378 
Spiritus  JEtheHs  Nitrosi. 
J  Am.  Jour.  Pkarni. 
1       July,  1884. 
SPIRITUS  iETHERIS  NITROSI:  COMPOSITION  IN  RE- 
LATION TO  DETERIORATION.1 
By  Petr  Macewan. 
"  What  this  spirit  is,"  says  Professor  Redwood,2  "  has  hitherto 
eluded  investigations;  it  contains  nitrite  of  ethyl,  aldehyde,  and  pro- 
bably other  compounds,  but  in  what  proportion  it  is  extremely  diffi- 
cult to  indicate,  all  that  we  can  say  is  that  it  always  contains  the  same 
proportion  of  the  same  ingredients." 
Recognizing  fully  the  difficulty  here  alluded  to,  it  is  with  some 
hesitancy  that  I  approach  the  subject,  for  though  Professor  Redwood 
made  this  statement  about  six  years  ago  little  has  been  done  to  increase 
our  knowledge  of  the  complex  mixture,  spiritus  setheris  nitrosi.  True, 
pharmaceutical  literature  published  since  then  shows  that  it  does  not 
"  always  contain  the  same  proportion  of  the  same  ingredients,"  and  the 
reason  why  was  very  clearly  shown  in  the  discussion  which  followed 
Mr.  Abraham's  paper  at  the  South  port  meeting  of  the  Pharmaceutical 
Conference.  This  paper  is  not  intended  to  add  to  our  knowledge  of 
the  composition  ;  I  can  only  consider  it  as  a  preliminary  statement  of 
the  work  which  I  have  been  enabled  to  do  in  the  subject.  Without 
entering,  therefore,  into  the  question  of  the  "  other  compounds,"  I 
meanwhile  propose  to  discuss  the  composition  as  related  to  deteriora- 
tion ;  that  is,  the  existence  in  the  spirit  of  ethyl  nitrite  and  aldehyde 
and  the  influence  they  exert  in  causing  deterioration.  Taking  the 
official  spirit  as  our  standard  we  find  that  our  opinion  is  fairly  agreed 
as  to  ethyl  nitrite  and  aldehyde  being  always  present  in  it.  Their 
presence  can  very  readily  be  demonstrated,  as  by  the  tests  which  I 
show  you. 
Proportiom  of  Ethyl  Nitrite  in  the  Spirit. — Were  all  the  nitric  acid 
ordered  in  the  official  process  reacting  with  the  alcohol  to  form  only 
ethyl  nitrite  (C2H5N02),  we  should  expect  to  find  somewhat  over  6'5  per 
-cent,  in  the  finished  spirit ;  but  in  practice  we  find  that  the  theoretical 
yield  is  not  obtained,  and  only  with  extreme  care  can  we  obtain  a  pro- 
duct containing  4  per  cent,  of  ethyl  nitrite.  There  is  really  no  author- 
itative standard  to  go  upon,  the  Pharmacopoeia  tests  being  empirical, 
but  Dr.  Dupr6,  in  a  paper3  read  before  the  Society  of  Public  Analysts, 
1  Read  at  an  Evening  Meeting  of  the  North  British  Branch  of  the  Phar- 
maceutical Society,  March  19,  1884. 
2  "Pharm.  Jour."  [3],  viii,  377. 
3  "Pharm.  Jour."  [3],  x,  93. 
