Am.  Jour.  Pharm.  ) 
Feb.,  1879.  J 
Nitrite  of  Amy  I. 
67 
potassium  carbonate,  and  drying  it  with  solid  potassium  carbonate,  it  is 
distilled  and  all  that  passes  below  ioo°  may  be  retained. 
Perfectly  pure  nitrite  of  amyl  can  only  be  obtained  by  many  and 
careful  fractionations,and  would  be  too  expensive  for  pharmaceutial  use. 
It  boils  constantly  at  960,  the  boiling  point  given  by  Balard,  and  its 
vapor  is  not  dissociated  at  its  boiling  point.  Mr.  Tichborne's  state- 
ment, made  some  ten  years  ago  and  subsequently  contradicted  by 
Chapman,  that  nitrite  of  amyl  is  decomposed  by  boiling,  is  erroneous. 
No  gas  of  any  description  is  evolved  during  the  distillation  of  amyl 
nitrite,  as  can  be  demonstrated  by  most  rigorous  experiment. 
It  might  naturally  be  expected  that  there  would  be  a  diminution  of 
5  or  6  per  cent,  of  the  portion  passing  between  900  and  ioo°  at  each 
fractionation.  Ten  degrees  is  a  very  considerable  range,  and  the  very 
fact  that  Mr.  Dott  could  not  get  all  of  his  nitrite  to  pass  between  90 
and  ioo°,  should  have  indicated  to  him  that  his  product  was  not  per- 
fectly pure,  but  it  was  gradually  approaching  purity  as  shown  by  the 
residue  left  at  ioo°. 
Much  time  may  be  saved  in  fractionating,  especially  such  substances 
as  nitrite  of  amyl  which  has  a  high  tension  of  vapor,  by  the  use  of  the 
Le  Bel  and  Henninger  apparatus  described  in  the  Comptes  Rendus  (vol. 
Ixxiv,  p.  480),  as  two  or  three  fractionations  will  then  effect  an 
almost  perfect  separation. 
I  have  examined  specimens  of  nitrite  of  amyl  from  reputable  houses, 
and  have  found  boiling  points  between  70  and  1800.  Such  products, 
it  is  needless  to  say,  have  never  been  rectified.  The  whole  result  of 
the  action  has  been  distilled  and  bottled  as  nitrite  of  amyl.  One  speci- 
men had  not  entirely  distilled  at  2200  ;  another  contained  about  ten 
per  cent,  of  water,  twenty-five  per  cent,  of  amyl  nitrite  (90  to  ioo°C)., 
and  the  remainder  was  composed  almost  entirely  of  unaltered  amylic 
alcohol. 
The  boiling  point  of  the  nitropentane  derived  from  ordinary  amylic 
acid  is  in  the  neighborhood  of  i6o°C.  I  have  found  traces  of  it  in  all 
of  the  commercial  nitrite  of  amyl  I  have  examined  ;  and  sometimes 
the  proportion  is  not  inconsiderable.  It  may  be  detected  by  subjecting 
that  portion  which  passes  between  150  and  I70°C.  to  the  action  of 
nascent  hydrogen.  Amylamine  is  thus  formed.  Commercial  amyl 
nitrite  seems  also  to  contain  very  small  quantities  of  nitrate  of  amyl. 
11.29  Cherry  Street,  Philadelphia. 
