522  JOURNAL  OR  HORTICULTURE  AND  COTTAGE  GARDENER.  December  2,  i89?.- 
CHEMISTRY  IN  THE  GARDEN. 
{Continued  from  page  212.) 
We  find  it  necessary  to  leave  somewhat  abruptly  our  consideration 
of  soils,  because  we  think  it  of  little  practical  value  to  give  attention 
to  the  absorptive  power  they  have  for  certain  compounds,  unless  it  can. 
he  shown  that  these  substances  are  of  value  to  crops.  We  shall  now 
])roceed  to  describe  (1)  of  what  substances  plants  consist,  (2)  from 
v\’here  they  are  obtained,  and  (3)  how  they  may  be  applied  ;  and  then 
we  hope  to  be  in  a  position  to  point  out  the  value  of  soil  absorption 
when  certain  manures  are  applied  to  the  soil. 
The  Food  oe  Crops. 
D^hen  we  try  to  fathom  the  mysteries  of  plant  life  and  what 
substances  constitute  their  food,  we  soon  find  out  how  little  we  know 
concerning  this  subject ;  but  we  also  ascertain  how  simple  is  the  food 
of  plants,  and  what  a  few  ingredients  are  needed  to  nourish  them. 
True  it  is  that  manure  merchants  ofEer  us  many  dozens  of  different 
compounds  which  may  be  applied  to  the  soil  for  the  purpose  of 
supplying  crops  with  food  ;  but  we  shall  find  that  although  the  array 
of  manures  is  great,  the  ingredients  they  supply  to  plants  are  few. 
In  our  first  article  on  chemistry  in  the  garden  we  state)^  that 
ten  elements  or  simple  substances  were  present  in  all  plants.  How¬ 
ever,  to  refresh  our  readers’  memory,  we  may  be  allowed  to  again  give 
the  names  of  these  elements,  which  are  as  follows: — Hydrogen, 
oxygen,  carbon,  nitrogen,  phosphorus,  sulphur,  potash,  lime,  magnesia, 
and  iron.  Soda,  chlorine,  and  many  other  elements  are  also  present  in 
most  plants,  but  we  may  look  upon  the  first  ten  as  being  those  of 
vital  importance  to  crops. 
Hydrogen  and  oxygen,  as  previously  described,  are  two  gases,  but 
when  they  are  chemically  united  they  form  the  substance  wo  know 
as  water.  Water,  therefore,  is  composed  of  the  two  gases  just  named, 
and  no  other  two  substances  in  the  world  could  form  this  liquid.  The 
greater  part  of  all  plants  is  water.  We  all  know  that  if  the  soil  in 
which  plants  are  growing  is  allowed  to  get  dry  they  wilt  or  flag. 
Plants  take  up  the  water  from  the  soil  by  means  of  their  roots,  and 
after  j^assing  through  the  stems  into  the  leaves  most  of  it  is  given  off 
into  the  atmosphere  in  the  form  of  invisible  vapour.  If  there  be  not 
a  sufficient  supply  of  water  within  the  reach  of  the  roots  the  plants 
wilt  or  flag  because  more  moisture  is  evaporated  or  transpired  from 
the  leaves  than  is  absorbed  by  the  roots.  Put  a  bladder  on  the  water 
tap  and  turn  on  the  water.  The  bladder  fills  and  becomes  stiff  or 
turgid.  Allow  the  water  to  run  out  and  the  bladder  becomes  soft  or 
flaccid.  A  plant  is  built  up  of  millions’of  tiny  bags  or  bladders  called 
cells.  When  the  roots  have  plenty  of  water  at  their  command  these 
cells  are  filled  with  water  and  keep  the  plant  turgid;  but  if,  on  the 
other  hand,  they  cannot  get  sufficient  moisture,  the  cells  are  not  filled, 
consequently  they  are  flaccid,  and  the  whole  plant  flags.  Water  also 
enters  into  the  composition  of  the  plants  and  performs  other  work 
which  will  be  considered  in  due  time ;  but  from  these  few  facts  we  see 
that  water  is  a  part  of  plants. 
If  we  set  fire  to  a  heap  of  wood,  and  when  it  is  burning  cover  it 
with  soil,  the  wood  will  char  or  only  partly  burn,  and  a  black 
substance  known  as  charcoal  will  be  formed.  Now  charcoal  is  a  good 
example  of  the  substance  w'e  call  carbon.  But  supposing,  instead  of 
covering  the  burning  wood  with  soil,  we  had  allowed  it  to  burn.  All 
the  charcoal  or  carbon  w'ould  have  disappeared,  and  only  a  small 
quantity  of  a  greyish  ash,  called  wood  ashes,  would  have  remained.  If 
we  burn  leaves,  roots,  or  any  part  of  plants,  we  always  get  a  certain 
amount  of  ash  from  them,  showung  that  the  ash,  of  whatever  it ' 
consists,  is  present  in  all  kinds  of  vegetation. 
Take  equal  weights  of  dried  wood  and  dried  soil,  and  try  to  set  fire 
to  them.  The  wood  will  burn  freely,  but  the  soil — unless  it  be  of  a 
peaty  nature — will  not  do  so.  The  wood  is  composed  chiefly  of  carbon, 
and  this  substance  will  burn  readily ;  but  the  soil  contains  scarcely 
any,  consequently  will  not  burn.  Try  to  set  fire  to  a  heap  of  wood 
ashes,  and  you  will  find  that  these  will  not  burn  any  better  than  soil. 
I  his  shows  us  that  wood  ashes  and  soil  are  similar  in  character,  inso¬ 
much  as  neither  of  them  will  burn,  and  as  we  proceed  we  hope  to  be 
able  to  show  that  the  part  of  plants  which  burns  is  the  portion  they 
have  derived  from  the  atniosimere,  while  the  ash  which  remains  and 
cannot  be  burnt  is  the  part  which  has  been  obtained  from  the  soil. 
I  suppose  every  reader  of  the  Journal  of  Horticulture  knows  what 
valuable  substances  wood  ashes  are  to  apply  to  every  kind  of  crop,  it 
matters  not  whether  they  be  grown  in  the  garden  or  greenhouse. 
They  contain  the  very  essence  of  plant  food,  as  the  following  experi¬ 
ments  will  show : — A  well-known  agricultural  chemist  (Boussingault) 
carried  out  a  series  of  experiments  with  plants  growing  in  sand.  He 
filled  four  pots — two  with  pure  sand,  and  two  with  pure  sand  in  which 
he  mixed  a  small  quantity  of  plants’  ashes.  In  each  pot  he  placed 
two  Sunflower  seeds,  and  these  were  watered  with  pure  water  until 
they  had  germinated  and  began  to  grow.  After  they  had  grown  for  a 
short  time,  one  of  the  pots  containing  the  pure  sand  and  one  containing 
the  pure  sand  and  plants’  ashes  he  watered  with  pure  water ;  the 
other  two  were  always  watered  with  pure  water,  in  which  was 
dissolved  a  small  quantity  of  nitrate  of  potash. 
The  seedlings  in  the  pure  sand  and  plants’  ashes,  which  were 
watered  with  pure  V'ater,  absolutel}^  refused  to  grow  more  than  about 
1  inch  in  height.  The  seedlings  in  the  pure  sand,  which  were 
watered  with  the  weak  solution  of  nitrate  of  potash,  did  not  grow 
any  better  than  the  two  last  named ;  but  those  seedlings  growing  in 
pure  sand  and  plants’  ashes,  and  watered  with  the  weak  solution  of 
nitrate  of  potash,  grew  into  perfect  plants,  which  produced  normal 
flowers  and  seeds.  Indeed,  these  plants  were  quite  as  large  as  if  they 
had  been  grown  in  fertile  soil  instead  of  sand.  What  do  these 
simple  experiments  teach  us  ?  Firstly,  that  plants  cannot  grow 
unless  they  have  a  supply  of  food  given  them ;  secondly,  that  sand, 
water,  and  plants’  ashes  do  not  contain  all  the  elements  of  food  unless 
nitrate  of  potash  be  added ;  and  thirdly,  that  plants’  ashes  and  nitrate 
of  potash  contain  all  the  elements  necessary  to  produce  fully 
developed  plants. — W.  Dyke. 
(To  be  continued) 
INTELLiaENCE  IN  PLANTS. 
{Concluded  from  page  498.  J 
In  the  Arctic  regions  it  is  too  cold  for  seeds  to  germinate  witli 
any  prospect  of  future  success,  and  the  plants  are  quite  alive  to  the 
fact,  and,  as  a  rule,  develop  none.  Instead  of  seeds  they  send  out 
suckers,  or  the  stems  run  along  or  under  the  ground  and  take  root. 
In  some  cases  trailing  roots  are  dropped  from  the  plant.  Wheat  taken 
there  but  educated  here  to  depend  on  the  autumn  sun,  retains  its 
vitality  for  years,  but  has  no  opportunity  of  goingt through  its  usual 
curriculum  and  fails;  but  I  fancy  if  a  few  bushels  woe  carefully 
distributed,  it  is  likely  enough  some  of  it  would  discover  a  modus 
vivendi,  and  adapt  itself  and  probably  get  rechristened  as  a  new  plant. 
Now  let  us  go  a  little  farther.  Perhaps  some  of  us  may  by  this 
time  have  conceded  the  question  of  intelligence,  and  think  that  by 
doing  so  all  difficulties  are  at  an  end ;  l)ut  they  are  not.  They  are 
rather  beginning  again.  By  conceding  intelligence  to  plants  and  to 
their  visitors,  the  insects,  also,  we  land  ourselves  not  exactly  in  clear 
daylight,  but  in  denser  fog  than  ever.  If  we  say  a  bee  has  senses  of 
sight,  hearing,  touch,  and  smell,  also  a  memory,  and  profits  by  its 
experience,  we  go  a  long  way ;  but  it  is  not  far  enougli,  as  you  will 
see  by  noting  what  takes  place  in  the  fertilisation  of  the  Yucca  plant. 
The  flowers  each  open  for  one  night  only.  You  need  not  ask  me  why, 
for  I  don’t  know;  but  when  the  flowers  open  a  guest  enters.  The 
moth,  Yuccaselia,  collects  the  pollen,  packs  it  into  a  bag,  and  flics  off 
to  another  flower,  clearly  knowing  where  the,  as  yet,  undeveloped  seed¬ 
lings  are,  and  inserts  her  ovipositor — a  hollow  tube  with  horny 
apparatrrs  attached,  and  down  this  tube  drops  her  eggs  amongst  the 
future  seeds.  This  would  be  no  use  if  she  did  not  afterwards  proceed 
to  the  stigma  of  the  same  flower  and  empty  her  bagful  of  pollen 
there ;  but  she  never  forgets,  for  it  is  her  life  mission.  Without  all 
this  these  seedlings  could  never  be  fertilised,  and  her  own  grubs, 
wffiich  hatch  out  in  a  few  days,  would  die  for  want  of  food.  But  note, 
wffien  these  grubs  hatch  they  devour  the  future  seedlings  ;  but  not  all 
of  them.  Somebody  or  something  know's  that  would  not  do,  and 
some  fertilised  seedlings  must  be  left  to  continue  the  race  of  the  plant, 
and  they  always  are.  Where  and  whence  has  she  learnt  her  life 
duties  ? 
Clearly  we  are  not  within  sight  of  the  ultimate  facts  and  facto:  s  of 
life.  There  are  deeper  and  yet  deeper  depths  for  human  intellect  to 
fathom,  and  to  learn  yet  more  to  wonder  at  and  to  adore  the  great  and 
unknown  Core  of  things,  for  we  shall  have  to  credit  the  cells  of  which 
all  animal  and  plant  life  are  composed  with  that  wondrous  intelligence, 
and  look  on  man,  animal,  and  plant,  not  as  an  individual,  but  as  a 
co-operative  society,  each  one  of  which  is  an  individual  endowed  with 
all  potentiality  for  progress. 
What  is  a  flower  ?  By  what  conglomeration  of  incidental 
happenings  has  it  been  formed  ?  What,  or  who  planned  out  these 
multitudinous  modifications  ?  It  is  only  a  modified  leaf,  specialised 
for  the  production,  protection,  and  distribution  of  seeds,  but  specialised 
with  wondrous  ingenuity,  such  self-evident  forethought  and  intelli¬ 
gence,  such  cute  and  cunning  adaptation  of  means  to  their  ends. 
An  Orchid,  weird  and  bizarre  as  it  may  be,  is  just  three  sepals,  two 
petals;  three  pistils  and  four  stamens  make  the  column;  the  lip  is  a 
petal  and  two  petal-like  stamens.  The  nectary  is  several  modified 
stamens.  Of  the  seven  organs  which  form  the  column,  four  have 
given  up  their  proper  functions  ;  one  anther  and  two  stigmas  do  their 
usual  business,  and  the  others  just  help  them ;  three  anthers  no  longer 
producing  pollen,  but  protecting  the  one  that  does.  What  wondrous 
change  of  function  !  what  a  curious  abnegation  of  self  in  all  this  !  and 
by  what  law,  what  force,  and  by  what  intelligence  ?  One  apart  and 
outside  the  plant,  or  an  intelligence  in  the  plant? — {Bead  hy  Mr. 
W.  Pickard  at  a  meeting  of  the  Sheffield  Chrysanthemum  Society.) 
