284 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ April 6, 1882. 
not at al] likely to present difficulties to the cultivator. It will 
undoubtedly take a high place in all large collections of plants 
when it is placed in commerce. 
Our engraving (fig. 56), represents a reduced drawing of a small 
plant in Messrs. Yeitch’s Chelsea nursery. The form and markings 
of the leaves are faithfully depicted. 
GALVANISED WIRE AGAIN. 
I have thought the following facts and enclosed specimens 
mighty be interesting to you and some of your readers. I had 
read with interest, and I hoped with profit too, the able articles 
on the above subject which you gave us in the Journal some 
fifteen months ago, and began to think that the mysteries in 
connection with the different effects of the use of galvanised 
wire for horticultural purposes were pretty well cleared away ; 
but at the present moment I am again in doubt on the subject. 
Last December we used some remnants of galvanised wire 
diamond trelliswork, and trained some young Roses to it. This 
trellis had been previously fixed in another position about eight 
years ago, but the Roses then trained to it, though of several years’ 
growth and in fine condition, did not thrive afterwards. The 
trellis was taken down and stowed away on the roof of a shed 
until about two years ago, when half of it was used for making a 
light fence, on which we trained plants of Clematis and variegated 
Honeysuckle alternately. These plants have made plenty of 
growth, twining closely round the wires without the slightest 
symptom of any injury. The remainder of the trellis was put up 
last December, as stated above, and the Roses tied to it, with the 
result, as you will observe by the examples I send, that without 
exception every portion of the plants that came in contact with 
the wire was blackened through and killed. Mr. Wright proved 
by experiment that Vine shoots were uninjured by contact with 
three-year-old galvanised wire, but here are Rose shoots killed 
after the wire has been exposed eight years, and yet we have 
galvanised wire arches covered with Clematis, and under glass 
Stephanotis, Bougainvilleas, Dipladenia boliviensis, Lapagerias, 
and Marechal Niel Roses trained to galvanised wires several 
years without injury.—G. Duffield, Winchmorc Hill , N. 
[The shoots are very severely injured. It has been proved that 
some wire is comparatively safe, other samples being decidedly 
injurious, and that the injury is greater within the smoke radius 
of towns than in the purer air of country districts. See page 588, 
vol. i., and page 2, vol. ii., new series. Two or three coats of paint 
will render galvanised wire innocuous to vegetation.] 
FERTILISERS. 
A press of other matters has prevented my replying to 
“ Inquirer ” (page 236) sooner, but an opportunity now offer¬ 
ing, I hasten to do so. 
Your courteous correspondent raises, in the first place, the 
question whether the artificial application of potash be necessary. 
He says he “lately heard from a gentleman who has the best 
means of knowing what is the practice of the agricultural chemist; 
that the chemist, in returning the fertilisers of a manure, does not, 
unless specially requested to do so, take any notice of the potash 
that may be present.” This rather surprises me, for I had thought 
that with nitrogen and phosphoric acid scientific men were agreed 
that potash should be associated in a generally applicable manure. 
1 was perfectly aware that much land, nearly all loam and clay 
soil in fact, contain what may be regarded as an almost inex¬ 
haustible supply of that compound, and that in such instances its 
application would be useless. When a soil contains from 1 to 
2 per cent, of available potash in addition to what is contained in 
the fragments of rock, which form the bulk of all soils, it may be 
regarded as settled that for agricultural crops any application of 
potash would be quite useless. Many thousands of cultivated 
acres, however, contain no more than 1 per cent., and though, theo¬ 
retically, this is a sufficient amount to supply the necessary potash 
for many crops, practically it is found that it is profitable to add 
potash. We know one scientific farmer who finds that even sul¬ 
phate of potash applied alone to the corn crop, although benefit¬ 
ing that crop little, markedly affects his second crop of hay by 
causing a luxuriant growth of Clover, which is only moderate 
unless helped. Yet his soil contains 012 per cent, of potash. 
It ha3 been calculated that 0*1 per cent, of potash in the upper 
6 inches of soil is equal to a ton per acre. As a crop of Potatoes 
amounting to ten tons per acre would not remove more than 
100 lbs., we might say that before such land could be exhausted 
of its potash twenty such crops could be raised before the neces¬ 
sity for potash could arise. Practical men find, however, that 
it pays to add potash at least to the Potato crop, even when 
there is a ton per acre lying available. 
The application of carbonate of potash alone to land containing 
0'5 per cent, in America, increased the Potato crop repeatedly from 
150 to 200 bushels of Potatoes. Even on our land the crop in¬ 
creased largely when carbonate of potash was applied, and this 
land contains potash available for 180 crops of ten tons each per 
acre—that is, theoretically. As a matter of fact, we have made 
many experiments—practical, not scientific ones—and have been 
completely bewildered thereby, and unable to come to any conclu¬ 
sion. With the help of superphosphate and nitrate of soda alone 
we have raised thirteen tons of Magnum Bonum Potatoes per acre. 
The inference of this would be that all that our land needs is phos¬ 
phoric acid and nitrogen, and that the supply of potash is suffi¬ 
cient, as in one sense it is. But with a mixture of sulphate of 
ammonia and carbonate of potash we have done the same. The 
inference of this is that only nitrogen and potash are wanted, and 
that there is enough of phosphoric acid. With sulphate of am¬ 
monia and lime the same results can be obtained, the inference 
being that neither phosphoric acid nor potash is wanted. With 
only wood ashes the same amount may be raised, so that not even 
nitrogen seems to be needed. Yet with no application the crop 
is under six tons. The fact is there is enough of everything in our 
soil to raise one or two moderate crops without any application, 
but the application of almost any plant-food—salt and soot even—• 
increases the crop. Such treatment is only practical and far 
too inexact to claim to be called scientific. It satisfies us, however, 
that in order to maintain it in full productive fertility we cannot 
better do than return as nearly as possible what is taken out. It 
may be granted at once, though, that for grain crops only phos¬ 
phoric acid and nitrogen need be applied. We find that one cart¬ 
load of manure, prepared by being sprinkled with sulphate of 
potash at the rate of 4 lbs. per ton, produces an effect equal to 
ten of unprepared manure. Whether this is brought about by the 
potash or the sulphate of ammonia we are not in a position to say, 
but believe both have some effect. 
That chemists do value the potash, and recognise the fact that 
it is often wanting, the following quotation proves. The words 
are Dr. Voelcker’s, and his authority is second to none. “ What 
they should do was to endeavour to convert cheap materials into 
more expensive ones—to supply the deficiency of any material, 
whether potash, phosphoric acid, or nitrogen, in a cheaper form, 
and to convert it into produce for which a higher price could be 
obtained.” Any number of quotations could be made to prove 
that we have not valued potash higher than we ought, nor higher 
than is commonly done. The above we quote just because it 
came handy and saved us searching further. 
“ Inquirer ” wishes me to revert to the following. “ He says 
that it takes time to convert the sulphate into the carbonate, 
‘ in which state potash is alone available practically as plant food.’ 
Is your correspondent right in this?” No: that was an unfor¬ 
tunate slip of the pen. What was meant was that the sulphate 
was practically unavailable until it was converted into the 
carbonate. 
Your correspondent wishes me to again consider the question 
of the conversion of the sulphate of potash into the carbonate, 
and the otherwise escaping ammonia into a sulphate. I cannot 
do this better than by making the following quotation from the 
Agricultural Gazette , where it appeared some time ago. “ I [Mr. 
Clement Cadle] consulted with Mr. Embry, one of the science 
masters in the Government Science Schools at Gloucester, and as 
the proposal (the chemical reaction in question) appeared to be 
chemically correct, the experiment was carried out with the more 
confidence. A quantity of fresh horse dung was taken to the 
Science Schools and placed in a large stone cistern, and between 
different beds of manure of a few inches thick we scattered the 
kainit. The smell of the dung was strong and offensive, and the 
pupils complained of it on the day it was mixed, but in a few 
hours the smell entirely disappeared. On the following day and 
subsequently no smell was observed; and when Mr. Embry tested 
the manure chemically three months after, he found a mutual ex¬ 
change had been effected, and instead of sulphate of potash and 
carbonate of ammonia evolved from decomposed manure we had 
carbonate of potash and sulphate of ammonia.” 
There is this difference between agricultural and horticultural 
chemistry—a soil with the plant food spread thinly through it may 
raise full corn crops, but the same amount of food would grow 
even the commonest vegetables but very poorly. The consequence 
is that even the most fertile agricultural land would not grow 
satisfactory crops of vegetables. Even 2 per cent, of phosphoric 
acid, potash, and nitrogen, although almost too much for Wheat, 
would not suffice for Cauliflowers. Garden crops really take so 
much from the soil that gardeners have to ignore to a great extent 
