Jan.  2,  1893.] 
THE  TROPICAL  AGRICULTURIST. 
443 
cent  of  gravel,  nearly  pure  quartz,  and  '654  per 
cent  of  organic  matter  in  the  shape  of  roots,  seeds, 
Ac.  The  soil  was  of  a free  sandy  nature,  contain- 
ing a very  large  proportion  of  insoluble  siliceous 
matter.  By  a fusion  analysis,  the  80  parts  of  in- 
soluble siliceous  matter  were  found  to  contain  72 
parts  of  silica  leaving  only  about  S per  cent  of 
basic  substances  asthe  future  resources  of  the  soil. 
The  element  of  plant  food  on  which  this  soil 
appears  to  be  especially  deficient  is  phosphoric 
acid.  I therefore  took  special  pains  in  the  deter- 
mination of  this  ingredient.  I made  two  deter- 
minations of  the  phosphoric  acid  soluble  in  hydro- 
chloric acid  with  closely  concordant  results,  ob- 
taining only  ‘034  per  cent.  A third  determination 
of  the  phosphoric  acid,  in  which  the  solvent  used 
was  nitric  acid,  yielded  "045  per  cent.  This  defi- 
ciency of  phosphoric  acid  accounts  for  the  paddy 
not  yielding  seed,  as  this  ingredient  of  plant  food  is 
by  far  the  most  abundant  of  the  mineral  consti- 
tuents of  rice  grain,  and  even  in  the  husk  it  is 
present  in  greater  proportion  than  potash  or  lime, 
as  may  be  seen  from  a glance  at  the  following 
analyses : — 
A nalysis  of  Eice  Ash. 
Ash  of  Grain. 
* Average  of 
different  chemists. 
| Ash  of  Grain. 
(Muspratt. ) 
j Ash  of  Husk. 
| (Muspratt. ) 
Phosphoric  acid 
Potash  
Soda  
Lime  
Magnesia  
Oxide  of  iron  
Sulphuric  acid  
Chlorine 
Silica  
55-00 
23'70 
4-00 
3-15 
12-10 
trace 
•05 
trace 
2-00 
53  36 
18-48 
10- 67 
1-27 
11- 69 
•45 
•27 
3-35 
1-86 
1-60 
1-58 
1-01 
1-96 
■54 
•92 
89-71 
100.00 
99-54 
99-18 
On  the  other  hand  the  whole  amount  of  mineral 
matter  in  rice  grain  is  so  very  small,  viz.,  in 
dried  rice  -9  per  cent,  and  in  naked  rice  ‘3  per 
cent  compared  with  other  cereals,  e.g.,  wheat,  dif- 
ferent kinds,  from  1'7  to  3 -02  per  cent.,  oats  2 '4 
to  3 '8,  peas  2-4,  beans  3-1,  that  paddy  might  be 
expected  to  succeed  on  land  in  which  cereals  richer 
in  mineral  ingredients  would  starve.  This  is  just 
a case  in  which  the  analytical  chemist  would  be 
materially  assisted  by  a table  of  analyses  of 
soils  from  fertile  paddy  lands  to  which  he  could 
refer.  When  compared  with  good  paddy  soils  of 
other  countries  which  have  been  analysed,  the 
soil  of  the  Walaganwala  paddy  fields  must  be 
pronounced  very  deficient  in  phosphoric  acid. 
The  soil  also  contained  '836  per  cent  of  protoxide 
of  iron,  an  ingredient  generally  regarded  as  un- 
favorable to  plant  growth  ; but  the  amount  of 
this  ingredient  is  rather  less  than  the  average 
of  six  determinations  of  the  same  in  coffee  soils. 
The  portion  of  the  above  soil  not  required  for 
analysis  was  divided  into  four  equal  parts  of 
somewhat  less  than  2 lb.  each.  These  were  placed 
in  four  pots.  One  was  left  unmanured,  one  was 
manured  with  sufficient  bone  dust  to  add  '111  per- 
cent of  phosphoric  acid  to  the  soil,  so  that  it 
* From  Johnston  and  Cameron’s  “Agricultural 
Chemistry.” 
now  had  as  much  phosphoric  acid  as  a good 
coffee  soil.  To  the  third  pot  of  earth  sufficient 
slaked  lime  was  added  to  increase  the  lime 
by  -260  per  cent.  The  fourth  pot  was  manured 
with  a little  dry  cow  dung.  Four  seeds  of  paddy 
were  planted  in  eacli  pot  on  the  19th  of  January. 
The  pots  were  placed  in  the  back  verandah  of 
my  bungalow  with  northern  exposure  and  were 
watered  daily.  From  their  position  they  could 
only  get  the  benefit  of  the  direct  rays  of  the  sun 
for  a short  time  in  the  afternoon,  a circumstance 
which  was  no  doubt  adverse  to  the  natural  de- 
velopment of  the  plants  ; but,  if  placed  on  the 
compound,  the  plants  would  have  been  liable  to 
be  cropped  by  animals. 
The  average  time  taken  for  the  first  three  seeds 
in  each  pot  to  germinate  and  appear  above  ground 
was,  in  the  soil  treated  with  lime,  9 days  ; in 
the  unmanured  soil,  12  days  ; in  the  soil  manured 
with  bone  dust  15  days ; in  the  soil  manured 
with  cow  dung,  the  first  two  seeds  took  14  and 
27  days  respectively.  On  the  26th  of  May  I 
measured  the  growth  from  the  ground  to  the 
tips  of  the  blades. 
The  rsults  with  other  data  are  talulated  below:— 
None  of  the  seeds  was  well  filled,  and  some  were 
mere  leaves.  Although  the  paddy  manured  with 
bone  dust  had  the  greatest  number  of  seeds,  these 
were  not  quite  equal  in  quality  to  those  grown 
in  the  unmanured  soil,  and  in  the  soil  manured 
with  cow  dung.  The  sickliest  plants  were  those 
in  the  soil  treated  with  lime,  although  these  were 
the  first  to  germinate.  These  last  came  to  nothing. 
The  blades  were  short,  of  a very  light  green, 
evidently  very  deficient  in  chlorophyll.  The 
blades  of  the  paddy  manured  with  bone  dust 
were  of  a rich  dark  green,  and  those  of  the  un- 
manured paddy  were  but  little  inferior.  It  is 
evident  that,  as  grown  to  a great  extent  in  the 
shade,  the  paddy  has  little  if  at  all  benefited  by 
the  phosphoric  acid  in  the  bone  dust  but  had 
rofited  somewhat  by  the  nitrogen  in  the  same, 
cannot,  however,  infer  from  this  experiment 
the  comparative  inutility  of  bone  dust  for  the 
paddy  crop ; but  simply  that,  having  been  added 
to  the  soil  at  the  time  of  planting,  this  insoluble 
or  rather  very  slowly  soluble  form  of  phosphate 
had  not  had  time  to  be  decomposed,  and  rendered 
