CHEMICAL  RESEARCHES  ON  AMYLENE. 
411 
an  aqueous  product.  The  second  recipient  contains  the  amylic 
alcohol,  which  is  to  be  separated  by  means  of  a  syphon.  In  this 
state  it  still  contains  a  little  ordinary  alcohol,  so  great  is  the 
affinity  of  the  two  liquids  for  each  other.  The  product  may  now 
be  washed  without  much  loss  ;  but  this  washing  not  having  all  the 
desired  efficacy,  unless  frequently  repeated,  I  have  recourse  to  a 
second  means,  which  has  been  perfectly  successful,  not  with  a 
view  of  removing  the  water  as  has  been  recommended,  but  with 
a  view  of  radically  separating  the  alcohol.  I  rectify  on  a  great 
quantity  of  dry  chloride  of  calcium,  this  salt  having  the  effect 
of  dehydrating  and  concentrating  ordinary  alcohol,  and  by  these 
means  giving  it  the  property  of  volatilizing  at  a  low  tempera- 
ture, and  by  this  means  also  the  alcohol  passes  immediately  by 
distillation.  After  this,  there  is  a  marked  arrest  of  distillation, 
though  the  heat  continue  the  same,  and  the  recipient  is  to  be  re- 
placed by  another  vessel  destined  to  receive  the  potato-oil,  which, 
by  increasing  the  heat,  is  now  wholly  distilled  over  in  the  desired 
purity. 
Preparation  of  Amylene. 
Whilst  physiologists  are  conducting  experiments  with  a  view 
of  studying  the  effects  of  amylene  on  man  and  animals,  an  un- 
certainty rests  on  the  whole,  from  the  fact  that  all  the  products 
employed  under  the  name  of  amylene,  are  only  multiple  com- 
pounds of  several  carburets,  and  I  shall  hereafter  show  that  these 
amylenes  contain  besides,  sometimes  ether,  but  up  to  the  present 
time,  always  amylic  alcohol.  Now  the  main  question  is  to  deter- 
mine, if  we  can,  as  an  industrial  process,  succeed  in  the  manu- 
facture of  amylene  properly  so  called.  If  the  difficulty  of  ob- 
taining pure  amylene  should  so  augment  the  price  as  to  render 
its  surgical  employment  impracticable,  and  if,  at  the  same  time, 
it  is,  nevertheless,  found  that  a  mixture  of  amylene,  paramylene, 
metamylene,  etc.,  possesses  a  real  value,  useful  properties,  and, 
in  fine,  is  worthy  of  being  adopted  as  an  anaesthetic,  we  ought,  at 
once,  to  determine  the  precise  character  of  the  article  to  be  used 
—the  quantity  of  absolute  amylene  which  this  compound  of  the 
hydro-carburets  ought  to  contain.  Thus  we  ought  to  determine 
the  highest  boiling  point,  and  never  to  use  a  product  leaving  a 
residuum,  on  distillation,  beyond  this  maximum  of  heat.  We 
should  seek  the  means  of  recognizing  its  bad  qualities,  and  of 
