jiine I, 1891.] 
Supplement to the “ Tropical Agriculturist. 
8S9 
matters into wliicli enquiry is called for, may be 
drawn up. But it is still more necessary that 
these reports should he entrusted to competent 
hands. It is an anomaly to depend for agricul- 
tural reports on those who have little knowledge 
of the subject and less judgement to exercise in 
agricultural affairs; and that these reports should 
he submitted to men who have made no study of 
the science and practice of agriculture, who have 
no .sympathy with any movement for the im- 
provement of agriculture, and Avhose opinions 
and recommendation are therefore of no value. 
So far as Ceylon is concerned the sooner a com- 
petent board of agriculture is appointed, the 
better for all concerned in the inqn-ovement of 
native agriculture. It has already been stated 
through the press that the establishment of a 
veterinary department is in prospect, surely on 
agricultural department should have precedence. 
Ii\ fact, veterinary work might with advantage 
be made a branch of the agricultural department, 
and double duty be done by the officers of the 
deiJartment, who will be both agricultural and 
veterinary insf)ectors in the rural districts. There 
is of course no radical reform to be brought about 
in native agriculture, but yet there are scores of 
Avays in Avhich an organized body of qualified 
and experienced men can encourage and help 
native agriculturists, and further their interests. 
The material is available, but it is for the 
Government to bring about the organization and 
to stamp it with its imprimatur. 
SILICIOUS 
SOILS. 
The reply Avhich the enquiry of a correspondent 
to the Ceylon Observer anent the silica question 
has elicited from Professor Geikie — we suppose 
Professor James Geikie — has naturally caused a 
good deal of consternation to some of our tropical 
agriculturists. It is to be noted hoAvever that 
Professor Geikie Avho has no pretension to be an 
agriculturi.st, does not give his own opinion a.s to 
tile value of silica in jilant economy, but that of 
Professor Johnstone. Now as there is more than 
one professor of this latter name, Ave are naturally 
anxious to knoAA’ Avho and Avhat Professor John- 
stone is ; Avhile Ave do not hesitate to say that 
the statement attributed to him is a A'ery mi.s- 
Icading one. The import of Professor Johnstone’s 
opinion is evidently intended to be that silica is 
“injurious” to the generality of plants inasmuch 
as the fertility of land (as generally reckoned) 
is in the inverse ratio to the amount 
of silica in the soil ; but as it is ex- 
pressed, the statement Avould naturally convey a 
Avider and less correct meaning to the ordinary 
reader. There is no doubt, ns Professor Wallace 
remarks in his Avork on India, that ]ilants draAV 
a much larger siqiply of their nitrogenous food 
from (he atmosphere, in tlie tropica, tlian they 
do in tenqierate regions, oAving to tlu' fact that 
there is so much electricity in the 
atmosphere of the tro|iic.s. Mlectricily is admit ted 
to be the only original .source of combined nitrogen, 
producing by its action nitrous acid Avhich is 
oxidized into nitric acid by ozoiu' or jiroxide of 
hydrogen. Thus it i.s that the almost jnire silicious 
soils of the trojiics are not barren Avastes, and 
fire enabled to 3U])port their OAvn peculiar natural 
groAAdh of vegetation, Avhicli cultivation has in 
particular cases raised to economic importance. 
Nitrogen is the only incumbustible (or organic, as 
it is sometimes less satisfactorily named) element 
of plant food Avhich there is difficulty to account 
tor a sufficient supply of. Silicious soils generally 
contain fragments of more complex minerals than 
qtini'tz which sloAvly inci’ease the ash or mineral 
constituents available for the plant. It is also 
A ery probable that from the more general, more 
complete, and more rapid rate of decomposition 
in tropical climes, the proportion of ammonia 
(A-ery variable in quantity) in the atmosphere is 
much higher than tliat in temperate regions. If 
however a sandy soil is composed of pure silica it 
cannot supply any plant food; and though the 
difficulty a.s to the supply of the chief incumbus- 
tihle elements of i.>lant food may ))e got over, 
the lack of the essential mineral ingredients 
Avill render such soils sterile whether in temperate 
or tropical regions. 
THE GRAPE VINE. 
(litis Tin (f era.) 
6. Prejiarafion of the The land selected 
for a vineyard should be dry and sufficiently ele- 
vated to preA'ent any Avater stagnating on it 
during heavy rains. If it slightly slopes so 
much the better. Open drains should be cut in 
order to jirevent ‘ Avasli ’ ; and under drains must 
l.ie comstructed if the subsoil is not sufficiently 
porous to drain aAvay all superfluous Avater. 
Stones broken to the size of the “metal” generally 
used for roads, or a little bigger, may be used for 
the subsoil drains. 
It is very important that the tillage of the land 
should be thorough and efficient. In Jaffna 
Batticaloa and other parts of Ceylon AA'here grapes 
are grown, Ave seldom find more tlian a couple 
of vines groAving in a garden. No proper system 
of tillage has therefore been practised as yet in 
viticulture here. It is customary to dig a hole, 
say, about 4 feet square and 3 feet deep and to 
fill it up Avith half-rotten cowdung and soil, and 
then to plant the vine in the centre of the hole. 
So long as it is young tlie plant thus treated seems 
to thrive as Avell as can be expected, but ns it 
groAvs older it Avill be seen that there is a tAvo- 
fold disadvantage by this pit-method of planting; 
viz,— ■(!) The roots of the vine instead of freely 
spreading out laterally Avill be confined to the pit, 
croAvding and coiling up in the loose rich .soil in 
it as they Avould do in a floAver pot. 
(2). The loAver roots are encouraged to go too 
deep regardless of the nature of the .soil beloAV,— 
Avhellier it he SAveet or .sour, cold or Avarm iVc. ' 
To give Sftme idea of the tillage adopted on the 
famous and extensive vineyards of Australia, I 
shall quote a feAv linos from 'the annual rejiort ’for 
1889oftho Agricultural De])artnient of Queens- 
land, asre])riuted in the Tropical Agriculturist 
of February 1890. In the course of .some remarks 
about Jlr. Searle’s vineyard, the report say.s; 
“Although as Dir. 8earle admits, he is but ipi 
amateur vi( icult uri.st, he apjiears to he possessed 
oi a good <leal of common-sense, and is tpiite 
aAvare that it is not sufficient for the groAvth of 
A'incs to dig a hole and stick a A ine into it, or to 
