170 
NOTES  UPON  AMYLENE. 
form,  and  it  was  possible,  by  referring  to  this  addition,  to  explain 
the  narcotic  operation  now  and  then  observed,  until  there  was 
exhibited  an  equal,  or  indeed  a  greater,  proportion  of  chlorine  in 
a  boiling  product  of  distillation  prepared  according  to  Balard's 
direction,  than  had  been  formerly  found  in  the  commercial  arti- 
cle. The  necessity  now  presented  itself  of  obtaining  positive 
conclusions  upon  the  proportion  of  chlorine  existing  in  amylene. 
Some  amylene  was  freshly  prepared,  with  especial  care  that  all 
impurity  from  chlorine  should  be  excluded.  The  chloride  of 
zinc  employed  in  the  process  was  treated  for  several  hours  at 
160°,  and  after  cooling  was  brought  to  the  test  of  ammonia,  in 
order  to  discover  by  this  means  the  accidental  presence  of  free 
hydrochloric  acid ;  but  it  was  quite  free  from  this  acid.  The 
amylene  collected  from  every  part  of  the  product  of  distillation, 
which  is  volatile  below  the  boiling  point  of  water,  was  left  to 
stand  for  twenty -four  hours,  frequently  stirring  with  some  frag- 
ments of  caustic  alkali  broken  into  a  coarse  powder,  and  then 
rectified.  Immediately  this  purified  amylene  exhibited  a  large 
proportion  of  chlorine. 
The  investigation  of  the  commercial  article  had  shown  that  no 
pure  amylene,  but  only  a  volatile  mixture  containing  chlorine 
compounds,  had  hitherto  fallen  into  the  hands  of  medical  men  ; 
and  the  circumstance  that  even  in  amylene  prepared  with  so  much 
care  such  a  large  proportion  of  chlorine  is  discovered,  leads  to 
the  conclusion  that  in  the  method  recommended  by  Balard,  by 
distillation  of  amyl-alcohol  with  chloride  of  zinc,  no  pure  amylene 
can  be  obtained.  What  remains  upon  the  medicinal  application 
of  a  preparation  which  shows  itself  to  be  a  mixture  of  bodies 
difficult  to  separate  from  one  another,  and  the  purity  of  which 
cannot  be  tested,  requires  no  further  discussion  ;  and  as  long  as 
no  method  is  discovered  for  the  preparation  of  actually  pure 
amylene,  and  as  long  as  no  actual  amylene  is  employed  for 
experiments,  all  further  trials  with  this  body  must  be  wanting  in 
the  most  necessary  foundation  of  a  scientific  experiment — namely, 
sound  logic. — British  and  Foreign  Med.  Chir.  Review,  Jan. 
1858,  from  Woch.  der  GeselL,  der  Arezt  zu  Wien,  June  22nd, 
1587. 
