JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
468 
June 9, 1881 
some of that valuable mixture for Peach trees—Scotch snuff, 
sulphur vivum, and quicklime in equal parts, with it I painted 
some of the young canes, planted them, and shortly after com¬ 
menced syringing. This washed the mixture down to the roots, 
and instead of the Vines growing they died, and on pulling them 
up the roots were all black and dead. The same fate undoubtedly 
has followed the application of other mixtures when reasonable 
precaution has not been taken.— Joseph Witherspoon. 
WHAT PLANTS USE. 
Possibly much of what appears in the following remarks may 
have appeared again and again in the Journal, but much of it 
needs reiteration in order to its being pressed home on the minds 
of those to whom it is addressed. Horticultural writers, who quite 
understand what they are writing about, often fail to convey 
their meaning to those they address ; and if they should accom¬ 
plish this much, still, little useful purpose is served, for unless 
readers understand the reason why certain courses should be 
followed it is seldom that they are followed. Thus it is no un¬ 
common thing for novices in Grape culture, after reading that 
“ Vines require abundant supplies of water,” to forthwith tho¬ 
roughly wet the surface of their Vine borders and nothing more, 
and be eminently satisfied with their work, while all the while 
the Vines are languishing for want of water. It is commonly 
understood that vineries need to be ventilated, but the why and 
the wherefore few seem to understand. We do not refer to 
novices only, for we are convinced “ air-giving” is not so well an 
understood matter by even many good gardeners as it ought to be. 
It is not seldom that men have gained laurels and made names 
for themselves by merely imitating the successful practice of 
others. Were there fewer mere imitators and more practitioners 
who acted understandiDgly, we should not read and hear such 
sentences as these,—“Where Mr. So-and-so succeeds others might 
fail”—so often. Men fail because they do their best to imitate 
only. Were they to do nothing without understanding it, systems 
practised with the greatest success by some would not become so 
often discredited by others failing to do likewise. Certainly our 
practice ought to be judged by the success or otherwise which 
attends it; but there can be no doubt that the man who under¬ 
stands is more likely to succeed than the mere imitator. The 
one walks in light and can see the rocks ahead and avoid them ; 
the other gropes in darkness, and suffers shipwreck or escapes by 
a miracle. To be able to steer a safe course some knowledge and 
much study are required. Indeed, every gardener would require 
to be somewhat of a philosopher. We lay no claim to that title. 
We have dabbled in science, and tried to make science helpful in 
our practice, and have imagined, at least, that it has been so ; and 
now beg to offer a few crude observations in the hope that at 
least the less informed among your readers may be thereby 
benefited. 
* We have headed our remarks “ What Plants Use,” and have 
incidentally mentioned vineries ; we will, therefore, make the 
following remarks apply as much to Vines as possible, although 
much of it may be applied to any other plant cultivated under 
glass. 
Vines use air, light, heat, water, and a number of mineral 
matters. We will in this paper confine our remarks to air, light, 
and heat. It may seem a wonderful statement to some to say 
that after water air yields to Vines the greater part of their 
substance. The Vines themselves are chiefly formed from the 
carbonic dioxide which is present in the atmosphere to the 
extent of 1 in 2500 only, and yet the leaves, the fruit, the stems, 
and even the very roots which burrow in the earth, derive nearly 
all their substance from water—pure water, and the very small 
amount of carbon which is everywhere present in air in the form 
of carbon dioxide gas. The roots take in the water, the leaves 
inhale the gas, and cause the water and gas to be converted into 
something quite different from either. Water is a compound 
consisting of hydrogen and oxygen, and carbon dioxide is a com¬ 
pound of carbon, familiar to us as charcoal, coke, soot, &c., and 
oxygen. By a wonderful process not quite understood the plant 
causes these substances to cease being water and carbon dioxide 
gas, and reconverts them into wood, starch, gum, sugar, and a 
great many other substances called carbo-hydrates (hydro-carbons), 
because they are formed from the elements of water (hydrogen 
and oxygen) and carbon. All our vast coalfields, our bogs—at 
least the peat that is in them—the mighty forests that supply our 
timber ; the cornfields that supply our bread, our sugars, oils, 
teas, coffees, spices, our clothes ; almost everything we possess, 
which is not stone or metal, has been formed of water and the 
carbonic dioxide which is present in the atmosphere in the small 
proportion we have named. 
Small as it is, it is amply sufficient, however, if a current of air 
be constantly passed over the leaves. In nature this is con¬ 
stantly occurring, but not always in vineries. The leaves of 
plants, and especially deciduous trees, are densely studded with 
open greedy mouths—stomata they are called—which inhale the 
air and rapidly extract the carbon from the carbon dioxide, and 
set the oxygen free. “ On a single square inch of the common 
Lilac as many as 120,000 have been counted, and the rapidity 
with which they act is so great that a thin current of air passing 
over the leaves of an actively growing plant is almost immediately 
deprived by them of the carbonic acid it contains—( Chemistry of 
Common Life , page 58, new edition). What is true of the Lilac 
is no less true of the Vine ; and as a matter of fact Vines, even 
under diffused sunlight, when in a temperature of over 60° deprive 
the air of its carbon as rapidly as it is admitted by ordinary 
ventilation, and when no ventilation at all is given the air very 
soon becomes quite exhausted, and the Vines fail to find what is 
absolutely necessary to their well-being. 
In the absence of light—that is, during darkness, plants cease 
to manufacture the raw materials—air and water, into tissue¬ 
forming matter. Nay, when growing temperatures are main¬ 
tained during darkness these operations are reversed, and much 
of the work done by day is undone by night. Vines in a tempera¬ 
ture of G0° and upwards are always doing something. By day 
they build their structures ; by night they, to an appreciable ex¬ 
tent, unbuild it. On the other hand, when the temperature falls 
below 50° they do next to nothing at all—they rest. 
We have seen that under a high temperature, strong sunshine, 
and a plentiful supply of air and other necessary matters, plants 
grow with rapidity. It requires no science to teach us that— 
we are familiar with the fact; but we are far too apt to ascribe 
the whole to the high temperature only. It is not so, however. 
Light is as necessary as heat, and heat of itself is not enough ; it 
may, indeed, do more mischief than good. Under a dull sky 
leaves do not perform their functions so rapidly as under bright 
sunshine, even though the temperature should be artificially kept 
high. The exclusion of air, then, in order to maintain, say, a tem¬ 
perature of 80° is not good practice, and certainly tends to cause 
weakness in time. It is better by far to maintain a current of 
air in order to maintain a proper supply of carbon, even although 
by so doing the temperature should not be over 70°; indeed, we 
doubt if Vines will decompose carbonic dioxide and water more 
rapidly in a temperature of 80°, when the light is weak, than they 
will in one of 70°. With unobstructed sunrays acting on the 
leaves the case may be different, but there can be no doubt that 
the right thing is to make the heat and air supplies correspond 
with the light. We are quite aware that high temperatures 
induce precocity, and that forciDg is a race against time with 
many; but hard forcing accompanied with closed ventilators 
means speedy ruin. It is not so much the unnatural season at 
which early Vines and Peaches are forced which causes their early 
decay as the unnatural way they are forced. It is quite true that 
we often cannot help ourselves—that is a phase of the subject we 
cannot enter into here—but the fact nevertheless remains that 
forwarding the Vines by night and cheating them of a full supply 
of air by day is ruinous.— Single-handed. 
(To be continued.) 
MANCHESTER ROYAL BOTANIC 
AND HORTICULTURAL SOCIETY.— June 3rd to 10th. 
The above Society has again held a grand display of plants. In 
few places can a society boast of some 50,000 spectators visiting their 
exhibition, as was the case last year, and no doubt it will be as much 
thronged this as in previous years. The long line of carriages and 
the vast stream of ladies and gentlemen that poured in as soon as the 
Exhibition was opened gave a good idea of the popularity of the 
Society and the success that evidently attends its shows. One of the 
chief features of the event was the large number of Orchids, which 
were admitted to be the best ever seen in the Botanic Gardens. The 
first-prize collection staged by R. B. Dodgson, Esq., Blackburn, will 
long be remembered. The Orchids were arranged along the front 
on either side of the large Exhibition house, with the collections of 
stove and greenhouse plants in the background. The long table 
down the centre contained the miscellaneous collections of plants 
from Messrs. B. S. Williams, London, and R. P. Kerr & Sons, Liver¬ 
pool. To the right were staged the large plants of Messrs. Cypher and 
Sons, Cheltenham, and on the left those of Messrs. Cole & Sons, 
Withington. At the further end of the house were arranged the 
amateurs’ collections, and J. F. Williams, Esq., Worcester, well de¬ 
served the honours awarded him. It is questionable if he ever 
staged plants in bhtter form and condition. Passing into the next 
large tent, hitherto so famous for the noble specimen Roses shown 
in previous years; although the Roses were missed, the tent con¬ 
tained a choice collection of hybrid Rhododendrons from Messrs. 
