652 
THE TROPICAL AGRICULTURIST. [April r, 1889. 
submitted to the Ooorg Planters' Association, it is 
possible this analyst's opinion has already beeu given 
through that medium. 
Mr. Pringle's opinion, conveyed to Mr. Meynell, 
ran thus : — 
Your memorandum of 31st December and correspon- 
dence re bitterns, asking for my opinion upon that 
substance duly received. 
2. I do not think it would be worth while experi- 
menting with ; it is said to be: — 
16'6 parts of magnesium chloride. 
4 G „ of sodium chloride. 
2'0 o" magnesium sulpbate. 
Neither magnesium nor sodium are essential consti- 
tuents of any manure, as there is in almost every case 
sufficient present in the soil ; and nearly every manure, 
contains them, though they are not often determined, 
being such unimportant factors. 
The mother liquor from the brine springs of Cheshire 
has been boiled down to dryness and applied, at the 
rate of one ton per acre ploughed in, the land being 
left fallow for a year ; it effectually killed all the 
weeds. Mangolds did well after it, but other crops 
not so well. It is very soluble, and would be washed 
out by the monsoon rains. It therefore might be use- 
ful to clean very weedy land that could be left fallow 
for a monsoon. It would be best applied at the 
beginning of the hot weather. The gypsum would 
in many cases be useful as a substitute for lime, 
in some cases it would give better results ; its value 
would be about tha s ime as that of lime. If superphos- 
phate is used as a manure, plenty of gypsum is applied 
with it, as it is a natural constituent of the manure ; 
and it is in that foim that it will be most valuable ; 
accompany a phosphatic manure. 
On 25th Jan. 1889, the Madras Board of Revenue 
summed up the above opinions and added : — 
A consideration of the foregoing papers points to 
.the conclusion that Mr. Benson's opinions noticed 
in paragraph 2 of Board's Proceedings, No. 192, date 
4th May 1888, regarding tbe manurial value of bittern 
and the possibility of profitably recovering the bye- 
products are correct, viz. : — 
(1) that bitterns might be used for mixing with 
manure heaps, if the cost of carriage is not prohibitive ; 
(2) that whether the bye-products can be profitably 
extracted in India cannot yet be stated. The solution 
of the last-mentioned problem will probably ba mate- 
rially advanced, if not completely attained by the 
experiments which Messrs. Hall, Wilson and Co. pro- 
pose to uodertake at the salt factory near Oocanada, 
the establishment of which by them has been recently 
sanctioned by Government. 
A separate set of proceedings ends with the following 
declaration : — 
Agriculturally the potassium salts are the only ones 
which it is desirable to secure from the brine ; 
natural gypsum is easily obtainable in the Trichinopoly 
district, and magnesium sulphate is an undesirable 
substance. 
«, 
SALT AND SALINE SUBSTANCES AS 
MANURES FOR COCONUT PALMS. 
After we had written what appears on page 
G49 on the question of the suitability of 
salt and its by-products mainly as a manure 
for leaf-yielding plants, our attention was at- 
tracted to a paper in the "Examiner" on the 
use of salt in the cultivation of a plant famous 
for many products, but especially renowned for 
highly developed fruits equally rich, at different 
stages of their existence, in saccharine and oleagi- 
nous properties, and which in the transition stage 
constitute a large portion of the food of tho in- 
habitants of Ceylon : the littoral-loving cooonut tree. 
Why does it spociully lovo littoral formations and 
flourish in the ocean breezes ? Is it solely for the 
sake of a soil and atmosphere largely impregnated 
with salt? We take leave to qualify to some extent 
this very popular belief. The sea-side zone which 
the coconuts chiefly affect, on the south-west shores 
of our island, possesses the two great advantages 
of a rainfall ample, but not excessive, such as the 
palm desiderates, chiefly for the sake of those por- 
tions of it which stand above ground ; while, o«ving 
to the great prevalence of swamps and backwaters a 
few miles inland and the gentle slope of the land, 
there is a constant supply of fresh water, per- 
colating through the soil and sand towards the 
sea. The brackish fluid from the backwaters doubt- 
less part gradually with their saline particles as 
they pass through the great earth filter and 
so the soil is permeated with diffused salt. Not 
in large quantities or in n<™regated deposits, how- 
ever, but widely spread and cjnstantly and largely 
qualified by the rainwater which sinks into the soil. 
With reference to Emerson Tennent's theory, 
when discussing the coral wells of Jaffna, that sea 
water can percolate inland and sink into the soil 
below sea-level as fresh water, we may state that it 
was impeached by the late Dr. Buist of Bombay as 
contrary to all dynamical laws. Dr. Buist's protest 
was published in one of the editions of Tennent's 
great work, but there is no mention made of it in the 
fifth and finaledition, in which the percolation theory of 
sea-water flowing inland and downwards is stated 
without qualification ! Our own inclination is to be- 
lieve that " all the waters run into the sea," and find 
their way back to the land only in the shape of 
evaporated moisture or wind-caught particles which 
are both deposited from the air. Of course we 
do not forget the more or less sensible action of tides, 
and doubtless the natural formations of salt on 
the sides of marine streams in the Jaffna peninsula 
and elsewhere prove that sea water projected inland 
and spread thinly over wide surfaces is compelled to 
part with much of the substances held by it in 
solution. But what we do not think probable (is 
it at all possible ?) is, that sea water flowing up 
the land sinks to the lower strata filtered into 
freshness, or that, apart from tides, sea water can 
gravitate shorewards through the earth and sink 
below the level of the great ocean reservoir. 
When we talk, too, of coconut palms flourish- 
ing where their roots are actually washed by the 
sea-waves, we must remember the grand difference 
between the amount of salt diffused in sea water 
and that concentrated in the concreted crystals. 
Salt in its ordinary state is fatal, in any large quantity, 
to vegetable and animal life, and is used to get rid 
of weeds and worms, parasites and fungi. Applied 
in very large quantities we are perfectly certain it 
would prove equally fatal to coconut plants as to any 
others. Residence close to the seaside at Colombo 
for thirty years has afforded us ample opportunity 
of observing the positive struggle for existence 
which cocount plants in the early years of their 
existence have to wage with the fierce salt-laden 
winds of the south-west monsoon. We have seen 
their foliage after a succession of salt-storms 
blackened as if a fierce fire had passed over them, 
even the well-grown trees which flourish in an 
ordinarily saline atmosphere showing signs of 
distress. We can assert from experience that 
young trees sheltered from the monsoon storms 
by fences of cadjans make far better progress 
than those- compelled to expend their energies in 
renewing foliage periodically salted to death by the 
south-west monsoon winds. But over-ground shelter 
is prohibitively sxpensive, and so the natives in 
our neighbourhood resort to the expedient of digging 
very deep holes for the reception of their plants, 
which aro thus largely sheltered up to the second 
