PRODUCTION  OF  CORK. 
541 
the  final  result  of  the  third  process  of  decomposition  of  woody 
fibre,  in  which  the  air  being  excluded  the  oxygen  is  shared  be- 
tween the  carbon  and  hydrogen,  would  be  C29H8.  A  similar 
result  would  be  obtained  with  the  simultaneous  evolution  of 
marsh-gas,  if  we  suppose  6  C02  +  8HO+3CH2  to  be  removed 
from  an  equivalent  of  woody  fibre,  leaving  C15H6=  C20H8= 
C^Hg.g,  which  approaches  the  composition  of  most  bituminous 
coals  and  of  idrialine.  A  further  elimination  of  marsh-gas 
would  leave  a  residue  of  pure  carbon,  and  thus,  as  Bischof  has 
suggested,  vegetable  matters  may  be  converted  into  anthracite 
without  the  intervention  of  a  high  temperature. 
The  elimination  of  the  whole  of  the  oxygen  in  the  form  of 
carbonic  acid  would  leave  a  compound  with  a  large  excess  of 
hydrogen,  of  which  it  would  be  necessary  to  remove  a  portion 
i  n  the  form  of  water  or  marsh-gas,  in  order  to  reduce  the  resi- 
due to  the  composition  of  petroleum.  We  know  of  no  combina- 
tion of  carbon  and  hydrogen  in  which  the  number  of  atoms  of 
hydrogen  surpasses  by  more  than  two,  those  of  hydrogen,  the 
general  formula  being  CnHn-j-2,  so  that  oils  like  C18H20  and 
C26H28  contain  nearly  the  maximum  quantity  of  hydrogen,  and 
a  body  like  C14H20,  whose  formation  we  have  supposed  above, 
could  not  exist,  but  must  break  up  into  marsh-gas  and  some  less 
hydrogenous  oil  like  petroleum. 
We  do  not  know  the  precise  conditions  which  in  certain  strata 
favor  the  production  of  petroleum  rather  than  of  lignite  or  coal; 
but  in  the  fermentation  of  sugar,  to  which  we  may  compare 
the  transformations  of  woody  fibre,  we  find  that  under  different 
conditions  it  may  yield  either  alcohol  and  carbonic  acid,  or 
butyric  and  carbonic  acids  with  hydrogen,  and  even  in  certain 
modified  fermentations  the  acetic,  lactic,  and  propionic  acids, 
and  the  higher  alcohols,  like  O10H12O2.  These  analogies  fur- 
nish suggestions  which  may  lead  to  a  satisfactory  explanation 
of  the  peculiar  transformation  by  which,  in  certain  sedimentary 
strata,  organic  matters  have  been  converted  into  bitumen. — 
Qhem.  News,  July  5th,  12th  andldth, from  the CanadianNaturalist. 
PRODUCTION  OF  CORK. 
In  the  "  Me'moires  de  la  Socie*te*  de  Physique  "  of  Geneva,  is 
an  interesting  paper  by  M.  Gasimir  de  Candolle  on  the  growth 
