AMe7iffi72M'}        Abietene  a  new  Hydrocarbon.  99 
remarkably  low  sp.  grav.  of  abietene,  which  is  only  0-694  at  16-5°  C.  ; 
that  of  terebene  being  0*840,  at  about  the  same  temperature;  again 
the  boiling  point  of  abietene  is  101°  C.  while  oil  of  turpentine  boils 
at  160°  C.  Terebene  absorbs  hydrochloric  acid  with  avidity,  form- 
ing hydrochlorate,  while  abietene  resists  the  prolonged  action  of  this 
gas  at  ordinary  temperatures.  Nitric  acid  acts  violently  upon  tere- 
bene, while,  on  the  other  hand,  with  abietene  no  action  was  instituted, 
and  it  was  only  by  the  application  of  heat  that  a  quiet  evolution  of 
nitrous  gas  was  observed.  The  action  of  chlorine  upon  abietene  seems 
to  furnish  a  true  substitution  product,  the  hydrogen  of  the  hydro-car- 
bon being  largely  replaced  by  chlorine,  sufficient  to  raise  the  spec, 
grav.  of  the  liquid  from  0  694  to  1*666.  When  this  substitution  com- 
pound was  subjected  to  distillation,  at  a  temperature  of  256-260°  C, 
hydro-chloric  acid  was  given  off  abundantly,  with  subsequent  blacken- 
ing and  the  disengagement  of  pyrogenous  products,  leaving,  finally,  a 
carbonaceous  residue. 
Abietene  is  a  powerful  solvent  for  the  fixed  and  volatile  oils,  with 
the  exception  of  castor  oil,  which  is  absolutely  insoluble  in  abietene  ; 
while,  on  the  other  hand,  castor  oil  is  capable  of  dissolving  nearly 
two-thirds  of  its  volume  of  the  hydro-carbon. 
Abietene  dissolves  balsam  of  capaiba  freely  and  in  all  proportions. 
Canada  balsam  is  dissolved  in  all  proportions  up  to  two  parts  of  abietene, 
an  excess  of  the  latter  precipitating  the  resinous  principle  of  the  bal- 
sam entirely  as  a  white  flocculent  precipitate,  the  volatile  oil  being  re- 
tained in  solution.  Balsam  of  Peru  requires  about  one-fifth  of  its  volume 
of  abietene  to  form  a  clear  solution,  but  if  a  quantity  greater  than  this 
is  added  a  turbid  mixture  will  result,  which,  on  repose,  will  allow  the 
excess  of  abietene  to  rise  to  the  surface.  It  will  be  seen  at  a  glance, 
from  these  data,  that,  although  abietene  possesses  the  properties  of  a 
general  solvent  for  fixed  and  volatile  oils  in  every  proportion,  it  yet 
is  incapable  of  dissolving  castor  oil,  balsam  of  Peru,  and  Canada  bal- 
sam, which  in  their  turn  exert  a  solvent  action  upon  abietene. 
When  abietene  is  burned  in  an  alcohol  lamp,  with  flame  not  too 
large,  a  brilliant  white  light  is  obtained,  without  smoking.  Its  vapor 
is  powerfully  anaesthetic  when  inhaled,  and  it  has  been  used  with  suc- 
cess as  an  insecticide  against  moths,  &c,  when  sprinkled  in  closed  re- 
ceptacles. Castor  oil  mixed  purposely  with  other  fixed  oils,  and  the 
mixture  then  shaken  with  four  times  its  volume  of  abietene,  the  castor 
oil  will  be  found  to  separate  and  collect  at  the  bottom  of  the  mixture, 
