3^2  Supphmmt  io  the  “ Trnpicnl  AgTiculturisV'  [Xov.  1, 189o. 
phlet  IS  replste  with  facts  and  figures  derived 
from  all  manner  of  experiments  with  crops, 
manures,  food-stuffs,  &c.,  and  should  prove  a 
valuable  work  of  reference. 
Whether  the  operation.s  of  the  Ciitch  Company 
in  the  Eustern  Province  will  result  in  the  ulti- 
mate extirpation  of  the  mangroves  that  flourish 
in  our  tidal  areas  is  more  than  we  can  say, 
but^  the  protest  that  has  been  raised  in  Jamaica 
against  tl>e  destruction  of  the  mangrove  in  tlnit 
colony  and  tlie  claim  put  forward  for  this  tree 
as  n sanitary  agent  are  undoubtedly  of  local  in- 
terest. Tlie  mangrove  is  said  to  solidify  the 
mnd  where  it  vegetates  and  to  raise  it.  From 
the  leaves,  bark  and  .''ceds  which  fall  from  the 
mangrove,  we  are  told  that  the  mud  receives 
an  immense  amount  of  tannin — a powerful 
antidote  against  jnitrefaction.  By  catching  and 
solidifying  the  mud  it  keeps  it  form  spread- 
ing, and  while  preventing  the  increase  of  the  fi.xed 
shell-flsh  aid  the  multiplication  of  other  species, 
particularly  the  crabs — the  greatest  consumers 
of  organic  matter  deposited  on  the  banks.  It 
is  further  stated  that  where  the  mangrove 
flourished,  yellow  fever  and  other  disorders  of  an 
endemic  character  were  unknown.  If  these  state- 
ments are  founded  on  fact,  it  would  be  well 
for  us  to  take  heed  lest  in  our  anxiety  to  encour- 
age enterprise,  we  open  the  door  to  fresh  evils. 
Dr.  George  Watt  suggested  enquiry  into  the 
possibility  of  increasing  the  vield  of  Cutch  by 
acacia  catechu,  by  mechanical  or  other  injuries 
to  the  plant.  Dr.  Leather,  the  argicultural 
chemist,  remarks  that  it  “ appears  to  be  pro- 
bable that  catechin  can  be  drawn  from  the  trees 
by  wounding  them,  for  it  is  a solid  substance 
found  in  the  heart-wood.”  The  Director  of  the 
Imperial  Forest  School  states,  “ if  catechin  were 
a gum  obtained  by  exudation  and  chiefly  from 
the  sap-wood,  no  doubt  wounding  the  trees 
would  increase  the  production,  but  it  is  not  a 
gum  but  a sub.stance  found  in  the  heart-wood, 
and  wounding  could  have  little  or  no  effect.” 
In  spite,  however,  of  these  opinions,  Dr.  Watt 
goes  on  to  point  out  that  the  removal  of  gum 
or  any  other  mechanical  disturbance  to  the  life 
of  the  plant  through  wounds,  diseases,  drought. 
&c.  might  easily  enough  cause  a deposition  of 
crystalline  matter  within  the  wood,  lie  further 
refers  to  analogous  cases  thus  : “ The  irritation 
caused  by  sand  within  the  oyster  shell  is 
believed  to  be  the  exciting  cause  to  the  forma- 
tion of  the  pearl.  Barus  camphor  is  deposited 
within  the  wood  of  Dryobalanops  camphora  very 
much  after  the  same  manner  as  catcehin  (kinsal) 
within  that  of  acacia  catechu.  The  crystals  of 
that  form  of  camphor  are  well  known  to  occur 
within  the  heart-wood,  hence  it  is  said  old  trees 
are  the  most  productive.  In  searching  for  trees 
likely  to  yield  camphor,  the  natives  pierce  the 
stems  to  the  heart-wood,  I Inis  injuring  them 
materially  ; but  it  is  said  that  a tree  left  for  seven 
or  eight  years  will  then  lie  found  to  contain 
deposits  of  camphor  freely,  so  that  the  tapping 
process  has  come  to  be  regarded  as  facilitating 
the  formation  of  the  much-prized  article.  The 
formation  of  Agar  (a  crystalline  substance  found 
within  the  wood  of  Aquilaria  ngallochn)is  believed 
to  be  due  to  .some  diseased  condition.  The 
formation  ol  the  crystalline  substance  tabashir 
within  the  bamboo  has  been  demonstrated  to  be 
due  to  an  insect.  A native  merchant  (according 
to  Mr.  I’eppe)  tried  to  imitate  the  action  of  tlie 
insect,  with  the  result  that  he  found  that  by 
making  a small  perforation  above  a joint  in 
half-mature  bamboos  the  .salt  formed  freely. 
This  he  practised  systematically  and  made  a 
considerable  sum  of  money  before  he  Anally 
glutted  the  market  with  tabashir.  {Diet.  Vol.  I., 
S85.)  It  is  not  unusual  in  fact  in  agricultural 
operations  to  check  the  growth  of  plants  so 
as  to  cause  the  formation  of  reserve  materials. 
In  the  production  of  f/n»ja  it  is  found  necessary 
to  remove  the  male  plants  since  the  fertiliza- 
tion of  the  female  destroys  the  formation  of 
the  narcotic.  But  in  some  parts  of  the 
country  (as  in  Burma)  this  same  result  is 
obtained  by  injuring  the  stem.s.  Witliout  men- 
tioning other  such  examples  it  may  fairly  well 
be  said  that  it  remains  to  be  demonstrated  that 
the  yield  of  catechin  is  not  a matter  that  is 
capable  of  control.  It  was,  however,  from 
analogy  in  similar  instances  that  the  writer 
ventured  to  make  the  suggestion  that  the 
formation  of  catechin  might  be  facilitated  by 
mechanical  agencies  or  other  disturbances  to  the 
life  uf  the  plant.  This,  however,  was  only  a 
suggestion,  though  it  is  one  that  might  still  be 
kept  in  view'.” 
RAINFALL  T4KFN  AT  TIIK  SCHOOL  OF 
AGRICULTURE  DURING  THE  MONTH 
OF 
OCTOBER, 
1895. 
1 
Tuesday 
•34 
19 
Saturdfiy 
Nil 
2 
Wednesday . 
• -14 
20 
Sunday 
2 '86 
3 
Thursday  . 
•08 
21 
Monday 
Nil 
4 
Friday 
•18 
22 
Tuesday 
1-91 
5 
Saturday  . 
. •.57 
23 
AVednesday . 
3-07 
6 
Sunday 
. -10 
24 
Thursday  . 
M7 
7 
Monday 
. -04 
25 
Friday 
•01 
8 
Tuesday 
. 1-98 
26 
Saturday  . 
•22 
9 
Wednesday . 
. ul 
27 
Sunday 
•59 
10 
Thursday  . 
. -30 
28 
Monday 
•30 
11 
Friday 
. -13 
29 
Tuesday 
5 -59 
12 
Saturday 
. l oo 
30 
Wednesday. 
3-91 
13 
Sunday 
. -30 
31 
Thursday  . 
•75 
14 
Monday 
. 1-78 
1 
Friday 
•07 
15 
Tuesday 
. -13 
— 
16 
Wednesd  ly . 
. 1-03 
Total . 
‘29-72 
17 
Thur.sday  . 
. -34 
— . — 
18 
Friday 
. -90 
Mean . 
•95 
Greatest  amount  of  rainfall  in  any  ‘24  hour 
on  the  29th  instant,  5 59  inches. 
Recorded  by  J.  D.  S.  Jayaw'U'krema. 
PRINCE  KRAPOTKIN’S  ARTICLE  IN  THE 
“ NINETEENTH  CENTURY.” 
Prince  Krapotkin  hasdonegood service  as  a chron- 
icDr  in  almost  every  department  of  Science, 
and  his  summary  of  the  re.snlt  of  the  researches 
into  the  nature  of  the  relation  between  the 
plants,  the  soil,  and  the  free  nitrogen  of  the 
atmosphere  is  a valuable  contribution  to  the 
literature  of  the  sulqect. 
Nitrogen,  in  one  form  or  another,  exists  both 
in  the  soil  and  in  the  atmosphere,  and  it  is 
curious  to  note  that  apparently  contradictory 
