January  22,  1903. 
JOUBNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
73 
Frost,  Snow,  and  Rain. 
All  vegetable  and  animal,life  is  derived  from  the  soil  and 
atmosphere.  Vegetable  and  animal  products  contain  no 
chemical  elements  which  cannot  also  be  found  either  in  the 
earth  or  in  the  air. 
To  the  soil  alone  special  attention  is  given  by  the  culti¬ 
vator  of  forest,  farm  and  garden  crops.  It  exists  all  over 
the  surface  of  the  earth,  nowhere  of  great  depth,  and  in 
some  places  very  shallow,  or  even  bare  uncultivatable  rock, 
though  seldom  devoid  of  the  lower  forms  of  vegetation  ; 
and  this  surface  is  usually  termed  mould.  Underneath  the 
surfacing  mould  or  true  soil,  something  that  differs  from  it 
is  reached,  and  is  termed  the  subsoil.  If  this  subsoil  be 
laid  bare  and  exposed  to  the  air  it  gradually  changes  on  the 
surface  into  mould  ;  therefore,  the  soil  may  be  regarded  as 
derived  from  the  subsoil,  and  the  chief  agents  in  effecting 
the  change  are  air,  moisture,  and  temperature,  aided  by 
plants  and  animals. 
There  are,  of  course,  different  kinds  of  soils,  visible  to 
the  eye,  felt  when  walked  upon  or  handled,  and  declared  in 
differences  by  the  plants  naturally  growing  upon  them. 
Black  soils  are  seen  on  moors,  in  fens,  in  many  fields,  and 
in  most  kitchen  and  market  gardens.  Yellowish  soils 
obtain  in  Northamptonshire,  greyish  soils  in  parts  of  the 
Thames  Valley  and  in  Kent,  bluish  soils  in  Gloucestershire, 
and  red  soils  in  Somerset  and  Herefordshire.  Some  soils 
are  loose,  ranging  from  fine  to  coarse  sandy,  gravelly  or 
stony.  Other  soils  are  close,  and  allow  water  to  rest  upon 
their  surface. 
Loose  open  soils  shift  beneath  the  feet,  do  not  adhere 
to  boots,  and  are  usually  dry.  Stiff,  tenacious  soils  retain 
the  imprint  of  the  foot,  are  very  adhesive,  particularly 
when  wet.  A  dry  loose  soil  runs  between  the  fingers  when 
a  handful  is  taken  up,  and  even  moist  do  not  cohere  when 
compressed  in  the  hand.  Tenacious  soils  retain  their  form 
when  handled,  and  when  moist  can  be  moulded  into  most 
forms.  A  sandy  soil  is  felt  to  be  sharp,  coarse,  and  gritty 
when  rubbed  between  the  thumb  and  finger.  A  clayey  soil 
has  the  particles  so  fine  and  unctuous  as  to  feel  soapy  or 
greasy  when  portions  are  rubbed  by  the  hands. 
Heather  and  Bracken  affect  poor  sands,  and  with  other 
vegetation  surface  them  with  vegetable  mould  in  due  course 
of  nature,  thus  fitting  heaths  and  moors  for  the  growth  of 
Fir  trees  and  Larches.  Bushes,  Sedges,  Cotton-grass,  and 
Sundew  grow  in  wet  and  marshy  places  ;  mosses,  and  other 
aquatic  or  semi-aquatic  vegetation,  yield  bog-earth  by 
Cyclamen  grown  at  the  Manor  House,  Kineton 
decay  and  accumulation.  Beech,  Yew,  and  Box  affect 
soils  derived  from  chalk  and  limestone.  Cowslips  and  Oak 
trees  are  seen  specially  thriving  upon  clay  soils. 
Soils  contain  chemical  elements  other  than  those  known 
as  mineral.  Foremost  is  water,  of  which  dry  soil  contains 
less  than  moist,  and  this  less  than  wet,  easily  ascertained 
by  experiments  in  drying  or  in  wetting,  in  various  degrees. 
Quite  as  important  is  the  organic  matter  of  the  soil  termed 
hutnus,  which  is  formed  of  the  decaying  remains  of  plants 
and  animals.  It  obtains  in  greater  joercentage  in  a  well- 
manured  garden  or  clayey  soil  than  in  a  light  sandv  or  lime¬ 
stone  with  a  similar  amount  of  manure. 
If  mould  that  has  been  made  red-hot — the  water  driven 
off  as  vapour  and  the  organic  matter  converted  into  gases— 
be  mixed  w’ith  clean  rain  water  when  cooled  and  allowed  co 
stand  for  twenty-four  hours,  and  the  clear  water  poured  olf 
into  a  saucer,  which  is  then  placed  in  an  oven  ;  a  deposit  will 
be  left  in  the  saucer  after  ilie  water  has  been  evaporated 
into  the  air,  showing  that  water  is  capable  of  dissolving- 
something  which  the  practically  sterile  soil  contains,  ami 
also  that  the  sediment  left  in  the  bottle  after  the  clear  -w’ater 
has  been  drawn  olf  is  matter  the  -water  cannot  dissolve.  The 
part  that  disappears  in  the  water  from  the  bulk  is  called 
the  soluble  part,  -whilst  that  which  has  not  been  dissolved 
is  termed  the  insoluble  part.  These  distinctions  are  impor¬ 
tant,  for  plants  make  use  of  the  soluble  parts  of  the  soil,, 
imbibing  them  along  -with  -water  by  means  of  their  roots. 
This  water,  in  the  case  of  soils,  trickles  through  and  flows- 
away  in  the  drainage  water,  bearing  in  solution  some  of 
the  soluble  matter. 
As  foreshown,  the  soils  of  the  British  Islands  vary  in  , 
colour,  in  texture,  and  in  the  plants  they  naturally  produce  ; 
also  that  they  contain  variable  proportions  of  moisture,  and 
that  whilst  a  part  of  a  given  soil  is  soluble  in  water,  a  very 
much  larger  proportion  of  it  is  insoluble  ;  in  other  words, 
the  soil  contains  some  elements  in  an  available  form  as 
food,  and  other  elements,  or  portions  of  the  same  elements, 
“  locked  up  ”  as  regards  immediate  use.  The  soil  in  Nature 
and  in  fields  and  gardens  is  in  such  condition,  and  repre¬ 
sents  the  final  product  of  a  series  of  changes  inducted  by 
Nature,  and  aided,  as  regards  cultivation,  by  the  art  of  man. 
Though  the  study  of  soil  derivation  belongs  to  the  science 
of  geology,  it  is  vain  to  detach  Nature  from  cultural  art, 
for  the  agents  of  disintegration  are  quite  as  actively  engaged 
in  the  soils  which  it  is  the  business  of  the  farmer  and 
gardener  to  cultivate  as  in  promoting  the  decay  of  the 
rocks  from  -which  the  various  soils  have  been  derived. 
Of  the  agents  of  disintegration  water  acts  physically 
and  chemically.  Its  physical  effect  is  seen  on 
rocks  permeated  by  -water  and  then  frozen,  inas¬ 
much  as  it  expands  about  one-fourth,  and  the 
force  of  this  increase  in  volume  is  practically 
irresistible,  the  rock  being  rent,  particles  broken 
off,  and  more  or  less  crumbled  into  dust.  On 
soils  that  are  left  rough  and  bare  through  the 
winter  the  effects  of  the  alternate  freezing  anti 
thawing  of  the  soil  moisture  are  -well  defined. 
The  water,  in  freezing,  expands,  pushes  apart  the 
constituent  particles  of  the  soil,  and  the  usugl 
effect  is  the  crumbling  into  that  state  known  as 
mellow\  Chalk  placed  on  land  in  autumn  is 
crumbled  down  by  spring,  a  result  largely  due  to 
the  disruptive  effects  of  frost.  Similar  remarks 
apply  to  marl.  Water  also  denudes— lays  bare— 
the  surface  along  which  it  flows,  and  it  carries 
aw’ay  and  deposits  else-where  the  material  -which 
is  removed  from  rocks.  Thus  alluvial  soils  ai-e 
formed  bordering  the  estuaries  of  rivers  ;  valle.vs 
deeper  in  fertile  soil  than  mountains,  and  even 
hollows  in  fields  and  gardens  possess  greater 
depth  of  mould  than  hillocks. 
The  chemical  action  of  water  upon  rocky 
matter  is  mainly  dependent  on  the  solvent  power 
derived  from  the  atmosphere,  for  rain  in  falling 
to  the  earth  dissolves  some  of  the  carbonic  acid 
gas  (carbon  dioxide)  of  the  air,  and  water  thus 
charged  with  carbonic  acid  is  capable  of  dis 
solving  certain  substances  which  are  insoluble  m 
pure  water,  the  most  important  of  which  is 
bonate  of  lime.  Silica  or  sand  is  slightly  soluble 
in  pure  water,  and  more  so  in  water  containing 
carbonic  acid,  though  not  very  soluble  in  either, 
and  various  crystalline  substances  found  n 
