244 
THE  TROPICAL  AGRICULTURIST. 
[Oct.  i,  1892. 
the  sandy  soil  from  one  portion  of  a property,  even 
if  it  is  flat  land,  to  the  clayey  portions,  and 
vice  versa.  It  may  then  he  asked  “ How  is  the 
improvement  of  the  soil  to  be  carried  on  ? ” That 
problem  is  not  an  easy  one  to  solve  generally,  but 
is  possible  at  a not  very  high  cost  in  Colombo. 
There  are  mountains  of  fibre  dust  at  the  various 
coir  mills  in  Colombo,  very  much  in  their  way, 
which  it  will  pay  owners  of  properties  to  remove 
and  apply  to  them.  Carts  specially  fitted  up  with 
high,  open  sides  are  necessary  so  as  to  transport  a 
good  load.  This  substance,  if  spread  over  the  land 
and  dug  into  it,  cannot  but  improve  all  classes  of 
soils.  If  some  manurial  substance  be  added  to  it  the 
effect,  as  a matter  of  course,  will  be  greater. 
The  “ Magazine  of  the  School  of  Agriculture” 
announced  not  very  long  ago  that  an  attempt  was 
about  to  be  made  to  systematically  improve  the 
soil  of  the  School  grounds  by  the  penning  of  cattle 
on  them.  The  work  will  be  accelerated  and  be 
rendered  more  thorough,  if  a thick  layer  of  fibre 
pust  be  spread  daily  over  the  cattle  droppings.  By 
this  means  the  volatile  ammonia  will  be  conserved 
and  the  ground  can  be  gone  over  very  much  faster. 
The  School  will  have  to  establish  its  own  cart 
service,  the  cattle  of  which  will  aid  in  the  opera- 
tions of  manuring  and  enriching  the  soil. 
Fibre  dust  has  been  recently  suggested  as  a suit- 
able basis  for  the  manufacture  of  a compost  to 
take  the  place  of  cattle  manure.  The  question  of 
transport  stands  in  the  way  of  its  being  used  largely 
away  from  Colombo.  Its  cost  can  to  a very  great 
©xteat  be  reduced  if  the  very  large  quantity  of 
moisture  it  contains  be  pressed  out  of  it.  If 
the  coir  mills  undertake  to  do  this  at  a moder- 
rate  cost,  they  will  benefit  themselves  and  the 
agriculturist.  I do  not  believe  that  the  cost  of 
transport  of  fibre  dust  and  the  price  of  guano, 
which  has  been  suggested  to  be  composted  with  it, 
will  anything  like  equal  the  cost  of  making  cattle 
manure  on  an  upeountry  estate,  involving  as  it  does 
large  and  costly  sheds,  the  wages  of  grass  cutters 
for  food  and  bedding,  poonac,  and  the  risks  run  with 
rinderpast  or  murrain. 
The  relative  values  of  cattle  manure  and  a com- 
post made  of  fibre  dust  and  guano  can  be  judged 
when  it  is  stated  that  a ton  of  well-rotted  dung  is 
said  to  contain 
Nitrogen  . . 9 to  15  lb. 
Potash  . . 9 to  15  lb. 
Phos.  acid  . . 2 to  9 lb. 
While  guano  contains : — 
Organic  matter  and  ammonaical  salts  59T1  per  cent 
Phosphate  of  lime  and  magnesia  19'31  „ 
Alkaline  salts,  chiefly  chlorides  of 
potassium  and  sodium  8T3  „ 
The  proportion  of  guano  to  fibre  dust,  so  as  to 
assimilate  the  mixture  as  nearly  as  possible  to  cattle 
manure,  will  be  for  an  agricultural  chemist  to  deter- 
mine ; but  every  practical  planter  can,  after  he 
determines  the  quantity  of  guano  the  particular  form 
of  vegetation  he  cultivates  requires,  and  the  quantity 
of  the  fibre  dust  he  is  going  to  give  each  bush  or 
tree  of  his,  regulate  the  mixture  of  his  compost.  It 
may  be  well  to  reproduce  the  opinion  of  an  authority  on 
guano : — “This  substance  is  remarkably  rich  in  fertiliz- 
ing materials,  nearly  every  one  of  its  constituents  being 
material  highly  valuable  for  the  growth  of  plants. 
For  this  reason  guano  may  be  considered  as  the 
richest  and  most  concentrated  of  manures.  Most  of 
the  complaints  against  this  manure,  and  the  disappoint- 
ments that  follow  its  use,  may  be  traced  to  the 
ignorance  of  the  fact  that  it  is  too  stimulating  a 
manure — too  concentrated— to  be  used,  but  with  the 
utmost  caution.  Nearly  two-thirds  of  its  weight  con- 
sist of  salts  and  other  combinations  of  ammonia,  more 
than  a fourth  of  which  is  real  or  pure  ammonia.  This 
portion  of  guano  contains  many  of  the  same  com- 
pounds as  are  found  in  the  urine  of  domestic  animals 
so  that  we  may  regard  this  portion  of  guano  as  urine 
divested  of  its  large  quantity  of  water.  Nearly  a 
fourth  of  its  weight  consists  of  phosphate  of  lime.” 
It  will  be  of  interest  and  great  value  to  have  the 
opinion  of  so  competent  an  authority  and  one  so 
well  acquainted  with  pur  means  of  transport,  soil 
and  climate  as  Mr.  John  Hughes  on  this  important 
subject.  Ville,  the  great  apostle  of  chemical  manures 
as  opposed  to  farmyard  manure,  says  in  praise  of 
them,  that  they  are  more  powerful  than  farmyard 
manure  which  contains  foreign  matter  which  hinders 
the  action  of  its  chief  constituents.  I do  not  think 
this  objection  will  apply  to  the  compost  I have  sug- 
gested, which  to  my  thinking  will  contain  fertilizing 
matter  in  a readily  available  form  in  combination  with 
a mass  of  vegetable  matter,  which  while  helping  to 
regulate  the  supply,  will  in  its  decay  improve  the 
chemical  and  mechanical  condition  of  the  soil. 
I will  in  another  commiuncation  give  my  ideas,  the 
result  of  experience,  observation  and  thought,  on 
manuring.  B. 
GUTTA-PERCHA. 
The  following  is  translated  from  L'Industrie 
Electrique,  and  is  a report  of  a Paper  read  be- 
fore the  Soci^te  d’Encouragement  in  June  last  by 
M.  Jungfleisoh.  An  abstract  of  a Paper  read 
before  the  same  Society  by  M.  Setullas  appeared 
in  The  Electrician  of  May  20. h ; and  in  the 
following  issue  an  article  appeared  traversing 
several  of  M.  Serullas’  statements:  — 
Two  months  ago  M.  Serullas,  in  giving  an  account 
of  his  expedition  to  Malaysia  to  discover  the  best 
gutta-percha  tree,  alluded  to  a new  method  of  ob- 
taining gutta-percha,  but  did  not  enter  into  details. 
Having,  in  conjunction  with  M.  Damoiseau,  in- 
vestigated the  principal  constituents  of  gutta-percha, 
the  author  succeeded  in  obtaining  all  three  of  them 
in  a crystallised  state,  and  in  ascertaining  some 
precise  data  with  respect  to  their  nature.  The  vari- 
ability of  commercial  samples  and  the  consequent 
impossibility  of  reproducting  with  any  degree  of 
certainty  the  results  obtained  with  any  given  sample, 
however,  made  him  postpone  publication.  The  wish  to 
carry  on  these  investigations  with  gutta-percha,  the 
origin  of  which  was  certain,  called  the  author’s  at- 
tention to  the  results  of  the  French  expeditions  then 
at  work  elucidating  the  question  of  our  gutta-percha 
resources,  and  especially  to  the  results  obtained  by 
MM.  Seligmann-Lui  and  Serullas. 
In  fact,  until  quite  lately,  only  vague  information 
had  been  available  with  respect  to  gutta  trees.  The 
plants  themselves  had,  indeed,  been  described  with 
all  possible  botanic  science,  but  no  relation  had  been 
established  between  a given  plant  and  the  quality  of 
its  gum.  The  French  expeditions  fixed  attention  on 
these  important  points.  In  1888  M.  Serullas  had 
already  sufficiently  numerous  data  to  make  sure  that 
Hooker’s  Isonandra  gutta  was  the  gutta  plant  par 
excellence. 
By  all  accounts,  emanating  from  this  source  and 
from  foreign  expeditions,  the  Malay  method  of 
working,  an  essentially  destructive  one  to  the  Isonandra 
forests,  was  the  cause  of  the  approaching  exhaustion 
of  these  forests,  and,  therefore,  of  the  exhaustion 
of  a raw  product  now  become  indispensable  to  the 
electrical  industry.  The  Malays,  with  their  present 
mode  of  operation,  could  only  work  trees  28  to  30 
years  old,  or  shoots  of  from  14  to  15  years  ; and  the 
tapping  of  a tree  of  30  only  yielded  at  the  most 
265  grammes  (9f  oz.)  of  raw  gutta,  which  was  often 
mixed  with  half  its  weight  of  foreign  matters  of  no 
commercial  value.  Setting  to  work  with  more  care 
than  the  Malays,  M.  Serullas  had  only  been  able  to 
extract  220  grammes  from  a 30-year  old  tree ; the 
gum  was,  however,  purer  than  that  obtained  by  the 
natives.  M.  S6rullas  saw  a tree  T2  metres  in  diameter 
worked,  sJttd  it  only  gave  382  grammes  of  raw  gum. 
Such  improvident  and  unproductive  processes  were 
very  amazing  when  the  enormous  consumption  was 
called  to  mind.  'M.  Trevenen,  taking  note  of  the  gutta, 
good  or  bad,  exported  from  the  Malay  ports  in  1884, 
arrived  at  a total  of  3,144,847  kilogrammes  (3,200  tons), 
an  amount  which,  according  to  the  data  mentioned 
above,  corresponded  to  the  destruction  of  more  than 
12  million  30-year  old  Isonandra.  However,  Isonandra 
gutta  were  not  the  only  trees  cut  down,  and  it  might 
be  remarked  that  similar  spices  gave  bad  gutta  iq 
