468  RELATIONS  OF  THE  SOIL  TO  VEGETATION. 
ON  THE  EELATIONS  OF  THE  SOIL  TO  VEGETATION. 
By  M.  Boussingault. 
From  an  investigation  of  the  conditions  of  fertility  of  the  soil 
Boussingault  draws  the  following  conclusions  : — 
1.  That  in  an  extremely  fertile  soil  the  amount  of  nitrogen, 
although  derived  from  organic  matters,  and  in  part  still  com- 
bined in  them,  cannot  be  the  cause  of  fertility. 
2.  That  the  nitrates  and  ammoniacal  salts  are  the  only  com- 
pounds which  convey  assimilable  nitrogen  to  the  plant,  whether 
these  salts  pre-exist  in  the  soil,  or  are  only  formed  during  the 
progress  of  cultivation. 
3.  That  a  plant,  in  order  to  be  capable  of  its  normal  develop- 
ment, must  have  a  very  great  volume  of  earth  at  its  disposal, 
because  the  amounts  of  nitric  acid  and  ammonia,  which  are  con- 
tained in  a  given  volume  of  soil,  are  very  small. 
4.  TAat  tho  analysis  of  a  soil  as  to  its  amount  of  nitrogen  can- 
not serve  as  the  foundation  of  any  opinion  as  to  its  fertility,  be- 
cause it  gives  the  amounts  in  an  assimilable  form  together. 
5.  That  when  the  soil  is  lying  fallow,  a  considerable  quantity 
of  the  carbon  of  the  organic  matters  which  it  contains  is  lost,  but 
that  the  amount  of  nitrogen  does  not  diminish  but  increases. 
Whence  this  increase  arises,  whether  it  is  caused  by  nitrification, 
or  by  the  production  or  absorption  of  ammonia,  is  still  to  be 
ascertained. — Chem.  Graz.,  July  15th,  1859,  from  Comptes 
Rendus. 
CANOUIL'S    PROCESSES    FOR    MANUFACTURING  CHEMICAL 
MATCHES  WITHOUT  PHOSPHORUS  AND  CONTAINING  NO 
POISONOUS  SUBSTANCE. 
1.  Mass  without  Phosphorus  for  Sulphured  Matches. 
The  matches  without  phosphorus  manufactured  in  Paris  by 
Canouil,  are  ignited  by  rubbing  upon  any  hard  body,  whether  it 
be  rough  or  smooth  supposing  the  surface  against  which  they  are 
rubbed  to  present  a  certain  amount  of  resistance. 
Neither  a  blow,  nor  a  shock,  nor  a  temperature  of  356°  F.  are 
capable  of  igniting  these  matches ;  their  combustion  is  only  caused 
by  friction. 
