ANALYSIS  OP  PENNSYLVANIA  PETROLEUM. 
453 
The  results  of  the  distillation  were  very  different  from  what  I 
anticipated,  and  was  led  to  believe  they  would  be,  from  a  table 
experiment,  the  fractions  of  which  were  too  small  to  conve- 
niently take.  The  specific  gravity,  and  the  appearance  of  paraffin 
towards  the  latter  part  of  the  experiment,  caused  me  to  suppose 
that,  from  the  low  gravity  of  the  petroleum,  and  obtaining 
paraffin  in  the  distillate,  it  was  a  mixture  of  very  light  and 
heavy  fluid  hydrocarbon  only. 
In  the  manufacture  of  illuminating  oil  from  coal,  it  is  that 
portion  of  the  product  between  the  specific  gravity  of  -775  to 
•840  only,  that  makes  in  every  respect  a  burning  fluid  ;  and  in 
the  examination  of  this  petroleum,  it  was  my  intention  to  have 
taken  the  same  range  of  gravities  to  test  both  the  quantity  it 
yielded  of  such,  and  to  test  them  as  regards  the  illuminating 
value  compared  with  that  of  coal  oil.  It  will  be  seen  from  the 
table  of  gravities  above,  that  there  was  none  obtained  higher  than 
•825,  at  which  point  paraffin  made  its  appearance  ;  at  that  I 
concluded  it  would  be  best  not  to  carry  the  quantity  intended 
for  burning  fluid  any  further,  and  consequently  was  disappointed 
in  obtaining  a  fluid  having  the  same  range  of  gravities  as  that 
of  coal  oil,  with  which  I  intended  to  test  its  illuminating  value. 
That  portion  of  oil  that  came  over  after  the  above,  upon 
remaining  out  doors  over  night,  was  found  to  be  in  the  morning 
full  of  crystals  of  paraffin.  The  quantity,  however,  is  not  so 
large  as  that  present  in  coal  oil  of  higher  gravity.  A  slight 
elevation  of  temperature  caused  their  rapid  solution  in  the  ac- 
companying oil ;  and  an  attempt  at  the  separation,  at  present, 
I  found  difficult,  and  shall,  at  some  future  time,  separate  them. 
The  paraffin  from  this  petroleum,  I  am  satisfied,  is  a  very  differ- 
ent body  to  that  obtained  from  coal,  both  in  its  chemical  com- 
position and  physical  properties.  Its  low  boiling  point,  and  ap- 
parent low  specific  gravity  indicate  it. 
The  distillation  commenced  with  a  fluid  of  very  low  gravity 
and  exceedingly  volatile,  and  almost  colorless.  As  the  gravity 
increased,  it  became  gradually  colored,  and  the  last  fractions  of 
it  were  of  a  lemon  yellow  color.  The  odor  of  the  whole  pro- 
duct was  similar  to  that  of  the  original,  but  more  penetrating ; 
by  exposure  to  light,  the  oil  gradually  acquired  a  dark  color. 
That  portion  of  the  oil  included  within  the  brace,  in  the  column 
