510 
JOCRXAL OF HORTICULTURE AXD COTTAGE GARDEXER. 
[ December 11, 18“0. 
contain iron, even pond and ditch scourings. They are sweetened 
by lime. 
Trap rocks by decay produce clay soil, containing iron 6 84, 
fertile—in fact, decomposing trap is a mineral fertiliser. Old red 
sandstone soil in Herefordshire contains “ cornstones ” embedded 
in marl, decomposing into a soil of great ferti ity—reddish through 
a large per-centage of oxide of iron. Apple and Pear trees have 
given Herefordshire cider and perry a world-wide fame. 
New red sandstone seems to form a soil specially suited to 
Apples ; they like red soil. Note the fact, the trias of Devonshire 
and Gloucestershire rival Herefordshire by its cider. Apple trees 
thrive on the middle lias of Somerset. Even a county (Rutland) 
takes its name from red land ; that on the mi idle lias is very 
fertile. Stilton and double Gloucester cheese result from the rich 
pastures of the lias clays. Cheddar is produced by cows browsing 
on the pastures of the alluvium lias clay. Where fertility is there 
the soil is red—oxide of iron ; but malm (firestone) is a calcareous 
sandstone of the upper greensand upholding the rich land of 
Farnham. Alluvial soils consist of well mixed detiitusworn from 
various formations, and warping for the sake of the fertili-ing deposit 
is practised. Some livers leave a deposit containing 15*65 peroxide 
of iron. In Lincolnshire and Yorkshire rich meadows and pastures 
are produced by warping. The Ouse, Derwent, Trent, Humber, 
1 hames, and Severn have produced alluvial soils—all rich. Brick 
earths are “ wash '—detritus worn from hills rolled down to 
produce rich soil in plains. Drifts are generally fertile ; the 
boulder clay of Ilolderness, Yorkshire, is syenitic ; Norfolk boulder 
clay is schist, iron borne on the bosom of icedrifts from Sweden 
and higher latitudes. 
There are a few facts about iron in soils not, perhaps, generally 
known. They are mainly gleaned from a very handy book of 
1 <6 pages, entitled “ Soils and their Properties,” by Dr. W. 
Fream, and afford the best answer possible to the dictum, “ iron is 
a source of injury in soils," as is often asserted. In no case is 
it a cause of mischief where there is intelligent culture. It strikes 
Apple trees down with canker in light soils, aud uproots them 
through canker in wet. If there is anything in facts they go to 
show that fruit trees are stricken in light soils through poverty— 
want of iron to grip ammonia : in wet soils through iron failing to 
get ammoniated for lack of air. In any case iron is not an enemy 
to, but a friend of the cultivator. Dr. Griffiths, in “ Manures and 
their l ses, page 99, states that on the German moorlands 
'Thomas phosphate has proved equal to superphosphates. That 
is a clinching argument in favour of iron, but it is set down to 
economy—“ a cheaper source of phosphoric acid.” Thomas'phos¬ 
phate contains ferrous oxide 14*66, and ferric oxide 8*64 = 23 30 
iron. Teat soil contains when fertile 6 30 to 9 03, and 10 30 per 
cent. : sterile 0*46, 0*63, and 0 78. Moorland has all its iron washed 
out. hence the value of Thomas' phosphate, but this phosphate 
contains lime. Fertile peat contains 1 to 5 per cent., unfertile 
043, 0 32, 0.55, Thomas’ phosphate 41 to 47 per cent. Is the 
benefit, then, to be attributed to the iron'? According to the 
German savants, tie English agreeing, the phosphoric acid in 
Thomas phosphate is half as valuable as that contained in super¬ 
phosphate of lime, yet it gave “equal, if not better results than 
superphosphate on the German moorlands." Superphosphate 
ought not to contain iron oxide, but Dr. Yoelcker found 4 64 in 
adulterated bonemeal. Clearly iron made Thomas’ phosphate 
equal to superphosphate on the German moorlands. On loam over 
clay I found no benefit from the iron in Thomas' phosphate at 
8 to 10 cwt. to the acre. A good handful, it may be stated in 
passing, per square yard improved the colour of Yine and Peach 
foliage ; iron evidently is useful in forming chlorophyll, as will be 
shown presently. 
All barren soils are deficient of iron. Sandy with a pan caused 
by shallow culture contain ferric oxide 2*00, humus being low 1 50, 
which makes just all the difference, for a black sandy mould had 
very little more iron, 243, but nearly 10 per cent, humus, and over 
10 per cent, alumina, therefore it was fertile because alumina holds 
ammonia and iron, both ammoniating that substance. The barren 
had more sand, no more than a trace of potash, a half per cent, of 
alumina, nothing wherewith to grasp ammonia, the iron being iu 
nodules, and wanting lime : indeed, there is no such thing as barren¬ 
ness where iron exists along with lime, alumina each from 3 to 5 per 
cent., potash equal to 2 per cent., and phosphoric acid not under 
0 25. and sulphuric acid not less than 040 to the extent of 4 to 6 per 
cent. It is injurious because it wants something to render it use- 
inl : in fact, it requires work. If none be granted it may act 
deleteriously. M. Yille declares that using nothing but farmvard 
manure exhausts the soil, but the Rothamsted investigators on this 
paint state that where ** there is a liberal use of animal manures, an 
accumulation of nitrogenous and mineral matter takes place in the 
soil. Ihis is conclusive, and light soils require animal manures 
more than heavy, for the simple reason that they lose more through 
washing. Another reason is they last longer. M. Yille, however^ 
states that only nitrogen, potash, lime, and phosphoric acid need be 
added to any soil in the form of manure. It seems that fertility 
of soils depends largely, if not entirely, on nitrification, and this 
on organic matter. Of course there is the organic remains of pre¬ 
vious crops, and in the case of fruit trees their annual fibres to 
work on, else where does the organic matter originate where no 
manure is applied ? Ammonia results from nitrification, is oxidised, 
becoming nitric acid, this unites with potash, soda, and lime, form¬ 
ing nitrates, and these are soluble, and become plant foods. There 
is something more, organic matter wherever it ferments is con¬ 
verted into carbonic and other organic acids, these are neutralised 
by lime, potash, itc., rendering some plant foods active and con 
serving others. Iron is a conserver of ammonia, it fixes ammonium 
carbonate. The stench from piggeries is notorious, and manure 
heaps are not always particularly sweet. Iron sulphate saves the 
waste of ammonia from manure by fixing it, the heap being watered 
with a solution of it, say 1 lb. to 20 gallons of water. Iron, there¬ 
fore, is useful, a double sulphate of ammonium and iron is formed, 
the stench is taken away, the manure remains. 
Road scrapings have virtue—iron, especially where whinstone 
is used or slag. All fruit trees like rt along with lime ; that, and 
silica, and iron help them to form stouter cell walls, to form flinty 
bark, to resist their fungoid enemies. English coprolites contain 
iron oxide and alumina 4*87 to 5*39 iron oxide, foreign 2*82 to 
13*14 or more of iron oxide and alumina. They are best raw, 
especially for light soils. 
Iron is present in all fertile soils, in all natural waters, and iu 
all plants. Peroxide of iron and alumina, according to Liebig, 
form solid compounds with ammonia, and the precipitates obtained 
by the addition of ammonia to salts of alumina or iron are true 
salts, in which the ammonia is contained as a base. In fact, “ all 
rust of iron contaius a certain amount of ammonia” (Yauquelin), 
and Chevalier found ammonia a constituent of all mineral con¬ 
taining iron. “ Soils, therefore, containing oxides of iron and 
burned clay must absorb ammonia” (Liebig). They further pre 
vent, by their chemical properties, the escape of the ammonia once 
absorbed; but the ammonia absorbed by ferruginous oxides is 
separated by every shower of rain, and conveyed in solution to the 
soil. That gives iron some credit ; but it is only half-hearted, for 
if iron forms compounds with ammonia it must liberate (render 
insoluble substances soluble) plant food. Ammoniated iron is as 
useful as ammoniated guanos, and better on soils derived from 
limestone aud chalk rocks, for these set ammonia free, so that it 
volatilises into the air. Sulphate of iron, as before stated, prevents 
the escape of ammonia. 
Soot contains oxides of iron and alumina 15*69 per cent. (Dr. 
Yoelcker). How it beautifies sickly Wheat plants, puts green into 
Peas ! Dr. Sachs says iron is indispensable to the green matter 
(chlorophyll) in leaves. “ Iron sulphate,” Dr. Griffiths tells us, 
“ destroys Peronospora infestans (the Potato fungus).” Prince 
Silm-Hortsmar tested the value of iron on Oats, “sickly and 
almost colourless" without it. “Knop, in 1859,” states Dr. 
Griffiths, “ experimenting upon hybrids the most favourable to 
plant growth, recognised the necessity cf adding phosphate of iron, 
or of sprinkling the roots of plants upon which he operated with 
this salt, and from his experiments drew the conclusion that these 
four bases—lime, potash, magnesia, and iron oxide—were indis¬ 
pensable to plants.” 
Soils poor iu iron oxide and lime appear most benefited by iron 
sulphate with an addition of lime, and on land on which, it is 
alleged, iron causes Apple trees to canker—viz., light, sandy loam, 
well drained—iron sulphate brought nearly 2 tons more of Potatoes 
per acre than land manured with farmyard manure and night soil 
mixed. The manure produced 5 02 tons, a dressing of three- 
quarters of a hundredweight iron sulphate per acre 6*76 tons, again 
iu value of £3 2s. 3d. for an expenditure of less than £1. 
Copperas or iron sulphate has long been known as an agent in 
the destruction of fungoid germs. Cereals are steeped in it before 
sowing to get rid of smut, ergot (Claviceps purpurea)—indeed, it is 
an antiseptic of the first order. It effectually destroys ergot in 
grass seeds, and there foster ergot through farmers allowing grass 
seeds to mature, for where grass is cut in flower there is no ergot, 
and a dressing of iron sulphate destroys fungoid germs in grass: 
lands, and kills moss. Iron sulphate combats the Potato disease 
(Peronospora infestansl, also the fungus on the tubercles of the 
Pea and Bean, Clover and Yetch roats—indeed, on all the pod 
bearers. Nodular outgrowths on Turnips are due to a fungus 
(Plasmodiophora Brassicm), for which no remedies are so good as 
lime where the soil is not calcareous, and iron sulphate where it is, 
or both where there is a deficiency of soil constituents. 
Now. I would ask space for a little inquiry into some disease I 
have occasionally of late years had to contend with in Cucumbers 
and Melons. The late Mr. R. Fish, in the Journal of Horticulture % 
