  however1 the
 above mentioned conclusions4    ,in the
 course of experimenting1 ,i passed the 
electric spark1 for  a quarter of an    
hour1 through about #fj measures of     
phosphorated  hydrogene4 ,it underwent  
no alteration of volume4 ,phosphorus was
  apparently precipitated from it1 and  
it had wholly lost its power of         
inflaming1 in contact with common air4  
,,vi4 ,decomposition of ,nitrous ,oxide 
by ,sulphur4    ,from the phnomena      
before mentioned1#agg relating to the   
combustion  of sulphur in nitrous oxide1
 it was evident that this gas was only  
decomposable by it1 at a much higher    
temperature than common air4    #agg    
,res4 ,i4 ,div4 ,,iii4 ,s4 ,,ii4    ,i  
introduced into sulphur in contact with 

nitrous oxide1 over mercury  heated to  
#aab-aad1 a wire intensely ignited4 ,it 
lost much of its heat  in passing       
through the mercury1 but still appeared 
red in the vessel4  ,the sulphur rapidly
 fused1 and sublimed without being at   
all luminous4  ,this experiment was     
repeated five or six times1 but in no   
instance  could the combustion of       
sulphur1 by means of the ignited wire1  
be  effected4    ,i inflamed sulphur in 
nitrous oxide in the same manner as     
phosphorus2  namely1 by introducing it  
into the small vessel filled with       
oxygene1  and igniting it by means of   
the heated wire4 ,in these experiments  
the  sulphur burnt with a vivid         
rose-colored light1 and much sulphuric1 
with  a little sulphureous acid1 was    
formed4    ,experimenting in this way ,i
 was never1 however1 able to decompose  
more  than one third of the quantity of 
nitrous oxide employed2 not only the    
nitrogene evolved1 but likewise the     
sulphuric and sulphureous acids         

produced1 stopping the combustion4    ,i
 found that sulphur in a state of vivid 
inflammation1 when introduced  into a   
mixture of one fourth nitrogene1 and    
three fourths nitrous  oxide1 burnt with
 a flame very much enlarged1 and of a   
vivid rose  color4 ,in one third        
nitrogene1 and two thirds nitrous oxide1
 it burnt  feebly with a yellow flame4  
,in equal parts of nitrous oxide and    
nitrogene1 it was instantly             
extinguished4    ,sulphur burnt feebly1 
with a light yellow flame1 when         
introduced  ignited into a mixture of #e
 nitrous gas1 and #f nitrous oxide4 ,in 
one  third nitrous oxide1 and two thirds
 nitrous gas1 it was instantly          
extinguished4 ,from many circumstances1 
,i am inclined to believe that  sulphur 
is incapable1 at any temperature1 of    
slowly decomposing nitrous  oxide1 so as
 to burn in it with a blue flame1       
forming sulphureous  acid alone4 ,it    
appears to attract oxygene from it only 
when intensely  ignited1 so as to form  

chiefly sulphuric acid1 and that with   
great  rapidity1 and vivid inflammation4
      ,,vii4 ,decomposition of ,nitrous 
,oxide by ,sulphurated ,hydrogene4    a4
 ,though nitrous oxide and sulphurated  
hydrogene do not act  upon each other at
 common temperatures1 yet they undergo a
 mutual  decomposition when mingled     
together in certain proportions1 and    
ignited  by the electric spark4    ,from
 more than twenty experiments made on   
the inflammation of  sulphurated        
hydrogene in nitrous oxide1 ,i select   
the following as the  most conclusive   
and accurate4 ,the temperature at which 
they were made  was from #da to #di4    
b4 ,e4 #a4 ,about #ce measures of       
nitrous oxide were fired with #aj  of   
sulphurated hydrogene2 the expansion    
during inflammation was very  great1 and
 the flame sky-blue4 ,immediately after1
 the gases filled  a space equal to #dh 
nearly4 ,white fumes were then formed1  
and they  gradually contracted to #dj4  
,on the admission of a little strontian 

lime water1 a slight absorption took    
place1 with white precipitation2  and   
the volume occupied by the residual gas 
nearly equalled #cg4 ,on  admitting     
nitrous gas to these1 no perceptible    
diminution took place4    ,e4 #b4 #bj   
sulphurated hydrogene1 with #be nitrous 
oxide1 could not be  inflamed4    #cj   
nitrous oxide1 with #bb sulphurated     
hydrogene1 could not be inflamed4    #ce
 nitrous oxide1 with #bj sulphurated    
hydrogene1 inflamed with vivid  blue    
light1 and great expansion4 ,after the  
explosion1 the gases filled  exactly the
 same space as before the experiment2 no
 white fumes were  perceived1 and no    
farther contraction occurred4 ,on the   
addition of  strontian lime water1 a    
copious precipitation1 with diminution1 
took  place2 and the residual gas filled
 a space nearly equal to #ce4    ,e4 #c4
 #dg nitrous oxide1 and #ad sulphurated 
hydrogene1 inflamed4 ,after  the        
explosion1 the gases filled a space     
nearly equal to #fe2 then white  fumes  

formed1 and they gradually diminished to
 #eb4 ,on the introduction  of muriate  
of strontian1 a copious white           
precipitate was produced2 and  on the   
addition of water1 no further absorption
 took place4 ,to the  residual #eb1     
about #bj of nitrous gas were added2    
they filled together a  space equal to  
about #fg4    c4 ,in none of the        
experiments made on the inflammation of 
sulphurated  hydrogene and nitrous      
oxide1 could ,i ascertain with certainty
 the  precipitation of sulphur4 ,in one 
or two processes the detonating tube    
was rendered a little white at the      
points of contact with the mercury2  but
 this was most probably owing to the    
oxydation of the mercury1  either by the
 heated sulphuric acid formed1 or from  
nitrous acid  produced by the ignition4 
,the presence of nitrous acid ,i could  
not  ascertain in these processes by my 
usual tests1 because the combustion  of 
sulphur over white prussiate of iron1   
converts it into light green4    ,when  

,i introduced an inflamed taper into    
about #c parts of sulphurated           
hydrogene1 and #b parts of nitrous      
oxide1 in which proportions they  could 
not have been fired by the electric     
spark1 a blue flame passed  through     
them1 and much sulphur was deposited on 
the sides of the  vessel4 ,but this     
sulphur most probably owed its formation
 to the  decomposition of a portion of  
sulphurated hydrogene not burnt1 by the 
sulphureous acid formed from the        
combustion of the other portion4    ,we 
may then conclude with probability1 that
 sulphurated hydrogene and  nitrous     
oxide will not decompose each other1    
when acted on by the  electric spark1   
unless their proportions are such as to 
enable the  whole of the sulphurated    
hydrogene to be decomposed1 so that both
 of  its constituents may become        
oxygenated1 by attracting oxygene from  
the  nitrous oxide3 likewise1 that when 
the sulphurated hydrogene is at its     
maximum of inflammation1 the hydrogene  

and sulphur form with the  whole of the 
oxygene of nitrous oxide1 water and     
sulphureous acid2 ,e4  #b3 whereas at   
its minimum they produce water1 and     
chiefly1 perhaps  wholly1 sulphuric     
acid2 at the same time that the nitrous 
oxide  partially decomposed1 is         
converted into nitrogene1 and a gas     
analogous  to atmospheric air1 or into  
nitrogene1 nitrous acid1 and atmospheric
  air4 ,e4 #a4 ,e4 #c4    ,by pursuing  
those experiments1 and using larger     
quantities of gas1  we may probably be  
able to ascertain from them with        
accuracy1 the  composition of sulphuric 
and sulphureous acids4    ,i own ,i was 
disappointed in the results1 for ,i     
expected to have been  able to ascertain
 from them1 the relative affinities of  
sulphur1 and  hydrogene for the oxygene 
of nitrous oxide1 at the temperature of 
ignition4 ,i conjectured that nitrous   
oxide1 mingled with excess of           
sulphurated hydrogene1 would have been  
decomposed1 and one of the  principles  

of it evolved unaltered1 as was the case
 with phosphorated  hydrogene4    ,if we
 estimate the composition of nitrous    
oxide from the quantity of  nitrogene   
produced in ,e4 #b1 it is composed of   
about #fa nitrogene1 and  #ci oxygene4  
,,viii4 ,decomposition of ,nitrous      
,oxide by ,charcoal4    ,an account of  
the analysis of nitrous oxide by        
charcoal is given in  ,res4 ,i4 ,div4   
,,iii4 ,i have lately made two          
experiments on the combustion  of       
charcoal in nitrous oxide1 in which     
every precaution was taken to  prevent  
the existence of sources of error4 ,of  
one of these ,i shall give  a detail4   
,e4 ,temperature being #ea1 about a     
grain of charcoal1 which had been       
exposed for some hours to a red heat1   
was introduced whilst ignited1  under   
mercury1 and transferred into a         
graduated jar1 containing #c cubic      
inches of pure nitrous oxide1 standing  
over dry mercury4    ,the focus of a    
burning lens was thrown on the charcoal2

 it instantly  inflamed1 and burnt with 
great vividness for near a minute1 the  
gas  being much expanded4 ,the focus was
 continually applied to it for ten      
minutes1 when the process appeared at an
 end4 ,the gases1 when the  common      
temperature and pressure were restored1 
filled a space equal to  #d1b cubic     
inches4    ,on introducing into them a  
few grain measures of solution of green 
muriate of iron1 for the double purpose 
of saturating them with  moisture1 and  
ascertaining if any nitrous acid had    
been formed1 no  change of volume took  
place2 and prussiate of potash gave with
 the  muriate a white precipitate only4 
,on the admission of a small quantity of
 concentrated solution of  caustic      
potash1 a diminution of the gas slowly  
took place2 when it was  complete the   
volume equalled about #c4je cubic       
inches4 ,by agitation  in well boiled   
water1 about1#i of these were absorbed2 
the remainder  appeared to be pure      
nitrogene4    ,the difference between   

the estimation founded upon the         
nitrogene  evolved1 and that deduced    
from the carbonic acid generated in this
  experiment1 is not nearly so great as 
in that ,res4 ,i4 ,div4 ,,iii4 ,taking  
about the mean proportions1 we should   
conclude that nitrous oxide was         
composed of about #ch oxygene1 and #fb  
nitrogene4    ,charcoal burnt with      
greater vividness than in common air1 in
 a mixture  of one third nitrogene and  
two thirds nitrous oxide4 ,in equal     
parts  of nitrous oxide and nitrogene1  
its light was barely perceptible4  ,in  
one third nitrous oxide1 and two thirds 
nitrogene1 it was almost  immediately   
extinguished4    ,as charcoal burns     
vividly in nitrous gas1 when it has been
 previously  ignited to whiteness1 ,i   
introduced it into a mixture of equal   
parts of  nitrous oxide and nitrous gas2
 it burnt with a deep and bright red4   
,,ix4 ,decomposition of ,nitrous ,oxide 
by ,hydrocarbonate4    ,nitrous oxide1  
and hydrocarbonate1 possess no action on

 each other1  except at high            
temperatures4 ,when mingled in certain  
proportions1 and  exposed to the        
electric shock1 a new arrangement of    
their principles  takes place4    ,e4   
#a4 ,temperature being #ec1 #ce of      
nitrous oxide1 mingled with #ae of      
hydrocarbonate1 were fired by the       
electric spark2 the inflammation was    
very vivid1 and the light produced1     
bright red4 ,after the explosion1  the  
space occupied by the gases equalled    
about #fj4 ,on the admission of         
solution of strontian1 a copious white  
precipitate was produced1 and  the gas  
diminished by agitation1 to rather more 
than #ce4 ,when #cf of  nitrous gas were
 added to these1 white fumes appeared   
and the whole  diminished to #fb4 ,when 
a little muriatic acid was poured on the
 white  precipitate from the solution of
 strontian1 gas was evolved from it1    
and it was gradually dissolved4    ,e4  
#b4 #bb nitrous oxide were inflamed with
 #bj hydrocarbonate2 after  the         

explosion1 they filled a space equal to 
#de2 when strontian  lime water was     
introduced1 white precipitation took    
place1 and the  diminution was to #ca4  
,to these #ca1 #ad of nitrous oxide were
 admitted1 and the electric spark       
passed through them2 an inflammation    
took place3 carbonic acid was  formed1  
after the absorption of which1 the gas  
remaining filled a space  equal to #dc1 
and did not diminish with nitrous gas4  
,the hydrocarbonate employed in these   
experiments1 was procured from  alcohol 
by means of sulphuric acid4 ,in another 
set of experiments made  with less      
accuracy1 the same general results were 
obtained4 ,whenever  hydrocarbonate     
inflamed with nitrous oxide1 both its   
constituents were  oxygenated2 in all   
cases carbonic acid was formed1 and in  
no instance  free hydrogene evolved1 or 
charcoal precipitated4    ,in the       
decomposition of nitrous oxide by       
hydrocarbonate1 the residual  nitrogene 
is less than in other combustions4 ,this

 circumstance ,i am  unable to explain4 
,reasoning from analogy1 there can be   
little doubt1 but that when             
hydrocarbonate is inflamed with excess  
of nitrous oxide1 it will be  only      
partially decompounded1 or converted    
into nitrogene1 nitrous acid1  and      
atmospheric air4    ,the ,dutch         
,chemists have asserted1 that charcoal  
does not burn in  nitrous oxide1 except 
in consequence of the previous          
decomposition  of the gas by the        
hydrogene always contained in this      
substance2 and  likewise1 that when     
hydrocarbonate and nitrous oxide were   
mingled  together1 and fired by the     
electric spark1 the hydrogene only was  
burnt1 whilst the charcoal was          
precipitated4    ,it is difficult to    
account for these numerous mistakes4    
,their theory of  the non-respirability 
of nitrous oxide was founded upon them4 
,they  supposed that the chief use of   
respiration was to deprive the blood of 
its superabundant carbon1 by the        

combination of atmospheric oxygene  with
 that principle2 and that nitrous oxide 
was highly fatal to life1  because it   
was incapable of de-carbonating the     
blood#agh66    #agh ,journal de         
,physique1 xliii4 #ccd4    ,x4          
,combustion of ,iron in ,nitrous ,oxide4
    ,i introduced into a jar of the     
capacity of #bj cubic inches1 containing
  #aa cubic inches of nitrous oxide1    
over mercury1 a small quantity of  fine 
iron wire twisted together1 and having  
affixed to it a particle  of cork4 ,on  
throwing the focus of a burning glass on
 the cork1 it  instantly inflamed1 and  
the fire was communicated to the wire1  
which  burnt with great vividness for   
some moments1 projecting brilliant white
  sparks4 ,after it had ceased to burn  
the gas was increased in volume  rather 
more than three tenths of an inch4 ,the 
nitrous acid tests were  introduced1 but
 no acid appeared to have been formed4  
,on exposing the  gas to water1 near    
#d1b cubic inches were absorbed3 the    

#g1a remaining  appeared to be pure     
nitrogene4    ,from this experiment it  
is evident that iron at the temperature 
of  ignition1 is capable of decomposing 
nitrous oxide2 likewise that it  is     
incapable of burning in it when it      
contains more than three fifths         
nitrogene4    ,i attempted to inflame   
zinc in nitrous oxide1 in the same way  
as iron2  but without success4 ,by      
keeping the focus of a burning glass    
upon  some zinc filings1 in a small     
quantity of nitrous oxide1 ,i converted 
a little of the zinc into white oxide1  
and consequently decomposed a  portion  
of the gas4      ,,xi4 ,combustion of   
,pyrophorus in ,nitrous ,oxide4         
,pyrophorus1 which inflames in nitrous  
gas1 and atmospheric air1 at or  even   
below #dj1 requires for its combustion  
in nitrous oxide a much  higher         
temperature4 ,it will not burn in it1 or
 alter it1 even at #bab4    ,i have     
often inflamed pyrophorus in nitrous    
oxide over mercury1 by  means of a wire 

strongly heated1 but not ignited4 ,the  
light produced  by the ignition of      
pyrophorus in nitrous oxide is white1   
like that  produced by it in oxygene3 in
 nitrous gas it is red4    ,when        
pyrophorus burns out in nitrous oxide1 a
 little increase of the  volume of gas  
is produced4 ,strontian lime water      
agitated in this gas  becomes clouded2  
but the quantity of carbonic acid formed
 is extremely  minute4 ,i have never    
made any delicate experiments on the    
combustion of  pyrophorus in nitrous    
oxide4      ,,xii4 ,combustion of the   
,taper in ,nitrous ,oxide4    ,it has   
been noticed by different               
experimentalists1 that the taper burns  
with a flame considerably enlarged in   
nitrous oxide3 sometimes with a  vivid  
light and crackling noise1 as in        
oxygene2 at other times with a  white   
central flame1 surrounded by a feeble   
blue one4    ,my experiments on the     
combustion of the taper in nitrous      
oxide1 were  chiefly made with a view to

 ascertain the cause of the double      
flame4    ,when the inflamed taper is   
introduced into pure nitrous oxide1 it  
burns  at first with a brilliant white  
light1 and sparkles as in oxygene4 ,as  
the combustion goes on1 the brilliancy  
of the flame diminishes2 it  gradually  
lengthens1 and becomes surrounded with a
 pale blue cone of  light1 from the apex
 of which much unburnt charcoal is      
thrown off1  in the form of smoke4 ,the 
flame continues double to the end of the
  process4    ,when the residual gases  
are examined after combustion1 much     
nitrous  acid is found suspended in     
them2 and they are composed of carbonic 
acid1 nitrogene1 and about one fourth of
 undecompounded nitrous oxide4    ,the  
double flame depends upon the nitrous   
acid formed by the ignition2  for it can
 be produced by plunging the taper into 
common air containing  nitrous acid     
vapor1 or into a mixture of nitrous     
oxide and nitrogene1  through which     
nitrous acid has been diffused4 ,it is  

never perceived in  the combustion of   
the taper1 till much nitrous acid is    
formed4    ,in attempting to respire    
some residual gas of nitrous oxide1 in  
which  a taper had burnt out1 ,i found  
it so highly impregnated with nitrous   
acid1 as to disable me from even taking 
it into my mouth4    ,the taper burns in
 a mixture of equal parts nitrous oxide 
and  nitrogene1 at first with a flame   
nearly the same as that of a candle in  
common air2 white4 ,before its          
extinction the interior white flame1 and
  exterior blue flame1 are perceived4   
,the taper is instantly extinguished in 
a mixture of one fourth nitrous  oxide1 
and three fourths nitrogene4    ,in a   
mixture of equal parts nitrous oxide and
 nitrous gas1 the taper  burns at first 
with nearly as much brilliancy as in    
pure nitrous oxide2  gradually the      
double and feeble flame is produced4    
,,xiii4 ,on the ,combustion of different
 ,compound ,bodies in ,nitrous ,oxide4  
,all the solid and fluid compound       

inflammable bodies on which ,i have     
experimented1 burn in nitrous oxide1 at 
high temperatures4 ,wood1  cotton1 and  
paper1 are easily inflamed in it by the 
burning glass4  ,during their           
combustion1 nitrous acid is always      
formed1 carbonic acid1  and water       
produced1 and nitrogene evolved1 rather 
less in bulk than the  nitrous oxide    
decomposed4    ,i have already mentioned
 that alcohol and ether are soluble in  
nitrous  oxide4 ,when an ignited body is
 introduced into the solution of        
alcohol1 or ether in nitrous oxide1 a   
slight explosion takes place4           
,,xiv4 ,general ,conclusions relating to
 the ,decomposition of ,nitrous  ,oxide1
 and to its ,analysis4    ,from what has
 been said in the preceding sections1 it
 appears that  the inflammable bodies1  
in general1 require for their combustion
 in  nitrous oxide1 much higher         
temperatures than those at which they   
burn  in atmospheric air1 or oxygene4   
,when intensely heated they decompose   

it1 with the production of much  heat   
and light1 and become oxygenated4       
,during the combustion of solid or fluid
 bodies1 producing flame1 in  nitrous   
oxide1 nitrous acid is generated1 most  
probably from a new  arrangement of     
principles1 analogous to those observed 
in ,sect4 ,,ii1 by  the ignition of that
 part of the gas not in contact with the
 burning  substance4 ,likewise when     
nitrous oxide in excess is decomcomposed
 by  inflammable gases1 nitrous acid1   
and sometimes a gas analogous to  common
 air1 is produced1 doubtless from the   
same cause4    ,pyrophorus is the only  
body that inflames in nitrous oxide1    
below the  temperature of ignition4     
,phosphorus burns in it with the blue   
flame1 probably forming with its        
oxygene only phosphoreous acid at the   
dull red heat1 and with the  intensely  
vivid flame1 producing phosphoric acid  
at the white heat4    ,hydrogene1       
charcoal1 sulphur1 iron1 and the        
compound inflammable  bodies1 decompose 

it only at heats equal to1 or above1    
that of  ignition3 probably each a      
different temperature4    ,from the     
phnomena in ,sect4 ,v4 it appears1 that 
at the temperature of  intense ignition1
 phosphorus has a stronger affinity for 
the oxygene  of nitrous oxide than      
hydrogene2 and reasoning from the       
different  degrees of combustibility of 
the inflammable bodies1 in mixtures of  
nitrous oxide and nitrogene1 and from   
other phnomena1 we may conclude  with   
probability1 that at about the white    
heat1 the affinity of the  combustible  
bodies for oxygene takes place in the   
following order4  ,phosphorus1          
hydrogene1 charcoal1#agi iron1 sulphur1 
c4    ,this order of attraction is very 
different from that obtaining at the    
red heat2 in which temperature charcoal 
and iron have a much stronger  affinity 
for oxygene than either phosphorus or   
hydrogene4#ahj    #agi ,as is proved by 
the decomposition of oxide of iron and  
sulphuric  acid by charcoal1 at that    

temperature4    #ahj ,hydrogene at or   
about the red heat1 appears to attract  
oxygene  stronger than phosphorus4 ,see 
,dr4 ,priestley's experiments1 vol4 i4  
page  #bfb4    ,the smallest quantity of
 oxygene given in the different analyses
 of  nitrous oxide just detailed1 is    
thirty five hundred parts2 the greatest 
proportion is thirty-nine4    ,taking   
the mean estimations from the most      
accurate experiments1 we may  conclude  
that #ajj grains of the known ponderable
 matter of nitrous  oxide1 consist of   
about #cf1g oxygene1 and #fc1c          
nitrogene2 or taking  away decimals1 of 
#cg oxygene to #fc nitrogene2 which is  
identical with  the estimation given in 
,research ,i4      ,,xv4 ,observations  
on the combinations of ,oxygene and     
,nitrogene4    ,during the              
decompositions of the combinations of   
oxygene and nitrogene  by combustible   
bodies1 a considerable momentary        
expansion of the acting  substances1 and
 the bodies in contact with them is     

generally produced1  connected with     
increased temperature2 whilst light is  
often generated  to a great extent4     
,of the causes of these phnomena we are 
at present ignorant4 ,our  knowledge of 
them must depend upon the discovery of  
the precise nature  of heat and light1  
and of the laws by which they are       
governed4 ,the  application of general  
hypotheses to isolated facts can be of  
little  utility2 for this reason ,i     
shall at present forbear to enter into  
any  discussions concerning those       
agents1 which are imperceptible to the  
senses1 and known only by solitary      
effects4    ,analysis and synthesis     
clearly prove that oxygene and nitrogene
  constitute the known ponderable matter
 of atmospheric air1 nitrous  oxide1    
nitrous gas1 and nitric acid4    ,that  
the oxygene and nitrogene of atmospheric
 air exist in chemical  union1 appears  
almost demonstrable from the following  
evidences4    #ast4 ,the equable        
diffusion of oxygene and nitrogene      

through every part  of the atmosphere1  
which can hardly be supposed to depend  
on any other  cause than an affinity    
between these principles4#aha    #aha   
,that attraction must be called         
chemical1 which enables bodies of       
different specific gravities to unite in
 such a manner as to produce a          
compound1 in every part of which the    
constituents are found in the same      
proportions to each other4 ,atmospheric 
air1 examined after having been  at     
perfect rest in closed vessels1 for a   
great length of time1 contains  in every
 part the same proportions of oxygene   
and nitrogene2 whereas  if no affinity  
existed between these principles1       
following the laws  of specific gravity1
 they ought to separate2 the oxygene    
forming the  inferior1 the nitrogene the
 superior stratum4    ,the supposition  
of the chemical composition of          
atmospheric air1 has  been advanced by  
many philosophers4 ,the two first       
evidences have been  often noticed4     

#b;dly4 ,the difference between the     
specific gravity of atmospheric  air1   
and a mixture of #bg parts oxygene and  
#gc nitrogene1 as found by  calculation2
 a difference apparently owing to       
expansion in consequence  of            
combination4    #c;dly4 ,the conversion 
of nitrous oxide into nitrous acid1 and 
a gas  analogous to common air1 by      
ignition4    #dthly4 ,the solubility of 
atmospheric air undecompounded in water4
    ,,atmospheric ,,air1 then1 may be   
considered as the least intimate of the 
combinations of nitrogene and oxygene4  
,it is an elastic fluid1 permanent at   
all known temperatures1 consisting      
of1#gc nitrogene1 and1#bg oxygene4 ,it  
is decomposable at certain              
temperatures1 by most of the bodies     
possessing affinity for oxygene4 ,it  is
 soluble in about thirty times its bulk 
of water1 and as far as we  are         
acquainted with its affinities1         
incapable of combining with most of  the
 simple and compound substances4 #ajj   

cubic inches of it weigh about  #ca     
grains at #ee temperature1 and #cj      
atmospheric pressure4    ,,nitrous      
,,oxide is a gas unalterable in its     
constitution1 at temperatures  below    
ignition4 ,it is composed of oxygene and
 nitrogene1 existing  perhaps in the    
most intimate union which those         
substances are capable  of assuming4#ahb
 ,its properties approach to those of   
acids4 ,it is  decomposable by the      
combustible bodies at very high         
temperatures1 is  soluble in double its 
volume of water1 and in half its bulk of
 most of  the inflammable fluids4 ,it is
 combinable with the alkalies1 and      
capable  of forming with them peculiar  
salts4 #ajj grains of it are composed of
  about #fc nitrogene1 and #cg oxygene4 
#ajj cubic inches of it weigh #ej       
grains1 at #ee temperature1 and #cj     
atmospheric pressure4    #ahb ,for it is
 unalterable by those bodies which are  
capable of  attracting oxygene from     
nitrous gas and nitrous acid1 at common 

temperatures4    ,,nitrous ,,gas is     
composed of about1#ef oxygene1 and1#dd  
nitrogene1 in  intimate union4 ,it is   
soluble in twelve times its bulk of     
water1 and  is combinable with the      
acids1 and certain metallic solutions2  
it  is possessed of no acid properties1 
and is decomposable by most of  the     
bodies that attract oxygene strongly1 at
 high temperatures4 #ajj  cubic inches  
of it weigh about #cd grains1 at the    
mean temperature and  pressure4         
,,nitric ,,acid is a substance          
permanently ariform at common           
temperatures1  composed of about #a     
nitrogene1 to #b1c oxygene4 ,it is      
soluble to a  great extent in water1 and
 combinable with the alkalies1 and      
nitrous  gas4 ,it is decomposable by    
most of the combustible bodies1 at      
certain  temperatures4 #ajj cubic inches
 of it weigh1 at the mean temperature   
and  pressure1 nearly #gf grains4       
,,research ,,iii4    ,,relating ,,to    
,,the ,,respiration ,,of ,,nitrous      

,,oxide1 ,,and ,,other ,,gases4         
,,division ,i4        ,,experiments and 
,,observations on the ,,effects produced
         upon ,,animals by the          
,,respiration of ,,nitrous ,,oxide4     
,i4 ,preliminaries4    ,the term        
respirable1 in its physiological        
application1 has been  differently      
employed4 ,some times by the            
respirability of a gas has been  meant1 
its power of supporting life for a great
 length of time1 when  repeatedly       
applied to the blood in the lungs4 ,at  
other times all gases  have been        
considered as respirable1 which were    
capable of introduction  into the lungs 
by voluntary efforts1 without any       
relation to their  vitality4    ,in the 
last sense the word respirable is most  
properly employed4 ,in  this sense it is
 used in the following sections4        
,non-respirable gases are those1 which  
when applied to the external  organs of 
respiration1 stimulate the muscles of   
the epiglottis in inch  a way as to keep

 it perfectly close on the glottis2 thus
 preventing  the smallest particle of   
gas from entering into the bronchia1 in 
spite  of voluntary exertions2 such are 
carbonic acid1 and acid gases in        
general4#ahc    #ahc ,see the curious   
experiments of ,rosier1 ,journal de     
,physique1 #aghf1  vol4 #a1 pag4 #dai4  
,of respirable gases1 or those which are
 capable of being taken into the  lungs 
by voluntary efforts4    ,one only has  
the power of uniformly supporting       
life2--atmospheric air4  ,other gases1  
when respired1 sooner or later produce  
death2 but in  different modes4         
,some1 as nitrogene and hydrogene1      
effect no positive change in the  venous
 blood4 ,animals immersed in these gases
 die of a disease produced  by privation
 of atmospheric air1 analogous to that  
occasioned by their  submersion in      
water1 or non-respirable gases4         
,others1 as the different varieties of  
hydrocarbonate1 destroy life  by        
producing some positive change#ahd in   

the blood1 which probably  immediately  
renders it incapable of supplying the   
nervous and muscular  fibres with       
principles essential to sensibility and 
irritability4    ,oxygene1 which is     
capable of being respired for a much    
greater length  of time than any other  
gas1 except common air1 finally destroys
 life2  first producing changes in the  
blood1 connected with new living        
action4#ahe    #ahd ,as appears from the
 experiments of ,dr4 ,beddoes2 likewise 
those of  ,mr4 ,watt4    #ahe ,as       
appears from the experiments of         
,lavoisier and ,dr4 ,beddoes2 and  as   
will be seen hereafter4    ,after       
experiments1 to be detailed hereafter1  
made upon myself and  others1 had proved
 that nitrous oxide was respirable1 and 
capable  of supporting life for a longer
 time than any of the gases1 except     
atmospheric air and oxygene1 ,i was     
anxious to ascertain the effects of  it 
upon animals1 in cases where its action 
could be carried to a full  extent2 and 

to compare the changes occasioned by it 
in their organs1  with those produced by
 other powers4      ,,ii4 ,on the       
respiration of ,nitrous ,oxide by       
warm-blooded ,animals4    ,the nitrous  
oxide employed in the following         
experiments1 was procured  from nitrate 
of ammoniac1 and received in large jars1
 filled with water  previously saturated
 with the gas4 ,the animal was          
introduced into the  jar1 by being      
carried under the water2 after its      
introduction1 the jar  was made to rest 
on a shelf1 about half an inch below the
 surface of  the water2 and the animal  
carefully supported1 so as to prevent   
his  mouth from resting in the water4   
,this mode of experimenting1 either     
under water or mercury1 is  absolutely  
necessary1 to ascertain with accuracy   
the effects of  pure gases on living    
beings4 ,in some experiments that ,i    
made on the  respiration of nitrous     
oxide1 by animals that were plunged into
 jars  of it opened in the atmosphere1  

and immediately closed after their      
introduction1 the unknown quantities of 
common air carried in1 were  always     
sufficient to render the results        
perfectly inaccurate4    ,animals suffer
 little or nothing by being passed      
through water4    ,that the phnomena in 
these experiments might be more         
accurately  observed1 two or three      
persons were always present at the time 
of their  execution1 and an account of  
them was noted down immediately after4  
a4 ,a stout and healthy young cat1 of   
four or five months old1 was  introduced
 into a large jar of nitrous oxide4 ,for
 ten or twelve moments  he remained     
perfectly quiet1 and then began to make 
violent motions1  throwing himself round
 the jar in every direction4 ,in two    
minutes  he appeared quite exhausted1   
and sunk quietly to the bottom of the   
jar4 ,on applying my hand to the thorax1
 ,i found that the heart beat  with     
extreme violence2 on feeling about the  
neck1 ,i could distinctly  perceive a   

strong and quick pulsation of the       
carotids4 ,in about three  minutes the  
animal revived1 and panted very much2   
but still continued  to lie on his side4
 ,his inspirations then became longer   
and deeper1 and  he sometimes uttered   
very feeble cries4 ,in four minutes the 
pulsations  of the heart appeared       
quicker and feebler4 ,his inspirations  
were at  long intervals1 and very       
irregular2 in five minutes the pulse was
  hardly perceptible2 he made no        
motions1 and appeared wholly senseless4 
,after five minutes and quarter he was  
taken out1 and exposed to the           
atmosphere before a warm fire4 ,in a few
 seconds he began to move1 and  to take 
deep inspirations4 ,in five minutes he  
attempted to rise on his  legs2 but soon
 fell again1 the extremities being      
slightly convulsed4  ,in eight or nine  
minutes he was able to walk1 but his    
motions were  staggering and unequal1   
the right leg being convulsed1 whilst   
the  other was apparently stiff and     

immoveable2 in about half an hour he    
was almost completely recovered4    b4  
,a healthy kitten1 of about six weeks   
old1 was introduced into  nitrous oxide4
 ,she very soon began to make violent   
exertions1 and  in less than a minute   
fell to the bottom of the receiver1 as  
if  apoplectic4 ,at this moment1        
applying my hand to her side1 ,i felt   
the  heart beating with great violence4 
,she continued gasping1 with long       
inspirations1 for three minutes and     
half2 at the end of five minutes  and   
half she was taken out completely dead4 
c4 ,another kitten of the same breed was
 introduced into nitrous  oxide1 the day
 after4 ,she exhibited the same         
phnomena1 and died in it  in about five 
minutes and half4    d4 ,a small dog    
that had accidentally met with a        
dislocation of the  vertebr of the      
loins1 and was in great pain1 as        
manifested by his  moaning and whining1 
was introduced into a large jar of      
nitrous oxide4  ,he immediately became  

quiet1 and lay on his side in the jar1  
breathing  very deeply4 ,in four minutes
 his respiration became noisy1 and his  
eyes sparkled very much4 ,i was not able
 to apply my hand to the  thorax4 ,in   
five minutes he appeared senseless1 and 
in seven minutes was  perfectly dead4   
e4 ,a strong rabbit1 of ten or twelve   
months old1 was introduced into  nitrous
 oxide4 ,he immediately began to        
struggle very much1 and in a  minute    
fell down senseless3 in two minutes the 
legs became convulsed1  and his         
inspirations were deep and noisy3 in    
less than five minutes he  appeared     
perfectly dead4    f4 ,a rabbit of a    
month old introduced into nitrous oxide1
 became  senseless in less than a       
minute2 the pulsations of the heart were
 very  strong at this moment3 they      
gradually became weaker1 and in three   
minutes and half the animal was dead4   
g4 ,another rabbit of the same breed1   
after being rendered senseless  in      
nitrous oxide in a minute and half1 was 

taken out4 ,he soon became  convulsed2  
in a minute began to breathe quickly2 in
 two minutes  attempted to rise1 but    
staggered1 and fell again on his side4  
,his  hinder legs were paralytic for    
near five minutes4 ,in twenty he had    
almost recovered4    h4 ,a middle sized 
guinea-pig was much convulsed1 after    
being in  nitrous oxide for a minute4   
,in two minutes and half he was         
senseless4  ,taken out at this period1  
he remained for some minutes by the side
 of  a warm fire1 without moving2 his   
fore legs then became convulsed2 his    
hind legs were perfectly paralytic4 ,in 
this state he continued1 without        
attempting to rise or move1 for near an 
hour1 when he died4    i4 ,a large and  
old guinea-pig died in nitrous oxide1   
exhibiting the  same phnomena as the    
other animals1 in about five minutes and
 quarter4  ,a young one was killed in   
three minutes and half4    j4 ,a small  
guinea-pig1 after breathing nitrous     
oxide for a minute and  half1 was taken 

out1 and placed before a warm fire4 ,he 
was for a few  minutes a little         
convulsed2 but in a quarter of an hour  
got quite well1  and did not relapse4   
k4 ,a large mouse introduced into       
nitrous oxide1 was for a few  seconds   
very active4 ,in half a minute he fell  
down senseless2 in a  minute and quarter
 he appeared perfectly dead4    l4 ,a   
mouse taken out of nitrous oxide1 after 
being in it for half a  minute1         
continued convulsed for some minutes1   
but finally recovered4    m4 ,a young   
hen was introduced into a vessel filled 
with nitrous  oxide4 ,she immediately   
began to struggle very much2 fell on her
 breast  in less than half a minute1 and
 in two minutes was quite dead4    n4 ,a
 goldfinch died in nitrous oxide in less
 than a minute4    ,in each of these    
experiments a certain absorption of the 
gas was always  perceived1 the water    
rising in the jar during the respiration
 of the  animal4 ,from them we learn    
#ast4 ,that nitrous oxide is destructive

 when respired for a certain time  to   
the warm-blooded animals1 apparently    
previously exciting them to a  great    
extent4    #b;dly4 ,that when its       
operation is stopped before compleat    
exhaustion is  brought on1 the healthy  
living action is capable of being       
gradually  reproduced1 by enabling the  
animal to respire atmospheric air4      
#c;dly4 ,that exhaustion and death is   
produced in the small animals by        
nitrous oxide sooner than in the larger 
ones1 and in young animals of  the same 
species1 in a shorter time than in old  
ones1 as indeed ,dr4  ,beddoes had      
conjectured a priori would be the case4 
,most of the animals destroyed in these 
experiments were examined after  death2 
the appearances in their organs were    
peculiar4 ,to prevent  unnecessary      
repetitions1 an account of them will be 
given in the fourth  section4           
,,iii4 ,effects of the respiration of   
,nitrous ,oxide upon animals1 as        
compared with those produced by their   

immersion in ,hydrogene and ,water4     
,before the following experiments were  
made1 a number of circumstances  had    
convinced me that nitrous oxide acted on
 animals by producing some  positive    
change in their blood1 connected with   
new living action of the  irritable and 
sensitive organs1 and terminating in    
their death4    ,to ascertain however1  
the difference between the effects of   
this gas  and those of hydrogene and    
non-respirable gases1 ,i proceeded in   
the  following way4    a4 ,of two       
healthy rabbits of about two months old1
 of the same breed1  and nearly of the  
same size4    ,one was introduced into  
nitrous oxide4 ,in a half a minute1 it  
had  fallen down apparently senseless4  
,on applying my hand to the thorax1  the
 action of the heart appeared at first1 
very quick and strong1 it  gradually    
became weaker1 and in two minutes and   
half1 the animal was  taken out quite   
dead4    ,the other was introduced into 
a jar of pure hydrogene through water4  

,he immediately began to struggle very  
much1 and in a quarter of a  minute fell
 on his side4 ,on feeling the thorax1   
the pulsations of the  heart appeared   
very quick and feeble1 they gradually   
diminished2 his  breathing became       
momentarily shorter1 and in rather more 
than three  quarters of a minute1 he was
 taken out dead4 ,dr4 ,kinglake was     
present  at this experiment1 and        
afterwards dissected both of the        
animals4    b4 ,of two similar rabbits  
of the same breed1 nearly three months  
old4 ,one was introduced into nitrous   
oxide1 and after being rendered         
senseless by the respiration of it for  
nearly a minute and half1 was  exposed  
to the atmosphere1 before a warm fire4  
,he recovered gradually1  but was       
occasionally convulsed1 and had a       
paralysis of one of his  hinder legs for
 some minutes3 in an hour he was able to
 walk4 ,the  other1 after being immerged
 in hydrogene for near half a minute1   
was  restored to the atmosphere         

apparently inanimate4 ,in less than a   
minute  he began to breathe1 and to     
utter a feeble noise2 in two minutes    
was able to walk1 and in less than three
 minutes appeared perfectly  recovered4 
c4 ,a kitten of about two months old1   
was introduced into a jar of  nitrous   
oxide1 at the same time that another of 
the same breed was  plunged under a jar 
of water4 ,they both struggled very     
much4 ,the  animal in the nitrous oxide 
fell senseless before that under water  
had  ceased to struggle1 and to throw   
out air from its lungs4 ,in two minutes 
and three quarters1 the animal under    
water was quite dead3 it was taken  out 
and exposed to heat and air1 but did not
 shew the slightest signs  of life4 ,at 
the end of three minutes and half1 the  
animal in nitrous  oxide began to gasp1 
breathing very slowly2 at four minutes  
and three  quarters it was yet alive2 at
 the end of five minutes and quarter it 
appeared perfectly dead4 ,it was taken  
out1 and did not recover4    ,from these

 experiments it was evident1 that       
animals lived at least  twice as long in
 nitrous oxide as in hydrogene or water4
 ,consequently  from this circumstance  
alone1 there was every reason to suppose
 that  their death in nitrous oxide     
could not depend on the simple privation
  of atmospheric air2 but that it was   
owing to some peculiar changes  effected
 in the blood by the gas4      ,,iv4 ,of
 the changes effected in the            
,organisation of warm-blooded  ,animals1
 by the respiration of ,nitrous ,oxide4 
,the external appearance of animals that
 have been destroyed in nitrous  oxide1 
is very little different from that of   
those killed by privation  of           
atmospheric air4 ,the fauces and tongue 
appear of a dark red1 and the  eyes are 
dull1 and a little protruded4 ,their    
internal organs1 however1  exhibit a    
very peculiar change4 ,the lungs are    
pale brown red1 and  covered here and   
there with purple spots2 the liver is of
 a very bright  red1 and the muscular   

fibre in general dark4 ,both the        
auricles and  ventricles of the heart   
are filled with blood4 ,the auricles    
contract  for minutes after the death of
 the animal4 ,the blood in the left     
ventricle1 and the aorta1 is of a tinge 
between purple and red1 whilst  that in 
the right ventricle is of a dark color1 
rather more purple  than the venous     
blood4 ,but these appearances1 and their
 causes1 will  be better understood     
after the following comparative         
observations are  read4    a4 ,of two   
similar rabbits1 about eight months old1
 one ,a1 was killed  by exposure for    
near six minutes to nitrous oxide1 the  
other1 ,b1 was  destroyed by a blow on  
the head4    ,they were both opened as  
speedily as possible4 ,the lungs of ,b  
were  pale1 and uniform in their        
appearance2 this organ in ,a was redder1
 and  every where marked with purple    
spots4 ,the liver of ,a was of a dark   
and  bright red1 that of ,b of a pale   
red brown4 ,the diaphragm of ,b1 when   

cut1 was strongly irritable2 that of ,a 
rather darker1 and scarce at all        
contractile4 ,all the cavities of the   
heart contracted for more than #ej      
minutes in ,b4 ,the auricles contracted 
for near #be minutes with force  and    
velocity in ,a3 but the ventricles were 
almost inactive4 ,the vena  cava1 and   
the right auricle1 in ,a1 were filled   
with blood1 apparently a  shade darker  
than in ,b4 ,the blood in the left      
auricle1 and the aorta1  appeared in ,a 
of a purple1 a shade brighter than that 
of the venous  blood4 ,in the left      
auricle of ,b it was red4    ,i opened  
the head of each1 but not without       
injuring the brains1 so  that ,i was    
unable to make any accurate comparison4 
,the color of the  brain in ,a appeared 
rather darker than in ,b4    b4 ,two    
rabbits1 ,c and ,d1 were destroyed1 ,c  
by immersion in nitrous  oxide1 ,d in   
hydrogene3 they were both dissected by  
,dr4 ,kinglake4  ,the blood in the      
pulmonary vein and the left auricle of  

,c was of a  different tinge1 from that 
in ,d more inclined to purple red4 ,the 
membrane of the lungs in ,c was covered 
with purple spots1 that of ,d was  pale 
and uniform in its appearance4 ,the     
brain in ,c was rather darker  than in  
,d2 but there was no perceptible        
effusion of blood into the  ventricles  
either in ,d or ,c4 ,the liver in ,c was
 of a brighter red than  in health1 that
 in ,d rather paler4    c4 ,in the last 
experiment1 the comparative irritability
 of the  ventricles and auricles of the 
heart and the muscular fibre in the two 
animals1 had not been examined4 ,that   
these circumstances might be  noticed1  
two rabbits1 ,e and ,f were killed2 ,e  
under water in about a  minute1 and ,f  
in nitrous oxide in three minutes4 ,they
 were immediately  opened1 and after a  
minute1 the appearance of the heart1 and
 organs of  respiration observed4       
,both the right and left ventricles of  
the heart in ,f contracted but  very    
feebly2 the auricles regularly and      

quickly contracted2 the aorta  appeared 
perfectly full of blood4 ,in ,e1 a      
feeble contraction of the  left sinus   
venosus and auricle was observed2 the   
left ventricle did not  contract3 the   
right contracted1 but more slowly than  
in ,f4 ,in a few  minutes1 the          
contractions of the ventricles in ,f had
 ceased1 whilst  the auricles contracted
 as strongly and quickly as before4 ,the
 blood  in the pulmonary veins of ,f was
 rather of a redder purple than in ,e2  
the difference of the blood in the vena 
cava was hardly perceptible1  perhaps it
 was a little more purple in ,f4 ,the   
membranous substance of  the lungs in ,f
 was spotted with purple as from        
extravasated blood1  whilst that in ,e  
was pale4 ,the brain in ,f was darker   
than in ,e4 ,on  opening the ventricles 
no extravasation of blood was           
perceptible4 ,the  auricles of the heart
 in ,f contracted strongly for near     
twenty minutes1  and then gradually     
their motion became less frequent2 in   

twenty-eight  minutes it had wholly     
ceased4 ,the right auricle and ventricle
 in ,e1  occasionally contracted for    
half an hour4 ,the livers of both       
animals  were similar when they were    
first opened1 of a dark red2 that of ,f 
preserved its color for some time when  
exposed to the atmosphere2  whilst that 
of ,e almost immediately became paler   
under the same  circumstances4    ,the  
peristaltic motion continued for nearly 
an equal time in both  animals4    d4   
,the sternum of a young rabbit was      
removed so that the heart and  lungs    
could be perceived1 and he was          
introduced into a vessel filled  with   
nitrous oxide2 the blood in the         
pulmonary veins gradually became  more  
purple1 and the heart appeared to beat  
quicker than before1 all  the muscles   
contracting with great force4 ,after he 
had been in about  a minute1 spots began
 to appear on the lungs1 though the     
contractions  of the heart became       
quicker and weaker2 in three minutes and

 half he  was quite dead2 after death   
the ventricles contracted very feebly1  
though the contractions of the auricles 
were as strong almost after the  end of 
five minutes as at first4 ,this animal  
was passed through water  saturated with
 nitrous oxide2 possibly this fluid had 
some effect on  his organs4    ,besides 
these animals1 many others1 as          
guinea-pigs1 mice and birds1  were      
dissected after being destroyed in      
nitrous oxide2 in all of them  the same 
general appearance was observed4 ,their 
muscular fibre almost  always appeared  
less irritable than that of animals     
destroyed1 by  organic lsion of part of 
the nervous system1 in the atmosphere4  
,the  ventricles of the heart in        
general1 contracted feebly and for a    
very  short time2 whilst the auricles   
continued to act for a great length of  
time4 ,the lungs were dark in their     
appearance1 and always suffused here    
and there with purple2 the blood in the 
pulmonary veins when slightly  observed1

 appeared dark1 like venous blood1 but  
when minutely examined1  was evidently  
much more purple4 ,the blood in the vena
 cava1 was darker  than that in the     
pulmonary veins4 ,the cerebrum was dark4
    ,in a late experiment1 ,i thought ,i
 perceived a slight extravasation of    
blood in one of the ventricles of the   
brain in a rabbit destroyed in  nitrous 
oxide2 but as this appearance had not   
occurred in the animals  ,i had examined
 before1 or in those dissected by ,dr4  
,kinglake1 and ,mr4  ,king1 ,surgeon1 ,i
 am inclined to refer it to an          
accidental cause4 ,at my  request1 ,mr4 
,smith1 ,surgeon1 examined the brain of 
a young rabbit that  had been killed in 
his presence in nitrous oxide2 he was of
 opinion  that no effusion of blood into
 the ventricles had taken place4    ,in 
comparing the external appearance of the
 crural nerves in two  rabbits that had 
been dissected by ,dr4 ,kinglake1 having
 been destroyed  one in hydrogene1 the  
other in nitrous oxide1 we could        

perceive no  perceptible difference4    
,it deserves to be noticed1 that        
whenever the gall bladder and the       
urinary bladder have been examined in   
animals destroyed in nitrous  oxide1    
they have been always distended with    
fluid2 which is hardly ever  the case in
 animals killed by privation of         
atmospheric air4    ,in the infancy of  
my experiments on the action of nitrous 
oxide upon  animals1 ,i thought that it 
rendered the venous blood less          
coagulable2  but this ,i now find to be 
a mistake4 ,the blood from the pulmonary
  veins of animals killed in nitrous    
oxide1 does not sensibly differ in  this
 respect from the arterial blood of     
those destroyed in hydrogene1  and both 
become vermilion nearly in the same time
 when exposed to the  atmosphere4    ,in
 describing the various shades of color 
of the blood in the preceding           
observations on the different dissected 
animals1 the poverty of  the language of
 color1 has obliged me to adopt terms1  

which ,i fear  will hardly convey to the
 mind of the reader1 distinct notions of
  the differences observable by minute  
examination in the venous and  arterial 
blood of animals that die of privation  
of atmospheric air1  and of those       
destroyed by the action of nitrous      
oxide4 ,this difference  can only be    
observed in the vessels by means of a   
strong light2 it  may however be easily 
noticed in the fluid blood by the       
introduction  of it from the arteries or
 veins at the moment of their incision1 
between two polished surfaces of white  
glass1#ahf so closely adapted  to each  
other1 as to prevent the blood from     
coming in contact with the  atmosphere4 
#ahf ,the colour of common venous blood1
 examined in this way1  resembles that  
of the paint called by colour-men red   
ochre2 that of  blood saturated with    
nitrous oxide1 approaches to the tinge  
of lake4    ,having four or five times  
had an opportunity of bleeding people in
  the arm for trifling complaints1 ,i   

have always received the blood in       
phials1 filled with various gases1 in a 
mode to be described hereafter4  ,venous
 blood agitated in nitrous oxide1       
compared with similar blood  in common  
air1 hydrogene1 and nitrogene1 was      
always darker and more  purple than the 
first1 and much brighter and more florid
 than the  two last1 which were not     
different in their color from venous    
blood1  received between two surfaces of
 glass4 ,it will be seen hereafter1 that
  the coagulum of venous blood is       
rendered more purple when exposed to    
nitrous oxide1 whilst the gas is        
absorbed2 likewise that blood altered   
by nitrous oxide1 is capable of being   
again rendered vermilion1 by  exposure  
to the air4    ,the appearances noticed 
in the above mentioned experiments1 in  
the  lungs of animals destroyed in      
nitrous oxide1 are similar to those     
observed by ,dr4 ,beddoes1 in animals   
that had been made to breathe  oxygene  
for a great length of time4    ,there   

were many reasons for supposing that the
 large purple spots  in the lungs of    
animals destroyed in nitrous oxide1 were
 owing to  extravasation of venous blood
 from the capillary vessels2 their coats
  being broken by the highly increased  
arterial action4 ,to ascertain  whether 
these phnomena existed at a period of   
the action of nitrous  oxide1 when the  
animal was recoverable by exposure to   
the atmosphere4    ,i introduced a      
rabbit of six months old1 into a vessel 
of nitrous  oxide1 and after a minute1  
when it had fallen down apparently      
apoplectic1 plunged him wholly under    
water2 he immediately began to          
struggle1 and what surprised me very    
much1 died in less than a minute  after 
submersion4 ,on opening the thorax1 the 
blood in the pulmonary  veins was nearly
 of the color of that in animals that   
have been simply  drowned4 ,the lungs   
were here and there1 marked with a few  
points2  but there were no large purple 
spots1 as in animals that have been     

wholly destroyed in nitrous oxide3 the  
right side of the heart only            
contracted4 ,in this experiment1 the    
excitement from the action of the  gas  
was probably carried to such an extent1 
as to produce indirect  debility4 ,there
 are reasons for supposing1 that animals
 after having  been excited to but a    
small extent by the respiration of      
nitrous oxide1  will live under water   
for a greater length of time1 than      
animals  previously made to breathe     
common air4      ,v4 ,of the respiration
 of mixtures of ,nitrous ,oxide1 and    
other gases1  by warm-blooded ,animals4 
a4 ,a rabbit of near two months old1 was
 introduced into a mixture of  equal    
parts hydrogene and nitrous oxide       
through water4 ,he immediately  began to
 struggle2 in a minute fell on his side2
 in three minutes  gasped1 and made long
 inspirations2 and in four minutes and  
half1 was  dead4 ,on dissection1 he     
exhibited the same appearances as       
animals  destroyed in nitrous oxide4    

b4 ,a large and strong mouse was        
introduced into a mixture of three      
parts hydrogene to one part nitrous     
oxide4 ,he immediately began to         
struggle very much1 in half a minute1   
became convulsed1 and in about a        
minute1 was quite dead4    c4 ,into a   
mixture of one oxygene1 and three       
nitrous oxide1 a small  guinea-pig was  
introduced4 ,he immediately began to    
struggle1 and in two  minutes reposed on
 his side1 breathing very deeply4 ,he   
made afterwards  no violent muscular    
motion2 but lived quietly for near      
fourteen  minutes3 at the end of which  
time1 his legs were much convulsed4 ,he 
was  taken out1 and recovered4    d4 ,a 
mouse lived apparently without          
suffering1 for near ten minutes1  in a  
mixture of #a atmospheric air1 and #c   
nitrous oxide1 at the end of  eleven    
minutes he began to struggle1 and in    
thirteen minutes became  much convulsed4
    e4 ,a cat of three months old1 lived
 for seventeen minutes1 in a  very large

 quantity of a mixture of #a atmospheric
 air1 and #ab nitrous  oxide4 ,on her   
first introduction she was very much    
agitated and  convulsed1 in a minute and
 half she fell down as if apoplectic1   
and  continued breathing very deeply    
during the remainder of the time1       
sometimes uttering very feeble cries4   
,when taken out1 she appeared  almost   
inanimate1 but on being laid before the 
fire1 gradually began to  breathe and   
move2 being for some time1 like most of 
the animals that  have recovered after  
breathing nitrous oxide1 convulsed on   
one side1  and paralytic the other4     
f4 ,a goldfinch lived for near five     
minutes in a mixture of equal  parts    
nitrous oxide and oxygene1 without      
apparently suffering4 ,taken  out1 he   
appeared faint and languid1 but finally 
recovered4#ahg    #ahg ,small birds     
suffer much from cold when introduced   
into gases  through water4 ,in this     
experiment1 the goldfinch was           
immediately  inserted into a large      

mouthed phial1 filled with the gases1   
and opened  in the atmosphere4          
,,vi4 ,recapitulation of facts relating 
to the respiration of ,nitrous  ,oxide1 
by warm-blooded ,animals4    #a4        
,warm-blooded animals die in nitrous    
oxide infinitely sooner than in  common 
air or oxygene2 but not nearly in so    
short a time as in gases  incapable of  
effecting positive changes in the venous
 blood1 or in  non-respirable gases4    
#b4 ,the larger animals live longer in  
nitrous oxide than the smaller  ones1   
and young animals die in it sooner than 
old ones of the same  species4    #c4   
,when animals1 after breathing nitrous  
oxide1 are removed from it  before      
compleat exhaustion has taken place1    
they are capable of being  restored to  
health under the action of atmospheric  
air4    #d4 ,peculiar changes are       
effected in the organs of animals by the
  respiration of nitrous oxide4 ,in     
animals destroyed by it1 the arterial   
blood is purple red1 the lungs are      

covered with purple spots1 both the     
hollow and compact muscles are          
apparently very inirritable1 and the    
brain is dark colored4    #e4 ,animals  
are destroyed by the respiration of     
mixtures of nitrous  oxide and hydrogene
 nearly in the same time as by pure     
nitrous oxide2  they are capable of     
living for a great length of time in    
nitrous oxide  mingled with very minute 
quantities of oxygene or common air4    
,these facts will be reasoned upon in   
the next division4      ,,vii4 ,of the  
respiration of ,nitrous ,oxide by       
amphibious ,animals4    ,as from the    
foregoing experiments1 it appeared that 
the nitrous oxide  destroyed            
warm-blooded animals by increasing the  
living action of their  organs to such  
an extent1 as finally to exhaust their  
irritability and  sensibility2 it was   
reasonable to conjecture that the       
cold-blooded  animals1 possessed of     
voluntary power over respiration1 would 
so  regulate the quantity of nitrous    

oxide applied to the blood in their     
lungs as to bear its action for a great 
length of time4 ,this conjecture  was   
put to the test of experiment2 the      
following facts will prove its  error4  
a4 ,of two middle sized water-lizards1  
one was introduced into a small  jar    
filled with nitrous oxide1 over moist   
mercury1 by being passed  through the   
mercury2 the other was made to breathe  
hydrogene1 by being  carried into it in 
the same manner4    ,the lizard in      
nitrous oxide1 in two or three minutes1 
began to make  violent motions1 appeared
 very uneasy1 and rolled about the jar  
in  every direction1 sometimes          
attempting to climb to the top of it4   
,the  animal in hydrogene was all this  
time very quiet1 and crawled about the  
vessel without being apparently much    
affected4 ,at the end of twelve         
minutes1 the lizard in nitrous oxide was
 lying on his back seemingly  dead2 but 
on agitating the jar he moved a little2 
at the end of fifteen  minutes he did   

not move on agitation1 and his paws were
 resting on his  belly4 ,he was now     
taken out stiff and apparently lifeless1
 but after  being exposed to the        
atmosphere for three or four minutes1   
took an  inspiration1 and moved his head
 a little2 he then raised the end of his
  tail1 though the middle of it was     
still stiff and did not bend when       
touched4 ,his four legs remained close  
to his side1 and were apparently        
useless2 but on pricking them with the  
point of a lancet1 they became          
convulsed4 ,after being introduced into 
shallow water1 he was able to  crawl in 
a quarter of an hour1 though his motions
 were very irregular4  ,in an hour he   
was quite well4 ,the animal in hydrogene
 appeared to have  suffered very little 
in three quarters of an hour1 and had   
raised  himself against the side of the 
jar4 ,at the end of an hour he was taken
  out1 and very soon recovered4    b4   
,some hours after1 the same lizards were
 again experimented upon4  ,that which  

had been inserted into hydrogene in the 
last experiment1  being now inserted    
into nitrous oxide4    ,this lizard was 
apparently lifeless in fourteen minutes1
 having tumbled  and writhed himself    
very much during the first ten minutes4 
,taken out  after being in twenty-five  
minutes1 he did not recover4 ,the other 
lizard lived in hydrogene for near an   
hour and quarter1 taken out after  an   
hour and twenty minutes1 he was dead4   
,these animals were both opened1 but the
 viscera of the nitrous oxide  lizard   
were so much injured by the knife1 that 
no accurate comparison  of them with    
those of the other could be made1 ,i    
thought that the lungs  appeared rather 
redder4    c4 ,of two similar large     
water-lizards1 one was introduced into a
  vessel standing over mercury1 wholly  
filled with water that had been  long   
boiled and suffered to cool under       
mercury4    ,the animal very often rose 
to the top of the jar as1 if in search  
of air1 during the first half hour2 but 

shewed no other signs of  uneasiness4   
,at the end of three quarters of an     
hour1 he became very  weak1 and appeared
 scarcely able to swim in the water4    
,taken out at the  end of fifty minutes1
 he recovered4    ,the other was        
inserted into nitrous oxide4 ,after much
 struggling1  he became senseless in    
about fifteen minutes1 and lay on his   
back4  ,taken out at the end of twenty  
minutes1 he remained for a long time    
motionless and stiff1 but in a quarter  
of an hour1 began to move some  of his  
limbs4    ,from these experiments1 we   
may conclude1 that water-lizards1 and   
most  probably the other amphibious     
animals1 die in nitrous oxide in a much 
shorter time than in hydrogene or pure  
water2 consequently their death  in it  
cannot depend on the simple privation of
 atmospheric air4    ,at the season of  
the year in which this investigation was
 carried on1 ,i  was unable to procure  
frogs or toads4 ,this ,i regret very    
much4    ,supposing that cold-blooded   

animals die in nitrous oxide from       
positive  changes effected in their     
blood by the gas1 it would be extremely 
interesting to notice the apparent      
alterations taking place in their       
organs of respiration and circulation   
during its action1 which  could easily  
be done1 the membranous substance of    
their lungs being  transparent4 ,the    
increase or diminution of the           
irritability of their  muscular fibre1  
might be determined by comparative      
galvanic experiments4      ,,viii4      
,effects of solution of nitrous oxide in
 water on ,fishes4    a4 ,a small       
flounder was introduced into a vessel   
filled with solution  of nitrous oxide  
in water over mercury4 ,he remained at  
rest for ten  minutes and then began to 
move about the jar in different         
directions4  ,in a half an hour he was  
apparently dying1 lying on his side in  
the  water4 ,he was now taken out1 and  
introduced into a vessel filled with    
water saturated with common air1 he very

 soon recovered4    b4 ,of two large    
thornbacks1#ahh equally brisk and       
lively4 ,one1 ,a1  was introduced into a
 jar containing nearly #c cubic inches  
of water1  saturated with nitrous oxide1
 and which previous to its impregnation 
had been long boiled2 the other1 ,b1 was
 introduced into an equal  quantity of  
water which had been deprived of air by 
distillation  through mercury4    #ahh  
,i use the popular name4 ,this fish is  
very common in every part of  ,england2 
it is nearly of the same size and color 
as the minnow1 and is  distinguished    
from it by two small bony excresences at
 the origin of  the belly4 ,it is       
extremely susceptible4    ,a1 appeared  
very quiet for two or three minutes1 and
 then began to move  up and down in the 
jar1 as if agitated4 ,in eight minutes  
his motions  became very irregular1 and 
he darted obliquely from one side of the
  jar to the other4 ,in twelve minutes1 
he became still1 and moved his  gills   
very slowly4 ,in fifteen minutes he     

appeared dead4 ,after sixteen  minutes  
he was taken out1 but shewed no signs of
 life4    ,b was very quiet for four    
minutes and half4 ,he then began to move
  about the jar4 ,in seven minutes he   
had fallen on his back1 but still       
continued to move his gills4 ,in eleven 
minutes he was motionless2 taken  out   
after thirteen minutes1 he did not      
recover4    c4 ,of two thornbacks1 one1 
,c was introduced into about an ounce of
  boiled water in contact with          
hydrogene1 standing over mercury4 ,the  
other1 ,d1 was introduced into well     
boiled water saturated with nitrous     
oxide1 and standing in contact with it  
over mercury4 ,c lived near  thirteen   
minutes1 and died without being         
previously much agitated4 ,d  was       
apparently motionless1 after having the 
same affections as ,a in the  last      
experiment1 in sixteen minutes4 ,at the 
end of this time he was  taken out and  
introduced into common water4 ,he soon  
began to move his  gills1 and in less   

than a quarter of an hour was so far    
recovered as to  be able to swim4       
,the last experiment was repeated on two
 smaller thornbacks2 that in the        
aqueous solution of nitrous oxide lived 
near seventeen minutes1 that in  the    
water in contact with hydrogene1 about  
fifteen and half4    ,the experiments in
 ,res4 ,i4 ,div4 #c1 prove the          
difficulty1 and indeed  almost          
impossibility of driving from water by  
boiling1 the whole of the  atmospheric  
air held in solution by it2 they        
likewise show that nitrous  oxide by its
 strong affinity for water1 is capable  
of expelling air  from that fluid after 
no more can be procured from it by      
ebullition4    ,hence1 if water         
saturated with nitrous oxide had no     
positive effects  upon fishes2 they     
ought to die in it much sooner than in  
water deprived  of air by ebullition4   
,from their living in it rather         
longer2#ahi we  may conclude1 that they 
are destroyed not by privation of       

atmospheric  air1 but from some positive
 change effected in their blood by the  
gas4    #ahi ,a priori ,i expected that 
fishes1 like amphibious animals would   
have been very quickly destroyed by the 
action of nitrous oxide4    ,a long     
while ago1 from observing that the gills
 of fish became rather  of a lighter red
 during their death1 in the atmosphere2 
,i conjectured  that the disease of     
which they died1 was probably           
hyperoxygenation  of the blood connected
 with highly increased animal heat4 ,for
 not  only is oxygene presented to their
 blood in much larger quantities in     
atmospheric air than in its aqueous     
solution2 but likewise1 to use  common  
language1 in a state in which it        
contains much more latent  heat4        
,without however laying any stress on   
this supposition1 ,i had the  curiosity 
to try whether thornbacks would live    
longest in atmospheric  air or nitrous  
oxide4 ,in one experiment1 they appeared
 to die in them  nearly in the same     

time4 ,in another1 the fish in nitrous  
oxide lived  nearly half as long again  
as that in atmospheric air4      ,,ix4  
,effects of ,nitrous ,oxide on ,insects4
    ,the winged insects furnished with  
breathing holes1 become motionless  in  
nitrous oxide very speedily2 being      
however possessed of a certain          
voluntary power over respiration1 they  
sometimes recover1 after having  been   
exposed to it for some minutes1 under   
the action of atmospheric  air4    ,a   
butterfly was introduced into a small   
jar1 filled with pure nitrous  oxide1   
over mercury1 ,he struggled a little    
during the first two or  three seconds2 
in about seven seconds1 his legs became 
convulsed1 and  his wings were wrapt    
round his body2 in about half a minute  
he was  senseless2 taken out after six  
minutes1 he did not recover4    ,another
 butterfly introduced into hydrogene1   
became convulsed in about  a quarter of 
a minute1 was senseless in twenty       
seconds1 and taken out  after five      

minutes1 did not revive4    ,a large    
drone1 after being in nitrous oxide for 
a minute and a quarter1  was taken out  
senseless4 ,after being for some time   
exposed to the  atmosphere1 he began to 
move1 and at last rose on his wings4    
,for some  time1 however1 he was unable 
to fly in a straight line2 and often    
after describing circles in the air1    
fell to the ground as if giddy4    ,a   
large fly1 became motionless in nitrous 
oxide after being convulsed1  in about  
half a minute4 ,another was rendered    
senseless in hydrogene1 in  less than a 
quarter of a minute4    ,a fly          
introduced into hydrocarbonate1 dropt   
immediately senseless2  taken out after 
about a quarter of a minute1 he         
recovered2 but like the  fly that had   
lived after exposure to nitrous oxide1  
was for some time  vertiginous4         
,flies live much longer under water1    
alcohol1 or oil1 than in  non-respirable
 gases1 or gases incapable of supporting
 life4 ,a certain  quantity of air      

always continues attached in the fluid  
to the fine  hairs surrounding their    
breathing holes1 sufficient to support  
life for  a short time4    ,snails and  
earth-worms1 live in nitrous oxide a    
long while1 they die in  it however1    
much sooner than in water or hydrogene2 
probably from the  same causes as the   
amphibious animals4      ,,division     
,,ii4        ,of the ,,changes effected 
in ,,nitrous ,,oxide1 and other         
,,gases1 by the ,,respiration of        
,,animals4      ,i4 ,preliminaries4     
,as soon as ,i had discovered that      
nitrous oxide was respirable1 and       
possessed of extraordinary powers of    
action on living beings1 ,i was  anxious
 to be acquainted with the changes      
effected in it by the venous  blood4 ,to
 investigate these changes1 appeared at 
first a simple  problem2 ,i soon however
 found that it involved much preliminary
  knowledge of the chemical properties  
and affinities of nitrous oxide4  ,after
 ,i had ascertained by experiments      

detailed in the preceding  ,researches1 
the composition of this gas its         
combinations1 and the  physical changes 
effected by it in living beings1 ,i     
began my enquiry  relating to the mode  
of its operation4    ,finding that the  
residual gas of nitrous oxide after it  
had been  breathed for some time in silk
 bags1 was chiefly nitrogene1 ,i at     
first  conjectured that nitrous oxide   
was decomposed in respiration in the    
same manner as atmospheric air1 and its 
oxygene only combined with the  venous  
blood2 the following experiments soon   
however convinced me of my  error4      
,,ii4 ,absorption of ,nitrous ,oxide by 
venous blood4 ,changes effected in  the 
blood by different ,gases4    a4 ,though
 the laws of the coagulability of the   
blood are unknown1  yet we are certain  
that at the moment of coagulation1 a    
perfectly new  arrangement of its       
principles takes place2 consequently1   
their powers  of combination must be    
newly modified4 ,the affinities of      

living blood  can only be ascertained   
during its circulation in the vessels of
  animals4 ,at the moment of effusion   
from those vessels1 it begins to  pass  
through a series of changes1 which first
 produce coagulation1 and  finally its  
compleat decomposition4                 
,consequently1 the action of fluid blood
 upon gates out of the vessels1  will be
 more analogous to that of circulating  
blood in proportion as it  is more      
speedily placed in contact with them4   
b4 ,to ascertain the changes effected in
 nitrous oxide by fluid venous  blood4  
,a jar1 six inches long and half an inch
 wide1 graduated to1#je cubic  inches1  
having a tight stopper adapted to it1   
was filled with  nitrogene1 which is a  
gas incapable of combining with1 and    
possessing  no power of a action upon   
venous blood4 ,a large orifice was made 
in the  vein of a tolerably healthy man1
 and the stopper removed from the jar1  
which was brought in contact with the   
arm so as to receive the blood1  and    

pressed close against the skin1 in such 
a way as to leave an  orifice just      
sufficient for the escape of the        
nitrogene1 as the blood  flowed in4     
,when the jar was full1 it was closed1  
and carried to the  pneumatic apparatus1
 the mercury of which had been          
previously a little  warmed4 ,a small   
quantity of the blood was transferred   
into another  jar to make room for the  
gas4 ,the remaining quantity equalled   
exactly  two cubic inches2 to this was  
introduced as speedily as possible1     
eleven measures equal to1#ee cubic      
inches of nitrous oxide1 which  left a  
residuum of _/ only1 when absorbed by   
boiled water1 and was  consequently1    
perfectly pure4 ,on agitation1 a rapid  
diminution of the  gas took place4      
,in the mass of blood which was opaque1 
but little change of color could  be    
perceived2 but that portion of it       
diffused over the sides of the  jar1 was
 evidently of a brighter purple than the
 venous blood4    ,it was agitated for  

two or three minutes1 and then suffered 
to rest2 in  eight minutes it had wholly
 coagulated2 a small quantity of serum  
had  separated1 and was diffused over   
the coagulum4 ,this coagulum was dark2  
but evidently of a more purple tinge    
than that of venous blood2 no gas  had  
apparently been liberated during its    
formation4    ,the nitrous oxide        
remaining1 was not quite equal to seven 
measures2  hence1 at least four measures
 of it had been absorbed4    ,to        
ascertain the nature of the residuum1 it
 was necessary to transfer  it into     
another vessel1 but this ,i found very  
difficult to accomplish1  on account of 
the coagulated blood4 ,by piercing      
through the coagulum  and removing part 
of it by means of curved iron forceps1  
,i at last  contrived to introduce about
 #d measures of the gas into a small    
cylinder1 graduated to1#be cubic inches1
 in which it occupied of course1  nearly
 #i measures2 when a little solution of 
strontian was admitted to  these1 it    

became very slightly clouded2 but the   
absorption that took  place did not more
 than equal half its bulk4              
,consequently1 the quantity  of carbonic
 acid evolved from the blood1 or formed1
 must have been  extremely minute4      
,on the introduction of pure water1 a   
rapid absorption of the gas took  place1
 and after agitation1 not quite #c      
measures remained4 ,these did  not      
perceptibly diminish with nitrous gas2  
their quantity was too  small to be     
examined by any other test2 but there is
 reason to suppose  that they were      
chiefly composed of nitrogene4    ,from 
this experiment1 it appeared that       
nitrous oxide is absorbed when  placed  
in contact with venous blood2 at the    
same time1 that a very  minute quantity 
of carbonic acid and probably nitrogene 
is produced4    c4 ,in another similar  
experiment when nearly half a cubic inch
 of  nitrous oxide was absorbed by about
 a cubic inch and three quarters of     
fluid blood1 the residual gas did not   

equal more than 1 the quantity  absorbed
 being taken as unity4 ,this fact       
induced me to suppose that  the         
absorption of nitrous oxide by venous   
blood1 was owing to a simple  solution  
of the gas in that fluid1 analogous to  
its solution in water  or alcohol4      
,to ascertain if nitrous oxide could be 
expelled from blood impregnated  with   
it1 by heat2 ,i introduced to #b cubic  
inches of fluid blood taken  from the   
medial vein1 about1#f cubic inches of   
nitrous oxide4 ,after  agitation1 in    
seven minutes nearly1#d were absorbed4  
,in ten minutes1  after the blood had   
completely coagulated1 the cylinder     
containing it1  was transferred in      
contact with mercury1 into a vessel of  
solution of  salt in water2 this        
solution was heated and made to boil4   
,during its  ebullition1 the whole of   
the blood became either white or pale   
brown1  and formed a solid coherent     
mass2 whilst small globules of gas were 
given out from it4 ,in a few minutes1   

about1#be of gas had collected4  ,after 
the vessel had cooled1 ,i attempted to  
transfer this gas into  a small         
graduated jar in the mercurial          
apparatus1 but in vain2 the  mass in the
 jar was so solid and tough1 that ,i    
could not remove it4  ,by transferring  
it to the water apparatus1 ,i succeeded 
in displacing  enough of the coagulum to
 suffer the water to come in contact    
with  the gas2 an absorption of nearly  
half of it took place2 hence1 ,i        
conjecture1 that nitrous oxide had been 
given out by the impregnated  blood4    
d4 ,some fresh dark coagulum of venous  
blood1 was exposed to nitrous  oxide4 ,a
 very slight alteration of color took   
place at the surface of  the blood1     
perceptible only in a strong light1 and 
a minute quantity of  gas was absorbed4 
,a taper burnt in the remaining gas as  
brilliantly as  before1 hence1 it had   
apparently suffered no alteration4    e4
 ,to compare the physical changes       
effected in the venous blood  by nitrous

 oxide1 with those produced by other    
gases1 ,i made the  following           
experiments4--,i filled a large phial1  
containing near #ad cubic  inches1 with 
blood from the vein of the arm of a man1
 and immediately  transferred it to the 
mercurial apparatus4 ,different portions
 of it  were thrown into small graduated
 cylinders1 filled with the following   
gases3 nitrogene1 nitrous gas1 common   
air1 oxygene1 nitrous oxide1  carbonic  
acid1 and hydrocarbonate4    ,the blood 
in each of them was successively        
agitated till it began  to coagulate2   
and making allowances for the different 
periods of  agitation1 there was no     
marked difference in the times of       
coagulation4    ,the color of the       
coagulum in every part of the cylinder1 
containing  nitrogene1 was the same very
 dark red4 ,when it was agitated so as  
to  tinge the sides of the jar1 it      
appeared exactly of the color of venous 
blood received between two surfaces of  
glass2 no perceptible absorption  of the

 gas had taken place4    ,the blood in  
nitrous gas was dark1 and much more     
purple on the top than  that in         
nitrogene4 ,when agitated so as to      
adhere to the jar as a thin  surface1   
this purple was evidently deep and      
bright4 ,an absorption of  rather more  
than  of the volume of gas had taken    
place4    ,the blood in oxygene and     
atmospheric air1 were of a much brighter
  tinge than that in any of the other   
gases4 ,on the top1 the color was       
vermilion1 but no perceptible absorption
 had taken place4    ,the coagulum in   
nitrous oxide1 when examined in the mass
 was dark1  and hardly distinguishable  
in its color from venous blood2 but when
  minutely noticed at the surface where 
it was covered with serum1 and in  its  
diffusion over the sides of the jar1 it 
appeared of a fine purple  red1 a tinge 
brighter than the blood in nitrous gas4 
,an absorption had  taken place in this 
cylinder1 more considerable than in any 
of the  others4    ,in carbonic acid1   

the coagulum was of a brown red1 much   
darker than the  venous blood1 and a    
slight diminution of gas had taken      
place4    ,in the hydrocarbonate1#aij   
the blood was red1 a shade darker than  
the  oxygenated blood1 and a very slight
 diminution of the gas#aia was          
perceptible4    #aij ,the hydrocarbonate
 employed1 was procured from alcohol1 by
 means  of sulphuric acid4 ,this gas    
contains more carbon1 than              
hydrocarbonate  from water and charcoal4
    #aia ,the curious fact of the       
reddening of venous blood by            
hydrocarbonate1 was discovered by ,dr4  
,beddoes4    f4 ,to human blood that had
 been saturated with nitrous oxide      
whilst  warm and constantly agitated for
 four or five minutes1 to prevent its   
uniform coagulation1 oxygene was        
introduced2 the red purple on the       
surface of it1 immediately changed to   
vermilion2 and on agitation1  this color
 was diffused through it4 ,on comparing 
the tinge with that  of oxygenated      

blood1 no perceptible difference could  
be observed4  ,no change of volume of   
the oxygene introduced1 had taken place2
 and  consequently1 no nitrous oxide had
 been evolved from the blood4    g4     
,blood1 impregnated with nitrous gas1   
was exposed to oxygene2 but  after      
agitation in it for many minutes1 no    
change of its dark purple  tinge could  
be observed1 though a slight diminution 
of the oxygene  appeared to take place4 
h4 ,blood that had been rendered        
vermilion in every part by long         
agitation in atmospheric air1 the       
coagulum of which was broken and        
diffused with the coagulable lymph      
through the serum1 was exposed to       
nitrous oxide2 for some minutes no      
perceptible change of color took  place2
 but by agitation for two or three      
hours1 it evidently affirmed a  purple  
tinge1 whilst a a slight absorption of  
gas took place4 ,it never  however1     
became nearly so dark as venous blood   
that had been exposed to  nitrous oxide4

    i4 ,blood1 oxygenated in the same   
manner as in the last experiment1  the  
coagulum of which had been broken1 was  
exposed to nitrous gas4 ,the  surface of
 it immediately became purple1 and by   
agitation for a few  minutes1 this color
 was diffused through it4 ,a slight     
diminution of the  gas was observed4 ,on
 comparing the tinge with that of venous
 blood that  had been previously exposed
 to nitrous gas1 there was no           
perceptible  difference4    k4 ,blood   
exposed to oxygenated muriatic acid is  
wholly altered in its  constitution and 
physical properties1 as has been often  
noticed2 the  coagulum becomes black in 
some parts1 and brown and white in      
others4  ,venous blood1 after agitation 
in hydrogene or nitrogene1 oxygenates   
when exposed to the atmosphere in the   
same manner as simple venous  blood4 ,i 
had the curiosity to try whether venous 
blood exposed to  hydrogene1 would      
retain its power of being oxygenated    
longer than  blood saturated with       

nitrous oxide3 for this purpose some    
similar black  coagulum was agitated for
 some time in two phials1 one filled    
with  hydrogene1 the other with nitrous 
oxide4 ,they were then suffered to  rest
 for three days at a temperature from   
about #ef to #fc4 ,after being  opened1 
no offensive smell was perceived in     
either of them1 the blood  in hydrogene 
was rather darker than at the time of   
their exposure1  whilst that in nitrous 
oxide was of a brighter purple4 ,on     
being  agitated for some time in the    
atmosphere1 the blood in nitrous oxide  
became red1 but not of so bright a tinge
 as oxygenated venous blood4  ,the color
 of the blood in hydrogene did not at   
all alter4    l4 ,to ascertain whether  
impregnation with nitrous oxide         
accelerated  or retarded the            
putrefaction of the blood2 ,i exposed   
venous blood in  four phials1 the first 
filled with hydrocarbonate1 the second  
with  hydrogene2 the third with         
atmospheric air1 and the fourth with    

nitrous  oxide4 ,examined after a       
fortnight1 the blood in hydrogene and   
common  air were both black1 and stunk  
very much2 that in hydrocarbonate was   
red1 and perfectly sweet2 that in       
nitrous oxide appeared purple and had   
no disagreeable smell4    ,in a second  
experiment1 when blood was exposed for  
three weeks to  hydrocarbonate and      
nitrous oxide1 that in nitrous oxide was
 darker than  before and stunk a little2
 that in hydrocarbonate was still       
perfectly  sweet4 ,the power of         
hydrocarbonate to prevent the           
putrefaction of  animal matters1 was    
long ago noticed by ,mr4 ,watt4    m4   
,having accidentally cut one of my      
fingers so as to lay bare a  little     
muscular fibre1 ,i introduced it whilst 
bleeding into a bottle of  nitrous      
oxide2 the blood that trickled from the 
wound evidently became  much more       
purple2 but the pain was neither        
alleviated or increased4  ,when however1
 the finger was taken out of the nitrous

 oxide and exposed  to the atmosphere1  
the wound smarted more than it had done 
before4  ,after it had ceased to bleed1 
,i inserted it through water into a     
vessel  of nitrous gas2 but it did not  
become more painful than before4        
,from all these observations1 we may    
conclude1        #ast4 ,that when       
nitrous oxide is agitated in fluid      
venous blood1 a certain portion of the  
gas is           absorbed2 whilst the   
color of the blood changes              
from dark red to red purple4            
#b;dly4 ,that during the absorption of  
nitrous oxide by            the venous  
blood1 minute portions of nitrogene and 
carbonic acid are produced1 either by   
evolution from            the blood1 or 
from a decomposition of part of the     
nitrous oxide4        #c;dly4 ,that     
venous blood impregnated with nitrous   
oxide            is capable of          
oxygenation2 and vice versa2 that       
oxygenated blood may be combined with   
nitrous oxide4    ,when blood separated 

into coagulum and serum1 is exposed to  
nitrous  oxide1 it is most probable that
 the gas is chiefly absorbed by the     
serum4 ,that nitrous oxide however is   
capable of acting upon the  coagulum1 is
 evident from d4 ,in the fluid blood1 as
 we shall see  hereafter1 nitrous oxide 
is absorbed by the attractions of the   
whole  compound4      ,,iii4 ,of the    
changes effected in ,nitrous ,oxide by  
,respiration4    ,to ascertain whether  
the changes effected in nitrous oxide by
 the  circulating blood acting through  
the moist coats of the pulmonary  veins 
of living animals1 were highly analogous
 to those produced in  it by fluid      
venous blood removed from the vessels1  
,i found extremely  difficult4    ,i    
have before observed1 that when animals 
are made to respire nitrous  oxide1 a   
certain absorption of the gas always    
takes place2 but the  smaller animals1  
the only ones that can be experimented  
upon in the  mercurial apparatus1 die in
 nitrous oxide so speedily and occasion 

so  slight a diminution of gas1 that ,i 
judged it useless to attempt to  analise
 the residuum of their respiration1     
which supports flame as well  as pure   
nitrous oxide1 and is chiefly absorbable
 by water4    ,in the infancy of my     
researches1 ,i often respired nitrous   
oxide in a  large glass bell1 furnished 
with a breathing tube and stop-cock1 and
  poised in water saturated with the    
gas4    ,in two or three experiments in 
which the nostrils being closed after   
the exhaustion of the lungs1 the gas was
 inspired from the bell and  respired   
into it1 a considerable diminution was  
perceived1 and by the  test of lime     
water some carbonic acid appeared to    
have been formed2 but  on account of the
 absorption of this carbonic acid by the
 impregnated  water1 and the liberation 
of nitrous oxide from it1 it was        
impossible  to determine with the least 
accuracy1 the quantities of products    
after  respiration4    ,about this time 
likewise1 ,i often examined the residuum

 of nitrous  oxide1 after it had been   
respired in silk bags4 ,in these        
experiments  when the gas had been      
breathed for a long time1 a considerable
  diminution of it was observed1 and the
 remainder extinguished flame and  gave 
a very slight diminution with nitrous   
gas4 ,but the great quantity  of this   
remainder as well as other phnomena1    
convinced me that  though the oiled silk
 was apparently air-tight when dry1     
under slight  pressure1 yet during the  
action of respiration1 the moist and    
warm gas  expired1 penetrated through   
it1 whilst common air entered through   
the  wetted surface4    ,to ascertain   
accurately1 the changes effected in     
nitrous oxide by  respiration1 ,i was   
obliged to make use of the large        
mercurial airholder  mentioned in       
,research ,i4 of the capacity of #bjj   
cubic inches4 ,the upper  cylinder of it
 was accurately balanced so as to be    
constantly under the  pressure of the   
atmosphere4 ,to an aperture in it1 a    

stop-cock having  a very large orifice  
was adapted1 curved and flattened at its
 upper  extremity1 so as to form an     
air-tight mouth-piece4    ,by accurately
 closing the nose1 and bringing the lips
 tight on the  mouth-piece1 after a few 
trials ,i was able to breathe oxygene or
 common  air in this machine for two    
minutes or two minutes and half1 without
  any other uneasy feeling than that    
produced by the inclination of the  neck
 and chest towards the cylinder4 ,the   
power of uniformly exhausting  the lungs
 and fauces to the same extent1 ,i did  
not acquire till after  many            
experiments4 ,at last1 by preserving    
exactly the same posture  after         
exhaustion of the lungs before the      
inspiration of the gas to be            
experimented upon1 and during its       
compleat expiration1 ,i found that ,i   
could always retain nearly the same     
quantity of gas in the bronchial        
vessels and fauces2 the difference in   
the volume expired at different  times1 

never amounting to a cubic inch and     
half4    ,by connecting the conducting  
pipe of the mercurial airholder1 during 
the respiration of the gas1 with a small
 trough of mercury by means of  a curved
 tube1 it became a perfect and excellent
 breathing machine4  ,for by exerting a 
certain pressure on the airholding      
cylinder1 it was  easy to throw a       
quantity of gas after every inspiration 
or expiration1  into tubes filled with  
mercury standing in the trough4 ,in     
these tubes  it could be accurately     
analised1 and thus the changes taking   
place at  different periods of the      
process ascertained4    ,whenever ,i    
breathed pure nitrous oxide in the      
mercurial airholder1  after a compleat  
voluntary exhaustion of my lungs1 the   
pleasurable  delirium was very rapidly  
produced1 and being obliged to stoop on 
the  cylinder1 the determination of     
blood to my head from the increased     
arterial action in less than a minute   
became so great1 as often to  deprive me

 of voluntary power over the muscles of 
the mouth4 ,hence1 ,i  could never rely 
on the accuracy of any experiment1 in   
which the gas  had been respired for    
more than three quarters of a minute4   
,i was able to respire the gas with     
great accuracy for more than half  a    
minute2 it at first1 rather increasing  
than diminishing the power  of volition2
 but even in this short time1 very      
strong sensations  were always produced1
 with sense of fulness about the head1  
somewhat  alarming2 a feeling which     
hardly ever occurs to me when the gas is
  breathed in the natural posture4      
,in all the numerous experiments that ,i
 made on the respiration of  nitrous    
oxide in this way1 a very considerable  
diminution of gas always  took place2   
and the diminution was generally        
apparently greater to the  eye during   
the first four or five inspirations4    
,the residual gas of an experiment was  
always examined in the following        
manner4 ,after being transferred through

 mercury into a graduated  cylinder1 a  
small quantity of concentrated solution 
of caustic potash  was introduced to it1
 and suffered to remain in contact with 
it for  some hours2 the diminution was  
then noted1 and the quantity of gas     
absorbed by the potash1 judged to be    
carbonic acid4 ,to the remainder1  twice
 its bulk of pure water was admitted4   
,after agitation and rest for  four or  
five hours1 the absorption by this was  
noticed1 and the gas  absorbed          
considered as nitrous oxide4 ,the       
residual unabsorbable gas  was mingled  
over water with twice its bulk of       
nitrous gas2 and by this  means1 its    
composition1 whether it consisted wholly
 of nitrogene1 or of  nitrogene mingled 
with small quantities of oxygene1       
ascertained4    ,from a number of       
experiments made at different times on  
the respiration  of nitrous oxide1 ,i   
select the following as the most        
accurate4    ,e4 #a4 ,at temperature    
#ed1 ,i breathed #ajb cubic inches of   

nitrous oxide1  which contained near _/ 
common air1 for about half a minute1    
seven  inspirations and seven           
expirations being made4 ,after every    
expiration1  an evident diminution of   
gas was perceived2 and when the last    
full  expiration was made1 it filled a  
space equal to #fb cubic inches4        
,these #fb cubic inches analised1 were  
found to consist of        ,carbonic    
acid    #c1b      ,nitrous oxide   #bi1j
      ,oxygene          #d1a            
,nitrogene       #be1g                  
--------                      #fb1j     
--------    ,hence1 accounting for the  
two cubic inches of common air          
previously  mingled with the nitrous    
oxide1 #ga cubic inches had disappeared 
in this  experiment4    ,in the last    
respirations1 the quantity of gas was so
 much diminished1  as to prevent the    
full expansion of the lungs2 and hence  
the apparent  diminution was very much  
less after the first four inspirations4 
,e4 #b4 ,at temperature #dg1 ,i breathed

 #ahb cubic inches of nitrous oxide1    
mingled with #b cubic inches of         
atmospheric air1 which previously       
existed in the airholder1 for near #dj  
seconds2 having in this time  made #h   
respirations4 ,the diminution after the 
first full inspiration1  appeared to a  
by-stander nearly uniform4 ,when the    
last compleat  expiration was made1 the 
gas filled a space equal to #abh cubic  
inches1  the common temperature being   
restored4 ,these #abh cubic inches      
analised1  were found to consist of     
,carbonic acid      #e1be      ,nitrous 
oxide     #hh1ge      ,oxygene          
#e1jj      ,nitrogene         #bi1jj    
,consequently1 in this experiment1      
#ic1be cubic inches of nitrous oxide    
had disappeared4    ,in each of these   
experiments1 the cylinder was covered   
with condensed  watry vapor exactly in  
the same manner as if common air had    
been  breathed in it4 ,it ought to be   
observed that1 ,e4 #a4 was made in the  
morning1 four hours and half after a    

moderate breakfast2 whereas1 ,e4  #b4   
was made but an hour and quarter after a
 plentiful dinner2 at which  near three 
fourths of a pint of table-beer had been
 drank4    ,from these experiments we   
learn1 that nitrous oxide is rapidly    
absorbed by the venous blood1 through   
the moist coats of the pulmonary  veins4
 ,but as after a compleat voluntary     
exhaustion of the lungs1  much residual 
air must remain in the bronchial vessels
 and fauces1  as appears from their     
incapability of compleatly collapsing1  
it is  evident that the gas expired     
after every inspiration of nitrous oxide
  mast be mingled with different        
quantities of the residual gas of the   
lungs2#aib whilst after a complete      
expiration1 much of the unabsorbed      
nitrous oxide must remain as residual   
gas in the lungs4 ,now when  a complete 
expiration is made after the breathing  
of atmospheric  air1 it is evident that 
the residual gas of the lungs consists  
of  nitrogene1#aic mingled with small   

portions of oxygene and carbonic  acid4 
,and these are the only products found  
after the respiration of  nitrous oxide4
    #aib ,by lungs1 ,i mean in this     
place1 all the internal organs of       
respiration4    #aic ,because these     
products are formed during the          
respiration of  common air4    ,to      
ascertain whether these products were   
partially produced1 during  the process 
of respiration1 as ,i was inclined to   
believe from the  experiments in the    
last section1 or whether they were      
wholly the  residual gases of the lungs1
 ,i found extremely difficult4    ,i at 
first thought of breathing nitrous oxide
 immediately after my  lungs had been   
filled with oxygene2 and to compare the 
products  remaining after the full      
expiration1 with those produced after a 
full  expiration of pure oxygene2 but on
 the supposition that oxygene and       
nitrous oxide1 when applied together to 
the venous blood1 must effect  changes  
in it different from either of them     

separately1 the idea was  relinquished4 
,i attempted to inspire nitrous oxide1  
after having made two  inspirations and 
a complete expiration of hydrogene2 but 
in this  experiment the effects of the  
hydrogene were so debilitating1 and the 
consequent stimulation by the nitrous   
oxide so great1 as to deprive  me of    
sense4 ,after the first three           
inspirations1 ,i lost all power of      
standing1 and fell on my back1 carrying 
in my lips the mouth-piece  separated   
from the cylinder1 to the great alarm of
 ,mr4 ,patrick ,dwyer1  who was noting  
the periods of inspiration4    ,though  
experiments on successive inspirations  
of pure nitrous oxide  might go far to  
determine whether or no any nitrogene1  
carbonic acid  and oxygene were products
 of respiration1 yet ,i distinctly saw  
that it  was impossible in this way to  
ascertain their quantities1 supposing   
them produced1 unless ,i could first    
determine the capacity of my lungs2  and
 the different proportions of the gases 

remaining in the bronchial  vessels     
after a compleat expiration1 when       
atmospheric air had been  respired4     
,in some experiments 7that ,i made on   
the respiration of hydrogene1  with a   
view to determine whether carbonic acid 
was produced by  the combination of     
carbon loosely combined in the venous   
blood1  with the oxygene respired1 or   
whether it was simply given out as      
excrementitious by this blood7 ,i found1
 without however being able to  solve   
the problem ,i had proposed to myself1  
that in the respiration of  pure        
hydrogene1 little or no alteration of   
volume took place2 and that  the        
residual gas was mingled with some      
nitrogene1 and a little oxygene  and    
carbonic acid4    ,from the comparison  
of these facts with those noticed in the
 last  section and in ,r4 ,,iii4 ,div4  
,i4 there was every reason to suppose   
that hydrogene was not absorbed or      
altered when respired3 but only  mingled
 with the residual gases of the lungs4  

,hence1 by making a full  expiration of 
atmospheric air1 and afterwards taking  
six or seven  respirations of hydrogene 
in the mercurial airholder1 and then    
making  a compleat expiration1 ,i       
conjectured that the residual gas and   
the  hydrogene would be so mingled1 as  
that nearly the same proportions  should
 remain in the bronchial vessels1 as in 
the airholder4 ,by  ascertaining these  
proportions and calculating from them1  
,i hoped to be  able to ascertain with  
tolerable exactness1 the capacity of my 
fauces  and bronchia1 as well as the    
composition of the gas remaining in     
them1  after a complete expiration of   
common air4      ,,iv4 ,respiration of  
,hydrogene4    ,the hydrogene that ,i   
employed1 was procured from the         
decomposition of  water by means of     
clean iron filings and diluted sulphuric
 and muriatic  acids4 ,it was breathed  
in the same manner as nitrous oxide1 in 
the  large mercurial airholder4         
,after a compleat voluntary exhaustion  

of my lungs in the usual  posture1 ,i   
found great difficulty in breathing     
hydrogene for so  long as half a minute1
 so as to make a compleat expiration of 
it4 ,it  produced uneasy feelings in the
 chest1 momentary loss of muscular      
power1 and sometimes a transient        
giddiness4    ,in some of the           
experiments that ,i made2 on account of 
the giddiness1  the results were        
rendered inconclusive1 by my removing my
 mouth from  the mouth-piece after      
expiration1 before the assistant could  
turn the  stop-cock4    ,the purity of  
the hydrogene was ascertained           
immediately before the  experiment by   
the test of nitrous gas1 and by         
detonation with oxygene  or atmospheric 
air2 generally #ab measures of          
atmospheric air were fired  with #d of  
the hydrogene1 and if the diminution was
 to ten or a little  more1 the gas was  
judged to be pure4    ,after the        
experiment1 when the compleat expiration
 had been made and  the common          

temperature restored2 the volume of the 
gas was noticed1  and then a small      
quantity of it thrown into the mercurial
 apparatus by  means of the conducting  
tube1 to be examined4 ,the carbonic acid
 was  separated by from it by means of  
solution of potash or strontian2 the    
quantity of oxygene it contained1 was   
ascertained by means of nitrous  gas of 
known composition2 the superabundant    
nitrous gas was absorbed  by solution of
 muriate of iron2 and the proportions of
 hydrogene  and nitrogene in the        
remaining gas1 discovered by            
inflammation with  atmospheric air or   
oxygene in the detonating tube by the   
electric spark4    a4 ,the two following
 experiments made upon quantities of    
hydrogene1  equal to those of the       
nitrous oxide respired in the           
experiments in the  last section1 are   
given as the most accurate of five4     
,e4 #a4 ,i respired at #ei #ajb cubic   
inches of hydrogene apparently pure1    
for rather less than half a minute1     

making in this time seven quick         
respirations4    ,after the complete    
expiration1 when the common temperature 
was  restored1 the gas occupied a space 
equal to #ajc cubic inches nearly4      
,these analised were found to consist of
        ,carbonic acid    #d1j          
,oxygene          #c1g      ,nitrogene  
#ag1c      ,hydrogene       #gh1j       
----------                     #ajc1j   
,now as in this experiment1 the gas was 
increased in bulk only a cubic  inch2   
supposing that after the compleat       
expiration the gas in the  lungs1       
bronchia and fauces was of nearly       
similar composition with  that in the   
airholder1 and that no hydrogene had    
been absorbed by the  blood1 it would   
follow that #bd cubic inches of         
hydrogene remained in  the internal     
organs of respiration1 and consequently1
 by the rule of  proportion1 about #g1h 
of the mixed residual gas of the common 
air4  ,and then the whole quantity of   
residual gas of the lungs1 supposing    

the temperature #ei1 would have been    
#ca1h cubic inches2 but as its          
temperature was nearly that of the      
internal parts of the body1 #ih1 it     
must have filled a greater space2       
calculating from the experiments of     
,guyton and ,vernois1#aid about #cg1eaie
 cubic inches4    ,from the increase of 
volume1 it would appear that a minute   
quantity  of gas had been generated     
during the respiration1 and this was1 as
 we  shall see hereafter1 most probably 
carbonic acid4#aif ,likewise there  is  
reason to suppose1 that a little of the 
residual oxygene must have  been        
absorbed4 ,making allowances for those  
circumstances1 it would  follow1 that   
the #cg1e cubic inches of gas remaining 
in my lungs1 after  a compleat          
expiration of atmospheric air at animal 
heat #ih1 equal to  #ca1h cubic inches  
at #ei1 were composed of                
,nitrogene       #ba1i      ,carbonic   
acid    #d1i      ,oxygene          #e1j
                      --------          

#ca1h    #aid ,annales de ,chimie1 vol4 
#a1 page #bgi4    #aie ,this is only an 
imperfect approximation2 the ratio of   
the  increase of expansibility of gases 
to the increase of temperature1 has  not
 yet been ascertained4 ,it is probable  
that the expansibility of  gases is     
altered by their mixture4    #aif ,for  
there is no reason to suppose the       
production of nitrogene4    ,e4 #b4 ,i  
respired for near a half a minute in the
 mercurial airholder at  #fa1 #ahb cubic
 inches of hydrogene2 having made during
 this time1 six  long inspirations4     
,after the last expiration1 the gas     
filled a space  nearly equal to #ahd    
cubic inches1 and analised1 was found to
 consist of        ,carbonic acid       
#d1h      ,oxygene          #d1f        
,nitrogene       #ba1j      ,hydrogene  
#aec1f                     ----------   
#ahd1j    ,now in this experiment1      
reasoning in the same manner as before1 
#bh1d  cubic inches of hydrogene must   
have remained in the lungs1 and likewise

  #e1e of the atmospheric residual gas4 
,consequently1 the whole residual  gas  
was nearly equal to #cd cubic inches at 
#fa1 which at #ih would  become about   
#dj1d cubic inches4 ,and reasoning as   
before1 it would  appear from this      
experiment1 that the quantity of gas    
remaining in my  lungs after a compleat 
voluntary respiration1 equalled at #ih1 
about #dj  cubic inches1 and at #fa1 #cd
 nearly3 making the necessary           
corrections2  that after common air had 
been breathed1 these #cd cubic inches   
consisted of        ,carbonic acid      
#d1a      ,oxygene          #e1e        
,nitrogene       #bd1d    b4 ,it would  
have been possible to prove the truth of
 the postulate on  which the experiments
 were founded1 by respiring common air  
or oxygene  after the compleat          
expiration of the hydrogene1 for the    
same time as  the hydrogene was respired
 and in equal quantities4    ,for if    
portions of hydrogene were found in the 
airholder equal to  those of the        

residual gases in the two experiments1  
it would prove  that a uniform mixture  
of residual gas with the gas inspired1  
was  produced by the respiration4 ,that 
this mixture must have taken place1     
appeared1 however1 so evident from      
analogous facts1 that ,i judged the     
experimental proof unnecessary4         
,indeed1 as most gases1 though of       
different specific gravities1 when      
brought in contact with each other1     
assume some sort of union1 it  is more  
than probable1 that gas inspired into   
the lungs1 from being  placed in contact
 with the residual gas on such an       
extensive surface1  must instantly      
mingle with it4 ,hence1 possibly one    
deep inspiration  and compleat          
expiration of the whole of a quantity of
 hydrogene1 will  be sufficient to      
determine the capacity of the lungs     
after compleat  voluntary exhaustion1   
and the nature of the residual air4     
,that two inspirations are sufficient1  
appears probable from the  following    

experiment4    ,e4 #c4 ,after a compleat
 voluntary expiration of common air1 ,i 
made two  deep inspirations of #ada     
cubic inches of hydrogene4 ,after the   
compleat  expiration1 they filled a     
space equal to rather more than #adb    
cubic  inches1 and analised1 were found 
to consist of        ,carbonic acid     
#c1a      ,oxygene          #d1e        
,nitrogene       #ah1h      ,hydrogene  
#aae1f                     ----------   
#adb1j    ,now calculating on the       
exhausted capacity of my lungs from this
  experiment1 supposing uniform mixture1
 they would contain after  expiration of
 common air1 about #cj1g cubic inches at
 #eh1 equal to #cf  at #ih1 composed of 
about        ,nitrogene       #bj1i     
,oxygene          #e1h      ,carbonic   
acid    #d1j                            
--------                      #cj1g     
,one should suppose a priori that in    
this experiment much less of the        
residual oxygene of the lungs must have 
been absorbed1 than in ,expts4 #a  and  

#b2 yet there is no very marked         
difference in the portions evolved4     
,that a tolerably accurate mixture took 
place1 appears from the quantity  of    
nitrogene4 ,the smaller quantity of     
carbonic acid is an evidence in  favour 
of its evolution from the venous blood4 
c4 ,it is reasonable to suppose that the
 pressure upon the residual  gas of the 
exhausted lungs1 must be nearly equal to
 that of the  atmosphere4 ,but as       
aqueous vapour is perpetually given out 
by the  exhalents1 and perhaps evolved  
from the moist coats of the pulmonary   
vessels1 it is likely that the residual 
gas is not only fully saturated  with   
moisture at #ih1 but likewise           
impregnated with uncombined vapor2  and 
hence its volume enlarged beyond the    
increment of expansion of  temperature4 
,considering all these circumstances1   
and calculating from the mean  of the   
three experiments on the composition of 
the residual gas1 ,i  concluded1        
#ast4 ,that the exhausted capacity of my

 lungs was equal to about #da  cubic    
inches4    #b;dly4 ,that the gas        
contained in my bronchial vessels and   
fauces1 after  a compleat expiration of 
atmospheric air1 was equal to about #cb 
cubic  inches1 its temperature being    
reduced to #ee4    #c;dly4 ,that these  
#cb cubic inches were composed of about 
,nitrogene       #bc1j      ,carbonic   
acid    #d1a      ,oxygene          #d1i
    d4 ,in many experiments made in the 
mercurial airholder on the  capacity of 
my lungs under different circumstances1 
,i found that ,i  threw out of my lungs 
by a full forced expiration at          
temperatures from  #eh to #fb           
cub4     cub4                           
in4      in4      ,after a full         
voluntary inspiration1 from  #ahi  to   
#aia      ,after a natural inspiration1 
from          #gh  to   #gi      ,after 
a natural expiration1 from           #fg
  to   #fh    ,so that making the       
corrections for temperature1 it would   
appear1 that  my lungs in a state of    

voluntary inspiration1 contained about  
#bed  cubic inches2 in a state of       
natural inspiration about #ace2 in a    
state  of natural expiration1 about     
#aah2 and in a state of forced          
expiration  #da4aig    #aig ,this       
capacity is most probably below the     
medium1 my chest is  narrow1 measuring  
in circumference1 but #bi inches1 and my
 neck rather  long and slender4    ,as  
the exhausted capacity as well as       
impleted capacity of the internal       
organs of respiration must be different 
in different individuals1  according as 
the forms and size of their thorax1     
fauces1 and bronchia  are different1 it 
would be almost useless to endeavour to 
ascertain a  standard capacity4 ,it is  
however probable1 that a ratio exists   
between  the quantities of air inspired 
in the natural and forced inspiration1  
those expired in the natural and forced 
expiration1 and the whole  capacity of  
the lungs4 ,if this ratio were          
ascertained1 a single  experiment on the

 natural inspiration and expiration of  
common air1  would enable us to         
ascertain the quantity of residual gas  
in the lungs  of any individual after a 
compleat forced expiration4#aih    #aih 
,dr4 ,goodwyn in his excellent work on  
the connexion of life with  respiration1
 has detailed some experiments on the   
capacity of the lungs  after natural    
expiration4 ,he makes the medium        
capacity about #aji cubic  inches1 which
 agrees very well with my               
estimation4--page #bg4      ,v4         
,additional observations and experiments
 on the ,respiration of  ,nitrous       
,oxide4    a4 ,having thus ascertained  
the capacity of my lungs1 and the       
composition of the residual gas of      
expiration1 ,i proceeded to reason      
concerning the experiments in section   
,,iii1 on the respiration of  nitrous   
oxide4    ,in ,exp4 ,i4 nearly #ajj     
cubic inches of nitrous oxide1 making   
the  corrections on account of the      
common air1 were respired for half a    

minute4 ,in this time1 they were reduced
 to #fb cubic inches1 which  consisted  
of #c1b carbonic acid1 #bi nitrous      
oxide1 #d1a oxygene1 and #be1g          
nitrogene4    ,but1 as appears from the 
last section1 there existed in the lungs
  before the inspiration of the nitrous 
oxide1 about #cb cubic inches of  gas1  
consisting of #bc nitrogene1 #d1a       
carbonic acid1 and #d1i oxygene1        
temperature being reduced to #ei4 ,this 
gas must have been perfectly  mingled   
with the nitrous oxide during the       
experiment2 and consequently1  the      
residual gas in the lungs after the     
experiment1 was of the same  composition
 as that in the airholder4    ,supposing
 it as before1 to be about #cb cubic    
inches3 from the rule of  proportion1   
they will be composed of        ,nitrous
 oxide   #ad1g      ,nitrogene          
#ac1c      ,carbonic acid    #a1i       
,oxygene          #b1a    ,and the whole
 quantity of gas in the lungs and the   
airholder1 supposing  the temperature   

#ei1 will equal #id cubic inches1 which 
are composed of        ,nitrous oxide   
#dc1g      ,nitrogene         #ci1j     
,carbonic acid     #e1b      ,oxygene   
#f1a                       --------     
#id    ,but before the experiment1 the  
gas in the lungs and airholder equalled 
#acd cubic inches1 and these1 reckoning 
for the common air1 were  composed of   
,nitrous oxide     #ajj      ,nitrogene1
         #bd1c      ,carbonic acid      
#d1a      ,oxygene             #e1f     
,hence1 it appears1 that #ef1c cubic    
inches of nitrous oxide were  absorbed  
in this experiment1 and #ac1g of        
nitrogene produced1 either  by evolution
 from the blood1 or decomposition of the
 nitrous oxide4  ,the quantities of     
carbonic acid and oxygene approach so   
near to those  existing after the       
respiration of hydrogene1 that there is 
every reason  to believe that no portion
 of them was produced in consequence of 
the  absorption1 or decomposition of the
 nitrous oxide4    b4 ,in ,exp4 #b1     

calculating in the same manner1 before  
the first  inspiration1 a quantity of   
gas equal to #baf1e cubic inches at #dg1
  existed in the lungs and airholder1   
and these #baf1e cubic inches were      
composed of        ,nitrous oxide1      
#ahb1j      ,nitrogene           #bd1i  
,carbonic acid        #d1a      ,oxygene
              #e1e                      
------------                            
#baf1e    ,after the compleat           
expiration1 #afj cubic inches remained  
in the lungs  and airholder1 which was  
composed of        ,nitrous oxide       
#aaj1f      ,nitrogene          #cf1c   
,carbonic acid       #f1h      ,oxygene 
#f1c  ,hence1 it appears1 that #ga1d    
cubic inches of nitrous oxide were      
absorbed in this experiment1 and about  
#ab of nitrogene produced4 ,the         
quantity of carbonic acid and oxygene is
 rather greater than that which  existed
 in the experiments on hydrogene4    c4 
,from these estimations1 ,i learned that
 a small quantity of  nitrogene was     

produced during the absorption of       
nitrous oxide in  respiration4 ,it      
remained to determine1 whether this     
nitrogene owed its  production to       
evolution from the blood1 or to the     
decomposition of a  portion of the      
nitrous oxide4    ,analogical evidences 
were not in favour of the hypothesis of 
decomposition4 ,it was difficult to     
suppose that a body requiring the       
temperature of ignition for its         
decomposition by the most inflammable   
bodies1 should be partially absorbed and
 partially decompounded at #ih1  by a   
fluid apparently possessed of uniform   
attractions4    ,it was more easy to    
believe1 that from the immense quantity 
of  nitrogene taken into the blood in   
nitrous oxide2 the system soon  became  
overcharged with this principle1 which  
not being wholly  expended in new       
combinations during living action1 was  
liberated in  the ariform state by the  
exhalents1 or through the moist coats of
 the  veins4    ,now if the last        

rationale were true1 it would follow1   
that the  quantity of nitrogene produced
 in respiration1 ought to be increased  
in proportion as a greater quantity of  
nitrous oxide entered into  combination 
with the blood4    d4 ,to ascertain     
whether this was the case1 ,i made after
 full  voluntary exhaustion of my lungs1
 one full voluntary inspiration and     
expiration of #ajh cubic inches of      
nitrous oxide4 ,after this1 it filled  a
 space nearly equal to #ii cubic inches4
 ,the quantities of carbonic  acid and  
oxygene in these were not determined2   
but by the test of  absorption by water1
 they appeared to contain only #ah      
nitrogene2 which  is very little more   
than should have been given from the    
residual gas  of the lungs4    ,in a    
second experiment1 ,i made two          
respirations of #ajh cubic inches  of   
nitrous oxide nearly pure4 ,the         
diminution was to #ie4 ,on analysing    
these #ie1 ,i found to my great         
surprise1 that they contained only #ag  

nitrogene4 ,hence1 ,i could not but     
suspect some source of error in the     
process4    ,i now introduced into a    
strong new silk bag1 the sides of which 
were  in perfect contact1 about #h      
quarts of nitrous oxide4 ,from the mode 
of  introduction1 this nitrous oxide    
must have been mingled with a little    
common air1 not however sufficient to   
disturb the results4    ,i then adapted 
a cork cemented to a long curved tube to
 my right  nostril2 the tube was made to
 communicate with the water apparatus2  
and the left nostril being accurately   
closed1 and the mouth-piece of  the silk
 bag tightly adapted to the lips1 ,i    
made a full expiration  of the common   
air of my lungs1 inspired nitrous oxide 
from the bag1  and by carefully closing 
the mouth-piece with my tongue1 expired 
it  through the curved tube into the    
water apparatus4 ,in this way1 ,i made  
nine respirations of nitrous oxide4 ,the
 expired gas of the first  respiration  
was not preserved2 but part of the gas  

of the second1  third1 fifth1 seventh   
and ninth1 were caught in seperate      
graduated  cylinders4 ,the second1      
analised by absorption1 consisted of    
about #bi  absorbable gas1 which must   
have been chiefly nitrous oxide2 and #ag
  unabsorbable gas1 which must have been
 chiefly nitrogene2 and the third  of   
#bb absorbable gas1 and #h unabsorbable4
 ,the fifth was composed of #bg  to #f2 
the seventh of #bc to #g1 and the ninth 
of #bf to #aa4    e4 ,though the results
 of these experiments were not so       
conclusive as  could be wished2 yet1    
comparing them with those of the        
experiments in  section ,,iii4 it seemed
 reasonable to conclude1 that the       
production of  nitrogene was increased1 
in proportion as the blood became more  
fully  impregnated with nitrous oxide4  
,from this conclusion1 compared with the
 phnomenon noticed in section  #b1 and  
in ,div4 ,i4 section #d1 ,i am induced  
to believe that the  production of      
nitrogene during the respiration of     

nitrous oxide1 is  not owing to the     
decomposition of part of the nitrous    
oxide1 in the  ariform state immediately
 by the attraction of the red particles 
of venous blood for its oxygene2 but    
that it is rather owing to a new        
arrangement produced in the principles  
of the impregnated blood1 during        
circulation2 from which1 becoming       
supersaturated with nitrogene1 it  gives
 it out through the moist coats of the  
vessels4    ,for if any portion of      
nitrous oxide were decomposed           
immediately by the  red particles of the
 blood1 one should conjecture1 that the 
quantity of  nitrogene produced1 ought  
to be greater during the first          
inspirations1  before these particles   
became fully combined with condensed    
oxygene4  ,if on the contrary1 the whole
 of the nitrogene and oxygene of the    
nitrous oxide were both combined with   
the blood1 and carried through  the     
pulmonary veins and left chamber of the 
heart to the arteries2  then1 supposing 

the oxygene chiefly expended in living  
action1 whilst  the nitrogene was only  
partially consumed in new combinations1 
it  would follow1 that the venous blood 
of animals made to breathe nitrous      
oxide1 hyper-saturated with nitrogene1  
must be different from common  venous   
blood2 and this we have reason to       
believe from the phnomena in  ,div4 ,i4 
section #d1 is actually the case4    f4 
,besides the nitrogene generated during 
the respiration of nitrous  oxide1 we   
have noticed the evolution of other     
products1 carbonic  acid1#aii and water4
    #aii ,the oxygene as we have before 
noticed1 most probably wholly  existed  
in the residual gas4    ,now as nearly  
equal quantities of carbonic acid are   
produced1 whether  hydrogene or nitrous 
oxide is respired1 provided the process 
is carried  on for the same time2 there 
is every reason to believe1 as we have  
said  before1 that no part of the       
carbonic acid produced1 is generated    
from  the immediate decomposition of    

nitrous oxide by carbon existing in the 
blood4    ,consequently1 in these       
experiments1 it must be either evolved  
from the  venous blood2 or formed1 by   
the slow combination of the oxygene of  
the  residual air of respiration with   
the charcoal of the blood4    ,but if it
 was produced by the decomposition of   
residual atmospheric  air1 it would     
follow1 that its volume must be much    
less than that  of the oxygene of the   
residual air1 which had disappeared2 for
 some  of this oxygene must have been   
absorbed by the blood1 and during  the  
conversion of oxygene into carbonic acid
 by charcoal1 a slight  diminution of   
volume is produced4    ,in the          
experiments when nitrous oxide and      
hydrogene were respired for  about half 
a minute1 the medium quantity of        
carbonic acid produced1 was  #e1f cubic 
inches nearly4    ,now we will assume1  
that the quantity of carbonic acid      
produced1 is  in the ratio of the       
oxygene diminished2 and there is every  

reason to  believe1 that in the         
expiration of atmospheric air1 the      
expired air and  the residual air are   
nearly of the same composition4         
,hence1 no more carbonic acid can remain
 in the lungs or be produced  from the  
residual gas after the compleat         
expiration of common air1  than that    
which can be generated from a volume of 
atmospheric air  equal to the residual  
gas of the lungs4    ,the residual gas  
of the lungs1 after compleat expiration1
 equals at  #ee1 #cb cubic inches1 and  
#cb cubic inches of common air contain  
#h4f  cubic inches of oxygene4    ,but  
in the experiments on the respiration of
 hydrogene1 not only  #e4f cubic inches 
of carbonic acid were produced1 but more
 than #d of  residual oxygene remained  
unabsorbed4    ,hence it appears        
impossible that all the carbonic acid   
evolved from the  lungs during the      
respiration of nitrous oxide or         
hydrogene could have  been produced by  
the combination of charcoal in the      

venous blood with  residual atmospheric 
oxygene3 there is consequently every    
reason to  believe that it is wholly or 
partially liberated from the venous     
blood  through the moist coats of the   
vessels4    g4 ,the water carried out of
 the lungs in solution by the expired   
gas  of nitrous oxide1 could neither    
have been wholly or partially formed  by
 the decomposition of nitrous oxide4    
,the coats of the vessels in the  lungs1
 and indeed in the whole internal       
surface of the body1 are always  covered
 with moisture1 and the solution of part
 of this moisture by  the inspired      
heated gas1 and its deposition by the   
expired gas1 are  sufficient causes for 
the appearance of the phnomenon4        
,there are no reasons for supposing that
 any of the residual atmospheric        
oxygene is immediately combined with    
fixed or nascent hydrogene1 or          
hydrocarbonate1 in the venous blood at  
#ih1 by slow combustion1 and            
consequently none for supposing that    

water is immediately formed in          
respiration4    ,the evolution of water 
from the vessels in the lungs1 is almost
 certain  from numerous analogies4    h4
 ,as from the experiments in section    
,,ii4 it appeared that nitrous  oxide   
was capable of being combined with      
oxygenated blood1 and vice  versa1 blood
 impregnated with nitrous oxide capable 
of oxygenation2 ,i  was curious to      
ascertain what changes would be effected
 in nitrous  oxide when it was respired1
 mingled with atmospheric air or        
oxygene4  ,for this purpose1 without    
making a very delicate experiment1 ,i   
breathed  in the large mercurial        
airholder about #aab cubic inches of    
nitrous  oxide1 mingled with #dd of     
common air1 for near half a minute1 in  
the  usual mode4 ,the gas1 after        
expiration1 filled a space nearly equal 
to  #aai4 ,i did not exactly ascertain  
the composition of the residual gas2  it
 supported flame rather better than     
common air1 and after the nitrous  oxide

 was absorbed1 gave much less diminution
 with nitrous gas than  atmospheric air4
    i4 ,i breathed a mixture of four    
quarts of nitrous oxide with three      
quarts of hydrogene1 in a dry silk bag1 
for near a minute2 an evident           
diminution was produced2 but on account 
of the mode of experimenting it  was    
impossible to determine the quantity of 
nitrous oxide absorbed1 or  the exact   
nature of the products4 ,when a taper   
was introduced into a  little of the    
residual gas1 it inflamed with a very   
feeble explosion4  ,now a mixture of #d 
parts nitrous oxide and #c hydrogene1   
detonates when  inflamed with very great
 violence4    k4 ,nitrous oxide can be  
respired without danger by the human    
animal  for a much longer time than that
 required for the death of the smaller  
quadrupeds in it4    ,i have breathed it
 two or three times in a considerable   
state of  purity1 in a dry silk bag1 for
 four minutes and quarter and four      
minutes and half3 some diseased         

individuals have respired it for        
upwards of five minutes4    ,in the     
infancy of my experiments1 from general 
appearances1 ,i thought  that the       
proportion of nitrous oxide absorbed in 
respiration was  greater in the first   
inspirations than the last2 but this ,i 
have  since found to be a mistake4 ,in  
the last respirations the apparent      
absorption is indeed less2 but this is  
on account of the increased  evolution  
of nitrogene from the blood4 ,when      
nitrous oxide is respired  for a long   
time1 the last inspirations are always  
fuller and quicker  than the first2 but 
the consumption by the same individual  
is nearly in  the ratio of the time of  
respiration4 ,three quarts1 i4 e4 about 
#agd  cubic inches1 are consumed so as  
to be unfit for respiration1 by an      
healthy individual with lungs of        
moderate capacity1 in about a minute    
and quarter2 six quarts1 or #cdh cubic  
inches1 last generally for two  minutes 
and half or two minutes and three       

quarters2 eight quarts1 or  #dfd cubic  
inches1 for more than three minutes and 
half2 and twelve1 or  #fif cubic inches1
 for nearly five4    ,the quantities of 
nitrous oxide absorbed by the same      
individual1 will1  as there is every    
reason to suppose1 be different under   
different  circumstances1 and will      
probably be governed in some measure by 
the  state of the health4 ,it is        
reasonable to suppose1 that the velocity
 of  the circulation must have a        
considerable influence on the absorption
  of nitrous oxide2 probably in         
proportion as it is greater a larger    
quantity of gas will be consumed in     
equal times4    ,i am inclined from two 
or three experiments1 to believe that   
nitrous oxide is absorbed more rapidly  
after hearty meals or during            
stimulation from wine or spirits1 than  
at other times4 ,as its  absorption     
appears to depend on a simple solution  
in the venous blood2  probably          
diminution of temperature will increase 

its capability of  being absorbed4    l4
 ,the quantities of nitrous oxide       
absorbed by different individuals1  will
 probably be governed in some measure by
 the size of their lungs  and the       
surface of the blood vessels1 all other 
circumstances being the  same4    ,from 
the observations that ,i have been able 
to make on the absorption  of nitrous   
oxide1 as compared with the capacity of 
the lungs1 the range  of the consumption
 of different individuals does not      
extend to more  than a pint1 or #cj     
cubic inches at the maximum dose4    ,we
 may therefore conclude1 that the medium
 consumption of nitrous oxide  by the   
respiration of different individuals1 is
 not far from two cubic  inches1 or     
about a grain every second1 or #abj     
cubic inches1 or #fj  grains every      
minute4    m4 ,when nitrous oxide is    
breathed in tight silk bags1 towards the
 end  of the experiment as the internal 
surface becomes moist1 as ,i have       
before mentioned1 a certain quantity of 

common air penetrates through  it and   
becomes mixed with the residual gas of  
the experiment2 but this  quantity is   
always too small to destroy any of the  
effects of the  nitrous oxide4 ,the     
residual gas of the common air1 the     
nitrogene and  carbonic acid produced in
 the process1 and the residuum of the   
admitted  atmospheric air1 hardly ever  
amount after the experiment1 to one half
  of the volume of the nitrous oxide    
absorbed4 ,there is consequently1 a     
perfect propriety in successively       
inspiring and expiring the whole of  a  
given quantity of nitrous oxide1 till it
 is nearly consumed4 ,in the            
respiration of nitrous oxide as the gas 
is absorbed and not decomposed1  little 
will be gained in effect1 by perpetually
 inspiring and expiring  new portions1  
whilst an immense quantity of gas will  
be idly wasted1  and this circumstance1 
considering the expence of the          
substance1 is of  importance4      ,,vi4
 ,on the respiration of ,atmospheric    

,air4    ,having thus ascertained the   
absorption of nitrous oxide in          
respiration1  and the evolution of      
nitrogene and carbonic acid from the    
lungs during  its absorption3           
considering atmospheric air as a        
compound in which  principles identical 
with those in nitrous oxide existed1    
though in  different quantities and     
looser combination1 ,i was anxious to   
compare  the changes effected in this   
gas by respiration1 with those produced 
in  nitrous oxide and oxygene2          
particularly as they are connected with 
the  health and life of animals4    ,the
 ingenious experiments of ,lavoisier and
 ,goodwyn1 prove the  consumption of    
oxygene in respiration1 and the         
production of carbonic  acid4 ,from many
 experiments on the respiration of      
common air1 ,dr4  ,priestly suspected   
that a certain portion of nitrogene1 as 
well as  oxygene1 was absorbed by the   
venous blood4    b4 ,in the following   
experiments on the respiration of       

atmospheric  air in the mercurial       
airholder2 the composition of the gas   
before  inspiration and after           
expiration1 was ascertained in the      
following  manner4    ,forty measures of
 it were agitated over mercury in       
solution of  caustic potash1 and        
suffered to remain in contact with it   
for two or  three hours4 ,the diminution
 was noted1 and the gas absorbed judged 
to be carbonic acid4 ,twenty measures of
 the gas1 freed from carbonic  acid1    
were mingled with thirty of nitrous gas1
 in a tube of1#e inches  diameter2 they 
were not agitated1#bjj but suffered to  
rest for an hour  or an hour and half1  
when the volume occupied by them was    
noticed3 and  #ej-m the volume occupied1
 divided by #c considered as the oxygene
 x1  and #bj-x considered as the        
nitrogene4    #bjj ,when they are       
agitated1 a greater proportion of       
nitrous gas is  absorbed1 condensed in  
the nitric acid by the water2 and to    
find the  oxygene1             7#ej - m7

    7#ej - m7      x                    
-------------------- or                 
------------------ 4              7#c1d7
         7#c1e7      c4 ,to ascertain   
the changes effected in atmospheric air 
by single  inspirations1    ,i made1    
after a compleat voluntary exhaustion of
 my lungs1 at  temperature #fa1 one     
inspiration and expiration of #ada cubic
 inches of  atmospheric air4 ,after     
expiration1 they filled a space equal to
 #aci  cubic inches nearly4 ,these #aci 
cubic inches analised were found to     
consist of        ,nitrogene       #aja 
,oxygene          #cb      ,carbonic    
acid     #f    ,the #ada cubic inches   
before inspiration1 were composed of    
#ajc  nitrogene1 #a carbonic acid and   
#cg oxygene4 ,the time taken to perform 
the inspiration and full expiration1 was
 nearly a quarter of a minute4    ,i    
repeated this experiment seven or eight 
times1 and the quantity of  oxygene     
absorbed was generally from #e to #f    
cubic inches1 the carbonic  acid formed 

from #e to #e1e1 and the quantity of    
nitrogene apparently  diminished by from
 #a to #c cubic inches4    ,e4 #b4 ,i   
made1 after a voluntary expiration of   
common air1 one  inspiration and full   
expiration of #ajj cubic inches of      
atmospheric air4  ,it was diminished    
nearly to #ih or #ii cubic inches1 and  
analised1 was  found to consist of      
,nitrogene       #ga1g      ,oxygene    
#bb1e      ,carbonic acid    #d1e       
,this experiment ,i likewise repeated   
four or five times1 with very  little   
difference of result1 and there always  
seemed to be a small  diminution of     
nitrogene4 ,i made no corrections on    
account of the  residual air of the     
lungs in these processes1 because there 
was every  reason to suppose that it was
 always of similar composition4    c4   
,before ,i could ascertain whether      
similar changes were effected  in       
atmospheric air1 by natural inspirations
 as by forced ones1 ,i  was obliged to  
practise respiration in the mercurial   

airholder1 by  differing the conducting 
tube to communicate with the atmosphere 
till ,i  had attained the power of      
breathing in it naturally1 without labor
 or  attention2 ,i then found by a      
number of experiments1 that ,i took into
 my  lungs at every natural inspiration1
 about #ac cubic inches of air1 and     
that ,i threw out of my lungs at every  
expiration1#bja rather less than  this  
quantity2 about #ab cubic inches4       
#bja ,the diminution of air by single   
inspirations1 was particularly  noticed 
by ,dr4 ,goodwyn4    ,the mean          
composition of the #ac cubic inches of  
air inspired1 was                       
cub4 in4      ,nitrogene        #i1e    
,oxygene          #c1d      ,carbonic   
acid    #j1a    ,that of the #ab1g of   
air expired        ,nitrogene           
#i1c      ,oxygene          #b1b        
,carbonic acid    #a1b    ,these results
 ,i gained from more than #bj           
experiments1 so that ,i could  not      
possibly entertain any doubt of this    

accuracy4    ,i found1 by making a      
person observe my respirations when ,i  
was  inattentive to the process1 that ,i
 made about #bf or #bg natural          
inspirations in a minute4 ,so that      
calculating from the above  estimations1
 it would follow1 that #ca1f cubic      
inches of oxygene were  consumed1 and   
#e1b inches of nitrogene lost in        
respiration every minute1  whilst #bf1f 
cubic inches of carbonic acid were      
produced4    ,to collect the products of
 a great number of natural expirations  
so  as to ascertain whether their       
composition corresponded with the above 
accounts1 ,i proceeded in the following 
manner4    ,i fastened my lips tight on 
the mouth-piece of the exhausted        
airholder1  and suffering my nostrils to
 remain open1 inspired naturally through
  them1 throwing the expired air through
 my mouth into the airholder4    ,in    
many experiments1 ,i found that in about
 a half a minute1 ,i made in  this way  
#ad or #ae expirations4 ,the mean       

quantity of air collected was  #aga     
cubic inches1 and consisted of          
cub4 in4      ,nitrogene       #abh     
,oxygene          #bi      ,carbonic    
acid    #ad    ,comparing these results 
with the former ones1 we find the mean  
quantities of air respired in equal     
terms rather less2 but the  proportions 
of carbonic acid1 nitrogene and oxygene 
in the respired  air1 nearly identical4 
e4 ,to ascertain the changes effected in
 a given quantity of  atmospheric air by
 continued respirations1 ,i breathed    
after a compleat  expiration1 at        
temperature #fc1 #afa cubic inches of   
air for near a  minute1 making in this  
time1 #ai deep inspirations4 ,after the 
compleat  expiration1 which was very    
carefully made1 the gas filled a space  
nearly equal to #aeb cubic inches1 so   
that #i cubic inches of gas had         
disappeared4    ,the #aeb cubic inches  
analised1 were found to consist of      
cub4 in4      ,nitrogene        #aaa1f  
,oxygene           #bc1      ,carbonic  

acid1    #ag1d    ,the #afa cubic inches
 before inspiration1 were composed of   
cub4 in4      ,nitrogene       #aag1j   
,oxygene          #db1d      ,carbonic  
acid     #a1f    ,but the residual gas  
in the lungs before the experiment1 was 
of  different composition from that     
remaining in the lungs after the        
experiment4 ,making corrections on      
account of this circumstance1 as in     
section ,,iv4 it appears that about #e1a
 of nitrogene were absorbed in          
respiration1 #bc1i of oxygene consumed1 
and #ab of carbonic acid produced4    ,i
 repeated this experiment three times2  
in each experiment the  diminution after
 respiration1 was nearly the same2 and  
the residual  gas making the necessary  
allowances1 of similar composition4 ,so 
that  supposing the existence of no     
source of error in the experiments from 
which the quantity and composition of   
the residual gas of the lungs  were     
estimated in section ,,iv4 the          
absorption of nitrogene by the venous   

blood1 appears almost demonstrated4     
f4 ,to compare the changes effected in  
atmospheric air by respiration  of the  
smaller quadrupeds1 with those in the   
experiments just detailed1  ,i          
introduced into a jar of the capacity of
 #bj cubic inches filled  with mercury  
in the mercurial trough1 #ae cubic      
inches of atmospheric  air which had    
been deprived of its carbonic acid by   
long exposure1 to  solution of potash4  
,temperature being #fd1 a healthy small 
mouse was quickly passed under  the     
mercury into the jar1 and suffered to   
rest on a very thin bit of  cheese1     
which was admitted immediately after4   
,he continued for near #dj minutes      
without apparently suffering1           
occasionally raising himself on his hind
 legs4 ,at the end of #ej  minutes1 he  
was lying on his side1 and in #ee       
minutes was apparently  dying4 ,he was  
now carefully taken out through the     
mercury by the tail1  and exposed before
 the fire1 where he soon recovered4     

,after the cheese  had been carefully   
removed1 the gas in the jar filled a    
space nearly  equal to #ad cubic inches2
 so that a diminution of a cubic inch   
had  taken place4 ,these #ad cubic      
inches analised1 were found to consist  
of                        cub4 in4      
,carbonic acid      #b1j      ,oxygene  
#a1d      ,nitrogene         #aj1f      
,the #ae cubic inches before the        
experiment1 consisted of                
cub4 in4      ,oxygene            #d    
,nitrogene         #aa    ,hence it     
appeared1 that #b1f cubic inches of     
oxygene had been consumed1  #b cubic    
inches of carbonic acid produced1 and   
about #j1d of nitrogene  lost4    ,the  
relation between the quantities of      
oxygene consumed in this  experiment1   
and the carbonic acid produced1 are     
nearly the same as  that of those in the
 experiments just detailed2 but the     
quantity of  nitrogene lost is much     
smaller4      ,,vii4 ,respiration of    
,oxygene4    ,the gases before and after

 respiration1 were analised in these    
experiments in the manner described in  
the last section1 except that #c  of    
nitrous gas were always employed to one 
of oxygene4    ,e4 ,i4 ,at temperature  
#ec1 after a full forced respiration1 ,i
 respired  in the mercurial airholder1  
for half a minute1 #ajb cubic inches of 
oxygene1 making seven very long and deep
 inspirations4 ,after the  compleat     
expiration1 the gases filled a space    
equal to #ic cubic inches2  these #ic   
cubic inches analised1 were found to    
consist of                        cub4  
in4      ,carbonic acid      #e1i       
,nitrogene         #cc1h      ,oxygene  
#ec1c    ,the #ajb cubic inches before  
the experiment1 were composed of        
cub4 in4      ,oxygene           #gh    
,nitrogene    #bd    ,the residual gas  
in the lungs before the experiment1 was 
#cb cubic  inches1 and composed of about
 #bc nitrogene1 #d1a carbonic acid1 and 
#d1i  oxygene1 ,section ,,iv4 ,the      
residual gas after expiration1 was      

composed of  #ah1b oxygene1 #b carbonic 
acid1 and #aa1h nitrogene4    ,hence the
 whole of the gas in the lungs and      
airholder before  inspiration1 was #acd 
cubic inches1 composed of               
cub4 in4      ,oxygene          #hb1i   
,nitrogene        #dg1j      ,carbonic  
acid     #d1a      ,and after           
respiration1 #abe cubic inches1         
consisting of                       cub4
 in4      ,oxygene          #ga1e       
,nitrogene        #de1f      ,carbonic  
acid     #g1i    ,so that comparing the 
quantities1 it appears1 that #aa1d of   
oxygene and  #a1d of nitrogene1 were    
consumed in this experiment1 and #c1h of
 carbonic  acid produced4    ,i was much
 surprised at the small quantity of     
oxygene that had been  consumed in this 
experiment4 ,this quantity was less than
 that expended  during the respiration  
of atmospheric air for half a minute3   
the  portion of carbonic acid evolved   
was likewise smaller4 ,i could detect   
no source of inaccuracy1 and it was     

difficult to suppose that the  greater  
depth and fulness of the inspirations   
could make any difference4    ,e4 #b4 ,i
 now respired at the same temperature1  
after a full expiration1  #afb cubic    
inches of gas1 composed of #acc oxygene 
and #bj nitrogene for  two minutes1     
imitating as much as possible1 the      
natural respiration4  ,after the        
experiment1 they filled a space equal to
 #abc cubic inches4  ,and when the      
analysis and calculations had been made 
as in the last  experiment1 it appeared 
that #eg cubic inches of oxygene1 and #b
 of  nitrogene had been absorbed1 whilst
 #ba cubic inches of carbonic acid  had 
been formed4    ,now from the           
estimations in the last section1 it     
appears that #fc cubic  inches of       
oxygene are consumed1 and about #eb     
cubic inches of carbonic  acid produced 
every two minutes during the natural    
respiration of  common air4 ,so that    
supposing the experiment accurate1 #f   
cubic inches  of oxygene less are       

absorbed1 and #cj cubic inches less of  
carbonic acid  produced every minute1   
when oxygene nearly pure is respired1   
than when  atmospheric air is respired4 
,both these experiments were made in the
 morning1 at a time when ,i was  in     
perfect health2 so that there could be  
apparently no source of error  from     
accidental circumstances4    ,the       
uncommon and unexpected nature of the   
results1 made me however1  very         
sceptical concerning them2 and before ,i
 would draw any inferences1  ,i resolved
 to ascertain the comparative           
consumption of atmospheric air  and     
oxygene by the smaller quadrupeds1 for  
which purpose1 ,i made the  following   
experiment4    ,e4 #c4 ,of two strong   
and healthy small mice1 apparently of   
the same  breed1 and exactly similar4   
,one was introduced into a jar          
containing #aj cubic inches and half of 
oxygene1 and #c cubic inches of         
nitrogene1 and made to rest on a bit of 
cheese4    ,the other was introduced    

into a jar containing fifteen cubic     
inches and  half of atmospheric air1 and
 made to rest in the same manner on     
cheese4    ,the mouse in oxygene began  
apparently to suffer in about half an   
hour1  and occasionally panted very     
much2 in about an hour he lay down on   
his  side as if dying4 ,the jars were   
often agitated1 that the gases might be 
well mingled4    ,the mouse in          
atmospheric air became very feeble in   
#dj minutes1 and at  the end of #ej     
minutes was taken out through the       
mercury alive1 but  unable to stand4    
,the mouse in oxygene was taken out in  
the same manner after an hour and       
quarter1 alive1 but motionless1 and     
breathing very deeply4    ,the gas in   
the jars was examined4 ,that in the     
oxygene jar filled a  space exactly     
equal to #ab1g cubic inches1 and        
analised1 was found to  consist of #a1g 
carbonic acid1 #b1f of nitrogene1 and   
#h1d of oxygene4 ,so  that absolutely1  
#b1a cubic inches of oxygene and1#d of  

nitrogene had  been consumed1 and #a1g  
of carbonic acid produced4    ,the gas  
in the atmospheric air jar was          
diminished nearly to #ad1d1 and         
consisted of #b1a carbonic acid1 #a1d   
oxygene2 and #aj1i nitrogene4 ,so  that 
#b1g of oxygene and1#e of nitrogene1 had
 been consumed by the mouse2  and #b1a  
of carbonic acid produced4    ,hence it 
appears1 that the mouse in atmospheric  
air consumed nearly  one third more     
oxygene and produced nearly one fourth  
more carbonic  acid in respiration in   
#ee minutes1 than the other in an hour  
and  quarter in oxygene4 ,and if we     
consider the perpetual diminution of the
  oxygene of the atmospheric air2 from  
which at last it became almost          
incapable of supporting the life of the 
animal2 we may conclude1 that  the      
quantity of oxygene consumed by it1 had 
the air been perpetually  renovated1    
would have been much more considerable4 
,i design very shortly1 to repeat these 
experiments1 and to make others  on the 

comparative consumption of oxygene and  
atmospheric air1 by the  larger         
quadrupeds4 ,whatever may be the        
results1 ,i hope to be able to          
ascertain from them1 why pure oxygene is
 incapable of supporting life4          
,,viii4 ,observations on the changes    
effected in the blood1 by  atmospheric  
air and oxygene4    ,from the           
experiments of ,mr4 ,cigna and ,dr4     
,priestley1#bjb it appears  that the    
coagulum of the venous blood becomes    
florid at its surface  when exposed to  
the atmosphere1 though covered and      
defended from the  immediate contact of 
air by a very thick stratum of serum4   
#bjb ,dr4 ,priestley found that it      
likewise became florid at the surface   
when covered by milk2 but that it       
underwent little or no alteration of    
color under water and most other        
fluids4--,vol4 #c4 p4 #cgb4    ,hence it
 is evident1 that serum is capable of   
dissolving either the  whole compound   
atmospheric air1 or the oxygene of it4  

,supposing what indeed is most probable 
from numerous analogies1 that  it       
dissolves the whole compound2 it would  
follow1 that the coloring  of the       
coagulum of blood under serum1 depended 
upon the decomposition  of the          
atmospheric air condensed in the serum1 
the oxygene#bjc of it  combining with   
the red particles1 and the nitrogene    
either remaining  dissolved in the      
fluid1 or being liberated through it    
into the  atmosphere4    ,now the       
circulating blood consists of red       
particles1 floating in and  diffused    
through serum and coagulable lymph4     
#bjc ,there are many analogous          
decompositions4 ,dr4 ,priestley noticed 
7and ,i have often made the observation7
 that green oxide of iron1 or  the      
precipitate from pale green sulphate of 
iron by caustic alkali1  became red at  
the surface1 when covered by a thick    
stratum of water4 ,in  my experiments on
 the green muriate and sulphate of iron1
 ,i observed  that part of some dark    

oxide of iron which was at the bottom of
 a  trough of water #i inches deep1     
became red at the surface nearly in the 
same time as another portion of the same
 precipitation that was exposed  to the 
atmosphere4 ,this oxygenation must      
depend upon the decomposition  of       
atmospheric air constantly dissolved by 
the water4    ,in natural respiration1  
the red particles are rendered of a     
brighter  tinge during the passage of   
the blood through the pulmonary veins4  
,and  as we have seen in the last       
sections1 during respiration atmospheric
  air is decomposed2 all the oxygene of 
it consumed1 apparently a small  portion
 of the nitrogene lost1 and a           
considerable quantity of carbonic  acid 
produced4    ,it seems therefore        
reasonable to suppose1 that the whole   
compound  atmospheric air passing       
through the moist coats of the vessels  
is first  dissolved by the serum of the 
venous blood1 and in its condensed      
state1  decomposed by the affinity of   

the red particles for its oxygene2 the  
greater part of the nitrogene being     
liberated unaltered2 but a minute       
portion of it possibly remaining        
condensed in the serum and coagulable   
lymph1 and passing with them into the   
left chamber of the heart4    ,from the 
experiments on the respiration of       
nitrous oxide and hydrogene1  it appears
 that a certain portion of the carbonic 
acid produced in  respiration1 is       
evolved from the venous blood2 but as a 
much greater  quantity is generated     
during the respiration of common air and
 oxygene1  than during that of hydrogene
 in equal times1 it is not impossible   
but  that some portion of it may be     
formed by the combination of charcoal in
  the red particles with the oxygene    
dissolved in the serum2 but this can    
only be determined by farther           
experiments4    ,supposing that no part 
of the water evolved in solution by the 
expired  gas of common air is formed    
immediately in respiration1 it will     

follow  that a very considerable        
quantity of oxygene must be constantly  
combined with the red particles1 even   
allowing the consumption of  a certain  
portion of it to form carbonic acid2 for
 the carbonic acid  evolved1 rarely     
amounts to more than three fourths of   
the volume of the  oxygene consumed4    
,perhaps the serum of the blood is      
capable of dissolving a larger  quantity
 of atmospheric air than of pure        
oxygene4 ,on this supposition1  it would
 be easy to explain the smaller         
consumption of oxygene in the           
experiments in the last section4        
,,ix4 ,observations on the respiration  
of ,nitrous ,oxide4    ,the experiments 
in the first ,division of this          
,research1 prove that  nitrous oxide    
when respired by animals1 produces      
peculiar changes in  their blood and in 
their organs1 first connected with      
increased living  action2 but           
terminating in death4    ,from the      
experiments in this ,division1 it       

appears1 that nitrous oxide  is rapidly 
absorbed by the circulating venous      
blood1 and of course its  condensed     
oxygene and nitrogene distributed in the
 blood over the whole  of the system4   
,concerning the changes effected in the 
principles of the impregnated  blood    
during circulation and its action upon  
the nervous and muscular  fibre2 it is  
useless to reason in the present state  
of our knowledge4    ,it would be easy  
to form theories referring the action of
 blood  impregnated with nitrous oxide1 
to its power of supplying the nervous   
and muscular fibre with such proportions
 of condensed nitrogene1  oxygene and   
light or etherial fluid1 as enabled them
 more rapidly  to pass through those    
changes which constitute their life3 but
 such  theories would be only           
collections of terms derived from known 
phnomena and applied by loose analogies 
of language to unknown things4    ,we   
are unacquainted with the composition of
 dead organised matter2 and  new        

instruments of experiment and new modes 
of research must be found1  before we   
can ascertain even our capabilities of  
discovering the laws  of life4          
,,research ,,iv4    ,,relating ,,to     
,,the ,,effects ,,produced ,,by ,,the   
,,respiration ,,of ,,nitrous ,,oxide4   
,,division ,i4        ,,history of the  
,,discovery4--,effects produced by the  
,,respiration of different ,,gases4     
,a short time after ,i began the study  
of ,chemistry1 in ,march #agih1  my     
attention was directed to the           
dephlogisticated nitrous gas of         
,priestley1 by ,dr4 ,mitchill's ,theory 
of ,contagion4#bjd    #bjd ,dr4         
,mitchill attempted to prove from some  
phnomena connected  with contagious     
diseases1 that dephlogisticated nitrous 
gas which he  called oxide of septon1   
was the principle of contagion1 and     
capable of  producing the most terrible 
effects when respired by animals in the 
minutest quantities or even when applied
 to the skin or muscular fibre4    ,the 

fallacy of this ,theory was soon        
demonstrated1 by a few coarse           
experiments made on small quantities of 
the gas procured from zinc and  diluted 
nitrous acid4 ,wounds were exposed to   
its action1 the bodies of  animals were 
immersed in it without injury2 and ,i   
breathed it mingled  in small quantities
 with common air1 without remarkable    
effects4 ,an  inability to procure it in
 sufficient quantities1 prevented me at 
this time1 from pursuing the experiments
 to any greater extent4 ,i  communicated
 an account of them to ,dr4 ,beddoes4   
,in #agii1 my situation in the ,medical 
,pneumatic ,institution1 made it my     
duty to investigate the physiological   
effects of the ariform fluids1  the     
properties of which presented a chance  
of useful agency4 ,at this  period ,i   
recommenced the investigation4    ,a    
considerable time elapsed before ,i was 
able to procure the gas in a  state of  
purity1 and my first experiments were   
made on the mixtures of  nitrous oxide1 

nitrogene and nitrous gas1 which are    
produced during  metallic solutions4    
,in the beginning of ,march1 ,i prepared
 a large quantity of impure  nitrous    
oxide from the nitrous solution of zinc4
 ,of this ,i often  breathed the        
quantities of a quart and two quarts    
generally mingled  with more than equal 
parts of oxygene or common air4 ,in the 
most  decisive of those trials1 its     
effects appeared to be depressing1 and  
,i imagined that it produced a tendency 
to fainting3 the pulse was  certainly   
rendered slower under its operation4    
,at this time1 ,mr4 ,southey respired it
 in an highly diluted state2 it         
occasioned a slight degree of giddiness1
 and considerably diminished  the       
quickness of his pulse4    ,mr4 ,c4     
,coates likewise respired it highly     
diluted1 with similar effects4    ,in   
,april1 ,i obtained nitrous oxide in a  
state of purity1 and  ascertained many  
of its chemical properties4 ,reflections
 upon these  properties and upon the    

former trials1 made me resolve to       
endeavour  to inspire it in its pure    
form1 for ,i saw no other way in which  
its  respirability1 or powers could be  
determined4#bje    #bje ,i did not      
attempt to experiment upon animals1     
because they die  nearly in equal times 
in non-respirable gases1 and gases      
incapable of  supporting life and       
possessed of no action on the venous    
blood4    ,i was aware of the danger of 
this experiment4 ,it certainly would    
never  have been made if the hypothesis 
of ,dr4 ,mitchill had in the least      
influenced my mind4 ,i thought that the 
effects might be possibly  depressing   
and painful1 but there were many reasons
 which induced me  to believe that a    
single inspiration of a gas apparently  
possessing  no immediate action on the  
irritable fibre1 could neither destroy  
or  materially injure the powers of     
life4    ,on ,april #aath1 ,i made the  
first inspiration of pure nitrous oxide2
  it passed through the bronchia without

 stimulating the glottis1 and  produced 
no uneasy feeling in the lungs4    ,the 
result of this experiment1 proved that  
the gas was respirable1 and  induced me 
to believe that a farther trial of its  
effects might be made  without danger4  
,on ,april #afth1 ,dr4 ,kinglake being  
accidentally present1 ,i breathed  three
 quarts of nitrous oxide from and into a
 silk bag for more than  half a minute1 
without previously closing my nose or   
exhausting my  lungs4    ,the first     
inspirations occasioned a slight degree 
of giddiness4 ,this  was succeeded by an
 uncommon sense of fulness of the head1 
accompanied  with loss of distinct      
sensation and voluntary power1 a feeling
  analogous to that produced in the     
first stage of intoxication2 but        
unattended by pleasurable sensation4    
,dr4 ,kinglake1 who felt my pulse1      
informed me that it was rendered quicker
 and fuller4    ,this trial did not     
satisfy me with regard to its powers2   
comparing it  with the former ones ,i   

was unable to determine whether the     
operation  was stimulant or depressing4 
,i communicated the result to ,dr4      
,beddoes1 and on ,april the #agth1 he   
was  present1 when the following        
experiment was made4    ,having         
previously closed my nostrils and       
exhausted my lungs1 ,i breathed  four   
quarts of nitrous oxide from and into a 
silk bag4 ,the first  feelings were     
similar to those produced in the last   
experiment2 but  in less than half a    
minute1 the respiration being continued1
 they  diminished gradually1 and were   
succeeded by a sensation analogous to   
gentle pressure on all the muscles1     
attended by an highly pleasurable       
thrilling1 particularly in the chest and
 the extremities4 ,the objects  around  
me became dazzling and my hearing more  
acute4 ,towards the last  inspirations1 
the thrilling increased1 the sense of   
muscular power  became greater1 and at  
last an irresistible propensity to      
action was  indulged in2 ,i recollect   

but indistinctly what followed2 ,i know 
that my  motions were various and       
violent4    ,these effects very soon    
ceased after respiration4 ,in ten       
minutes1 ,i had  recovered my natural   
state of mind4 ,the thrilling in the    
extremities1  continued longer than the 
other sensations4#bjf    ,this          
experiment was made in the morning2 no  
languor or exhaustion was  consequent1  
my feelings throughout the day were as  
usual1 and ,i passed  the night in      
undisturbed repose4    #bjf ,dr4        
,beddoes has given some account of this 
experiment1 in his  ,notice of some     
observations made at the ,medical       
,pneumatic ,institution4  ,it was       
noticed in ,mr4 ,nicholson's ,phil4     
,journal for ,may #agii4    ,the next   
morning the recollections of the effects
 of the gas were  very indistinct1 and  
had not remarks written immediately     
after the  experiment recalled them to  
my mind1 ,i should have even doubted of 
their reality4 ,i was willing indeed to 

attribute some of the strong  emotion to
 the enthusiasm1 which ,i supposed must 
have been necessarily  connected with   
the perception of agreeable feelings1   
when ,i was  prepared to experience     
painful sensations4 ,two experiments    
however1  made in the course of this    
day1 with sceptism1 convinced me that   
the  effects were solely owing to the   
specific operation of the gas4    ,in   
each of them ,i breathed five quarts of 
nitrous oxide for rather a  longer time 
than before4 ,the sensations produced   
were similar1 perhaps  not quite so     
pleasurable2 the muscular motions were  
much less violent4    ,having thus      
ascertained the powers of the gas1 ,i   
made many experiments  to ascertain the 
length of time for which it might be    
breathed with  safety1 its effects on   
the pulse1 and its general effects on   
the health  when often respired4    ,i  
found that ,i could breathe nine quarts 
of nitrous oxide for three  minutes1 and
 twelve quarts for rather more than     

four4 ,i could never  breathe it in any 
quantity1 so long as five minutes4      
,whenever its  operation was carried to 
the highest extent1 the pleasurable     
thrilling  at its height about the      
middle of the experiment1 gradually     
diminished1  the sense of pressure on   
the muscles was lost2 impressions ceased
 to be  perceived2 vivid ideas passed   
rapidly through the mind1 and voluntary 
power was altogether destroyed1 so that 
the mouth-piece generally dropt  from my
 unclosed lips4    ,whenever the gas was
 in a high state of purity1 it tasted   
distinctly  sweet to the tongue and     
palate1 and had an agreeable odor4 ,i   
often  thought that it produced a       
feeling somewhat analogous to taste1 in 
its application to my lungs4 ,in one or 
two experiments1 ,i perceived a         
distinct sense of warmth in my chest4   
,i never felt from it any thing like    
oppressive respiration3 my  inspirations
 became deep in proportion as ,i        
breathed it longer2  but this phnomenon 

arose from increased energy of the      
muscles of  respiration1 and from a     
desire of increasing the pleasurable    
feelings4    ,generally when ,i breathed
 from six to seven quarts1 muscular     
motions  were produced to a certain     
extent2 sometimes ,i manifested my      
pleasure  by stamping or laughing only2 
at other times1 by dancing round the    
room  and vociferating4    ,after the   
respiration of small doses1 the         
exhilaration generally lasted  for five 
or six minutes only4 ,in one or two     
experiments when ten quarts  had been   
breathed for near four minutes1 an      
exhilaration and a sense of  slight     
intoxication lasted for two or three    
hours4    ,on ,may #c;d4 ,to ascertain  
whether the gas would accelerate or     
retard  the progress of sleep1 ,i       
breathed at about #h o'clock in the     
evening1  #be quarts of nitrous oxide1  
in quantities of six at a time1 allowing
  but short intervals between each dose4
 ,the feelings were much less           

pleasurable than usual1 and during the  
consumption of the two last  doses1     
almost indifferent2 indeed the gas was  
breathed rather too soon  after its     
production and contained some suspended 
acid vapour which  stimulated the lungs 
so as to induce coughing4    ,after the 
experiments1 for the first time ,i was  
somewhat depressed and  debilitated2 my 
propensity to sleep however1 came on at 
the usual hour1  and as usual was       
indulged in1 my repose was sound and    
unbroken4    ,between ,may and ,july1 ,i
 habitually breathed the gas1           
occasionally three  or four times a day 
for a week together2 at other periods1  
four or five  times a week only4    ,the
 doses were generally from six to nine  
quarts2 their effects  appeared         
undiminished by habit1 and were hardly  
ever exactly similar4  ,sometimes ,i had
 the feelings of intense intoxication1  
attended with but  little pleasure2 at  
other times1 sublime emotions connected 
with highly  vivid ideas2 my pulse was  

generally increased in fulness1 but     
rarely in  velocity4    ,the general    
effects of its operation upon my health 
and state of mind1  are extremely       
difficult of description2 nor can ,i    
well discriminate  between its agency   
and that of other physical and moral    
causes4    ,i slept much less than      
usual1 and previous to sleep1 my mind   
was long  occupied by visible imagery4  
,i had a constant desire of action1 a   
restlessness1 and an uneasy feeling     
about the prcordia analogous to  the    
sickness of hope4    ,but perhaps these 
phnomena in some measure depended on the
 interest  and labour connected with the
 experimental investigation relating  to
 the production of nitrous oxide1 by    
which ,i was at this time  incessantly  
occupied4    ,my appetite was as usual1 
and my pulse not materially altered4    
,sometimes for an hour after the        
inspiration of the gas1 ,i experienced  
a species of mental indolence#bjg       
pleasing rather than otherwise1 and     

never ending in listlessness4    #bjg   
,mild physical pleasure is perhaps      
always destructive to action4  ,almost  
all our powerful voluntary actions1     
arise either from hope1  fear1 or       
desire2 and the most powerful from      
desire1 which is an emotion  produced by
 the coalescence of hope or ideal       
pleasure with physical  pain4    ,during
 the last week in which ,i breathed it  
uniformly1 ,i imagined that  ,i had     
increased sensibility of touch3 my      
fingers were pained by any  thing rough1
 and the tooth edge produced from       
slighter causes than  usual4 ,i was     
certainly more irritable1 and felt more 
acutely from  trifling circumstances4   
,my bodily strength was rather          
diminished than  increased4    ,at the  
end of ,july1 ,i left off my habitual   
course of respiration2  but ,i continued
 occasionally to breathe the gas1 either
 for the sake  of enjoyment1 or with a  
view of ascertaining its operation under
  particular circumstances4    ,in one  

instance1 when ,i had head-ache from    
indigestion1 it was  immediately removed
 by the effects of a large dose of gas2 
though it  afterwards returned1 but with
 much less violence4 ,in a second       
instance1  a slighter degree of         
head-ache was wholly removed by two     
doses of gas4    ,the power of the      
immediate operation of the gas in       
removing intense  physical pain1 ,i had 
a very good opportunity of ascertaining4
    ,in cutting one of the unlucky teeth
 called dentes sapienti1 ,i  experienced
 an extensive inflammation of the gum1  
accompanied with  great pain1 which     
equally destroyed the power of repose1  
and of  consistent action4    ,on the   
day when the inflammation was most      
troublesome1 ,i breathed  three large   
doses of nitrous oxide4 ,the pain always
 diminished after  the first four or    
five inspirations2 the thrilling came on
 as usual1  and uneasiness was for a few
 minutes1 swallowed up in pleasure4 ,as 
the  former state of mind however       

returned1 the state of organ returned   
with it2 and ,i once imagined that the  
pain was more severe after the          
experiment than before4    ,in ,august1 
,i made many experiments with a view of 
ascertaining whether  any analogy       
existed between the sensible effects of 
the different gases  which are sooner or
 later fatal to life when respired1 and 
those of  nitrous oxide4    ,i respired 
four quarts of ,hydrogene#bjh nearly    
pure produced from  zinc and muriatic   
acid1 for near a minute1 my lungs being 
previously  exhausted and my nostrils   
carefully closed4 ,the first six or     
seven  inspirations produced no         
sensations whatever2 in half a minute1  
,i  perceived a disagreeable oppression 
of the chest1 which obliged me to       
respire very quickly2 this oppression   
gradually increased1 till at last  the  
pain of suffocation compelled me to     
leave off breathing4 ,i felt no         
giddiness during or after the           
experiment2 my pulse was rendered       

feebler  and quicker2 and a by-stander  
informed me that towards the last1 my   
cheeks became purple4    #bjh ,pure     
hydrogene has been often respired by    
different ,philosophers1  particularly  
by ,scheele1 ,fontana1 and the          
adventurous and unfortunate  ,rosier4   
,in a second experiment1 when the       
hydrogene was procured from iron and    
diluted sulphuric acid1 ,i was unable to
 respire it for so long as three        
quarters of a minute2 a transient       
giddiness and muscular debility  were   
produced1 the pulse was rendered very   
feeble1 and the pain of  suffocation was
 greater than before4    ,i breathed    
three quarts of ,nitrogene mingled with 
a very small portion  of carbonic acid1 
for near a minute4 ,it produced no      
alteration in  my sensations for the    
first twenty seconds2 then the painful  
sense  of suffocation gradually came on1
 and increased rapidly in the  last     
quarter of the minute1 so as to oblige  
me to desist from the  experiment4 ,my  

pulse was rendered feebler and quicker4 
,i felt no  affection whatever in the   
head4    ,mr4 ,watt's observations on   
the respiration of diluted              
,hydrocarbonate  by men1 and ,dr4       
,beddoes's experiments on the           
destruction of animals by  pure         
hydrocarbonate1 proved that its effects 
were highly deleterious4    ,as it      
destroyed life apparently by rendering  
the muscular fibre  inirritable without 
producing any previous excitement1 ,i   
was anxious  to compare its sensible    
effects with those of nitrous oxide1    
which at  this time ,i believed to      
destroy life by producing the highest   
possible  excitement1 ending in lsion of
 organisation4    ,in the first         
experiment1 ,i breathed for near a      
minute1 three quarts of  hydrocarbonate 
mingled with nearly two quarts of       
atmospheric air4#bji  ,it produced a    
slight giddiness and pain in the head1  
and a momentary  loss of voluntary      
power3 my pulse was rendered much       

quicker and  feebler4 ,these effects    
however1 went off in five minutes1 and  
,i had no  return of giddiness4    #bji 
,i believe it had never been breathed   
before by any individual1 in  a state so
 little diluted4    ,emboldened by this 
trial1 in which the feelings were not   
unlike those  ,i experienced in the     
first experiments on nitrous oxide1 ,i  
resolved to  breathe pure               
hydrocarbonate4    ,for this purpose1 ,i
 introduced into a silk bag1 four quarts
 of gas  nearly pure1 which was         
carefully produced from the             
decomposition of  water by charcoal an  
hour before1 and which had a very strong
 and  disagreeable smell4    ,my friend1
 ,mr4 ,james ,tobin1 ,junr4 being       
present1 after a forced  exhaustion of  
my lungs1 the nose being accurately     
closed1 ,i made  three inspirations and 
expirations of the hydrocarbonate4 ,the 
first  inspiration produced a sort of   
numbness and loss of feeling in the     
chest and about the pectoral muscles4   

,after the second inspiration1  ,i lost 
all power of perceiving external things1
 and had no distinct  sensation except a
 terrible oppression on the chest4      
,during the  third expiration1 this     
feeling disappeared1 ,i seemed sinking  
into  annihilation1 and had just power  
enough to drop the mouth-piece from  my 
unclosed lips4 ,a short interval must   
have passed during which ,i  respired   
common air1 before the objects about me 
were distinguishable4  ,on recollecting 
myself1 ,i faintly articulated1 8,i do  
not think ,i shall  die40 ,putting my   
finger on the wrist1 ,i found my pulse  
thread-like and  beating with excessive 
quickness4    ,in less than a minute1 ,i
 was able to walk1 and the painful      
oppression  on the chest directed me to 
the open air4    ,after making a few    
steps which carried me to the garden1 my
 head  became giddy1 my knees trembled1 
and ,i had just sufficient voluntary    
power to throw myself on the grass4     
,here the painful feeling of the  chest 

increased with such violence as to      
threaten suffocation4 ,at  this moment1 
,i asked for some nitrous oxide4 ,mr4   
,dwyer brought me a  mixture of oxygene 
and nitrous oxide4 ,i breathed this for 
a minute1  and believed myself relieved4
 ,in five minutes1 the painful feelings 
began gradually to diminish4 ,in an hour
 they had nearly disappeared1  and ,i   
felt only excessive weakness and a      
slight swimming of the head4  ,my voice 
was very feeble and indistinct4 ,this   
was at two o'clock in the  afternoon4   
,i afterwards walked slowly for about   
half an hour1 with ,mr4 ,tobin1  ,junr4 
and on my return1 was so much stronger  
and better1 as to believe  that the     
effects of the gas had disappeared2     
though my pulse was #abj  and very      
feeble4 ,i continued without pain for   
near three quarters of  an hour2 when   
the giddiness returned with such        
violence as to oblige  me to lie on the 
bed2 it was accompanied with nausea1    
loss of memory1  and deficient          

sensation4 ,in about an hour and half1  
the giddiness went  off1 and was        
succeeded by an excruciating pain in the
 forehead and  between the eyes1 with   
transient pains in the chest and        
extremities4  ,towards night these      
affections gradually diminished4 ,at    
ten1#baj no  disagreeable feeling except
 weakness remained4 ,i slept sound1 and 
awoke in the morning very feeble and    
very hungry4 ,no recurrence of the      
symptoms took place1 and ,i had nearly  
recovered my strength by the  evening4  
,i have been minute in the account of   
this experiment because it  proves1 that
 hydrocarbonate acts as a sedative1 i4  
e4 that it  produces diminution of vital
 action1 and debility1 without          
previously  exciting4 ,there is every   
reason to believe1 that if ,i had taken 
four  or five inspirations instead of   
three1 they would have destroyed life   
immediately without producing any       
painful sensation4 ,perhaps most of  the
 uneasy feelings after the experiment1  

were connected with the  return of the  
healthy condition of organs4#baa    #baj
 ,i ought to observe1 that between eight
 and ten1 ,i took by the  advice of ,dr4
 ,beddoes1 two or three doses of diluted
 nitric acid4    #baa ,by whatever cause
 the exhaustion of organs is produced1  
pain  is almost uniformly connected with
 their returning health4 ,pain is       
rarely ever perceived in limbs          
debilitated by fatigue till after they  
have been for some hours at rest4 ,pain 
is uniformly connected with the         
recovery from the debility induced by   
typhus1 often with the recovery  from   
that produced by the stimulation of     
opium and alcohol4    ,about a week     
after this experiment1 ,i attempted to  
respire ,carbonic  acid1 not being at   
the time acquainted with the experiments
 of ,rosier4    ,i introduced into a    
silk bag four quarts of well washed     
carbonic acid  produced from carbonate  
of ammoniac#bab by heat1 and after a    
compleat  voluntary exhaustion of my    

lungs1 attempted to inspire it4 ,it     
tasted  strongly acid in the mouth and  
fauces1 and produced a sense of burning 
at the top of the uvula4 ,in vain ,i    
made powerful voluntary efforts  to draw
 it into the windpipe2 at the moment    
that the epiglottis was  raised a       
little1 a painful stimulation was       
induced1 so as to close  it             
spasmodically on the glottis2 and thus  
in repeated trials ,i was  prevented    
from taking a single particle of        
carbonic acid into my lungs4    #bab    
,carbonic acid is produced in this way  
in a high state of purity1  and with    
great readiness4    ,i tried to breathe 
a mixture of two quarts of common air   
and three of  carbonic acid1 without    
success2 it stimulated the epiglottis   
nearly in  the same manner as pure      
carbonic acid1 and was perfectly        
non-respirable4    ,i found that a      
mixture of three quarts of carbonic acid
 with seven of  common air was          
respirable1 ,i breathed it for near a   

minute4 ,at the  time1 it produced a    
slight degree of giddiness1 and an      
inclination to  sleep4 ,these effects   
however1 very rapidly disappeared after 
,i had  ceased to breathe1#bac and no   
other affections followed4    #bac      
,carbonic acid possesses no action on   
arterial blood4 ,hence  perhaps1 its    
slight effects when breathed mingled    
with large quantities  of common air4   
,its effects are very marked upon venous
 blood6 ,if  it were thrown forcibly    
into the lungs of animals1 the momentary
  application of it to the pulmonary    
venous blood would probably destroy     
life4    ,during the course of          
experiments on nitrous oxide1 ,i several
 times  breathed ,oxygene procured from 
manganese by heat1 for from three to    
five minutes4    ,in respiring eight or 
ten quarts2 for the first two or three  
minutes  ,i could perceive no effects4  
,towards the end1 even when ,i breathed 
very slowly1 my respiration became      
oppressed1 and ,i felt a sensation      

analogous to that produced by the want  
of fresh air2 though but little  of the 
oxygene had been consumed4    ,in one   
experiment when ,i breathed from and    
into a bag containing #bj  quarts of    
oxygene for near six minutes2 ,dr4      
,kinglake felt my pulse1  and found it  
not altered in velocity1 but rather     
harder than before4 ,i  perceived no    
effects but those of oppression on the  
chest#bad4    #bad ,in a conversation   
with ,mr4 ,watt1 relating to the powers 
of gases1  that excellent philosopher   
told me he had for some time entertained
  a suspicion1 that the effects         
attributed to oxygene produced from     
manganese by heat1 in some measure      
depended upon nitrous acid suspended  in
 the gas1 formed during ignition by the 
union of some of the oxygene  of the    
manganese with nitrogene likewise       
condensed in it4    ,in the course of   
experiments on nitrous acid1 detailed in
 ,research  ,i4 made in ,september1     
,october1 and ,december1 #agii1 ,i      

several times  experienced a severe     
oppression on the chest and difficulty  
of  respiration1 not unanalogous to that
 produced by oxygene1 but much more     
violent1 from breathing an atmosphere   
loaded with nitrous acid vapour4  ,this 
fact seemed to confirm ,mr4 ,watt's     
suspicion4 ,i confess1 however1  that ,i
 have never been able to detect any     
smell of nitrous acid1 either  by means 
of my own organs or those of others1    
during the production  of oxygene2 when 
the gas is suffered to pass into the    
atmosphere4 ,the  oxygene breathed in   
the experiments detailed in the text1   
had been for  some days in contact with 
water4    ,having observed in my        
experiments upon venous blood1 that     
,nitrous gas  rendered that fluid of a  
purple tinge1 very like the color       
generated  in it by nitrous oxide2 and  
finding no painful effects produced by  
the application of nitrous gas to the   
bare muscular fibre1 ,i began to        
imagine that this gas might be breathed 

with impunity1 provided it were         
possible in any way to free the lungs of
 common air before inspiration1  so as  
to prevent the formation of nitrous     
acid4    ,on this supposition1 during a 
fit of enthusiasm produced by the       
respiration of nitrous oxide1 ,i        
resolved to endeavour to breathe        
,nitrous gas4    #aad cubic inches of   
nitrous gas were introduced into the    
large  mercurial airholder2 two small   
silk bags of the capacity of seven      
quarts were filled with nitrous oxide4  
,after a forced exhaustion of my lungs1 
my nose being accurately closed1  ,i    
made three inspirations and expirations 
of nitrous oxide in one  of the bags1 to
 free my lungs as much as possible from 
atmospheric  oxygene2 then1 after a full
 expiration of the nitrous oxide1 ,i    
transferred my mouth from the           
mouth-piece of the bag to that of the   
airholder1 and turning the stop-cock1   
attempted to inspire the nitrous        
gas4--,in passing through my mouth and  

fauces1 it tasted astringent and  highly
 disagreeable2 it occasioned a sense of 
burning in the throat1  and produced a  
spasm of the epiglottis so painful as to
 oblige me to  desist instantly from    
attempts to inspire it4 ,after moving my
 lips from  the mouth-piece1 when ,i    
opened them to inspire common air1      
ariform  nitrous acid was instantly     
formed in my mouth1 which burnt the     
tongue  and palate1 injured the teeth1  
and produced an inflammation of the     
mucous membrane which lasted for some   
hours4    ,as after the respiration of  
nitrous oxide in the experiments in the 
last ,research1 a small portion of the  
residual atmospheric air remained  in   
the lungs1 mingled with the gas1 after  
forced expiration2 it is  most probable 
that a minute portion of nitrous acid   
was formed in this  experiment1 when the
 nitrous gas was taken into the mouth   
and fauces1  which might produce its    
stimulating properties4 ,if so1 perhaps 
,i owe my  life to the circumstance2 for

 supposing ,i had taken an inspiration  
of  nitrous gas1 and even that it had   
produced no positive effects1 it is     
highly improbable1 that by breathing    
nitrous oxide1 ,i should have freed  my 
lungs from it1 so as to have prevented  
the formation of nitrous acid  when ,i  
again inspired common air4 ,i never     
design again to attempt so  rash an     
experiment4    ,in the beginning of     
,september ,i often respired nitrous    
oxide mingled  with different           
proportions of common air or oxygene4   
,the effects  produced by the diluted   
gas were much less violent than those   
produced  by pure nitrous oxide4 ,they  
were generally pleasant3 the thrilling  
was  not often perceived1 but a sense of
 exhilaration was almost constant4      
,between ,september and the end of      
,october1 ,i made but few experiments   
on respiration1 almost the whole of my  
time being devoted to chemical          
experiments on the production and       
analysis of nitrous oxide4    ,at this  

period my health being somewhat injured 
by the constant labour  of              
experimenting1 and the perpetual        
inhalation of the acid vapours of  the  
laboratory1 ,i went into ,cornwall2     
where new associations of ideas  and    
feelings1 common exercise1 a pure       
atmosphere1 luxurious diet and  moderate
 indulgence in wine1 in a month restored
 me to health and vigor4    ,nov4 #bgth4
 ,immediately after my return1 being    
fatigued by a long  journey1 ,i respired
 nine quarts of nitrous oxide1 having   
been precisely  thirty-three days       
without breathing any4 ,the feelings    
were different  from those ,i had       
experienced in former experiments4      
,after the first  six or seven          
inspirations1 ,i gradually began to lose
 the perception  of external things1 and
 a vivid and intense recollection of    
some  former experiments passed through 
my mind1 so that ,i called out 8what  an
 amazing concatenation of ideas60 ,i had
 no pleasurable feeling  whatever1 ,i   

used no muscular motion1 nor did ,i feel
 any disposition  to it2 after a minute1
 when ,i made the note of the           
experiment1 all  the uncommon sensations
 had vanished2 they were succeeded by a 
slight  soreness in one of the arms and 
in the leg3 in three minutes these      
affections likewise disappeared4        
,from this experiment ,i was inclined to
 suppose that my newly acquired  health 
had diminished my susceptibility to the 
effects of the gas4  ,about ten days    
after1 however1 ,i had an opportunity of
 proving the  fallacy of this           
supposition4    ,immediately after a    
journey of #abf miles1 in which ,i had  
no sleep the  preceding night1 being    
much exhausted1 ,i respired seven quarts
 of gas  for near three minutes4 ,it    
produced the usual pleasurable effects1 
and slight muscular motion4 ,i continued
 exhilarated for some minutes           
afterwards3 but in half an hour found   
myself neither more or less  exhausted  
than before the experiment4 ,i had a    

great propensity to sleep4    ,i        
repeated the experiment four or five    
times in the following week1  with      
similar effects4 ,my susceptibility was 
certainly not diminished4 ,i  even      
thought that ,i was more affected than  
formerly by equal doses4    ,though1    
except in one instance1 when indeed the 
gas was impure1 ,i had  experienced no  
decisive exhaustion after the excitement
 from nitrous  oxide1 yet still ,i was  
far from being satisfied that it was    
unanalogous  to stimulants in           
general4--,no experiment had been made  
in which the  excitement from nitrous   
oxide had been kept up for so great a   
length of  time and carried to so great 
an extent as that in which it is        
uniformly  succeeded by excessive       
debility under the agency of other      
powers4    ,it occurred to me1 that     
supposing nitrous oxide to be a         
stimulant  of the common class1 it would
 follow that the debility produced in   
consequence of excessive stimulation by 

a known agent1 ought to be  increased   
after excitement from nitrous oxide4#bae
    #bae ,in the same manner as the     
debility from intoxication by two       
bottles of wine is increased by a third4
    ,to ascertain whether this was the  
case1 ,i made on ,december #bc;d1 at    
four ,p4 ,m4 the following experiment4  
,i drank a bottle of wine in  large     
draughts in less than eight minutes4    
,whilst ,i was drinking1  ,i perceived a
 sense of fulness in the head1 and      
throbbing of the  arteries1 not         
unanalogous to that produced in the     
first stage of  nitrous oxide           
excitement4 ,after ,i had finished the  
bottle1 this fulness  increased1 the    
objects around me became dazzling1 the  
power of distinct  articulation was     
lost1 and ,i was unable to walk         
steadily4 ,at this  moment the          
sensations were rather pleasurable than 
otherwise1 the sense  of fulness in the 
head soon however increased so as to    
become painful1  and in less than an    

hour ,i sunk into a state of            
insensibility4#baf    #baf ,i ought to  
observe that my usual drink is water1   
that ,i had  been little accustomed to  
take wine or spirits1 and had never been
  compleatly intoxicated but once before
 in the course of my life4 ,this  will  
account for the powerful effects of a   
single bottle of wine4 ,in  this        
situation ,i must have remained for two 
hours or two hours and half4    ,i was  
awakened by head-ache and painful       
nausea4 ,the nausea continued  even     
after the contents of the stomach had   
been ejected4 ,the pain in  the head    
every minute increased2 ,i was neither  
feverish or thirsty2 my  bodily and     
mental debility were excessive1 and the 
pulse feeble and  quick4    ,in this    
state ,i breathed for near a minute and 
half five quarts of gas1  which was     
brought to me by the operator for       
nitrous oxide2 but as it  produced no   
sensations whatever1 and apparently     
rather increased my  debility1 ,i am    

almost convinced that it was from some  
accident1 either  common air1 or very   
impure nitrous oxide4    ,immediately   
after this trial1 ,i respired #ab quarts
 of oxygene for near  four minutes4 ,it 
produced no alteration in my sensations 
at the time2  but immediately after ,i  
imagined that ,i was a little           
exhilarated4    ,the head-ache and      
debility still however continuing with  
violence1 ,i  examined some nitrous     
oxide which had been prepared in the    
morning1 and  finding it very pure1     
respired seven quarts of it for two     
minutes and  half4    ,i was unconscious
 of head-ache after the third           
inspiration2 the usual  pleasurable     
thrilling was produced1 voluntary power 
was destroyed1 and  vivid ideas rapidly 
passed through my mind2 ,i made strides 
across the  room1 and continued for some
 minutes much exhilarated4 ,immediately 
after the exhilaration had disappeared1 
,i felt a slight return of the          
head-ache2 it was connected with        

transient nausea4 ,after two minutes1   
when a small quantity of acidified wine 
had been thrown from the  stomach1 both 
the nausea and head-ache disappeared2   
but languor and  depression not very    
different in degree from those existing 
before the  experiment1 succeeded4 ,they
 however1 gradually went off before bed 
time4 ,i slept sound the whole of the   
night except for a few minutes1  during 
which ,i was kept awake by a trifling   
head-ache4 ,in the morning1  ,i had no  
longer any debility4 ,no head-ache or   
giddiness came on after ,i  had arisen1 
and my appetite was very great4    ,this
 experiment proved1 that debility from  
intoxication was not  increased by      
excitement from nitrous oxide4 ,the     
head-ache and  depression1 it is        
probable1 would have continued longer if
 it had not  been administered4 ,is it  
not likely that the slight nausea       
following  the effects of the gas was   
produced by new excitability given to   
the  stomach8    ,to ascertain with     

certainty1 whether the most extensive   
action of  nitrous oxide compatible with
 life1 was capable of producing         
debility1  ,i resolved to breathe the   
gas for such a time and in such         
quantities1  as to produce excitement   
equal in duration and superior in       
intensity to  that occasioned by high   
intoxication from opium or alcohol4     
,to habituate myself to the excitement1 
and to carry it on gradually4    ,on    
,december #bfth1 ,i was inclosed in an  
air-tight breathing-box1#bag  of the    
capacity of about #i cubic feet and     
half1 in the presence of ,dr4           
,kinglake4    ,after ,i had taken a     
situation in which ,i could by means of 
a curved  thermometer inserted under the
 arm1 and a stop-watch1 ascertain the   
alterations in my pulse and animal heat1
 #bj quarts of nitrous oxide  were      
thrown into the box4    ,for three      
minutes ,i experienced no alteration in 
my sensations1 though  immediately after
 the introduction of the nitrous oxide  

the smell and  taste of it were very    
evident4#bah    #bag ,the plan of this  
box was communicated by ,mr4 ,watt4 ,an 
account of  it will be detailed in the  
,researches4    #bah ,the nitrous oxide 
was too diluted to act much2 it was     
mingled  with near #cb times its bulk of
 atmospheric air4    ,in four minutes ,i
 began to feel a slight glow in the     
cheeks1 and a  generally diffused warmth
 over the chest1 though the temperature 
of the  box was not quite #ej4 ,i had   
neglected to feel my pulse before ,i    
went  in2 at this time it was #ajd and  
hard1 the animal heat was #ih4 ,in ten  
minutes the animal heat was near #ii1 in
 a quarter of an hour #ii4e1  when the  
pulse was #ajb1 and fuller than before4 
,at this period #bj quarts more of      
nitrous oxide were thrown into the  box1
 and well-mingled with the mass of air  
by agitation4    ,in #be minutes the    
animal heat was #ajj1 pulse #abd4 ,in   
#cj minutes1 #bj  quarts more of gas    
were introduced4    ,my sensations were 

now pleasant2 ,i had a generally        
diffused warmth  without the slightest  
moisture of the skin1 a sense of        
exhilaration  similar to that produced  
by a small dose of wine1 and a          
disposition to  muscular motion and to  
merriment4    ,in three quarters of an  
hour the pulse was #ajd1 and animal heat
 not  #ii1e1 the temperature of the     
chamber was #fd4 ,the pleasurable       
feelings  continued to increase1 the    
pulse became fuller and slower1 till in 
about an hour it was #hh1 when the      
animal heat was #ii4    #bj quarts more 
of air were admitted4 ,i had now a great
 disposition to  laugh1 luminous points 
seemed frequently to pass before my     
eyes1 my  hearing was certainly more    
acute and ,i felt a pleasant lightness  
and  power of exertion in my muscles4   
,in a short time the symptoms became    
stationary2 breathing was rather        
oppressed1 and on account of the great  
desire of action1 rest was painful4     
,i now came out of the box1 having been 

in precisely an hour and quarter4       
,the moment after1 ,i began to respire  
#bj quarts of unmingled nitrous  oxide4 
,a thrilling extending from the chest to
 the extremities was  almost immediately
 produced4 ,i felt a sense of tangible  
extension  highly pleasurable in every  
limb2 my visible impressions were       
dazzling  and apparently magnified1 ,i  
heard distinctly every sound in the room
  of my situation4#bai ,by degrees as   
the pleasurable and was perfectly  aware
 sensations increased1 ,i lost all      
connection with external things2  trains
 of vivid visible images rapidly passed 
through my mind and  were connected with
 words in such a manner1 as to produce  
perceptions  perfectly novel4 ,i existed
 in a world of newly connected and newly
  modified ideas4 ,i theorised2 ,i      
imagined that ,i made discoveries4      
,when ,i was awakened from this         
semi-delirious trance by ,dr4 ,kinglake1
  who took the bag from my mouth1       
,indignation and pride were the first   

feelings produced by the sight of the   
persons about me4 ,my emotions  were    
enthusiastic and sublime2 and for a     
minute ,i walked round the room         
perfectly regardless of what was said to
 me4 ,as ,i recovered my former  state  
of mind1 ,i felt an inclination to      
communicate the discoveries  ,i had made
 during the experiment4 ,i endeavoured  
to recall the ideas1  they were feeble  
and indistinct2 one collection of terms1
 however1  presented itself3 and with   
the most intense belief and prophetic   
manner1 ,i exclaimed to ,dr4 ,kinglake1 
8,nothing exists but thoughts6--the     
universe is composed of impressions1    
ideas1 pleasures and pains60    #bai ,in
 all these experiments after the first  
minute1 my cheeks became  purple4       
,about three minutes and half only1 had 
elapsed during this experiment1  though 
the time as measured by the relative    
vividness of the  recollected ideas1    
appeared to me much longer4    ,not more
 than half of the nitrous oxide was     

consumed4 ,after a minute1  before the  
thrilling of the extremities had        
disappeared1 ,i breathed  the remainder4
 ,similar sensations were again         
produced2 ,i was quickly  thrown into   
the pleasurable trance1 and continued in
 it longer than  before4 ,for many      
minutes after the experiment1 ,i        
experienced the  thrilling in the       
extremities1 the exhilaration continued 
nearly two  hours4 ,for a much longer   
time ,i experienced the mild enjoyment  
before  described connected with        
indolence2 no depression or feebleness  
followed4 ,i ate my dinner with great   
appetite and found myself lively  and   
disposed to action immediately after4 ,i
 passed the evening in  executing       
experiments4 ,at night ,i found myself  
unusually cheerful and  active2 and the 
hours between eleven and two1 were spent
 in copying  the foregoing detail from  
the common-place book and in arranging  
the  experiments4 ,in bed ,i enjoyed    
profound repose4 ,when ,i awoke in the  

morning1 it was with consciousness of   
pleasurable existence1 and this         
consciousness more or less1 continued   
through the day4    ,since ,december1 ,i
 have very often breathed nitrous oxide4
 ,my  susceptibility to its power is    
rather increased than diminished4 ,i    
find six quarts a full dose1 and ,i am  
rarely able to respire it in any        
quantity for more than two minutes and  
half4    ,the mode of its operation is  
somewhat altered4 ,it is indeed very    
different at different times4    ,i am  
scarcely ever excited into violent      
muscular action1 the emotions  are      
generally much less intense and sublime 
than in the former  experiments1 and not
 often connected with thrilling in the  
extremities4    ,when troubled with     
indigestion1 ,i have been two or three  
times  unpleasantly affected after the  
excitement of the gas4 ,cardialgia1     
eructations and unpleasant fulness of   
the head were produced4    ,i have often
 felt very great pleasure when breathing

 it alone1 in  darkness and silence1    
occupied only by ideal existence4 ,in   
two or three  instances when ,i have    
breathed it amidst noise1 the sense of  
hearing  has been painfully affected    
even by moderate intensity of sound4    
,the  light of the sun has sometimes    
been disagreeably dazzling4 ,i have once
  or twice felt an uneasy sense of      
tension in the cheeks and transient     
pains in the teeth4    ,whenever ,i have
 breathed the gas after excitement from 
moral or  physical causes1 the delight  
has been often intense and sublime4     
,on ,may #eth1 at night1 after walking  
for an hour amidst the scenery of  the  
,avon1 at this period rendered          
exquisitely beautiful by bright         
moonshine2 my mind being in a state of  
agreeable feeling1 ,i respired  six     
quarts of newly prepared nitrous oxide4 
,the thrilling was very rapidly         
produced4 ,the objects around me were   
perfectly distinct1 and the light of the
 candle not as usual dazzling4  ,the    

pleasurable sensation was at first local
 and perceived in the  lips and about   
the cheeks4 ,it gradually however1      
diffused itself  over the whole body1   
and in the middle of the experiment was 
for a  moment so intense and pure as to 
absorb existence4 ,at this moment1 and  
not before1 ,i lost consciousness2 it   
was however1 quickly restored1  and ,i  
endeavoured to make a by-stander        
acquainted with the pleasure  ,i        
experienced by laughing and stamping4 ,i
 had no vivid ideas4 ,the  thrilling and
 the pleasurable feeling continued for  
many minutes2  ,i felt two hours        
afterwards1 a slight recurrence of them1
 in the  intermediate state between     
sleeping and waking2 and ,i had during  
the whole of the night1 vivid and       
agreeable dreams4 ,i awoke in the       
morning with the feeling of restless    
energy1 or that desire of action        
connected with no definite object1 which
 ,i had often experienced in  the course
 of experiments in #agii4    ,i have two

 or three times since respired nitrous  
oxide under similar  circumstances2 but 
never with equal pleasure4    ,during   
the last fortnight1 ,i have breathed it 
very often2 the effects  have been      
powerful and the sensations uncommon2   
but pleasurable only in  a slight       
degree4    ,i ought to have observed    
that a desire to breathe the gas is     
always  awakened in me by the sight of a
 person breathing1 or even by that of   
an air-bag or an airholder4    ,i have  
this day1 ,june #eth1 respired four     
large doses of gas4 ,the  first two     
taken in the morning acted very         
powerfully2 but produced  no thrilling  
or other pleasurable feelings4 ,the     
effects of the third  breathed          
immediately after a hearty dinner were  
pleasant1 but neither  intense or       
intoxicating4 ,the fourth was respired  
at night in darkness  and silence after 
the occurrence of a circumstance which  
had produced  some anxiety4 ,this dose  
affected me powerfully and pleasantly2 a

 slight  thrilling in the extremities   
was produced2 an exhiliration continued 
for some time1 and ,i have had but      
little return of uneasiness4 #aa ,p4 ,m4
    ,from the nature of the language of 
feeling1 the preceding detail  contains 
many imperfections2 ,i have endeavoured 
to give as accurate an  account as      
possible of the strange effects of      
nitrous oxide1 by making  use of terms  
standing for the most similar common    
feelings4    ,we are incapable of       
recollecting pleasures and pains of     
sense4#bbj ,it  is impossible to reason 
concerning them1 except by means of     
terms which  have been associated with  
them at the moment of their existence1  
and  which are afterwards called up     
amidst trains of concomitant ideas4     
#bbj ,physical pleasure and pain        
generally occur connected with a        
compound impression1 i4 e4 an organ and 
some object4 ,when the idea left  by the
 compound impression1 is called up by   
being linked accidentally  to some other

 idea or impression1 no recurrence1 or  
the slightest  possible1 of the pleasure
 or pain in any form will take place4   
,but when  the compound impression      
itself exists without the physical      
pleasure  or pain1 it will awaken ideal 
or intellectual pleasure or pain1 i4 e4 
hope or fear4 ,so that physical pleasure
 and pain are to hope and fear1  what   
impressions are to ideas4 ,for instance1
 assuming no accidental  association1   
the child does not fear the fire before 
he is burnt4 ,when  he puts his finger  
to the fire he feels the physical pain  
of burning1  which is connected with a  
visible compound impression1 the fire   
and his  finger4 ,now when the compound 
idea of the fire and his finger1 left   
by the compound impression are called up
 by his mother1 saying1 8,you  have     
burnt your finger10 nothing like fear or
 the pain of burning is  connected with 
it4 ,but when the finger is brought near
 the fire1 i4 e4  when the compound     
impression again exists1 the ideal pain 

of burning or  the passion of fear is   
awakened1 and it becomes connected with 
those  very actions which removed the   
finger from the fire4    ,when pleasures
 and pains are new or connected with new
 ideas1 they can  never be intelligibly 
detailed unless associated during their 
existence  with terms standing for      
analogous feelings4    ,i have sometimes
 experienced from nitrous oxide1        
sensations similar to  no others1 and   
they have consequently been             
indescribable4 ,this has been  likewise 
often the case with other persons4 ,of  
two paralytic patients  who were asked  
what they felt after breathing nitrous  
oxide1 the first  answered1 8,i do not  
know how1 but very queer40 ,the second  
said1 8,i  felt like the sound of a     
harp40 ,probably in the one case1 no    
analogous  feelings had ever occurred4  
,in the other1 the pleasurable          
thrillings  were similar to the         
sensations produced by music2 and hence1
 they were  connected with terms        

formerly applied to music4              
,,division ,,ii4        ,,details of the
 ,,effects produced by the ,,respiration
         of ,,nitrous ,,oxide upon      
different ,,individuals                 
furnished by ,,themselves4      ,the    
experiments related in the following    
details1 were made in the  ,medical     
,pneumatic ,institution4    ,abstracts  
from many of them have been published by
 ,dr4 ,beddoes4#bba    #bba ,notice of  
some ,observations made at the ,medical 
,pneumatic  ,institution4      ,i4      
,detail of ,,mr4 ,j4 ,w4 ,,tobin4       
,having seen the remarkable effects     
produced on ,mr4 ,davy1 by breathing    
nitrous oxide1 the #ahth of ,april2 ,i  
became desirous of taking some4    ,a   
day or two after ,i breathed #b quarts  
of this gas1 returning it back  again   
into the same bag1 after two or three in
 inspirations1 breathing  became        
difficult1 and ,i occasionally admitted 
common air into my  lungs4 ,while the   
respiration was continued1 my sensations

 became more  pleasant4 ,on taking the  
bag from my mouth1 ,i staggered a       
little1 but  felt no other effect4      
,on the second time of making the       
experiment1 ,i took nearly four quarts1 
but still found it difficult to continue
 breathing long1 though the air  which  
was left in the bag was far from being  
impure4    ,the effects however1 in this
 case1 were more striking than in the   
former4 ,increased muscular action was  
accompanied by very pleasurable         
feelings1 and a strong desire to        
continue the inspiration4 ,on removing  
the bag from my mouth1 ,i laughed1      
staggered1 and attempted to speak1  but 
stammered exceedingly1 and was utterly  
unable to pronounce some  words4 ,my    
usual state of mind1 however1 soon      
returned4    ,on the #bith1 ,i again    
breathed four quarts4 ,the pleasant     
feelings  produced at first1 urged me to
 continue the inspiration with great    
eagerness4 ,these feelings however1 went
 off towards the end of the  experiment1

 and no other effects followed4 ,the gas
 had probably been  breathed too long1  
as it would not support flame4 ,i then  
proposed to  ,mr4 ,davy1 to inhale the  
air by the mouth from one bag1 and to   
expire  it from the nose into another4  
,this method was pursued with less than 
three quarts1 but the effects were so   
powerful as to oblige me to take  in a  
little common air occasionally4 ,i soon 
found my nervous system  agitated by the
 highest sensations of pleasure1 which  
are difficult  of description2 my       
muscular powers were very much          
increased1 and ,i  went on breathing    
with great vehemence1 not from a        
difficulty of  inspiration1 but from an 
eager avidity for more air4 ,when the   
bags  were exhausted and taken from me1 
,i continued breathing with the same    
violence1 then suddenly starting from   
the chair1 and vociferating with        
pleasure1 ,i made towards those that    
were present1 as ,i wished they  should 
participate in my feelings4 ,i struck   

gently at ,mr4 ,davy and a  stranger    
entering the room at the moment1 ,i made
 towards him1 and gave  him several     
blows1 but more in the spirit of good   
humour than of anger4  ,i then ran      
through different rooms in the house1   
and at last returned  to the laboratory 
somewhat more composed2 my spirits      
continued much  elevated for some hours 
after the experiment1 and ,i felt no    
consequent  depression either in the    
evening or the day following1 but slept 
as  soundly as usual4    ,on the #eth of
 ,may1 ,i again attempted to breathe    
nitrous oxide1 but  it happened to      
contain suspended nitrous vapour which  
rendered it  non-respirable4    ,on the 
#gth1 ,i inspired #g quarts of pure gas 
mingled with an equal  quantity of      
common air1 the sensations were         
pleasant1 and my muscular  power much   
increased4    ,on the #hth1 ,i inspired 
five quarts without any mixture of      
common air1  but the effects were not   
equal to those produced the day before2 

,indeed  there were reasons for         
supposing that the gas was impure4      
,on the #ahth1 ,i breathed nearly six   
quarts of the pure nitrous oxide4 ,it   
is not easy to describe my sensations2  
they were superior to any thing  ,i ever
 before experienced4 ,my step was firm1 
and all my muscular powers  increased4  
,my senses were more alive to every     
surrounding impression2  ,i threw myself
 into several theatrical attitudes1 and 
traversed the  laboratory with a quick  
step2 my mind was elevated to a most    
sublime  height4 ,it is giving but a    
faint idea of the feelings to say1 that 
they  resembled those produced by a     
representation of an heroic scene on the
  stage1 or by reading a sublime passage
 in poetry when circumstances           
contribute to awaken the finest         
sympathies of the soul4 ,in a few       
minutes the usual state of mind         
returned4 ,i continued in good spirits  
for the rest of the day1 and slept      
soundly4    ,since the #ahth of ,may1 ,i

 have very often breathed nitrous oxide4
 ,in  the first experiments when pure1  
its effects were generally similar to   
those just described4    ,lately ,i have
 seldom experienced vivid sensations4   
,the pleasure  produced by it is slight 
and tranquil1 ,i rarely feel sublime    
emotions  or increased muscular power4  
,j4 ,w4 ,,tobin4      ,october1 #agii4  
,,ii4 ,detail of ,,mr4 ,,wm4            
,,clayfield4    ,the first time that ,i 
breathed the nitrous oxide1 it produced 
feelings  analogous to those of         
intoxication4 ,i was for some time      
unconscious of  existence1 but at no    
period of the experiment experienced    
agreeable  sensations1 a momentary      
nausea followed it2 but unconnected with
  languor or head-ache4    ,after this  
,i several times respired the gas1 but  
on account of the  fulness in the head  
and apparent throbbing of the arteries  
in the  brain1#bbb always desisted to   
breathe before the full effects were    
produced4 ,in two experiments however1  

when by powerful voluntary  efforts ,i  
succeeded in breathing a large quantity 
of gas for some  minutes1 ,i had highly 
pleasurable thrillings in the           
extremities1 and  such increase of      
muscular power1 as to be obliged to     
exert my limbs  with violence4 ,after   
these experiments1 no languor or        
depression  followed4        ,,william  
,,clayfield4    #bbb ,in some of these  
experiments1 hearing was rendered more  
acute4      ,,iii4 ,letter from ,,dr4   
,,kinglake4    ,in compliance with your 
desire1 ,i will endeavour to give you a 
faithful  detail of the effects produced
 on my sensations by the inhalation of  
nitrous oxide4    ,my first inspiration 
of it was limited to four quarts1       
diluted with  an equal quantity of      
atmospheric air4 ,after a few           
inspirations1 a  sense of additional    
freedom and power 7call it energy if you
 please7  agreeably pervaded the region 
of the lungs2 this was quickly succeeded
  by an almost delirious but highly     

pleasurable sensation in the brain1     
which was soon diffused over the whole  
frame1 imparting to the muscular  power 
at once an encreased disposition and    
tone for action2 but the  mental effect 
of the excitement was such as to absorb 
in a sort of  intoxicating placidity1   
and delight1 volition1 or rather the    
power  of voluntary motion4 ,these      
effects were in a greater or less degree
  protracted during about five minutes1 
when the former state returned1  with   
the difference however of feeling more  
cheerful and alert1 for  several hours  
after4    ,it seemed also to have had   
the further effect of reviving rheumatic
  irritations in the shoulder and       
knee-joints1 which had not been         
previously felt for many months4 ,no    
perceptible change was induced in  the  
pulse either at or subsequent to the    
time of inhaling the gas4    ,the       
effects produced by a second trial of   
its powers1 were more  extensive1 and   
concentrated on the brain4 ,in this     

instance1 nearly  six quarts undiluted1 
were accurately and fully inhaled4 ,as  
on the  former occasion1 it immediately 
proved agreeably respirable1 but  before
 the whole quantity was quite exhausted1
 its agency was exerted  so strongly on 
the brain1 as progressively to suspend  
the senses  of seeing1 hearing1 feeling1
 and ultimately the power of volition   
itself4 ,at this period1 the pulse was  
much augmented both in force  and       
frequency2 slight convulsive twitches of
 the muscles of the arms  were also     
induced2 no painful sensation1 nausea1  
or languor1 however1  either preceded1  
accompanied1 or followed this state1 nor
 did a minute  elapse before the brain  
rallied1 and resumed its wonted         
faculties1  when a sense of glowing     
warmth extending over the system1 was   
speedily  succeeded by a re-instatement 
of the equilibrium of health4    ,the   
more permanent effects were 7as in the  
first experiment7 an  invigorated feel  
of vital power1 improved spirits1       

transient  irritations in different     
parts1 but not so characteristically    
rheumatic  as in the former instance4   
,among the circumstances most worthy of 
regard in considering the  properties   
and administration of this powerful     
arial agent1 may be  ranked1 the fact of
 its being 7contrary to the prevailing  
opinion#bbc7  both highly respirable1   
and salutary1 that it impresses the     
brain  and system at large with a more  
or less strong and durable degree  of   
pleasurable sensation1 that unlike the  
effect of other violently  exciting     
agents1 no sensible exhaustion or       
diminution of vital power  accrues from 
the exertions of its stimulant property1
 that its most  excessive operation     
even1 is neither permanently nor        
transiently  debilitating2 and finally1 
that it fairly promises under judicious 
application1 to prove an extremely      
efficient remedy1 as well in the  vast  
tribe of diseases originating from      
deficient irritability and  sensibility1

 as in those proceeding from morbid     
associations1 and  modifications1 of    
those vital principles4    ,if you      
should deem any thing contained in this 
cursory narrative  capable of subserving
 in any degree the practical advantages 
likely to  result from your scientific  
and valuable investigation of the       
genuine  properties of the nitrous      
oxide1 it is perfectly at your disposal4
                                  ,i am 
,your sincere friend1                   
,,robert ,,kinglake4        ,bristol1   
,june #adth1 #agii4             ,to     
,,mr4 ,,davy4    #bbc ,dr4 ,mitchill 7an
 ,american ,chemist7 has erroneously    
supposed  its full admission to the     
lungs1 in its concentrated state1 to be 
incompatible with animal life1 and that 
in a more diluted form it  operates as a
 principal agent in the production of   
contagious diseases1  c4 ,this          
gratuitous position is thus             
unqualifiedly affirmed4 8,if a full     
inspiration of gaseous oxyd be made1    

there will be a sudden extinction  of   
life2 and this accordingly accounts for 
the fact related by ,russel  7,history  
of ,aleppo1 p4 #bcb47 and confirmed by  
other observers1 of many  persons       
falling down dead suddenly1 when struck 
with the contagion of  the plague40     
,vide ,remarks on the ,gaseous ,oxyd of 
,azote1 by ,samuel ,latham ,mitchill1   
,m4 ,d4      ,,iv4 ,detail of ,,mr4     
,,southey4    ,in breathing the nitrous 
oxide1 ,i could not distinguish between 
the  first feelings it occasioned and an
 apprehension of which ,i was unable  to
 divest myself4 ,my first definite      
sensation was a dizziness1 a  fulness in
 the head1 such as to induce a fear of  
falling4 ,this was  momentary4 ,when ,i 
took the bag from my mouth1 ,i          
immediately laughed4  ,the laugh was    
involuntary but highly pleasurable1     
accompanied by  a thrill all through me2
 and a tingling in my toes and fingers1 
a  sensation perfectly new and          
delightful4 ,i felt a fulness in my     

chest  afterwards2 and during the       
remainder of the day1 imagined that my  
taste  and hearing were more than       
commonly quick4 ,certain ,i am that ,i  
felt  myself more than usually strong   
and chearful4    ,in a second trial1 by 
continuing the inhalation longer1 ,i    
felt a thrill  in my teeth2 and         
breathing still longer the third time1  
became so full  of strength as to be    
compelled to exercise my arms and feet4 
,now after an interval of some months1  
during which my health has been         
materially impaired1 the nitrous oxide  
produces an effect upon me  totally     
different4 ,half the quantity affects   
me1 and its operation is  more violent2 
a slight laughter is first induced1#bbd 
and a desire  to continue the           
inhalation1 which is counteracted by    
fear from the  rapidity of respiration2 
indeed my breath becomes so short and   
quick1  that ,i have no doubt but the   
quantity which ,i formerly breathed1    
would  now destroy me4 ,the sensation is

 not painful1 neither is it in the      
slightest degree pleasurable4           
,,robert ,,southey4    #bbd ,in the     
former experiments1 ,mr4 ,southey       
generally respired six  quarts1 now he  
is unable to consume two4    ,in an     
experiment made since this paper was    
drawn up1 the effect was  rather        
pleasurable4      ,v4 ,letter from ,,dr4
 ,,roget4    ,the effect of the first   
inspirations of the nitrous oxide was   
that of  making me vertiginous1 and     
producing a tingling sensation in my    
hands  and feet3 as these feelings      
increased1 ,i seemed to lose the sense  
of  my own weight1 and imagined ,i was  
sinking into the ground4 ,i then  felt a
 drowsiness gradually steal upon me1 and
 a disinclination to  motion2 even the  
actions of inspiring and expiring were  
not performed  without effort3 and it   
also required some attention of mind to 
keep  my nostrils closed with my        
fingers4 ,i was gradually roused from   
this  torpor by a kind of delirium1     

which came on so rapidly that the       
air-bag  dropt from my hands4 ,this     
sensation increased for about a minute  
after  ,i had ceased to breathe1 to a   
much greater degree than before1 and ,i 
suddenly lost sight of all the objects  
around me1 they being apparently        
obscured by clouds1 in which were many  
luminous points1 similar to what  is    
often experienced on rising suddenly and
 stretching out the arms1  after sitting
 long in one position4    ,i felt myself
 totally incapable of speaking1 and for 
some time lost all  consciousness of    
where ,i was1 or who was near me4 ,my   
whole frame felt  as if violently       
agitated3 ,i thought ,i panted          
violently3 my heart seemed  to          
palpitate1 and every artery to throb    
with violence2 ,i felt a singing  in my 
ears2 all the vital motions seemed to be
 irresistibly hurried on1  as if their  
equilibrium had been destroyed1 and     
every thing was running  headlong into  
confusion4 ,my ideas succeeded one      

another with extreme  rapidity1 thoughts
 rushed like a torrent through my mind1 
as if their  velocity had been suddenly 
accelerated by the bursting of a barrier
  which had before retained them in     
their natural and equable course4  ,this
 state of extreme hurry1 agitation1 and 
tumult1 was but transient4  ,every      
unnatural sensation gradually subsided2 
and in about a quarter of  an hour after
 ,i had ceased to breathe the gas1 ,i   
was nearly in the same  state in which  
,i had been at the commencement of the  
experiment4    ,i cannot remember that  
,i experienced the least pleasure from  
any of  these sensations4 ,i can        
however1 easily conceive1 that by       
frequent  repetition ,i might reconcile 
myself to them1 and possibly even       
receive  pleasure from the same         
sensations which were then unpleasant4  
,i am sensible that the account ,i have 
been able to give of my feelings  is    
very imperfect4 ,for however calculated 
their violence and novelty  were to     

leave a lasting impression on the       
memory1 these circumstances  were for   
that very reason unfavourable to        
accuracy of comparison with  sensations 
already familiar4    ,the nature of the 
sensations themselves1 which bore       
greater resemblance  to a half delirious
 dream than to any distinct state of    
mind capable  of being accurately       
remembered1 contributes very much to    
increase the  difficulty4 ,and as it is 
above two months since ,i made the      
experiment1  many of the minuter        
circumstances have probably escaped me4 
,i remain1                              
,yours1 c4                              
,p4 ,,roget4      ,to ,,mr4 ,,davy4     
,,vi4 ,letter from ,,mr4 ,,james        
,,thomson4    ,the first time ,i        
respired nitrous oxide1 the experiment  
was made  under a strong impression of  
fear1 and the quantity ,i breathed not  
sufficient1 as you informed me1 to      
produce the usual effect4 ,i did  not   
note very accurately my sensations4 ,i  

remember ,i experienced a  slight degree
 of vertigo after the third or fourth   
inspiration2 and  breathed with         
increased vigor1 my inspirations being  
much deeper and  more vehement than     
ordinary4 ,i was enabled the next time  
,i made the  experiment1 to attend more 
accurately to my sensations1 and you    
have  the observations ,i made on them  
at the time4    ,after the fourth       
inspiration1 ,i experienced the same    
increased action  of the lungs1 as in   
the former case4 ,my inspirations became
 uncommonly  full and strong1 attended  
with a thrilling sensation about the    
chest1  highly pleasurable1 which       
increased to such a degree as to induce 
a  fit of involuntary laughter1 which ,i
 in vain endeavoured to repress4  ,i    
felt a slight giddiness which lasted for
 a few moments only4 ,my  inspirations  
now became more vehement and frequent2  
and ,i inhaled the  air with an avidity 
strongly indicative of the pleasure ,i  
received4  ,that peculiar thrill which  

,i had at first experienced at the      
chest1 now  pervaded my whole frame2 and
 during the two or three last           
inspirations1  was attended with a      
remarkable tingling in my fingers and   
toes4 ,my  feelings at this moment are  
not to be described3 ,i felt a high1 an 
extraordinary degree of pleasure1       
different from that produced  by wine1  
being divested of all its gross         
accompaniments1 and yet  approaching    
nearer to it than to any other sensation
 ,i am acquainted  with4    ,i am       
certain that my muscular strength was   
for a time much increased4  ,my         
disposition to exert it was such as ,i  
could not repress1 and the  satisfaction
 ,i felt in any violent exertion of my  
legs and arms is  hardly to be          
conceived4 ,these vivid sensations were 
not of long  duration2 they diminished  
insensibly1 and in little more than a   
quarter  of an hour ,i could perceive no
 difference between the state ,i was    
then  in1 and that previous to the      

respiration of the air4    ,the         
observations ,i made on repeating the   
experiment1 do not differ from  the     
preceding1 except in the circumstance of
 the involuntary laughter1  which ,i    
never afterwards experienced1 though ,i 
breathed the air several  times2 and in 
the following curious fact1 which1 as it
 was dependent on  circumstances1 did   
not always occur4    ,having respired   
the same quantity of air as usual1 and  
with precisely  the same effects1 ,i was
 surprised to find myself affected a few
 minutes  afterwards with the recurrence
 of a pain in my back and knees1 which  
,i  had experienced the preceding day   
from fatigue in walking4 ,i was rather  
inclined to deem this an accidental     
coincidence than an effect of the  air2 
but the same thing constantly occurring 
whenever ,i breathed the  air1 shortly  
after suffering pain either from        
fatigue1 or any other  accidental cause1
 left no doubt on my mind as to the     
accuracy of the  observation4    ,i have

 now given you the substance of the     
notes ,i made whilst the  impressions   
were strong on my mind4 ,i cannot add   
any thing from  recollection that will  
at all add to the accuracy of this      
account1  or assist those who have not  
respired this air1 in forming a clearer 
idea of its extraordinary effects4 ,it  
is extremely difficult to convey  to    
others by means of words1 any idea of   
particular sensations1 of  which they   
have had no experience4 ,it can only be 
done by making use  of such terms as are
 expressive of sensations that resemble 
them1  and in these our vocabulary is   
very defective4 ,to be able at all to   
comprehend the effects of nitrous oxide1
 it is necessary to respire it1  and    
after that1 we must either invent new   
terms to express these new  and         
particular sensations1 or attach new    
ideas to old ones1 before we  can       
communicate intelligibly with each other
 on the operation of this  extraordinary
 gas4                                   

,i am c4                                
,,james ,,thomson4      ,london1 ,sept4 
#ba1 #agii4            ,to ,,mr4 ,,davy4
      ,,vii4 ,detail of ,,mr4           
,,coleridge4    ,the first time ,i      
inspired the nitrous oxide1 ,i felt an  
highly  pleasurable sensation of warmth 
over my whole frame1 resembling that    
which ,i remember once to have          
experienced after returning from a walk 
in the snow into a warm room4 ,the only 
motion which ,i felt inclined to  make1 
was that of laughing at those who were  
looking at me4 ,my eyes  felt distended1
 and towards the last1 my heart beat as 
if it were  leaping up and down4 ,on    
removing the mouth-piece the whole      
sensation  went off almost instantly4   
,the second time1 ,i felt the same      
pleasurable sensation of warmth1 but    
not ,i think1 in quite so great a       
degree4 ,i wished to know what effect   
it would have on my impressions2 ,i     
fixed my eye on some trees in the       
distance1 but ,i did not find any other 

effect except that they became  dimmer  
and dimmer1 and looked at last as if ,i 
had seen them through  tears4 ,my heart 
beat more violently than the first time4
 ,this was after  a hearty dinner4      
,the third time ,i was more violently   
acted on than in the two former4        
,towards the last1 ,i could not avoid1  
nor indeed felt any wish to avoid1      
beating the ground with my feet2 and    
after the mouth-piece was removed1  ,i  
remained for a few seconds motionless1  
in great extacy4    ,the fourth time was
 immediately after breakfast4 ,the few  
first  inspirations affected me so      
little that ,i thought ,mr4 ,davy had   
given  me atmospheric air3 but soon felt
 the warmth beginning about my chest1   
and spreading upward and downward1 so   
that ,i could feel its progress  over my
 whole frame4 ,my heart did not beat so 
violently2 my sensations  were highly   
pleasurable1 not so intense or          
apparently local1 but of  more unmingled
 pleasure than ,i had ever before       

experienced4#bbe        ,s4 ,t4         
,,coleridge4    #bbe ,the doses in these
 experiments were from five to seven    
quarts4      ,,viii4 ,detail of ,,mr4   
,,wedgwood4    ,july #bc1 ,i called on  
,mr4 ,davy at the ,medical ,institution1
 who asked  me to breathe some of the   
nitrous oxide1 to which ,i consented1   
being  rather a sceptic as to its       
effects1 never having seen any person   
affected4 ,i first breathed about six   
quarts of air which proved to be  only  
common atmospheric air1 and which       
consequently produced no effect4    ,i  
then had #f quarts of the oxide given me
 in a bag undiluted1 and  as soon as ,i 
had breathed three or four respirations1
 ,i felt myself  affected and my        
respiration hurried1 which effect       
increased rapidly  until ,i became as it
 were entranced1 when ,i threw the bag  
from me and  kept breathing on furiously
 with an open mouth and holding my nose 
with my left hand1 having no power to   
take it away though aware of  the       

ridiculousness of my situation4 ,though 
apparently deprived of all  voluntary   
motion1 ,i was sensible of all that     
passed1 and heard every  thing that was 
said2 but the most singular sensation ,i
 had1 ,i feel it  impossible accurately 
to describe4 ,it was as if all the      
muscles of the  body were put into a    
violent vibratory motion2 ,i had a very 
strong  inclination to make odd antic   
motions with my hands and feet4 ,when   
the  first strong sensations went off1  
,i felt as if ,i were lighter than the  
atmosphere1 and as if ,i was going to   
mount to the top of the room4 ,i  had a 
metallic taste left in my mouth1 which  
soon went off4    ,before ,i breathed   
the air1 ,i felt a good deal fatigued   
from a very  long ride ,i had had the   
day before1 but after breathing1 ,i lost
 all  sense of fatigue4      ,,ix4      
,detail of ,,mr4 ,,george ,,burnet4     
,i had never heard of the effects of the
 nitrous oxide1 when ,i breathed  six   
quarts of it4 ,i felt a delicious tremor

 of nerve1 which was rapidly  propagated
 over the whole nervous system4 ,as the 
action of inhaling  proceeds1 an        
irresistible appetite to repeat it is   
excited4 ,there is  now a general swell 
of sensations1 vivid1 strong1 and       
inconceivably  pleasurable4 ,they still 
become more vigorous and glowing till   
they are  communicated to the brain1    
when an ardent flush overspreads the    
face4  ,at this moment the tube inserted
 in the air-bag was taken from my       
mouth1 or ,i must have fainted in       
extacy4    ,the operation being over1   
the strength and turbulence of my       
sensations  subsided4 ,to this succeeded
 a state of feeling uncommonly serene   
and  tranquil4 ,every nerve being gently
 agitated with a lively enjoyment4  ,it 
was natural to expect that the effect of
 this experiment1 would  eventually     
prove debilitating4 ,so far from this ,i
 continued in a state  of high          
excitement the remainder of the day     
after two o'clock1 the  time of the     

experiment1 and experienced a flow of   
spirits not merely  chearful1 but       
unusually joyous4        ,,george       
,,burnet4      ,x4 ,detail of ,,mr4 ,t4 
,,pople4    ,a disagreeable sensation as
 if breaking out into a profuse         
perspiration1 tension of the tympanum1  
cheeks and forehead2 almost  total loss 
of muscular power2 afterwards increased 
powers both of  body and mind1 very     
vivid sensations and highly pleasurable4
 ,those  pleasant feelings were not new1
 they were felt1 but in a less degree1  
on ascending some high mountains in     
,glamorganshire4    ,on taking it the   
second time1 there was a disagreeable   
feeling about  the face4 ,in a          
fewseconds1 the feelings became         
pleasurable2 all the  faculties absorbed
 by the fine pleasing feelings of       
existence without  consciousness2 an    
involuntary burst of laughter4          
,,thomas ,,pople4      ,,xi4 ,detail of 
,,mr4 ,,hammick4    ,having never heard 
any thing of the mode of operation of   

nitrous oxide1  ,i breathed gas in a    
silk bag for some time1 and found no    
effects1 but  oppression of respiration4
 ,afterwards ,mr4 ,davy told me that ,i 
had been  breathing atmospheric air4    
,in a second experiment made without    
knowing what gas was in the bag1  ,i had
 not breathed half a minute1 when from  
the extreme pleasure ,i  felt1 ,i       
unconciously removed the bag from my    
mouth2 but when ,mr4 ,davy  offered to  
take it from me1 ,i refused to let him  
have it1 and said  eagerly1 8let me     
breathe it again1 it is highly pleasant6
 it is the  strongest stimulant ,i ever 
felt68 ,i was cold when ,i began to     
respire1  but had immediately a pleasant
 glow extending to my toes and fingers4 
,i  experienced from the air a pleasant 
taste which ,i can only call sweetly    
astringent2 it continued for some time3 
the sense of exhilaration was  lasting4 
,this air ,mr4 ,davy told me was nitrous
 oxide4    ,in another experiment1 when 
,i breathed a small dose of nitrous     

oxide1  the effects were slight1 and    
sometime afterwards ,i felt an unusual  
yawning and languor4    ,the last time  
that ,i breathed the gas1 the feelings  
were the most  pleasurable ,i ever      
experienced2 my head appeared light1    
there was a  great warmth in the back   
and a general unusual glow2 the taste   
was  distinguishable for some time as in
 the former experiment4 ,my ideas  were 
more vivid1 and followed the natural    
order of association4 ,i could  not     
refrain from muscular action4           
,,stephen ,,hammick1 ,junr4      ,sept4 
#aeth4      ,,xii4 ,detail of ,,dr4     
,,blake4    ,dr4 ,blake inhaled about   
six quarts of the air1 was affected     
during  the process of respiring it with
 a slight degree of vertigo1 which  was 
almost immediately succeeded by a       
thrilling sensation extending  even to  
the extremities1 accompanied by a most  
happy state of mind and  highly         
pleasurable ideas4 ,he felt a great     
propensity to laugh1 and  his behaviour 

in some measure appeared ludicrous to   
those around him4  ,muscular power      
seemed agreeably increased1 the pulse   
acquired strength  and firmness1 but its
 frequency was somewhat diminished4 ,he 
perceived  rather an unpleasant taste in
 the mouth and about the fauces for     
some hours afterwards1 but in every     
other respect1 his feelings were        
comfortable during the remainder of the 
day4          ,december1 #cjth4      ,to
 ,,mr4 ,,davy4      ,,xiii4 ,detail of  
,,mr4 ,,wansey4    ,i breathed the gas  
out of a silk bag1 believing it to be   
nitrous oxide1  and was much surprised  
to find that it produced no sensations4 
,after  the experiment1 ,mr4 ,davy told 
me it was common air4    ,i then        
breathed a mixture of common air and    
nitrous oxide4 ,i felt a  kind of       
intoxication in the middle of the       
experiment1 and stopping to  express    
this1 destroyed any farther effects4    
,i now breathed pure nitrous oxide2 the 
effect was gradual1 and ,i at  first    

experienced fulness in the head1 and    
afterwards sensations so  delightful1   
that ,i can compare them to no others1  
except those which  ,i felt 7being a    
lover of music7 about five years since  
in ,westminster  ,abbey1 in some of the 
grand choruses in the ,messiah1 from the
 united  powers of #gjj instruments of  
music4 ,i continued exhilarated         
throughout  the day1 slept at night     
remarkably sound1 and experienced when  
,i awoke  in the morning1 a recurrence  
of pleasing sensation4    ,in another   
experiment1 the effects was still       
greater1 the pulse was  rendered fuller 
and quicker1 ,i felt a sense of         
throbbing in the head  with highly      
pleasurable thrillings all over the     
frame4 ,the new feelings  were at last  
so powerful as to absorb all perception4
 ,i distinguished  during and after the 
experiment1 a taste on the tongue1 like 
that  produced by the contact of zinc   
and silver4        ,,henry ,,wansey4    
,,xiv4 ,detail of ,,mr4 ,,rickman4      

,on inhaling about six quarts1 the first
 altered feeling was a tingling  in the 
elbows not unlike the effect of a slight
 electric shock4 ,soon  afterwards1 an  
involuntary and provoking dizziness as  
in drunkenness4  ,towards the close of  
the inhalation1 this symptom decreased2 
though  the nose was still involuntary  
held fast after the air-bag was         
removed4 ,the dose was probably an      
undercharge1 as no extraordinary        
sensation was felt more than half a     
minute after the inhalation4        ,j4 
,,rickman4      ,,xv4 ,detail of ,,mr4  
,,lovell ,,edgworth4    ,my first       
sensation was an universal and          
considerable tremor4 ,i then  perceived 
some giddiness in my head1 and a violent
 dizziness in my  sight2 those          
sensations by degrees subsided1 and ,i  
felt a great  propensity to bite through
 the wooden mouth-piece1 or the tube of 
the  bag through which ,i inspired the  
air4 ,after ,i had breathed all the air 
that was in the bag1 ,i eagerly wished  

for more4 ,i then felt a strong         
propensity to laugh1 and did burst into 
a violent fit of laughter1 and  capered 
about the room without having the power 
of restraining myself4  ,by degrees     
these feelings subsided1 except the     
tremor which lasted  for an hour after  
,i had breathed the air1 and ,i felt a  
weakness in my  knees4 ,the principal   
feeling through the whole of the time1  
or what  ,i should call the             
characteristical part of the effect1 was
 a total  difficulty of restraining my  
feelings1 both corporeal and mental1 or 
in  other words1 not having any command 
of one'self4      ,,xvi4 ,detail of     
,,mr4 ,g4 ,,bedford4    ,i inhaled #f   
quarts4 ,experienced a sensation of     
fulness in the  extremities and in the  
face1 with a desire and power of        
expansion of  the lungs very            
pleasurable4 ,feelings similar to       
intoxication were  produced1 without    
being disagreeable4 ,when the bag was   
taken away1 an  involuntary though      

agreeable laughter took place1 and the  
extremities  were warm4    ,in about a  
quarter of an hour after the above      
experiment1 ,i inhaled  #h quarts4 ,the 
warmth and fulness of the face and      
extremities were  sooner produced during
 the inspiration4 ,the candle and the   
persons  about me1 assumed the same     
appearances as took place during the    
effect  produced by wine1 and ,i could  
perceive no determinate outline4 ,the   
desire and power to expand the lungs was
 increased beyond that in the  former   
experiment1 and the whole body and limbs
 seemed dilated without  the sense of   
tension1 it was as if the bulk was      
increased without  any addition to the  
specific gravity of the body1 which was 
highly  pleasant4 ,the provocation to   
laughter was not so great as in the     
former  experiment1 and when the bag was
 removed1 the warmth almost suddenly    
gave place to a coldness of the         
extremities1 particularly of the hands  
which were the first to become warm     

during the inspiration4 ,a slight       
sensation of fulness not amounting to   
pain in the head1 has continued  for    
some minutes4 ,after the first          
experiment1 a sensation in the wrists   
and elbows took place1 similar to that  
produced by the electric shock4         
,g4 ,c4 ,,bedford4      ,march #cjth1   
#ahjj4      ,,xvii4 ,detail of ,,miss   
,,ryland4    ,after having breathed five
 quarts of gas1 ,i experienced for a    
short  time a quickness and difficulty  
of breathing1 which was succeeded by    
extreme languor1 resembling fainting1   
without the very unpleasant  sensation  
with which it is usually attended4 ,it  
entirely deprived me of  the power of   
speaking1 but not of recollection1 for  
,i heard every thing  that was said in  
the room during the time2 and ,mr4      
,davy's remark 8that  my pulse was very 
quick and full48 ,when the languor began
 to subside1  it was succeeded by       
restlessness1 accompanied by involuntary
 muscular  motions4 ,i was warmer than  

usual1 and very sleepy for several      
hours4      ,,xviii4 ,letter from ,,mr4 
,m4 ,m4 ,,coates4    ,i will1 as you    
request1 endeavour to describe to you   
the effect  produced on me last ,sunday 
fe'nnight by the nitrous oxide1 and will
 at  the same time tell you what was the
 previous state of my mind on the       
subject4    ,when ,i sat down to breathe
 the gas1 ,i believed that it owed much 
of  its effect to the predisposing      
agency of the imagination1 and had no   
expectation of its sensible influence on
 myself4 ,having ignorantly  breathed a 
bag of common air without any effect1 my
 doubts then arose  to positive         
unbelief4    ,after a few inspirations  
of the nitrous oxide1 ,i felt a fulness 
in  my head1 which increased with each  
inhalation1 until1 experiencing         
symptoms which ,i thought indicated     
approaching fainting1 ,i ceased to      
breathe it1 and was then confirmed in my
 belief of its inability to  produce in 
me any pleasurable sensation4    ,but   

after a few seconds1 ,i felt an         
immoderate flow of spirits1 and an      
irresistible propensity to violent      
laughter and dancing1 which1 being      
fully conscious of the violence of my   
feelings1 and of their irrational       
exhibition1 ,i made great but           
ineffectual efforts to restrain2 this   
was  my state for several minutes4      
,during the rest of the day1 ,i         
experienced  a degree of hilarity       
altogether new to me4 ,for six or seven 
days  afterwards1 ,i seemed to feel most
 exquisitely at every nerve1 and was    
much indisposed to my sedentary         
pursuits2 this acute sensibility has    
been gradually diminishing2 but ,i still
 feel somewhat of the effects of  this  
novel agent4                            
,your's truly1                          
,m4 ,m4 ,,coates4        ,to ,mr4       
,,davy4        ,june #aath1 #ahjj4      
,,division ,,iii4        ,,abstracts    
from ,,additional                       
,,details4--,,observations         on   

the ,,effects of ,,nitrous ,,oxide1 by  
,dr4         ,,beddoes4--,,conclusion4  
,i4 ,abstracts from additional ,details4
    ,the trials related in the following
 abstracts1 have been chiefly made      
since the publication of ,dr4 ,beddoes's
 ,notice4 ,many of the individuals      
breathed the gas from pure curiosity4   
,others with a disbelief of its  powers4
           99       99       99       99
       99    ,mr4 ,,wynne1 ,m4 ,p4      
breathed five quarts of diluted nitrous 
oxide1 without  any sensation4 ,six     
quarts produced fulness in the chest1   
heat in  the hands and feet1 and sense  
of tension in the fingers1 slight but   
pleasant sensations4 ,seven quarts      
produced no new or different effects4   
,mr4 ,,mackintosh several times breathed
 nitrous oxide4 ,he had sense of        
fulness in the head1 thrillings1        
tingling in the fingers1 and generally  
pleasurable feelings4    ,mr4 ,,john    
,,cave1 ,junr4 from breathing four      
quarts of nitrous oxide1 felt           

sensations as from superior wine1 and   
general pleasant feelings4    ,mr4      
,,michael ,,castle1 from five quarts1   
experienced sensations of heat  and     
thrilling1 general spirits heightened   
considerably as from wine2  afterwards1 
slight pain in the back of the head4    
,mr4 ,h4 ,,cardwell1 from five quarts1  
had feelings so pleasurable as  almost  
to destroy consciousness2 almost        
convulsed with laughter2 for a  long    
time could not think of the feeling     
without laughing2 sensation of          
lightness for some time after4    ,mr4  
,,jarman1 from five quarts1 great       
pleasure1 laughter1 certainly  better   
spirits1 glow in the cheeks which       
continued long4    ,the gentleman who   
furnished the preceding detail1 had     
heard of  the effects of nitrous oxide1 
and was prepared to experience new      
sensations3 ,i therefore gave him a bag 
of common air which he respired1        
believing it to be nitrous oxide2 and   
was much surprised that no  effects were

 produced4 ,he then breathed five quarts
 of nitrous oxide1  and after the       
experiment1 gave this account of his    
sensations4    ,rev4 ,w4 ,a4 ,,cane1    
after inhaling the gas1 felt the most   
delicious  sensations accompanied by a  
thrill through every part of his body4  
,he did not think it possible so        
charming an effect could have been      
produced4 ,he had heard of the gas2 but 
the result of the experiment far        
exceeded his expectations4    ,may #fth1
 #ahjj4           99       99       99  
99       99    ,mr4 ,,joseph ,,priestley
 from breathing nitrous oxide1 generally
 had  unpleasant fulness of the head and
 throbbing of the arteries1 which       
prevented him from continuing the       
respiration4    ,dr4 ,,beddoes mentioned
 in his ,notice1 that ,mr4 ,,josiah     
,,wedgwood and ,mr4  ,,thomas ,,wedgwood
 experienced rather unpleasant feelings 
from the gas4  ,mr4 ,,josiah ,,wedgwood 
has since repeated the trial1 the       
effects were  powerful1 but not in the  

slighted degree pleasant4    ,mr4 ,r4   
,,boulton and ,mr4 ,g4 ,,watt have been 
much less affected than any             
individuals4    ,many other persons have
 respired the gas1 but as their accounts
 contain  nothing unnoticed in the      
details1 it is useless to particularise 
them4    ,the cases of all the males who
 have been unpleasantly affected since  
we have learnt to prepare the gas with  
accuracy1 are related in this  ,section 
and in the last ,division4 ,those who   
have been pleasurably  affected after a 
fair trial and whose cases are not      
noticed1 generally  experienced fulness 
in the head1 heat in the chest1         
pleasurable  thrillings1 and consequent 
exhilaration4    ,to persons who have   
been unaccustomed to breathe through a  
tube1 we  have usually given common air 
till they have learnt to respire with   
accuracy3 and in cases where the form of
 the mouth has prevented the  lips from 
being accurately closed on the breathing
 tube1 by the advice  of ,mr4 ,watt1 we 

have used a tin plate conical           
mouth-piece fixed to  the cheeks1 and   
accurately adapted to the lips2 by means
 of which  precautions1 all our later   
trials have been perfectly conclusive4  
,,ii4 ,of the effects of ,nitrous ,oxide
 upon persons inclined to  hysterical   
and nervous affections4    ,the case of 
,miss---- ,n4 and other cases1 detailed 
by ,dr4 ,beddoes in his  ,notice1 seemed
 to prove that the action of nitrous    
oxide was capable of  producing         
hysterical and nervous affections in    
delicate and irritable  constitutions4  
,on this subject1 we have lately        
acquired additional facts4    ,miss ,e4 
a young lady who had been subject to    
hysteric fits1 breathed  three quarts of
 nitrous oxide mingled with much common 
air1 and felt  no effects but a slight  
tendency to fainting4 ,she then breathed
 four  quarts of pure nitrous oxide3 her
 first inspirations were deep1 her  last
 very feeble4 ,at the end she dropt the 
bag from her lips1 and  continued for   

some moments motionless4 ,her pulse     
which at the beginning  of the          
experiment was strong1 appeared to me to
 be at this time1  quicker and weaker4  
,she soon began to move her hands and   
talked for  some minutes incoherently1  
as if ignorant of what had passed4 ,in  
less  than a quarter of an hour1 she had
 recovered1 but could give no account   
of her sensations4 ,a certain degree of 
languor continued through the  day4     
,a young lady who never had hysterical  
attacks1 wished to breathe the  gas4 ,i 
informed her of the disagreeable effects
 it had sometimes  produced1 and advised
 her if she had the slightest tendency  
to nervous  affection1 not to make the  
trial4 ,she persisted in her resolution4
    ,to ascertain the influence of      
imagination1 ,i first gave her a bag of 
common air1 which she declared produced 
no effect4 ,i then ordered for  her a   
quart of nitrous oxide mingled with two 
quarts of common air2 but  from the     
mistake of the person who prepared it1  

three quarts of nitrous  oxide were     
administered with one of common air4    
,she breathed this for  near a minute1  
and after the experiment1 described her 
sensations as  unpleasant1 and said she 
felt at the moment as if she was dying4 
,the  unpleasant feelings quickly went  
off1 and a few minutes after1 she had   
apparently recovered her former state of
 mind4 ,in the course of the  day1      
however1 a violent head-ache came on1   
and in the evening after she  had taken 
a medicine which operated violently1    
hysterical affections  were produced1   
followed by great debility4 ,they       
occasionally returned  for many days1   
and the continued weak and debilitated  
for a great  length of time4    ,mrs4   
,s4 a delicate lady1 liable to nervous  
affections who had heard  of the cases  
just detailed1 chose to breathe the gas4
 ,by three quarts  she was thrown into a
 trance1 which lasted for three or four 
minutes4  ,on recovering1 the could give
 no account of her feelings1 and had    

some  languor for half an hour          
afterwards4    ,these phnomena have     
rendered us cautious in administering   
the gas to  delicate females4 ,in a few 
instances however1 it has been taken by 
persons of this class1 and even by those
 inclined to hysterical and  nervous    
complaints with pleasurable effects4    
,miss ,l4 a young lady who had formerly 
had hysterical fits1 breathed a  quart  
of nitrous oxide with three quarts of   
common air without effects4  ,two quarts
 of nitrous oxide with one of common air
 produced a slight  giddiness2 four     
quarts of nitrous oxide produced a fit  
of immoderate  laughter1 which was      
succeeded by slight exhilaration1 her   
spirits were  good throughout the day1  
and no depression followed4    ,miss ,b4
 ,y---- and ,miss ,s4 ,y---- both       
delicate but healthy young ladies1  were
 affected very pleasantly2 each by three
 quarts of nitrous oxide1  the first    
time of respiring it4 ,miss ,b ,y----   
continued exhilarated and in  high      

spirits for some hours after the dose4  
,miss ,s4 ,y---- had a slight           
head-ache1 which did not go off for some
 hours4    ,mrs4 ,f4 inclined to be     
hysterical1 breathed four quarts of     
nitrous  oxide mingled with common air4 
,she was giddy and described her        
feelings  as odd2 but had not the       
slightest languor after the experiment4 
,,iii4 ,observations on the effects of  
,nitrous ,oxide1 by ,,dr4 ,,beddoes4    
,neither my notes nor my recollection   
supply much in addition to what  ,i     
formerly stated in the ,notice of       
,observations at the ,pneumatic         
,institution4 ,longman4 ,the gas        
maintains its first character as  well  
in its effects on me1 as in the benefit 
it confers on some of  the paralytic1   
and the injury it does or threatens to  
the hysterical  and the exquisitely     
sensible4 ,i find that five or six      
quarts operate  as powerfully as ever4  
,i seem to make a given quantity go     
farther by  holding my breath so that   

the gas may be absorbed in a great      
degree  without returning into the bag1 
and therefore1 be as little heated      
before inspiration as possible4--,this  
may be fancy4    ,after innumerable     
trials1 ,i have never once felt         
lassitude or  depression#bbf4 ,most     
commonly ,i am sensible of a grateful   
glow circum  prcordia4 ,this has        
continued for hours4--,in two or three  
instances  only has inhalation failed to
 be followed by pleasurable feeling1 it 
has never been followed by the contrary4
 ,on a few occasions before the  gas was
 exhausted1 ,i have found it impossible 
to continue breathing4    #bbf ,of the  
facts on which ,brown founded his law of
 indirect debility1  no prudent man will
 lose sight either in practising or     
studying  medicine4 ,they are           
incontrovertible4--,and our new facts   
may doubtless be  conciliated to the    
,brunonian doctrine4    ,but to suppose 
that the expenditure of a quality or a  
substance or a  spirit1 and its renewal 

or accumulation are the general         
principles of  animal phnomena1 seems to
 me a grievous and baneful error4 ,i    
believe  it often happens that          
excitement and excitability increase1   
and that  they oftener decrease         
together2--,in short1 without           
generalizing in  a manner1 of which     
,brown and similar theorists had no     
conception1  our notions of the living  
world will in my opinion1 continue to be
  as confused as the elements are said  
to have been in chaos4 ,on some  future 
occasion1 ,i may presume to point out   
the region through which ,i  imagine the
 path to wind1 that will lead the       
observers of some distant  generation to
 a point1 whence they may enjoy a view  
of the subtle1 busy  and intricate      
movements of the organic creation as    
clear as ,newton  obtained of the       
movements of the heavenly masses4       
,the pulse at first becomes fuller and  
stronger4 ,whenever1 after  exposure to 
a cold wind1 the warmth of the room has 

created a glow in  the cheeks1 the gas  
has increased this to strong            
flushing--which common  air breathed in 
the same way1 failed to do4    ,several 
times ,i have found that a cut which had
 ceased to be painful  has smarted      
afresh1 and on taking two doses in      
succession1 the smarting  ceased in the 
interval and returned during the second 
respiration4 ,i  had no previous        
expectation of the first smarting4      
,the only time ,i was near rendering    
myself insensible to present  objects by
 very carefully breathing several doses 
in quick succession1  ,i forcibly       
exclaimed1 ,,tones6--,in fact1 besides a
 general thrilling1  there seemed to be 
quick and strong alterations in the     
degree of  illumination of all          
surrounding objects2 and ,i felt as if  
composed  of finely vibrating strings4  
,on this occasion1 the skin seemed in a 
state of constriction and the lips glued
 to the mouth-piece1 and the  mucous    
membrane of the lungs contracted1 but   

not painfully4 ,however1 no             
constriction or corrugation of the skin 
could be seen4 ,i am conscious  of      
having made a great number of           
observations while breathing1 which ,i  
could never recover4    ,immediately    
afterwards ,i have often caught myself  
walking with a  hurried step and busy in
 soliloquy4 ,the condition of general   
sensation  being as while hearing       
chearful music1 or after good news1 or a
  moderate quantity of wine4    ,mr4    
,john ,cave1 ,junr4 and his three       
friends1 as well as others1  compared   
the effects to ,champagne4 ,most persons
 have had the idea  of the effect of    
fermented liquors excited by the gas4   
,it were to be  wished that we had1 for 
a standard of comparison1 observations  
on the  effect of these liquors as      
diversified and as accurate as we have  
obtained concerning the gas2 nor would  
more uniformity in the action  of these 
substances be observed if the enquiry   
were strictly pursued4  ,opium and      

spirits seem1 in particular states to   
sicken and distress  in the first       
instance2 how differently does wine at  
an early hour and  fasting act upon     
those who are accustomed to take it only
 after dinner6    ,i thought it might be
 an amusing spectacle to see the        
different tints  of blood flowing from a
 wound by a leech in consequence of     
breathing  different airs4 ,the purple  
from the nitrous oxide was very evident4
  ,oxygene1 we thought1 occasioned a    
quicker flow and brighter color in  the 
blood4 ,in another experiment1 an       
inflamed area round the puncture  from a
 leech applied the day before1 was      
judged by several spectators  to become 
much more crimson on the respiration of 
about #bj quarts  of oxygene gas1 which 
possibly acts more powerfully on        
inflamed  parts4#bbg ,these and many    
similar experiments1 require to be      
repeated  on the blood of single        
arteries opened in warm and cold        
animals4    #bbg ,after writing this1 ,i

 was present when an invalid1 in whose  
foot  the gout1 after much wandering1   
had at last fixed1 breathed #ab quarts  
of oxygene gas4 ,while breathing1 he    
eagerly pointed to the inflamed  leg2   
and afterwards said he had felt in it a 
new sensation1 somewhat  like           
tension4--,i never had seen oxygene     
respired where there was so much  local 
inflammation4    ,june #ah4 ,after four 
quarts of oxygene with #f of nitrous    
oxide and  then #f of nitrous oxide     
alone1 violent itching of the wounds    
made by  the leech2 and redness and     
tumour4--,both had healed1 and ,i did   
not  expect to feel any thing more from 
them4--,i tried this again with two     
doses of nitrous oxide--,the yellow halo
 round one wound changed to  crimson1   
and there was so much stinging and      
swelling that ,i feared                 
suppuration4--,absorption here was      
rapid4    ,it has appeared to me that ,i
 could hold my breath uncommonly long   
when  respiring oxygene gas mixed with  

nitrous oxide4 ,while trying this       
to-day1 7#agth ,june71 ,i thought the   
sense of smell much more acute after    
the nitrous oxide than before ,i began  
to respire at all2 and then ,i  felt    
conscious that this increased acuteness 
had before repeatedly  occurred--a fact 
very capable1 ,i apprehend1 of a        
pneumatological  interpretation4        
,time by my feelings has always appeared
 longer than by a watch4    ,i thought  
of trying to observe whether while ,i   
alternately breathed  quantities of     
nitrous oxide and oxygene gas and common
 air1 ,i could  observe any difference  
in the operation of a blister beginning 
to  bite the skin4 ,it would be of      
consequence to ascertain the effect  of 
regulating by compression the flow of   
blood1 while stimulants of  various     
kinds 7and heated bodies among the rest7
 were applied to or  near the           
extremities--because in erisipelas and  
various inflammatory  affections1 a     
ready and pleasant cure might be        

effected by partial  compression of the 
arteries going to the diseased part2 and
 a great  improvement in practice thus  
obtained4    ,but ,i should run into an 
endless digression1 were ,i to enumerate
  possible physiological experiments    
with artificial airs1 or to  speculate  
on the mechanical improvement of        
medicine1 which at present  as far as   
mechanical means of affecting the living
 system are  concerned1 is with us in a 
state that would almost disgrace a      
nation of  savages4      ,,iv4          
,,conclusion4    ,from the facts        
detailed in the preceding pages1 it     
appears that  the immediate effects of  
nitrous oxide upon the living system1   
are  analogous to those of diffusible   
stimuli4 ,both increase the force of    
circulation1 produce pleasurable        
feeling1 alter the condition of the     
organs of sensation1 and in their most  
extensive action destroy life4    ,in   
the mode of operation of nitrous oxide  
and diffusible stimuli1  considerable   

differences however1 exist4             
,diffusible stimuli act immediately on  
the muscular and nervous fibre4         
,nitrous oxide operates upon them only  
by producing peculiar changes in  the   
composition of the blood4    ,diffusible
 stimuli affect that part of the system 
most powerfully to  which they are      
applied1 and act on the whole only by   
means of its  sympathy with that part4  
,nitrous oxide in combination with the  
blood1  is universal in its application 
and action4    ,we know very little of  
the nature of excitement2 as however1   
life  depends immediately on certain    
changes effected in the blood in        
respiration1 and ultimately on the      
supply of certain nutritive matter  by  
the lymphatics2 it is reasonable to     
conclude1 that during the action  of    
simulating substances1 from the         
increased force of circulation1 not     
only more oxygene and perhaps nitrogene 
must be combined with the blood  in     
respiration1#bbh but likewise more fluid

 nutritive matter supplied  to it in    
circulation4    #bbh ,see ,dr4          
,beddoes's ,considerations1 part #a4    
page #bf4 ,his  observations in the note
 in the last section1 will likewise     
apply  here4--,is not healthy living    
action dependant upon a certain         
equilibrium  between the principles     
supplied to the blood by the pulmonary  
veins  from respiration and by the      
lymphatics from absorption8 ,does not   
sensibility more immediately depend upon
 respiration8 ,deprive an  animal under 
stimulation1 of air1 and it instantly   
dies2 probably if  absorption could be  
prevented1 it would likewise speedily   
die4 ,it would  be curious to try       
whether intoxication from fermented     
liquors cannot be  prevented by         
breathing during their operation1 an    
atmosphere deprived  of part of its     
oxygene4    ,by this oxygene and        
nutritive matter excitability may be    
kept up3 and  exhaustion consequent to  
excitement only produced1 in consequence

 of a  deficiency of some of the        
nutritive principles1 which are supplied
 by  absorption4    ,when nitrous oxide 
is breathed1 nitrogene 7a principle     
under common  circumstances chiefly     
carried into the blood by the absorbents
 in fluid  compounds7 is supplied in    
respiration2 a greater quantity of      
oxygene  is combined with the blood than
 in common respiration1 whilst less     
carbonic acid and probably less water   
are evolved4    ,hence a smaller        
quantity of nutritive matter is probably
 required from  the absorbents during   
the excitement from nitrous oxide1 than 
during  the operation of stimulants2 and
 in consequence1 exhaustion from the    
expenditure of nutritive matter more    
seldom occasioned4    ,since ,research  
,,iii4 has been printed1 ,i have        
endeavoured to ascertain  the quantities
 of nitrogene produced when nitrous     
oxide is respired  for a considerable   
time4 ,in one experiment1 when ,i       
breathed about four  quarts of gas in a 

glass bell over impregnated water for   
near a minute1  it was diminished to    
about two quarts2 and the residuum      
extinguished  flame4    ,now the        
experiments in ,research ,,ii4 prove    
that when nitrous oxide is  decomposed  
by combustible bodies1 the quantity of  
nitrogene evolved is  rather greater in 
volume than the pre-existing nitrous    
oxide4 ,hence  much of the nitrogene    
taken into the system during the        
respiration of  nitrous oxide1 must be  
either carried into new combinations1 or
 given  out by the capillary vessels    
through the skin4    ,it would be       
curious to ascertain whether the        
quantity of ammoniac in  the saline     
matters held in solution by the secreted
 fluids is increased  after the         
respiration of nitrous oxide4           
,experiments made upon the  consumption 
of nitrous oxide mingled with           
atmospheric air by the  smaller animals1
 would go far to determine whether any  
nitrogene is  given out through the     

skin4    ,the various effects of nitrous
 oxide upon different individuals and   
upon the same individuals at different  
times1 prove that its powers are        
capable of being modified both by the   
peculiar condition of organs1 and  by   
the state of general feeling4           
,reasoning from common phnomena of      
sensation1 particularly those  relating 
to heat1 it is probable that pleasurable
 feeling is uniformly  connected with a 
moderate increase of nervous action2 and
 that this  increase when carried to    
certain limits1 produces mixed emotion  
or  sublime pleasure2 and beyond those  
limits occasions absolute pain4         
,comparing the facts in the last        
division1 it is likely that individuals 
possessed of high health and little     
sensibility1 will generally be  less    
pleasurably affected by nitrous oxide   
than such as have more  sensibility1 in 
whom the emotions will sometimes so far 
enter the  limits of pain as to become  
sublime2#bbi whilst the nervous action  

in  such as have exquisite sensibility1 
will be so much increased as often  to  
produce disagreeable feeling4           
,modification of the powers of nitrous  
oxide by mixture of the gas  with       
oxygene or common air1 will probably    
enable the most delicately  sensible to 
respire it without danger1 and even with
 pleasurable  effects3 heretofore it has
 been administered to such only in its  
pure  form or mingled with small        
quantities of atmospheric air1 and in   
its  pure form even the most robust are 
unable to respire it with safety for    
more than five minutes4    #bbi ,sublime
 emotion with regard to natural objects1
 is generally  produced by the          
connection of the pleasure of beauty    
with the passion  of fear4    ,the      
muscular actions#bcj sometimes connected
 with the feelings  produced by nitrous 
oxide1 seem to depend in a great measure
 upon the  particular habits of the     
individual2 they will usually be of that
 kind  which is produced either by      

common pleasurable feelings or strong   
emotions4    #bcj ,the immortal         
,,hartley has demonstrated that all our 
motions are  originally automatic1 and  
generally produced by the action of     
tangible  things on the muscular fibre4 
,the common actions of adults may be    
distinguished into two kinds2  voluntary
 actions1 and mixed automatic actions4  
,the first are  produced by ideas1 or by
 ideas connected with passions4 ,the    
second by  impression1 or by pleasure   
and pain4    ,in voluntary action1      
regular associations of ideas and       
muscular motions  exist3 as when a      
chemist performs a pre-conceived        
experiment4    ,in mixed automatic      
actions1 the simple motions produced by 
impression  are connected with series of
 motions formerly voluntary1 but now    
produced without the intervention of    
ideas3 as when a person  accustomed to  
play on the harpsichord1 from           
accidentally striking  a key1 is induced
 to perform the series of motions which 

produce a  well-remembered tune4        
,evidently the muscular actions produced
 by nitrous oxide are mixed  automatic  
motions4    ,hysterical affection is    
occasioned by nitrous oxide1 probably   
only in  consequence of the strong      
emotion produced1 which destroys the    
power of  the will1 and calls up series 
of automatic motions formerly connected 
with a variety of less powerful but     
similar feelings4    ,the quickness of  
the operation of nitrous oxide1 will    
probably render  it useful in cases of  
extreme debility produced by deficiency 
of  common exciting powers4 ,perhaps it 
may be advantageously applied  mingled  
with oxygene or common air1 to the      
recovery of persons  apparently dead    
from suffocation by drowning or hanging4
    ,the only diseases in which nitrous 
oxide has been hitherto employed1  are  
those of deficient sensibility4--,an    
account of its agency in  paralytic     
affections1 will be speedily published  
by ,dr4 ,beddoes4    ,as by its         

immediate operation the tone of the     
irritable fibre is  increased1 and as   
exhaustion rarely follows the violent   
muscular  motions sometimes produced by 
it1 it is not unreasonable to expect    
advantages from it in cases of simple   
muscular debility4    ,the apparent     
general transiency of its operation in  
the pure form  in single doses has been 
considered as offering arguments against
  its power of producing lasting changes
 in the constitution4 ,it will1         
however1 be easy to keep up excitement  
of different degrees of  intensity for a
 great length of time1 either by        
administering the  unmingled gas in     
rapid successive doses1 or by preserving
 a permanent  atmosphere1 containing    
different proportions of nitrous oxide  
and  common air1 by means of a breathing
 chamber4#bca ,that single doses        
nevertheless1 are capable of producing  
permanent effects in some               
constitutions1 is evident1 as well from 
the hysterical cases as from  some of   

the details--particularly that of ,mr4  
,m4 ,m4 ,coates4    #bca ,see ,r4 ,,iv4 
,div4 ,i4 page #dgh4    ,as nitrous     
oxide in its extensive operation appears
 capable of  destroying physical pain1  
it may probably be used with advantage  
during  surgical operations in which no 
great effusion of blood takes place4    
,from the strong inclination of those   
who have been pleasantly affected  by   
the gas to respire it again1 it is      
evident1 that the pleasure  produced1 is
 not lost1 but that it mingles with the 
mass of feelings1  and becomes          
intellectual pleasure1 or hope4 ,the    
desire of some  individuals acquainted  
with the pleasures of nitrous oxide for 
the gas  has been often so strong as to 
induce them to breathe with eagerness1  
the air remaining in the bags after the 
respiration of others4    ,as           
hydrocarbonate acts as a sedative1#bcb  
and diminishes living action  as rapidly
 as nitrous oxide increases it1 on the  
common theory of  excitability#bcc it   

would follow1 that by differently       
modifying the  atmosphere by means of   
this gas and nitrous oxide1 we should be
 in  possession of a regular series of  
exciting and depressing#bcd powers      
applicable to every deviation of the    
constitution from health3 but  the      
common theory of excitability is most   
probably founded on a false             
generalisation4 ,the modifications of   
diseased action may be infinite  and    
specific in different organs2 and hence 
out of the power of agents  operating on
 the whole of the system4    #bcb ,r4   
,,iv4 ,div4 ,i4 page #dfg4    #bcc ,that
 of ,brown modified by his disciples4   
#bcd ,supposing the increase or         
diminution of living action when        
produced by different agents1 uniform1  
similar and differing only in  degree2  
it would follow1 that certain mixtures  
of hydrocarbonate and  nitrous oxide1 or
 hydrogene and nitrous oxide1 ought to  
be capable of  supporting the life of   
animals for a much longer time than pure

 nitrous  oxide4 ,from the experiments  
in ,res4 ,,iii4 ,div4 ,i4 it appears    
however1  that this is not the case4    
,it would seem1 that in life1 a variety 
of different corpuscular changes  are   
capable of producing phnomena apparently
 similar2 so that in the  science of    
living action1 we are incapable of      
reasoning concerning  causes from       
effects4    ,whenever we attempt to     
combine our scattered physiological     
facts1 we  are stopped by the want of   
numerous intermediate analogies2 and so 
loosely connected or so independant of  
each other1 are the different  series of
 phnomena1 that we are rarely able to   
make probable  conjectures1 much less   
certain predictions concerning the      
results of  new experiments4    ,an     
immense mass of pneumatological1        
chemical1 and medical information  must 
be collected1 before we shall be able to
 operate with certainty1  on the human  
constitution4    ,pneumatic chemistry in
 its application to medicine1 is an art 

in  infancy1 weak1 almost useless1 but  
apparently possessed of capabilities  of
 improvement4 ,to be rendered strong and
 mature1 she must be  nourished by      
facts1 strengthened by exercise1 and    
cautiously directed  in the application 
of her powers by rational scepticism4   
,,appendix4      ,no4 ,i4    ,effects of
 ,nitrous ,oxide on ,vegetation4    ,in 
,july #agii1 ,i introduced two small    
plants of spurge into nitrous  oxide1 in
 contact with a little water over       
mercury2 after remaining  in it two     
days1 they preserved their healthy      
appearance1 and ,i could  not perceive  
that any gas had been absorbed4 ,i was  
prevented by an  accident1 from keeping 
them longer in the gas4    ,a small     
plant of mint introduced into nitrous   
oxide and exposed to  light1 in three   
days became dark olive and spotted with 
brown2 and in  about six days was quite 
dead4--,another similar plant1 kept in  
the dark  in nitrous oxide1 did not     
alter in color for five days1 and at the

 end  of seven days1 was only a little  
yellower than before4 ,i could not      
ascertain whether any gas had been      
absorbed4    ,i introduced into nitrous 
oxide through water1 a healthy budding  
rose1  thinking that its colors might be
 rendered brighter by the gas4 ,i was   
disappointed1 it very speedily faded and
 died2 possibly injured by the  solution
 of nitrous oxide in water4    ,of two  
rows of peas just appearing above       
ground2 ,i watered one with  solution of
 nitrous oxide in water1 and the other  
with common water  daily1 for a         
fortnight4 ,at the end of this time1 ,i 
could perceive no  difference in their  
growth1 and afterwards they continued to
 grow  equally fast4    ,i introduced   
through water into six phials1 one of   
which contained  hydrogene1 one oxygene1
 one common air1 one hydrocarbonate1 one
  carbonic acid1 and one nitrous oxide1 
six similar plants of mint1  their roots
 being in contact with water and their  
leaves exposed to  light4    ,the plant 

in carbonic acid began to fade in less  
than two days1 and  in four was dead4   
,that in hydrogene died in less than    
five days2 that  in nitrous oxide did   
not fade much for the first two days1   
but on  the third1 drooped very much1   
and was dead at the same time as that   
in hydrogene4 ,the plant in oxygene for 
the first four days1 looked  flourishing
 and was certainly of a finer green than
 before1 gradually  however1 its leaves 
became spotted with black and dropped   
off one by  one1 till at the end of ten 
days they had all disappeared4 ,at this 
time the plant in common air looked     
sickly and yellow1 whilst that in       
hydrocarbonate was greener and more     
flourishing than ever4    ,i have       
detailed these experiments not on       
account of any important  conclusions   
that may be drawn from them2 but with a 
view of inducing  others to repeat them1
 and to examine the changes effected in 
the  gases4 ,if it should be found by   
future experiments1 that hydrocarbonate 

generally increased vegetation1 it would
 throw some light upon the use  of      
manures1 containing putrefying animal   
and vegetable substances1 from  which   
this gas is perpetually evolved4    ,the
 chemistry of vegetation though         
immediately connected with  agriculture1
 the art on which we depend for         
subsistence1 has been but  little       
investigated4 ,the discoveries of       
,priestley and ,ingenhousz1 seem  to    
prove that it is within the reach of our
 instruments of experiment4      ,no4   
,,ii4    ,,approximations ,,to ,,the    
,composition and ,weight of the ariform 
,,combinations of ,,nitrogene    ,at    
temperature #ee1 and atmospheric        
pressure #cj4                           
----------------------------------------
--------------------                    
#ajj ,cubic ,in4    grains              
,nitrogene ,oxygene                     
----------------------------------------
-------     ,nitro- ,with    ,nitrogene 
#cj4jd                              gene

  ,oxy-    ,oxygene         #ce4jf      
gene ----------------------- #ajj       
------------------                      
,atmospher4 air w  #ca4aj;grains  #gc4jj
    #bg4jj                    ,nitrous  
oxide  e  #ej4bj are    #fc4cj    #cf4gj
                    ,nitrous gas    i   
#cd4bf;com-    #dd4je    #ee4ie         
,nitric acid    g  #gf4jj posed  #bi4ej 
#gj4ej                                  
h         of  ------------------        
,nitrogene,hydrogene                    
------------------------------          
------------------            ,with     
hydro-,ammoniac          #ah4je         
#hj4jj    #bj4jj               gene     
----------------------------------------
--------------------      ,no4 ,,iii4   
,additional ,observations4    a4 ,in    
,res4 #ast4 ,div4 ,,iv4 ,sect4 ,,iii4 in
 the analysis of nitrous gas by         
pyrophorus1 as no absorption took place 
when the residual nitrogene was  exposed
 to water1 ,i inferred that if any      
carbonic acid was formed it  was in     

quantity so minute1 as to be unworthy of
 notice4 ,a few days ago1  ,i compleatly
 decomposed a quantity of nitrous gas by
 pyrophorus1 when  the residual         
nitrogene was exposed to solution of    
strontian1 the fluid  became slightly   
clouded2 but no perceptible absorption  
took place4    b4 ,if there was the     
least probability in any of ,dr4        
,girtanner's  speculations on the       
composition of ,azote1#bce the          
experiments on the  exhausted           
capacity#bcf of the lungs in ,res4      
,,iii4 might be supposed  inconclusive4 
,but there appears to be no more reason 
for supposing  that hydrogene is        
converted into nitrogene by respiration1
 than for  supposing that it is         
converted into water1 carbonic acid or  
oxygene2  for all these products are    
evolved when that gas is respired4 ,from
  the comparison of ,exp4 #a with ,exp4 
#c1 ,res4 iii4 ,div4 ii4 ,sec4 #d1 it   
is almost demonstrated that no          
ascertainable change is effected in     

hydrogene by respiration4 ,the          
experiment of the accurate ,scheele in  
which hydrogene after being respired    
thirty times in a bladder wholly  lost  
its inflammability1 may be easily       
accounted for from its mixture  with the
 residual gases of the lungs4    #bce   
,annales de ,chimie1 #ajj2 and ,mr4     
,tilloch's ,phil4 ,magazine4 #bd4       
#bcf ,i regret much that ,i could not   
procure ,dr4 ,menzies's observations  on
 ,respiration1 while ,i was making the  
experiments on the capacity of  the     
lungs3 they would probably have saved me
 some labor4    ,about a fortnight ago1 
,i respired1 after forced voluntary     
exhaustion of  my lungs1 my nose being  
accurately closed1 three quarts of      
hydrogene in  a silk bag1 at four       
intervals1 for near five minutes4 ,after
 this it was  highly inflammable1 and   
burnt with a greenish white flame in    
contact  with the atmosphere2 but was   
not so explosive as before4#bcg    #bcg 
,if loosely combined carbon exists in   

venous blood1 hydrogene may  probably   
dissolve a portion of it when respired  
and become slightly  carbonated4 ,at    
least there is as much probability in   
the supposition  that carbon in loose   
affinity may combine with hydrogene at  
#ih as that  it may combine with        
oxygene4    c4 ,from what we have lately
 heard of the curious experiments of    
,mr4  ,volta and ,mr4 ,carlisle1 it is  
very probable that the conversion of    
nitrous gas into nitrous oxide when     
exposed to wetted zinc1 copper  and tin1
 in contact with mercury1 as described  
in ,res4 ,i4 ,div4 ,v4 may  in some     
measure depend on the action of the     
galvanic fluid4 ,whilst ,i  was engaged 
in the experiments on this conversion1  
,dr4 ,beddoes#bch  mentioned to me some 
curious facts noticed by ,humboldt and  
,ritter1  relating to the oxydation of  
metals by the decomposition of water1   
which induced me to examine the phnomena
 with more attention than ,i  should    
have otherwise done4--,i recollect      

observing that some of the  wetted zinc 
filings in nitrous gas on the side of   
the jar not in  contact with the surface
 of mercury1 were very slowly oxydated4 
,whilst  on the surface of the mercury  
where small globules of that substance  
were mingled with the filings of zinc1  
the decomposition went on much  more    
rapidly2 possibly through the medium of 
the moisture1 a series of  galvanic     
circles were formed4    #bch ,dr4       
,,beddoes has since favoured me with the
 following account of  these facts4     
8,mr4 ,humboldt 7ueber die gereizte     
,faser ,i4 #dgc1 #agig7 quotes part of a
  letter from ,dr4 ,ash1 in which it is 
said that if two finely polished  plates
 of homogeneous zinc be moistened and   
laid together1 little  effect           
follows--but if zinc and silver be tried
 in the same way1 the  whole surface of 
the silver will be covered with oxydated
 zinc4 ,lead  and quicksilver act as    
powerfully on each other1 and so do iron
 and  copper4--,mr4 ,humboldt 7p4 #dgd7 

says that1 in repeating this experiment1
  he saw air-bubbles ascend1 which he   
supposes to have been hydrogene gas     
from the decomposition of water--,when  
he placed zinc simply on moist  glass1  
the same phnomena took place1 but more  
slowly and later4 ,the  quantity of oxyd
 of zinc upon the glass alone was in #bj
 hours to that  on the silver as one to 
three4    ,in a very ingenious but      
obscurely written tract by ,mr4 ,ritter1
  entitled1 ,evidence that the galvanic 
action exists in organic nature1  #hvo4 
,jena1 #ahjj--,the author observes1 that
 the care of ,dr4 ,ash and  ,mr4        
,humboldt that the metals should touch  
each other in as many points  as        
possible was superfluous1 even if we    
could grant that two metallic  plates   
might be made by polishing1 to touch in 
a number of points4  ,to shew that it   
was sufficient if by touching in one    
point only they  should form a compleat 
galvanic circle1 he dropped a single    
drop of  distilled water upon the bust  

of a large silver coin4 ,a piece of pure
  zinc was placed with its one end on   
the edge of the coin1 while the  other  
was supported by a bit of glass4 ,the   
drop of water was neither in  contact   
with the glass nor with the point at    
which the metals touched4  ,the         
materials were left in this situation   
for four hours at the  temperature of   
#fh4 ,on taking them apart1 the water   
had become quite  milky and had half    
disappeared2 and ,mr4 ,ritter actually  
separated a  quantity of white oxide    
that had been produced in the           
experiment4    ,the pieces of metal were
 cleaned and laid together in the same  
manner1  only that now a piece of paper 
was put between the metals at their     
former point of contact4 ,in four hours 
first1 and afterwards in ten1 a  faint  
ring of oxide only had been produced of 
which the quantity could  not be        
estimated1 nor could it be separated4   
,in this case1 the zinc  had scarce lost
 any thing of its splendour2 in the     

former it had been  corroded4 ,in many  
repetitions of the experiment1 he found 
that far more  oxide was formed when the
 metals touched1 than when they were    
separated  to the slightest distance by 
an insolating body1 even air4    ,on    
exposing these apparatuses with somewhat
 more water to a  considerable heat for 
four minutes1 the water in the          
interrupted circle  continued quite     
clear1 while that in the other had      
become milk-white4    ,the same phnomena
 were presented by other pairs of metals
 in a degree  proportional to their     
galvanic activity2 viz4 by zinc and     
molybdna1  zinc and bismuth1 zinc and   
copper1 as also with tin and silver1 tin
  and molybdna1 and lead and silver4    
,the experiment with tin was            
particularly decisive1 for when in      
contact with no other metal it was      
scarcely at all oxydated by water1      
though oxydation took place when tin    
was brought into contact with silver1   
and both were connected at the  other   

end by a drop of water--,what therefore 
took place in ,dr4 ,ash's  experiment1  
arose from an aggregation of galvanic   
circles of different  forms4    ,by the 
foregoing experiments1 concludes ,mr4   
,ritter1 which though  capable of the   
most various modifications1 uniformly   
coincide in  their main result1 it is   
abundantly proved that galvanic circles 
can be formed of merely inorganic       
bodies1 by whose completion there  is   
produced an action which ceases when the
 circle is opened4 ,the  manner in which
 this has been shewn1 proves also that  
this action can  effectuate sensible    
modifications in organic bodies2 and the
 process  by which these modifications  
have been effected1 made it evident that
  they were not consequences of a       
momentary action of the circle1 but  of 
an action that is kept up while the     
circle remains entire2 for the  process 
which brought this action under the     
cognizance of the senses  went on1 while
 the circle was unbroken1 and its figure

 not brought back  to that of a line4   
,it is scarce necessary to observe that 
the experiments here quoted1 are  far   
from being the only ones on which the   
above conclusions rest40        ,t4 ,b4 
d4 ,in ,res4 ,,ii4 ,div4 ,i4 it is      
stated1 that nitrous oxide during its   
solution by common water1 expels about  
_/ of atmospheric air the  volume of the
 water being unity4    ,from the        
delicate experiments of ,dr4 ,pearson1  
on the passage of the  electric spark   
through water1 it appears however       
probable1 that much  more than _/ of    
atmospheric air is sometimes held in    
solution by that  fluid1#bci possibly   
the whole of the air is not expelled by 
nitrous  oxide1 owing to some unknown   
law of saturation by which an           
equilibrium  of affinity is produced1   
forming a triple compound4    #bci      
,possibly a ratio exists between the    
solubility of gases in water1  and the  
solubility of water in gases4 ,it is    
probable from ,mr4 ,wm4  ,henry's       

curious experiments on the muriatic     
acid1 that the absolute  quantity of    
water in many gases1 may be ascertained 
by means of its  decomposition by the   
electric spark4      ,no4 ,,iv4         
,,description ,,of ,a ,,mercurial       
,,airholder4    ,suggested by an        
inspection of ,mr4 ,,watt',s ,machine   
for containing  ,factitious ,airs4      
,by ,,william ,,clayfield4      ,several
 modes of counteracting the pressure of 
a decreasing column of  mercury having  
been thought of in conjunction with ,mr4
 ,w4 ,cox1 the  following was at last   
adopted as the most simple and          
effectual4    ,plate #a ,fig4 #a1       
represents a section of the machine1    
which consists of  a strong glass       
cylinder ,a cemented to one of the same 
kind ,b1 fitted  to the solid block ,c1 
into which the glass tube ,d is cemented
 for  conveying air into the moveable   
receiver ,e4    ,the brass axis ,f1     
,fig4 #b1 having a double bearing at a1 
a1 is  terminated at one end by the     

wheel ,g1 the circumference of which is 
equal to the depth of the receiver1 so  
that it may be drawn to the  surface of 
the mercury by the cord b in one        
revolution2 to the other  end is fitted 
the wheel ,h1 over which the balance    
cord c runs in an  opposite direction in
 the spiral groove e1 a front view of   
the wheel  ,h is shewn at ,fig4 #c4     
,having loaded the receiver with the    
weight ,i1 something heavier than  may  
be necessary to force it through the    
mercury1 it is balanced by  the small   
weight ,k1 which hangs from that part of
 the spiral where the  radius is equal  
to that of the wheel ,g1 from this point
 the radius  of the spiral must be      
increased in such proportion1 that in   
every  part of its circuit1 the weight  
,k may be an exact counterpoise to the  
airholder4 ,in this way1 so little      
friction will be produced1 that  merely 
plunging the lower orifice of the tube  
,d under mercury contained  in the small
 vessel ,l1 will be sufficient to       

overcome every resistance1  and to force
 the gas discharged from the beak of a  
retort into the  receiver1 where        
whatever may be its quantity1 it will be
 subjected to  a pressure exactly       
corresponding to that of the atmosphere4
 ,the edge  of the wheel ,h being       
graduated1 the balance cord c may be    
made to  indicate its volume4    ,should
 it at any time be necessary to reduce  
the pressure to the medium  standard of 
the barometer1 it may easily be done by 
graduating the  lower end of the tube   
,d1 and adding to the weights ,i or ,k1 
as may be  found necessary2 the surface 
of the mercury in the tube pointing out 
the increase or diminution4    ,the     
concavity at the top of the internal    
cylinder is intended to  contain any    
liquid it may be thought proper to      
expose to the action of  the gas4       
,the upper orifice f1 with its ground   
stopper1 is particularly useful  in     
conveying air from the retort g1 with   
its curved neck1 into the  receiver1    

without its passing through the tube ,d4
 ,in all cases where a  rapid           
extrication of gas is expected the      
retort g1 should be firmly  luted to the
 orifice and the weight ,i1 removed from
 the top of the  receiver1 this by      
diminishing the pressure1 will admit the
 gas to  expand freely in the airholder 
at the instant of its formation1 and    
prevent an explosion of the vessels4    
,the same caution must be observed      
whenever any inflammation of gas is     
produced by the electric spark4    ,the 
air may be readily transferred through  
water or even mercury by the  tube h1   
,fig4 #a4    ,to prevent an absorption  
of mercury in case of a condensation    
taking  place in the retort made use of 
for generating air1 ,mr4 ,davy has      
applied the stop-cock i1 to which the   
neck is firmly luted4 ,this  stop-cock  
is likewise of great service in         
saturating water with acid or  alkaline 
gases1 which may be effected by luting  
one end of the tube k  to the stop-cock1

 and plunging the other into the fluid  
in the small  vessel l1 cemented at top1
 and terminating in the bent funnel     
m--the  tube h having been previously   
removed1 and the lower orifice of the   
tube ,d either sunk to a considerable   
depth in mercury1 or closed with a      
ground stopper4 ,the bend of the funnel 
m1 may be accurately closed by  the     
introduction of a few lines of mercury4 
,the application of the stop-cock n1 has
 enabled ,mr4 ,davy to perform  some    
experiments on respiration with         
considerable accuracy4        ,note4    
,this apparatus was first described in  
the third part of ,dr4 ,beddoes's       
,considerations2      its relation to   
,mr4 ,davy's experiments with the       
improvements it has lately received1 may
 probably be      deemed sufficient to  
excuse the re-printing it4--,the        
weight ,i4 ,fig4 #b1 having been omitted
 in the plate1      the reader must     
supply the deficiency4                  
,w4 ,c4          ,,proposals ,,for ,,the

 ,,preservation ,,of ,,accidental       
,,observations ,,in ,,medicine4      ,in
 times beyond the reach of history1 the 
medicinal application of  substances    
could have arisen from no other source  
than accident4 ,among  articles of the  
materia medica of known origin1 we are  
indebted to  accident for some of the   
most precious4    ,accident is every day
 presenting to different individuals the
 spectacle  of phnomena1 arising from   
uncommon quantities of drugs on the one 
hand1 and on the other1 from uncommon   
conditions of the system1 where         
ordinary powers only have been knowingly
 or recently applied4 ,what is  said of 
drugs may be extended to natural agents 
and mental affections4    ,from         
conversation with a variety both of     
medical practitioners and               
unprofessional observers1 the author of 
this proposal is persuaded  that such   
authentic occurrences only1 as have     
presented themselves to  persons now    
living would1 if they could be brought  

together1 compose  a body of fact1 so   
instructive to the philosopher1 and     
useful to the  physician1 that he       
despairs of finding a term worthy to    
characterize  it4    ,in some cases1 the
 influence of unsuspected powers would  
be detected4  ,in others1 resources     
available to the purpose of restoring   
health in  desperate situations would be
 directly presented1 or could be        
detected  by a short and easy process of
 reasoning4 ,some anomalous             
observations1  by shewing the absence or
 agency of contested causes1 would      
perform  the office of experimenta      
crucis--,unusual affections occur of    
which  an exact account would be among  
the means of removing from physic its   
opprobrious uncertainty3 for this       
uncertainty frequently depends upon  our
 inability to distinguish the subtler   
differences in cases which  resemble    
each other in their grosser features4   
,no striking fact can be accurately     
stated1 in conjunction with its         

antecedent and concomitant              
circumstances1 without improving our    
acquaintance with human nature4 ,our    
acquisitions in this most important     
branch of knowledge1 may be compared to 
a number of broken series1 of  which we 
have not always more than one or two    
members4 ,but every new  accession bids 
fair to fill up some deficiency2 and a  
large supply  would contribute towards  
connecting series apparently            
independent1 and  working up the whole  
into one grand all-comprehending chain4 
,there are complaints1 and those by far 
too frequent1 where no known  process   
has a claim to the title of remedial4   
,here the whole chance  of preservation 
depends on the physician's capacity for 
bringing  together facts that have      
heretofore stood remote4 ,but no power  
of  combination can avail where there   
are no ideas to combine4    ,every new  
observation therefore1 may be considered
 as a standard trunk1  sending forth    
analogies as so many branches crowned   

with blossoms1 some  of which cannot    
fail to be succeeded by salutary fruits4
 ,and were it  not absurd to extend the 
illustration of so plain a point1 it    
might  be added1 that when by the       
continual interposition of new trunks1  
the branches are brought near together1 
the produce of each will be  ennobled by
 the action of their respective         
principles of fecundation4    ,whenever 
the author has been able to obtain      
certain information  concerning any     
unusual appearance in animal nature1 it 
has been his  custom to preserve it2 and
 among his papers he has memorandums    
which  prove that to our present        
circumscribed ideas concerning the dose 
of  medicines may be sometimes imputed  
failures in practice2 that certain      
signs are not to be taken in the        
received signification2 and that many   
measures are adopted or omitted to the  
detriment of invalids1 because  it is   
assumed that circumstances are          
necessarily connected which may  exist  

separately1 or that one given natural   
operation is inconsistent  with another1
 to which it may really be synchronous  
or next in order4    ,assiduous         
observation of the daily states of the  
human microcosm will  be the unfailing  
consequence of attention to its striking
 phnomena4  ,such is the progress of    
curiosity4 ,such the origin of all the  
sciences4  ,the more uniformly clear the
 sky under which they tended their      
flocks1  the less likely were the       
shepherds of ,chalda1 to found the      
science of  the stars4 ,and however the 
disposition to study astronomy might    
have  been strengthened by the          
coincidence between the heliacal rising 
of  ,sirius and the overflowing of the  
,nile1 it must1 ,i conceive1 have been  
awakened by the aspect of meteors and   
eclipses4    ,whatever minute and       
authentic information this imperfect    
statement  may produce1 as soon as it   
shall amount to a certain mass1 the     
author  will present it to the public   

arranged4 ,he flatters himself that no  
correspondent will eke out by           
supposition the defect of genuine       
observation1 without clearly            
distinguishing the one from the other4  
,he still more confidently hopes that   
none will be instigated by this         
advertisement to exercise his invention 
in the manner of ,psalmanasar  and      
,chatterton4 ,whether any literary      
forgery can be innocent is              
questioned--but a forged medical report 
is a drawn dagger which the  arm of a   
credulous physician may any day plunge  
into the heart of his  defenceless      
patient4 ,the author has heard some     
inconsiderate wits avow1  that they have
 transmitted to the venders of quack    
medicines imaginary  cures1 attested by 
fictitious signatures2 and it is not    
without  apprehension from the          
propensity of men to display ingenuity  
and to  relate wonders that he announces
 the present design4 ,but he shall be on
  his guard1 and hopes to baffle        

attempts at imposition4                 
,,thomas ,,beddoes4                     
,,rodney-,,place1 ,clifton1 ,june #ahjj4
      ,,end4          ,,errata4         
,page #ai line #ae  for is read are     
--   #ce --  #g -- for principle read   
principles      --   #db -- #aa -- for  
take read takes      --   #fh ,table #e 
-- for #e1hh read #ae1hh      --   #id  
--  #d -- for #a_/ read _/4      --     
#ie --  #d -- for #cg read #cj1g      --
   #if --  #c -- for #ch read _/      --
  #aje --  #i -- for exactitude read    
exactness      --  #abi -- #ba -- for   
#da read #d1a      --  #acb --  #d --   
for into read in      --  #adc -- #ac --
 for #be read 1#be      --  #ahf -- #ae 
-- for by read from      --  #bjh last  
line -- for abstracted read attracted   
--  #bch --  #e -- for gas read oxide   
--  #bei --  #d -- for #ab read #b      
--  #bhc --  #d -- for potash read iron 
--  #cae -- #ad -- dele in      --  #dji
 -- #ae -- for respiration read         
expiration      --  #dfd -- #aj -- for  

latter end  read end      --  #edc --   
#c -- for exhalation  read inhalation4  
,a few literal errors are left to the   
reader's correction4    ,n4 ,b4 ,the    
term ignited is sometimes used to       
signify any temperature  equal to or    
above a red heat1 whether applied to    
solids1 fluids1 or  ariform substances4 
,the reasons for the use of the terms   
nitrogene and nitrous oxide1 are  given 
in ,mr4 ,nicholson's ,journal for       
,january4                               
,speedily will be ,published            
,,observations on the ,external and     
,internal ,use of                       
,,nitrous ,,acid4                       
,demonstrating its ,,permanent          
,,efficacy in                           
,,venereal ,,complaints2                
,and extending its use to other         
dangerous                           and 
painful ,diseases4                      
,,communicated                    ,by   
various ,practitioners in ,,europe      
and ,,asia4                             

,,to                           ,,thomas 
,,beddoes1 ,m4 ,d4                 ,of  
the ,publisher may be had1 price #as4   
#f;d4                                   
,,notice of ,,observations              
,,at ,,the ,,pneumatic ,,institution1   
,by ,,thomas ,,beddoes1 ,m4 ,d4         
,this ,notice contains some trials of   
nitrous oxide by healthy                
persons1 not in the present work1 and   
some cases of palsy                     
successfully treated by that gas4       
,printed by ,biggs and ,cottle1 ,st4    
,augustine's ,back4