March i, 1894.J THE TROPICAL AGRICULTURIST. 
587 
the soil into a state more favorable to the growth 
6f a sweeter and more nutritious herbage. It is 
usually exposed to the air for a considerable 
time before it is applied with a view to change 
the sulphuret of calcium into gypsum. This sub- 
stance is sometimes applied to land in England, 
in the proportion of 2 tons per acre, both on 
account of its chemical qualities, and of its effect 
upon the mechanical condition of the land, 
rendering stiff' heavy soils, more porous. I give 
below Professor Voelcker's analy.sis of gas lime, 
and, for comparison with it, Mr. Hughes' analy- 
sis of a sample of gas lime from the Colombo 
Gas Works. 
Composition of Gas Lime dried at 212° F. 
(VoELCKEE.) 
per cent. 
Water of combination and a little or- 
ganic matter... ... ... 7'27 
Oxide of Iron and Alumina with traces 
of Pliosphoric acid ... ... 2'49 
Sulphate of Lime (gypsum)... ... 4-64 
Sulphite of Lime ... ... 15-19 
Carbonate of Lime ... ... 49-40 
Caustic Lime ... ... ... 18-2.S 
Magnesia and Alkalies ... ... 2-53 
Insoluble Siliceous matter ... ... '28 
100-00 
In fresh gas lime the porportion of water 
varies usually from 30 to 40 per cent. 
Analysis of Gas Lime from Colombo Gas 
Works. (HUGHKS.) 
Moisture ... ... ... 16-96 
* (.h'ganic matters ... ... 2S2 
Carbonate of Lime .. ... 61-70 
Caustic Lime ... ... 7 01 
Sulphide of Lime ... ... 1-71 
Sulphide and Cyanide of Iron ... 2 40 
Magnesia, Alkalies, &c.... ... 4 40 
Insoluble Siliceous matters ... 2-90 
Containing Nitrogen 
Equal to Ammonia 
Common Salt. 
100-00 
•30 
•36 
Some writers to the Ceylon press state that 
common salt has been applied with advantage 
to coconut land situated in inland districts. 
The composition of common salt from sea 
water in Europe is found to vaiy between the 
following limits : — 
per cent. per cent. 
Sodium chloride from 89 to 96-3 
Magnesium Chloride ,, '2 to 1*58 
M.agnesium Sulphate ,, -4 to 0 20 
Calcium Sulpliiite ., -33 to 2-;{.') 
Water ,, — to 6-30 
Insoluble matter „ "07 to 3 60 
The following in like manner exhibits the 
composition of European Rock Sails : — 
Composition of Roth Salt. 
per cent. per cent, 
.■^iodium Chloride from 967 t" lou 
Caloinm Cliloriile ,, — to -08 
Magnesium Chloride ,, — to -('7 
Potassium Cliloride ,, — to trace 
Calcium Sulpliate — to 1-65 
Magncsiiim Sulnhatc ,, — to 2-30 
Magnesium Cari)onate ,, — to -15 
Calcium CarlnMiate 
Ferric Chloride 
Insoluble matter 
Water 
to 
to 
to 
to 
•16 
•05 
3-35 
■63 
Sulphate of Iron. 
It was formerly considered that most soils 
contained sufficient iron for the use of plants, 
and that iron in any form except jjeroxide exer- 
cised rather a hurtful effect on plant life. As 
the result of many experiments, however, Dr. 
Griffiths, author of. ("A Treatise on Manures) 
alreadj- quoted appears to prore the efficacy of 
applying iron in a soluble form even to land 
already containing a considerable proportion of 
U'on in an insoluble form. Dr. Griffiths says, 
that his original proposition, "that a fairly 
large proportion of soluble iron in a soil is 
favorable to the growth of plants developing 
a large amount of chlorophyll has been confirmed 
by all his subsequent investigations. He strongly 
recommends sulphate of iron both as a manure 
and as an antiseptic substance for application 
to other manures. Amongst the Tuany plants 
tliat are benefitted by it he mentions several 
tnat are cultivated in Ceylon, viz.. Tobacco, 
Indiarubber, Palm trees and Rose trees Thus 
from experiments on tobacco grown in England 
he has formed the opinion that the best manure 
for the tobacco plant is a mixture of 4 parts 
sulphate oj potash, 1 part iron sulphate, 1 part 
ammonium .sulphate. He quotes also Sibson's 
analysis of a favoi-ite horticultural manure 
called Zotikos, whicli in addition to a fair pro- 
portion of all the other manurial constituents 
contains also 2 '40 per cent of iron sulphate. 
The following is the : — 
Analysis of Zotikos. (SiBSON.) 
Iron sulphate (Fe^ So^) ... ... 2-40 
Organic matter and Ammonia Salts ... 34-28 
(Containing Nitrogen 4-4 = 5-34 of Ammonia) 
Sulphate of Lime ... ... ... 16 04 
Monocalcium Phosphate .. ... 7-48 
(Equal to Bone Phosphate made soluble 11-67) 
Insoluble Phosphates ... ... 8-13 
Nitrate of Potash and Alkaline Salts. .. 1.5-20 
(Containing Potash 4-62) 
(Containing Nitrogen 1-5 = 1-8 of Ammonia) 
Insoluble matter ... ... ... 2-13 
Moisture ... ... ... ... 14-34 
100-00 
This manure is much used by florists in 
England. 
In nearly all his experiments with iron sul- 
phate Dr. Griffith's applied it in the proportion 
of h an cwt. per acre, and he states that the 
limit of one cwt. per acre should not be exceeded, 
as sulphate of iron in e.xcess is poisonous to 
plants. 
To destroy fungal spores in farmyard manure, 
he waters tlif same with a solution of sulphate 
of iron cont:iining h lb. to a gallon of water, 
and to prevent the escape of ammonia from 
farmyard manure, as well as to destroy in- 
jurious germs, he recommends it to lie watered 
with a solution containiii'g 1 lb. oi the .salt to 
a gallon of wafej. Ccimmercial sulphate of iron 
contains, besides ferrous sul]>hate, a suifUl 1>»'<»- 
poitiou of alum, ferric sulphate, and otlier 
ingrotlients. 
