FOG, FLOWERS, AND FOLIAGE
“Air, air, fresh life-blood, thin and searching air,
The clear, dear breath of God that loveth us.”
Air is invisible, and earth a very tangible thing indeed, which makes
us forget sometimes how much air does for us, to feed and nourish. We
do not only live in it, we live of it; and by _we_ I mean all breathing
creatures, whether men or lower animals or plants. What brings the
truth most home to us is having to do without air--in a London fog, for
instance.
We have been talking a great deal about the flowers and plants of
London. Alas! very few of them are grown there; most of them have to
be imported. During the winter months fog is too terrible an enemy, so
insidious is it, playing havoc even with our indoor and conservatory
plants.
It is interesting to learn from the researches of the savants, that
the evil effect of urban fog on flowers and foliage is twofold. The
injuries are produced in two quite separate ways: one is the presence
of poison in the atmosphere; the other, the reduction of light, which
is the invariable result of the fog of cities and manufacturing towns.
Darkness and poison! Does not this sound worse than a plague of Egypt?
Yet we town-folk suffer it without much grumbling, and scientists
spend as much time in learning what the poison consists of, and in
tracing exactly how the injuries come about, as would suffice, one
would imagine, to discover a cure. Oddly enough, more poisons are
found in fog than even coal-burning altogether accounts for; the exact
nature of some of the substances which are present in the atmosphere of
foggy weather is a matter about which scientists themselves confess to
ignorance.
Still, there is one thing on which all agree, and that is the perfect
harmlessness of clean mist. Neither mountain nor country mists do any
wrong to plant life, and from the coasts of Kent and Sussex, Essex and
Norfolk, come assurances of the innocuous character of sea-fogs.
Of the known impurities of town-fog the following list gives most
of those suspected of being inimical to plants. “Suspected” is the
scientific way of putting it. Our scientists are wary; they must be,
for they know how everybody weighs their words; and besides that, they
can never be sure what fresh discoveries will be made to-morrow; the
latest are oftentimes upsetting.
The amount of miscellaneous ingredients that enrich a London fog is
startling. Our list is taken from an analysis of the deposits left on
the glass roofs of plant-houses at Chelsea and Kew during the severe
fogs of February, 1891:--
Carbon, hydrocarbons, organic bases, sulphuric acid, hydrochloric acid,
ammonia, metallic iron, and magnetic oxide, with other mineral matter,
chiefly silica and ferric-oxide. Sulphuric acid, it seems, is the
principal cause of injury to trees and shrubs, and sulphurous acid to
herbaceous and soft-wooded plants.
The effects of fog are seen sometimes in the breaking-down of the
plant, sometimes in its discoloration; leaves gradually turn yellow,
progressing from below upwards, and they drop off in the order in which
they showed the change of colour. Thus two things have happened:
destruction of the green colouring matter, and structural injury at
the point where leaf meets stalk. Where is the London flower-grower
who has not watched these processes with sad eyes? When an ill wind
blows soot-laden fog towards Kew or Chelsea--places where so many of
our choicest plants and trees and flowers are cherished--loud are the
lamentations because of damage done.
Mr. Watson, assistant curator of the Royal Kew Gardens, says he gathers
up bushels of leaves in the palm-houses every morning while a bad fog
lasts, and after a long spell of it many hard-wooded as well as the
more delicate plants are reduced to an unsightly condition of almost
bare stems, blotched and discoloured leaves, and fallen foliage. Among
certain groups even the soft stems disarticulate at the nodes.
Mr. W. Thiselton-Dye, Director of Kew Gardens, describes the substance
deposited on his glass-houses as a solid brown paint, weighing about
twenty-two pounds to the acre, or six tons to the square mile. This
makes our fog enemy appear a very real thing indeed; no wonder it
breaks plants down, and is the ruin of many fruit and floral industries
in the south of London.
Are there any means by which town cultivators may counteract these
malign influences? Only by very expensive appliances. The grower wants
an air-tight greenhouse, with definite openings where the admitted air
can be filtered. Filtering foggy air may counteract or even keep out
poison, but even then one has to make up for the darkness. This can
only be done by a generous installation of electric light.
[Illustration: A WATER GARDEN]
Horticulture thus carried on is extremely interesting from a scientific
point of view, but is not commercially desirable, nor could the
ordinary flower-grower afford it. Fog-annihilators, and the use of
chemicals in conservatories have also been tried, the latter with
very scant success. Charcoal seems to be by far the best filtering
medium. There is a Mr. Toope, who, in a small conservatory at his
offices at Stepney, is endeavouring to cultivate a collection of
orchids and other stove plants in safety by the use of charcoal filters
and warmed air.
The method he uses is ingenious. Boxes containing open-work trays,
upon which sticks of charcoal are loosely placed, are set upon the
floor under the staging. These communicate with the exterior by means
of apertures which can be opened or closed at will. The air (fog and
all) is led from outside through these trays, passes the charcoal,
impinges upon the hot-water pipes, and is then allowed to reach the
plants. Draught is regulated by valves. Results so far are considered
very encouraging, but not convincing. Mr. Toope has other things to
occupy his attention, and sometimes has to trust his pets to others; if
it were not for this, he thinks he would ensure a greater measure of
success.
It seems curious to think of plants taking to respirators, just as
human beings have discarded them; but the use of charcoal does sound
common-sensible. We are all familiar with the extraordinary power
charcoal has of absorbing and oxidizing the products of decomposition
of organic matter, and of rendering harmless the greater number of
easily alterable gases and vapours. A few years since, after some
nursing lectures at the Royal Hospital for children and women at the
Waterloo Road, the following examination question was put to the
students: “How would you ventilate a room of a smallpox patient on
the night of a dense fog?” The question puzzled us all. We were told
the right answer afterwards. “Open the window at the top, and hang up
a blanket.” This appeared to me to be a stifling arrangement; as at
present advised, I would treat patients as Mr. Toope treats his plants,
and give them charcoal filters instead of the blanket. The chemist
Stenhouse has devised a respirator for human beings on the charcoal
principle, for use in districts smitten with cholera or yellow fever.
_What Plants suffer least from Fog?_
This is such an important question for town people that I have given
it a separate heading. Here is the answer: Ferns and bulbous plants.
The latter have but a short reign ere they die off, so that we must put
down Ferns as the Londoners’ greatest stand-by. Considering the tender
and delicate nature of their foliage, this is one of the things we
should deem a miracle if we were not used to it, but the frailty of the
Fern is only in appearance.
Professor Oliver, in a Report to the Scientific Committee of the Royal
Horticultural Society, says, “At Kew Gardens I have examined the
various Fern-houses after spells of severe fog, when the collections of
stove plants in adjacent houses were completely disfigured from this
cause, without remarking any damage to the Ferns to speak of.”
How is this? Ferns are shade-loving plants, so that darkness, such a
terrible foe to most plants, is to them comparatively harmless. Other
things being equal, the more greedy a plant is of sunlight, the more
will it suffer when its illumination is reduced. There is another point
that tells in favour of the Fern. During the sunless months of autumn
and early winter the vitality of most flowering plants is lowered,
which renders them unfit to bear a strain--they are “run down,” and,
like ourselves in the same circumstances, liable to “catch” anything,
and go under. Ferns, on the other hand, meet the enemy and battle
with it in good condition; no doubt their excellent constitutions are
largely inherited from early forefathers who lived in an age that was
far too rough for flowers; they were giants in those days.
Bulbous plants stand fog well for a different reason. They rely on
the stores collected, each one for himself, in his own compact small
body. No squirrel nor dormouse is more thrifty, nor better understands
the art of making hay while the sun shines. This is how it is that
Londoners are so successful in growing bulbs. Look at the parks in the
spring-time, with their sheets of Crocuses, Snowdrops, and Tulips.
Allium, too, and Narcissus and Hyacinth, are just as happy close to,
and even in the midst of towns, showing very little injury after being
exposed to fog. Flowers and flower-buds are the first parts of any
plant to evince suffering; six or seven hours of a bad fog will suffice
to leave a scar, but the flower that shows the blemish is pretty sure
to be growing on a plant that has no useful bulb set at its base.
London fog is often the signal for much burning of gas. The usual
hardiness of the Fern deserts it here; no plants have a greater dislike
to fumes of gas; they resent them as much as any other of God’s
creatures who were meant to live and breathe in the sweet air which is
heaven’s best gift.
What precautions can be used in foggy weather? Experience shows that
a low temperature and a moist atmosphere are most conducive to the
well-being of plants indoors. It is not very easy to secure these
conditions; glass roofs are a source of dryness in cold weather. The
temperature of a roof is lowered by the external air, in consequence
of which, the moisture of the hot-house air is precipitated upon the
inside of the glass, whence it runs down in the form of “drip.” Drip
and dryness, what plants can put up with these? We must guard against
them.
The more one reads about and learns the ways of fogs, the more one
longs to scotch the snake itself, instead of endeavouring to cure its
bites. Why does not the Coal-smoke Abatement Society wake up and try a
little harder to do _something_?
At a meeting of this society at Grosvenor House, presided over by Sir
W. B. Richmond, there was a good deal of talk that was well worth
listening to. Principal Lodge moved that, “The injury and waste caused
by the escape of coal-smoke in cities demand the strict enforcement
of the laws existing for its elimination, and the adoption of such
further remedies as it is within the present power of science to
devise.” Very good, all that, but he went on to say that he thought the
continuance of the evil was largely due to the apathy of the public.
This resolution was seconded, and carried unanimously. _The Apathy of
the Public_--that means you and me, reader. What can we do to express
our feelings?
Sir W. B. Richmond moved another resolution, which was also agreed
to. He said the clause of the Public Health Act, 1891, which related
to the smoke nuisance, was practically set aside by many authorities
entrusted with its execution. “Three strong obstructions to the purity
and cleanliness of London air were--apathy, vested interests, and
insufficient fines for breaking the law.” An account of this meeting
was published in _The Garden_ of December 14th, 1901, where I read it
with mingled feelings of anger and amusement, but my conscience did not
accuse me of apathy.
[Illustration: LILIES IN LORD ILCHESTER’S JAPANESE GARDEN AT HOLLAND
HOUSE, KENSINGTON]