September 4, 1890. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
203 
the days lengthen and the plants insrease in size until cool airy 
treatment can be givqn, which is necessary from the time they are 
placed into 5-inch pots. During the early growth of the plants the 
house should be closed early in the afternoon, while later in the 
season the ventilators may remain open at night. 
If Cyclamens are kept growing and the syringe freely used 
insects are not a source of trouble ; but if the soil about the roots 
and the atmosphere of the structure become dry aphides increase, 
but are readily destroyed by slight fumigations with tobacco. 
Although a moist atmosphere is necessary a stagnant one must be 
avoided, or their beautiful foliage will damp and thus give the 
appearance of disease.— W. Bardney. 
PHOSPHORUS. 
This chemical element “ is never found uncombined in nature, 
but always in combination with oxygen and a metal (chiefly 
calcium) as a metallic phosphate. Apatite, phosphorite, and 
coprolites are minerals composed chiefly of calcium phosphate.”— 
(“ Murby’s Inorganic Chemistry,” p. 148). Apatite is a compound 
of phosphate of lime with fluoride and chloride of calcium, forming 
in Spanish Estremadura whole beds alternating with limestone and 
quartz. It is imported into this country, and used for the same 
purpose as-bones—namely, to enrich the soil with phosphoric acid. 
Phosphorite consists essentially of phosphate of calcium. Copro¬ 
lites are the fossil remains of extinct animals found abundantly in 
the lias, greensand, and Suffolk crag. Their constituents are 
chiefly phosphates of calcium and magnesium, carbonates of those, 
and some organic matter. They possess well-known fertilising 
properties. Reduced to powder they are used as ground bones, 
treated with sulphuric acid they form superphosphate of lime. 
Those are some of the sources from which phosphorus or phos¬ 
phoric acid is derived, but principally, as a fertilising agent, from 
bones consisting of calcium phosphate. Animals derive their 
substance from plants, these take it from the soil, in which it exists 
in small quantities, and soils are derived from the primitive rocks 
by disintegration. 
Phosphorus, combined with other elements, exists in the brain, 
the blood, and all the soft animal tissues, therefore is one of the 
essential chemical elements found in all living subjects. Uniting 
with oxygen it cannot remain unchanged when exposed to the air, 
therefore always occurs combined with other elements. 
Of the use of phosphorus to plants little is known, its uses not 
being determined with much certainty. It is considered that it acts 
not only in building up, but in energising the actual living substance 
of plants as well as animals—viz., the protoplasm, and is the 
principal agent in the transference of the living principle or the 
protoplasmic substances from the formative cells to those in which 
they are to be employed, whether those obtain in o!d tissues or the 
formation of new. Phosphorus on these premises is the energiser 
if not the inductor of the living substance in plants. These derive 
it from the soil, where it exists combined with other elements, the 
principal source of supply being phosphates of lime. These differ 
in the per-centage both of phosphoric acid and calcium. Some 
limestones contain as much as 7 per cent, of phosphoric acid, others 
scarcely a trace, and their value depends on the solubility in water. 
Phosphorus, however, seems to be inseparable from lime, at least 
those elements—viz., calcium and phosphorus—are found in the 
ashes of all plants in greater or less degree. 
Soils deficient in phosphoric acid cause a dwarf and stunted 
growth, which on the application of phosphatic matter is relieved, 
the plants are rendered vigorous and healthy by the presence of this 
essential element in their food. Lime or calcium supplies plants 
with sulphur and phosphorus from the sulphate and phosphate of 
that substance respectively, and equally important with that or the 
basic element—viz., calcium combined. Calcium neutralises acids, 
not only in the soil but in the plants ; oxalic acid forms largely in 
the tissues of growing plants, and is injurious when it is in excess ; 
lime of itself forms nitrate of that substance when applied to soils, 
and it is believed that bacteria remaining inert amid vegetable 
acids are on lime being present to neutralise the acids made active, 
and the lime through their agency is changed into nitrate. Lime 
on entering the plant tissues combines with the oxalic acid forming 
oxalate of lime, which is not injurious, therefore neutralising acids 
in soils by lime dressings converts their poisonous elements into 
nutrition of a wholesome nature, and prevents the acids formed 
within the plant becoming injurious. 
Oxalic acid combines with magnesium, forming an insoluble salt 
or oxalate of magnesium ; but when this substance is in excess the 
salt is reacted upon, and becomes soluble, or partly so, the acid 
acting with increased energy injuriously on the plant tissues. 
Oxalic acid also combines with potassium, and forms oxalates, but 
these are of two kinds—viz., a neutral and a supersalt, and practi¬ 
cally do not neutralise or render the acid innocuous. This com¬ 
bines with sodium, but the oxalate is dissolved by sulphuric acid, 
the decomposition resulting in free oxalic acid. Ammonium or 
ammonia is neutralised by oxalic acid, so that ammoniaeal, potassic, 
and sodic elements are not antiseptic. Calcium completely exorcises 
oxalic acid, eliminating and converting it from an injurious to a 
perfectly harmless if not beneficial and essential substance. So 
strong is the affinity of oxalic acid for lime that it separates it 
from all other acids unless they are present in excess, and forms 
with it an insoluble salt—viz , oxalate of lime. 
Oxalic acid is formed by potash and soda acting on vegetable 
matter or humus. The salts or oxalates resulting are decomposed 
by sulphuric acid, whereby free oxalic acid is obtained, but these 
oxalates must first become calcium salts ; in fact it is from sodium 
oxalate that the calcium salt is formed, which decomposed by sul¬ 
phuric acid liberates free oxalic acid. Therefore, the remedies for 
plant poison or an excess of oxalic acid are potash, soda, magnesia, 
and lime. These are most active when acted upon by nitric acid— 
that is, they are most stimulating to vegetation when applied to 
soils in the nitrate state. This is found in practice to produce the 
evils it is desired to eradicate, as a superabundance of potash and 
sodium have no neutralising effect on free oxalic acid, consequently 
these do not subdue its virulence in plants liable to fungoid attacks, 
but aggravate gum in the Apricot, Cherry, Nectarine, Peach, and 
Plum, unless they also are neutralised by sulphur, or there is lime 
neutralising the oxalic acid simultaneously counteracting their in¬ 
ducements to the formation of the virus. Instead, therefore, of 
administering nitrates of soda and potash, chloride of soda and 
muriate of potash are found most conducive to health and fertility 
when the tendency to disease is induced by sappy growths, and 
imperfect setting and stoning of the fruits of the trees named. 
Now we have some palliation, and singularly enough an acid— 
viz., hydrochloric. Chlorine or chloride of soda combines directly 
with hydrogen (that is produced where there is an excess of organic 
matter in soils), forming hydrochloric acid. This is also produced 
by application of salt or sodium, and the acid so formed has the 
property of rendering silica soluble. This substance passes into 
plants by their root hairs, is broken up by oxalic and citric acids in 
the plant tissues, forming new compounds, whilst silica is set free 
in the sap, and is added to the walls of the cells, whereby they are 
hardened, especially the cuticle, and the plant is better able to resist 
attack by fungi, it also prevents the softening sappy tendency of 
nitrates on the plant tissues. In lime we have sulphur, but its uses 
to plants are not known, or uncertain. It is, however, considered 
essential to living beings, and is absorbed by the roots of plants 
from the soil in sulphate form. It seems that sulphates are broken 
up on contact with oxalates, organic compounds built up into pro¬ 
toplasm, sulphur being an element always present in the living 
substance. Sulphur in sulphate form is, therefore, an antidote 
internally, and sulphides externally of plant diseases of the fungoid 
character. 
All the substances named are essential to plant life, but their 
benefit depends on the maintenance of a certain equilibrium 
between opposed and equally energetic forces. If oxalic acid is not 
converted into oxalates decomposition of another kind sets in, 
which results in disease and death. This is the case in gum ; it is 
the case in canker. The former was long considered referable to 
errors of culture, or unsuitability of soil and climate. Those 
undoubtedly have a predisposing tendency to render the plant 
tissues assailable by the fungus, and it is useless attempting to 
avoid its attacks by any external means without first inducing 
health in the tree liable to attack. 
Nitrates are useful in accelerating growth where there is weak¬ 
ness, and with their base forming their respective oxalates with 
oxalic acid, yet they are liable to induce grossness, whereby plants 
are rendered more easily permeable in their tissues by fungoid 
germs. Muriates and sulphates have an invigorating and at the 
same time a counteracting effect on plants. Muriate of potash 
whilst stimulating the living substance liberates silica, hardens 
the cell walls, energising the protoplasmic molecules, whereby 
health and fruitfulness are assured ; alien matters are utilised 
or eliminated, if not actually expelled. Sulphates contain the 
essential sulphur, but the counteracting or building up principle 
is less pronounced ; indeed an excess of sulphuric acid appears 
to react on itself or frustrate the object for which that it is com¬ 
bined with is applied. None of those objections arise.when the 
base is lime. In any form it is highly antiseptic, especially when 
combined, as it is more or less, with the protoplasmic energisers 
sulphur and phosphoric acid. It neutralises oxalic acid, forming it 
into an insoluble oxalate, eats up the free acid of the Apple and 
Pear, and prevents saccharine and starchy substances from being 
converted in the stone fruits into gum. 
Lime is more valuable still as a source of phosphorus. Soils 
generally contain, as before stated a small quantity of phosphates 
