Am.  Jour.  Pharm.) 
July, 1884.  J 
Spiritus  JEtheris  Nitrosi. 
of  III.,  which  decomposed  rapidly.  Without  denying  that  the  forma- 
tion of  acetic  acid  is  due  in  part  to  oxidation  of  aldehyde,  it  must  be 
admitted  that  another  explanation  is  required.  Rapid  decomposition 
is  the  result  of  atmospheric  influence,  and  is  analogous  to  the  observed 
fact  that  the  spirit  decomposes  much  more  rapidly  in  partially  filled 
bottles  than  in  full  bottles.  This  observation  leads  us  to  infer  that 
part,  at  least,  of  the  acetic  acid  is  due  to  oxidation  of  ethyl  nitrite. 
This  oxidation  might  be  expressed  in  one  formula,  in  which  acetic  and 
nitrous  acids  are  formed  : 
CsH8NOa  +  02  =  HC2H302  +  HN02. 
We  may  also  express  this  in  two  stages ;  in  the  first  we  have  alde- 
hyde and  nitrous  acid  formed  : 
C2H5N02  +  O  =  C2H40  +  HN02. 
In  the  second  the  aldehyde  is  oxidized  to  acetic  acid  : 
02H4O  +  O  =  H02H3O2. 
It  should  be  further  noted  that  in  spite  of  the  greatest  care  a  little 
nitrous  fumes  pass  over  with  the  distillate  in  the  course  of  preparation ; 
this  admixture,  though  minute,  is  sufficient  to  act  as  a  nucleus,  and 
hence  another  cause  of  decomposition  under  the  best  conditions  for 
preservation.  The  effect  of  water  in  influencing  decomposition  is  well 
seen  in  the  case  of  VII.,  which  contains  additional  water.  The  dis- 
appearance of  acetic  acid  in  the  case  of  I.  is  probably  due  to  combi- 
nation between  the  ethyl  radical  and  it,  acetic  ether  being  formed. 
Increase  in  aldehyde  may  be  due  to  such  a  reaction  as  that  expressed 
in  the  first  stage  of  the  formula  given,  effected  either  by  direct  oxida- 
tion or  by  the  action  of  nitrogen  acids  upon  ethyl  compounds.  An 
explanation  which  is  not  without  interest,  though  purely  suggestive, 
is  that  it  is  due  to  depolymerization  of  paraldehyde.  You  are  aware 
that  Mr.  Williams  stated  at  Southport  that  he  had  a  strong  suspicion 
that  sweet  spirit  of  nitre  contains  paraldehyde,  which  he  says  is  formed 
during  the  ordinary  process  adopted  in  making  the  spirit.  Well,  as- 
suming that  paraldehyde  (boiling  at  124°C.)  is  capable  of  passing 
over  with  the  distillate  between  70°  and  80°C,  we  would  expect  that 
the  action  of  nascent  nitrous  acid  would  be  to  resolve  it  into  aldehyde, 
and  hence  an  increase.  I  show  you  some  "  pure  paraldehyde  "  Avhich 
has  been  so  treated  and  you  will  notice  that  the  pleasant  odor  of 
paraldehyde  has  been  replaced  by  the  pungency  of  aldehyde,  and  it 
