656 
Siipplemmt  to  the  “ Tropical  Agriculturist.^'  [March  2,  1896, 
characteristic  slate  colour,  the  colour  of  poiulrette. 
There  was  absolutely  no  taint  or  odour  on  its  ex- 
posure at  the  surface.  It  had  been  buried  three 
or  four  weeks.” 
And  yet  Mr.  Mollison  believes  that  the  manu- 
facture of  poudrette  will  continue,  because  culti- 
vators will  prefer  to  use  this  form  of  night-soil, 
which  has  nothing  objectionable  about  it  and  is 
easy  of  transport,  and  also  because  manufacturers 
of  the  manure  can  count  on  a profitable  business 
in  it. 
The  Indian  Agriculturist  mentions  that  the  last 
quarterly  report  of  Surgeon-Lieutenant-Colonel 
King,  Sanitary  Commissioner  of  Madras,  contains 
some'  correspondence  which  he  has  had  with  the 
Coconada  Municipality  on  the  subject  of  sewage 
farming,  about  which  his  advice  was  sought.  It 
seems  that  the  Municipality  in  question  intended 
to  confine  its  operations  to  t he  manufacture  of 
poudrette : but  Surgeon-lueutenant-Colonel  King 
points  out  how  easy  it  is  to  combine  this  with 
ordinary  fluid  sewage  irrigation,  such  as  is  carried 
on  successfully  by  the  Madras  Municipality,  lie 
exulains  the  simple  means  by  which  this  can  be 
effected,  giving  all  the  necessary  details  as  regards 
the  best  and  cheapest  plant  and  the  easiest  sys- 
tem of  cultivation.  He  remarks  that  hurnall 
„rass  is  perlmps  the  most  satisfactory  crop  to  grow 
under  sewage.  The  only  care  requisite  is  that 
gewaue  irrigation  should  be  checked  as  the  crop 
becomes  ready  for  cutting  for  from  five  to  ten 
davs  previously.  As  regards  the  poudrette  system, 
the  main  feature  to  remember,  the  Sanitary  Com- 
missioner says,  is  that  the  trenches  should  be 
shallow.  What  degree  of  shallowness  is  used  must 
depend  upon  the  area  of  land  at  disposal.  At  no 
time  should  the  trenches  be  deeper  than  18  inches, 
the  depth  up  to  which  microbic  life  is  m st  active. 
No  rule,  he  says,  can  be  laid  down  as  to  when  the 
manure 'is  fit  for  use;  this  can  only  be  ascertained 
bv  direct  observation,  as  the  results  vary  much  in 
different  soils.  Some  period  within  six  months 
mav  be  taken  as  a safe  calculation.  But  by  occa- 
sionallv  opening  a trench  the  state  of  progress  can 
always  be  easily  gauged.  What  is  required  is  that 
before  removal  the  trench  contents  shall  in  no 
wav  be  distinguishable  from  the  surrounding  soil, 
unless  it  be  by  the  rich  dark  colour  and  a tendency 
to  the  character  of  garden  mould.  As  regards 
the  nature  of  the  soil  be^t  fitted  for  the  securing 
of  the  change  required,  the  nearer  the  soil  ap- 
proaches the  character  of  garden  mould,  the  better, 
Ld  from  this  one  may,  in  descending  order  of 
Soice,  select  gravel,  sand  or  clay.  The  latter 
soil  however,  unless  well  mixed  with  sand, 
veeetable  matter,  or  ashes,  cannot  be  expected 
to  enable  the  necessary  nitrification  to  piro- 
Zen  Having  prepared  the  soil,  the  question 
Suv  relolves  it«lf  i..to  one  of  careful  lu.s- 
P -,,l.v_the  only  care  requisite  being  to  guard 
against  the  tend'ency  to  overload  the  plants  with 
manure. 
Tir  Leather  in  his  note  on  night-soil  refers 
to  the  methods  of  preparing  poudrette  in  certain 
Indian  towns.  n ..  i i. 
The  practice  at  Nagpore,  m the  Central  l>ro- 
• c to  fill  night-soil  and  town-sweepings 
‘■lO  feet  by  4 feet  .,k1  4 feet 
deei)  into  which  about  KX)  cubic  feet  of  sewage 
3 emptied  in  10  or  12  portions,  3 or  4 inches 
of  earth  being  thrown  over  each  layer. 
At  Poona  a similar  practice  prevails,  the  pits 
there  being  18  feet  by  15  feet  and  only  1 foot 
deep).  Ashes  are  spiread  over  the  night-soil. 
A similar  system  prevails  at  Cawnpur. 
Alter  a time  the  material  becomes  dry  and 
nearly  odourless  and  is  taken  out  of  the  pits 
and  sold  for  manure. 
Regarding  the  chemical  composition  of  such 
poudrette,  it  will  be  evident  that  this  will 
depend  on  the  piroportion  of  earth  wdiicli  is 
mixed  with  the  refuse,  and  secondly,  on  the 
compiarative  dryness  or  wetness  of  the  material 
when  taken  out  of  the  pits.  The  larger  the 
proportion  of  earth  and  the  wetter  the  condi- 
tion of  the  poudrette,  the  smaller  will  be  the 
percentage  of  pdant-food  ingredients,  such  as 
phosphoric  acid  and  nitrogen. 
The  following  analyses  of  sampiles  of  poudrette 
which  have  been  made  by  Dr.  Leather,  himself, 
may  be  (piloted  : — 
Poudrette 
Poudrette 
for 
in  Cawnpur.  _ 
from  Poona. 
Moisture 
2'64 
22  91 
Organic  matter  . . 
7-82 
18-10 
ICarthly  substance 
89-64 
58-99 
Containing 
100-00 
100  00 
0-468 
0-906 
N itrogen 
Phosphoric  Acid 
0-499 
NOTES  ON  THE  TOMATO. 
Thi.s  having  of  late  become  one  of  our  most 
common  and  valuable  fruits,  it  may  interest  our 
readers  to  know  that  the  American  Agriculturist  • 
reports  a series  of  experiments  made  as  to  the 
chemical  comp  osition  of  both  the  fruit  and  the 
vine.  These  show  that  the  crop  requires  almost 
twice  as  much  potash  as  any  other  ingredient ; 
and  also  that  because  nitrogen,  the  most  expen- 
sive element  of  plant-food,  can  only  have  its  full 
effect  when  available  potash  and  pho.sphates  are 
present  in  excess  in  the  soil.  Any  excess  of  po- 
tash over  the  requirements  of  the  crop  will  not 
waste  from  the  soil  by  drainage,  but  will  be 
retained  in  combination  by  the  soil  for  use  in 
future  crops. 
The  e.vperiments  show  that  when  potash  is 
deficient  in  the  soil,  the  growdng  plant,  of  what- 
ever description  it  may  be,  becomes  much  more 
sensitive  to  adverse  conditions  of  soil  or  season, 
and  is  more  readily  attacked  by  disease,  e.specially 
mildew'  and  other  fungoid  growths. 
Wood  ashes  contain  a large  percentage  of  potash, 
and  will  be  found  an  excellent  manure  for 
tomatoes.  Not  only  do  they  correct  any  acidity 
in  the  soil,  but  they  favour  nitrification,  and  they 
supply  carbonate  of  lime,  of  which  a tomato 
crop  requiiesat  least  50  lb.  to  the  acre.  A small 
amount  of  available  phospihate  will  in  most 
cases  be  sufficient  for  a successful  tomato  crop. 
Having  made  sure  of  an  excess  of  lime,  phos- 
phates, and  potash  salts  in  the  soil,  nitrogen 
should  be  used  freely  but  economically ; a small 
quantity  given  frequently  is  much  better  than  a 
large  dose  supplied  all  at  once. 
Applications  of  soluble  forms  of  nitrogen,  and 
particularly  of  nitrates,  seem  to  increase  the  yield 
