Am  Jonr.  Pharm. ) 
April,  1885.  j 
Determination  of  Ethyl  Nitrite. 
183 
THE  DETERMINATION  OF  ETHYL  NITRITE  IN  THE 
SPIRIT  OF  NITROUS  ETHER  AND  KINDRED 
PREPARATIONS. 
By  Alfred  H.  Allen. 
During  many  months  past  I  have  been  engaged  at  intervals  on  a 
series  of  experiments  with  a  view  of  estimating  the  proportion  of  ethyl 
nitrite  and  other  nitrous  compounds  contained  in  sweet  spirit  of  nitre. 
In  the  course  of  the  investigation  I  have  tried  nearly  all  the  published 
methods  of  assay/  and  have  obtained  results  of  which  the  following 
description  is  an  epitome : 
The  British  Pharmacopoeia  test  for  the  presence  of  nitrous  com- 
pounds in  the  spirit  of  nitrons  ether  is  a  satisfactory  one  from  a  quali- 
tative point  of  view,  but  it  can  be  applied  in  a  more  advantageous 
manner  than  is  directed  in  the  British  Pharmacopceia  by  mixing  the 
sample  with  a  strong  aqueous  solution  of  ferrous  sulphate,  and  then 
pouring  concentrated  sulphuric  acid  down  the  side  of  the  tube  in  such 
a  manner  as  not  to  mix  with  the  lighter  liquid.  A  deep  brown  zone 
will  be  produced  at  the  junction  of  the  two  strata,  which,  in  the  case 
of  good  samples,  becomes  intensified  by  cautious  agitation. 
Many  samples  of  spirit  of  nitrous  ether  give  a  brown  color  with 
ferrous  solution  before  the  addition  of  acid,  but  the  coloration  is 
^  The  literature  of  spirit  of  nitrous  ether  is  somewhat  extensive.  The 
following  is  a  list  of  references  to  it  in  comparatively  recent  volumes  of  the 
"  Pharmaceutical  Journal :" 
T.  Redwood  [3],  viii,  377,  455. 
J.  Attfield  [3],  viii,  454. 
F.  W.  Rimmington  [3],  viii,  341,  362,  377;  x,  41,  220. 
J.  Williams  [3],  viii,  441,  453. 
W.  Smeeton  [3],  x,  21. 
A.  Dupre  [3],  x,  93. 
J.  Muter  [3],  x,  94. 
W.  Pollard  [3],  x,  100. 
J.  F.  Eykman  [3],  xiii,  63. 
W.  H.  Symons  [3],  xiv,  2S1. 
U.  S.  and  German  Preparations  [3],  xiv,  101. 
D.  J.  Leech  [3],  xiv,  322. 
A.  C.  Abraham  [3],  xiv,  390,  876,  915. 
P.  MacEwan  [3],  xiv,  817,  826,  896,  936. 
D.  B.  Dott  [3],  xiv,  819,  826,  895  ;  xv,  200,  492,  592. 
T.  S.  Dymond  [3],  xv,  101. 
