A%Ja°rch,m9!:m'}         The  Metameric  Amyl  Nitrites.  149 
nitrites,  of  more  or  less  perfectly  rectified  fusel  oil.  The  fraction 
boiling  between  127°-132°  C,  is  known  in  commerce  as  "amyl  alco- 
hol and  unless  the  operation  of  fractional  distillation  has  been  many 
times  repeated,  the  liquid  is  liable  to  contain  more  or  less  iso-butyl 
alcohol  (b.  p.  108*4°).  On  account  of  the  difficulty  of  completely  re- 
moving iso-butyl  alcohol,  as  well  as  substances  of  higher  boiling-point, 
from  fusel  oil  by  distillation,  we  decided  to  make  our  first  experi- 
ments with  amyl  alcohol  which  had  been  otherwise  purified.  Ad- 
vantage was  taken  of  the  superior  solubility  of  the  barium  salt  of  iso- 
butyl  sulphuric  acid. 
About  300  grams  of  the  fraction  of  fusel  oil  which  had  been  re- 
peatedly distilled  between  127°-130°  C.  were  warmed  for  some  days 
with  an  equal  quantity  of  sulphuric  acid.  The  liquid  was  then  poured 
into  5  litres  of  water.  The  dark  oily  layer  which  separated  was  re- 
moved, and  the  clear  liquid  neutralized  with  barium  carbonate.  This 
solution  of  the  barium  salts  of  iso-butyl  sulphuric  acid  and  the  two 
amyl-sulphuric  acids  was  evaporated  to  about  one-third  of  its  original 
volume.  The  salts  deposited  on  cooling  the  liquid  were  many  times 
recrystallized  from  water.  By  this  means  the  more  soluble  barium 
iso-butyl  sulphate  was  removed,  together  no  doubt  with  some  of  the 
barium  /9-amyl  sulphate,  which  is  rather  more  soluble  than  barium 
a-amyl  sulphate.  From  the  mixed  barium  salts  the  alcohols  were  re- 
generated by  conversion  into  the  sodium  salts,  which  were  distilled 
with  diluted  sulphuric  acid.  The  resulting  alcohols  were  dried  by  di- 
gestion with  ignited  potassium  carbonate  and  distilled.  Nearly  the 
whole  of  the  liquid  came  over  at  129°  C.  The  specific  gravity  was 
•813  at  15°  C.  (water  at  15°=1).  The  rotatory  power  at  15°  C.  de- 
termined with  Laurent's  instrument  in  a  column  200  mm.  long  was 
— 1*35°.  The  maximum  rotation  observed  by  Ley  in  a  specimen  of 
/9-amyl  alcohol  was  — 8*8°  for  a  column  200  mm.  long,  so  that  the 
specimen  above  described  contained  84*66  per  cent,  of  a-amyl  alcohol 
and  15*34  per  cent,  of  /9-amyl  alcohol.  The  alcohols  were  now  con- 
verted into  the  nitrites  by  reaction  with  sulphuric  acid  and  sodium 
nitrite.  The  respective  quantities  of  the  materials  used  were  calcu- 
lated from  the  equation 
2C5HnOH+H2S04+NaN02  =  2CfiH11N02+Na2804+2H20. 
The  method  was  very  successful,  and  the  nitrites  thus  easily  prepared 
were  washed  with  a  solution  of  potassium  carbonate  and  dried  by  di- 
gestion with  the  ignited  salt.    The  liquid  entirely  distilled  between 
