518 
ON  PINOLINE  AND  OLEONE. 
high  price  of  true  oil  of  turpentine  caused  the  purified  essence, 
which  was  cheaper,  to  find  a  good  market,  and  this  would  have 
been  all  very  well,  if  this  substance  had  been  capable  of  the  same 
applications  as  oil  of  turpentine.  In  general  turpentine  is  employed 
in  the  preparation  of  varnish  to  dissolve  the  different  resins,  it  also 
serves  to  thin  oil  colors,  and  cause  them  to  dry  rapidly.  When  oil 
of  turpentine  is  exposed  to  the  air,  a  portion  of  it  will  evaporate, 
whilst  another  portion  will  combine  with  the  oxygen  of  the  atmos- 
phere, that  is,  become  resinified,  and  consequently  leave  a  varnish- 
like coat.  Consequently  when  oil  colors  are  diluted  with  oil  of 
turpentine,  no  dulness  or  dryness  of  the  colors  will  be  produced 
thereby,  unless  the  dilution  has  been  carried  too  far. 
If  the  behaviour  of  this  essence  be  compared  with  that  of  oil  of 
turpentine,  the  distinction  is  most  striking.  This  essential  oil  is  in- 
deed subject  to  a  resinification,  but  in  a  very  small  degree  ;  conse- 
quently when  this  oil  is  employed  as  a  substitute  for  oil  of  turpen- 
tine in  diluting  oil  colors,  less  resin  remains  after  desiccation,  and 
the  coating  appears  less  shining  and  adhesive.  This  property  of  the 
essential  oil  of  resin  deprived  it  of  its  credit,  and  it  became  neces- 
sary to  find  another  application  for  this  subsidiary  product,  which 
is  obtained  in  considerable  quantities.  From  the  author's  investi- 
gation, the  composition  of  the  oil  is  nearly  the  same  as  that  of  oil 
of  turpentine  :  and  it  was  to  be  anticipated  that,  like  the  latter,  it 
might  be  used  for  illuminating  purposes.  The  "  essence,"  which 
almost  always  has  an  acid  reaction,  was  treated  with  solution  of 
caustic  alkali,  and  then  blown  off  by  steam. 
The  product  thus  obtained  was  limpid,  and  had  an  agreeable 
thyme-like  odor,  from  which  probably  has  originated  the  idea  enter- 
tained by  the  public  that  this  oil  is  turpentine  to  which  oil  of  thyme 
has  been  added  in  order  to  disguise  the  odor.  The  author  called 
this  oil  pinoline,  and  under  this  name  it  was  first  brought  into  com- 
merce as  a  fuel  for  lamps,  in  1856,  by  Brambach  &  Co.,  the  posses- 
sors of  a  factory  for  the  distillation  of  resin  at  Berge-Borbeck.  It 
is  burnt  in  lamps  of  peculiar  construction,  and  gives  a  light  similar 
to  that  of  camphine.  Pinoline,  as  already  stated,  is  subject  to  re- 
sin ization,  by  which  it  loses  in  value,  inasmuch  as  the  wick  be- 
comes impregnated  with  the  resin  formed,  when  the  absorbing  power 
is  diminished,  and  the  lamp  will  smoke.    These  disadvantages  ren- 
