62 
THE TROPICAL 
AQRIOULTURI87. [July i, 1891. 
with a substance which is its predominatiDg con- 
stituent and which is yet ' decidedly injurious' 
to all vegetation ?" I Bm afraid there will bo a 
good many ready to demur that the earth was 
mainly created for the growth and support of 
vegetation. This is indeed as revolutionary a 
theory as that of Mr, Eeeves I The appeal in 
the second sentence is modelled after the liack- 
nryed atheistic argument, against the exifctence 
ot a God, who, if He be the possessor of every 
attribute of goodness, cannot, it is said, consis- 
tently allow evil (and other things " decidedly 
injurious") to exist in the world. Ihe use of the 
argument (absurd in iteelf) to prove the value 
of silica is as novel as it is ridiculous 1 
We are asked, "Is it not against the laws of nature 
to find a piant deliberately choosing what is ' deci- 
dedly injurious' to it ? " Very pofsibly againHt 
the ' laws of nature." still tli' se that can deliberate 
a good deal more than plants do choose what 
is " decidedly injurious " to them. The 
fact is that plants may and often do take in 
BubstancfS present in the soil, but utterly 
useless in the plant economy, but the demand for 
these useless substances is limited as the rcfult of the 
action of the law of diffusion of liquids — the socalled 
" selective power " ot plants. The excretion of 
silica (or other substance) on the outer tissues of 
the plants is generally considered to be a means 
of "getting rid," as Krofessor Johns* s' ne puts it, of it 
from the growing parts of the plant, where, though 
it may have at one time perfoimed useful functions, 
it is no longer required, since it does not enter into 
the constitution of plant tissue. 1 admit that 
Professor Johnstone's statement of this fact is 
rather crudely put. 
I may say in passing that the value of "iron" 
as a commercial ingredient of agricultural soils 
depends altogether on the particular compound of 
iron that is present,* while the virtues of iron 
slag are mainly if not solely refeiablo to the com- 
pounds of phosphorus present in it. — I am, &o , 
SALT FOR COCONUTS. 
DEAfi Sib —In hii entbu.siastic advocacy of salt " B." 
i,,„ crndited it with bo many virtues, that if we ac- 
cent his authnrity (and he names no other) maukuid 
h,ve been through ail the age^, neglecting the most 
valuable and important of ail ftgricuitural agents; th»t 
which dissolves mineral., and sets free plaut food 
previously shut up in in.olu le c.mpo.md,s ; that 
Leohamcally ame icrates the soil to the extent of ren- 
ting tillage 8npe.fluou8; that absorbs water and 
hol.is it avaiable tor <heuse <.f plant, when all ar. und 
io drv and that -lestroys coarse and u^el vegetation 
whiu. highly beneficialt'. delicate and us^ fnl pl^'Us. 
It has been proved brvjond qneotion, that, with what- 
ever substance sUt may be mixe I, it can be e lain- 
ated without loss, and without chemical change on the 
o her ingredients' of the blend : it may therefore be 
fairlv inferred, that aalt has no ahemionl effect on soils 
whatever. R^in water effects a temp rary niecb>,nica 
chance in soil, and there is no reason to believe, that 
salt water will have a different or more pei-amnent 
effect ShU absorbs moisture from either earth or air 
but it again surrenders its mo.slure to dry ajr or hot 
Bun in common with the other ingredients of the soil 
and to the depth to which .uu and air penetrate. 
C complete liquefactinn, salt abaorbs three t-mes its 
own weight of water, when it foll-.ws the law, by which 
Hnuids sink by their own gravity through a porous 
Kum If an i-h deep of salt be i.aid on a ,:.yon 
^irfuce. and let the «oil under it he kept satu, a ed 
with water for a month, tho probah.hly is that not a 
rl^nTs^lt Jvin remain within HO.ne teet of Ihe sur- 
♦ Thin of course: for iron in a certain condi' on 
iB undoubteily a cause of sterility m the Oyleon 
pfttttuaS'— T. A. 
face. It has been known from time immemori»l, that 
salt is destructive to most kinds of terres rial vegetation, 
but it has probably never beiore been credited with 
the quality of discrimination between the noiious and 
the ufefal. 
That an excess of salt beyond its orgauio re- 
quirements is essential to the vigor and fraitfulness 
of the coconut has been so often assorted, and ''B." 
has laboured so bard to prove it, that it is gen'^rally 
accepted as an established fact, but that is still open 
to question. The c"oonut trees on sea sand do little 
honour to their unfailing supply of salt, by the crops 
they yiel 1; indeed, in this respect, they do not excel 
those that gr"W on hard grtivel, and steep inclines 
far inland. The strength and fruitfulness of the trees 
growing in the Cinnamon Uarden compounds may be 
r.adilv accounted for, on other grounds than their 
exposure to snlt bearing breeze". Besides, those are 
not the champion tr'-es of the Island, which must be 
sought on alluvial fleets on the banks of occasionally 
ov. jfiowing rivers, where some of the trees yield up 
to 400 nuts per annum, and there are other inland 
spott, where the trees will liold their ovsn, in oom- 
pnrison with the Cinnamon Gardens. 
It 18 true that much of t'ae inland undulating up. 
lands are not nil that could be desired fur cocouu 
onltivatioD, but there are ways of improving ibem 
without having recourse to salt ; salt cannot give 
moisture to the s 'ii in a three mouths' drought ; gait 
cannot pulverize a oompaci soil; and palt is no sub- 
stitute for nitrates, pbo-pba'cs and . .rganic matter. — 
Yours truly, COCONUT PLANTER. 
FLOUR FROM JAK SEEDS? 
Colombo, May 30th. 
SiE, — Has it struck anyone to utilize the seed 
of the jak fruit for the preparation of flour ? The 
only question to decide is whether it would be a 
wholesome diet. There is no reason why it should 
not form a nutritious food : it will certainly be a 
cheap one, considering the large quantity of seed 
that is allowed to run to waste. The seeds are 
of course eaten roasted to some extent by the. 
natives, and even ground to a flour for immediate 
use in the preparation of a sort of cake, after 
mixing with jaggery. If it prove to be a whole- 
some food and capable ot being made into a flour 
that will keep, why shouldn't a new industry be 
started ? The seeds might at least be exported. 
I should like to know whether the idea has 
struck anyone before, and whether anyone has 
tried the experiment of flour-making ? — I am, 
yours, Sic, A. 
(The first question to settle is, — "Are the seeds ever 
separated in any appreciable quantity from the other 
portions of the fruits ?" What we see in the markets 
are sections of the complete fruits, with the farinaceous 
seeds embedded in the mucilaginous and sacch&rine 
substance in which they are formed, and we are 
not aware that in cooking the fruits in curries, or 
otherwise, the seeds are ever rejected? We should, 
indeed, be greatly surprised to hear that they are. 
But if our observation has been at fault and a 
supply of seeds for grinding into flour is really 
available, the experiment suggested ought certainly 
to be tried,— Ed. T. A.'] 
HOW TO RECRUIT COOLIES. 
Kalutara, May 30th. 
Dear Sib, — Why not go in for the Assam system ? 
A kaugani is sent to his country with only enough 
m .ney to take him there. On his getting coolies to- 
gether, he is empowered to apply to an agent (a worthy 
native merchant) and they give him not money 
but rail or boat tickets to their destination for the 
coolies produced. 
Therefore there is no opportunity for the kangani to 
use tbe money for any otlier purpose than bringing 
oooliea.— Youi'S truly, A, A. 
