22  Nitrite  of  Amijl.  { AMjaJn0^;  jp» 
together  with  some  copper  wire,  and,  after  [cooling,  H  N  03  was 
added.  In  a  very  few  moments  the  evolution  of  gas  was  observed, 
the  liquid  became  hot  without  the  external  application  of  heat ;  and 
the  reaction  very  rapidly  increased  to  such  a  violence  that  the  entire 
charge  was  lost,  it  being  impossible  to  condense  any  of  the  vapors  in 
a  Liebig's  condenser/or  to  retain  much  of  the  liquid  forced  over  into 
the  receiver.  I  may  add,  that  I  have  repeated  this  experiment  with 
exactly  the  same  results  ;  nearly  the  whole  charge  was  forced  over 
into  the  receiver,  and,  while  there,  the  action  again  commenced,  and 
increased  to  such  violence  that  I  have  no  doubt  it  would  have  forced 
itself  back  into  the  retort  again  if  their  mutual  positions  had  been 
favorable.  As  it  was,  I  was  obliged  to  introduce  it  to  the  open  air, 
for  the  whole  house  became  filled  with  the  vapor,  and  every  one  who 
respired  it  became  suddenly  red  in  the  face.  Upon  one  of  my  assis- 
tants it  had  a  very  remarkable  effect ;  it  seemed  to  affect  the  muscles 
at  the  back  part  of  the  neck,  and  drew  the  head  backwards,  but  this 
soon  passed  off.  I  should  quite  expect  that  the  reaction  would  be 
just  as  violent  in  making  spirit  of  nitrous  ether,  if  we  used  anhydrous 
alcohol  instead  of  84  per  cent,  as  ordered.  In  preparing  the  nitrite 
of  amyl  by  the  process  I  employ,  it  is  of  the  utmost  importance  that 
the  amylic  alcohol  be  as  pure  as  possible.  Amylic  alcohol,  as  you  all 
know,  is  formed  during  the  fermentation  of  potatoes,  rye,  barley  and 
the  marc  of  grapes  ;  and  when  these  are  distilled  it  communicates  a 
very  pungent,  and  to  many  repulsive,  odor  and  taste  to  the  spirits. 
It  is  considerably  less  volatile  than  either  ordinary  alcohol  or  water, 
having  a  boiling  point,  when  pure,  of  132°  C.  ;  in  consequence  of 
this  property,  it  accumulates  in  the  last  portions  of  the  liquids  that 
are  distilled.  Its  name  is  derived  from  amylum,  starch, — this  being 
the  most  abundant  constituent  of  potatoes.  Liebig  states  that  amylic 
alcohol  is  formed  principally  in  the  fermentation  of  alkaline  or  neu- 
tral liquids,  and  its  production  in  the  potato  mash  may  be  prevented 
in  great  measure  by  adding  crude  tartar  to  the  fermenting  liquid. 
Its  formation  never  occurs  in  acidulous  fermenting  liquors  which 
contain  tartaric,  racemic,  or  citric  acids.  The  addition  of  hops  to 
the  liquid  has  a  similar  effect  in  checking  the  development  of  amylic 
alcohol,  or  fusel  oil,  as  it  is  generally  termed.  It  is,  when  pure,  a 
colorless  limpid  liquid,  of  a  penetrating  and  disagreeable  odor,  ex- 
citing headache  and  coughing  when  its  vapor  is  inhaled.  It  is  spar- 
ingly soluble  in  water,  though  it  mixes  in  all  proportions  with  alcohol, 
