HISTORY  OF  PETROLEUM  OR  ROCK  OIL. 
537 
nates ;  as,  however,  this  rock  underlies  more  than  one-half  of 
the  Western  Peninsula,  we  may  look  for  the  petroleum  springs 
much  further  east  than  Enniskillen.  A  well  yielding  consider- 
able quantities  of  petroleum  is  said  to  occur  in  the  township  of 
Dereham,  about  a  quarter  of  a  mile  southwest  of  Tilsonburg, 
and  we  may  reasonably  expect  to  find  others  along  the 
line  of  the  anticlinal,  or  of  the  folds  which  are  subordinate 
to  it. 
It  is  now  many  years  since  Sir  William  Logan  described  the 
occurrence  of  petroleum  springs  in  Gaspe,  and  collected  speci- 
mens of  the  oil,  which  are  preserved  in  the  Geological  Museum. 
One  of  these,  near  Gaspe'  Bay,  is  described  as  occurring  on  the 
south  side  of  the  St.  John's  River,  about  a  mile  and  a-half  above 
Douglas  Town,  where  it  may  be  collected  by  digging  pits  in  the 
mud  on  the  beach.  Another  locality  is  about  200  yards  up  a 
small  fork  of  the  Silver  Brook,  which  falls  into  the  south-west 
arm  six  or  seven  miles  above  Gaspe*  Basin.  The  oil  collects  in 
pools  along  the  stream,  and  may  be  gathered  in  considerable 
quantities.  The  cavities  in  a  greenstone  dyke  on  Gaspe'  Bay 
were  also  found  to  be  filled  with  petroleum,  and  the  odor  of  it 
from  the  rock  was  perceived  at  a  considerable  distance.  The 
dyke,  which  marks  a  fold  in  the  stratification,  runs  in  the  di- 
rection of  the  petroleum  springs,  and  the  evidences  of  the  dis- 
tribution of  petroleum  are  thus,  as  Sir  William  Logan  has  re- 
marked, visible  along  a  line  of  twenty  miles  (Report  for  1844, 
p.  41.)  Attention  has  recently  been  drawn  to  these  indications, 
and  a  company  formed  with  a  view  of  exploring  this  region  for 
petroleum.  Here,  as  well  as  in  Western  Canada  and  the  United 
States,  the  connection  is  evident  between  the  springs  and  un- 
dulations of  the  strata  which  favor  the  accumulation  of  the  pe- 
troleum. 
We  have  stated  in  the  preceding  paper  that  the  different 
mineral  combustibles  have  been  derived  from  the  transforma- 
tions of  vegetable  matters,-  or  in  some  cases  of  animal  tissues 
analogous  to  these  in  composition.  The  composition  of  woody 
fibre  or  cellulose,  in  its  purest  state,  may  be  represented  by  C24 
H20O20,  or  as  a  compound  of  the  elements  of  water  with  carbon  ; 
the  incrusting  matter  of  vegetable  cells,  to  which  the  name  of 
lignin  has  been  given,  contains,  however,  a  less  proportion  of 
