The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1883-04-28
Trees in Cities.


ty, or otherwise, of trees in the streets and
open spaces has been lately going on here
in the columns of the local press. The
controversy arose out of discussion in the
International Hygienic Congress which was
held here in August, and Dr. Piachaud, a
member of the congress, has since contend
ed, in a letter addressed to the Journal de
Genera, that trees in streets do more harm
than good, shat they impede the circulation
of air, and that, as for the shade they afford,
people who do not like sunshine have only
to keep on the shady side of the street.
Instead Of planting more trees in towns, as
some propose, he would rather in the in
terest of hygiene, remove all the existing
trees To him replies Prof Goret, of the
university, who, though an eminent physi-
cist and chemist, disclaims any special
knowledge of medicine or hygiene. He
treats the matter from an exclusively com
mon sense and scientific point of view. As
for people who want shade keeping on the
shade side of street, he points out that,
as streets have generally shops and houses
on either side, DIR. Piachaud's advice, in
this regard however ingenious, can hardly
be regarded practical. But the functions
of trees in streets are not limited to acting
as screens for sunshining wayfarers; they
temper the heat and serve as protection
against dust The evaporation from their
leaves tends to keep the surrounding air
cool and moist One of the best means of
refreshing the air of sick chamber is to
place in it plants and branches and sprinkle
them with water. 4 like effect is produc-
ed by trees. Sunlight is necessary to health;
but, trees, if not too thickly planted do
not intercept sunlight; the perpetual vibra-
ton of their leaves and swaying of their
branches admit the light every instant, and
in sufficient measure and serve, moreover,
to protect the eyes from the noon-day glare
SO far from trees impeding the circulation
of air, they help to purify the air, the avap-
Grafton from their leaves determine a cur
rent from above, and the fresh air thus
brought down helps to drive away the
heated and dust-impregnated gases of the
streets. Another useful property of foliage
is that while in hot, dry wether is moistens
the surrounding atmosphere, thereby rem
dering it filter to breathe, this effect, which
is due to evaporation, ceases in wet weather.
Trees, moreover, act as purifying agents by
absorbing carbonic acid and giving out
oxygen. But the action of the trees on
the air is far less important than their ac-
ton on the soil. Their roots draw up stag
nant waters absorb the organic matters
contained in the filth from which the streets
of town are never free, and which, after
inflerating the grould, are a frequent cause
of fevers and infections. Trees, in fact
have the same effect on the subsoil of towns
as fields; on the contents of their sewers
they act as disinfectants Taking these
facts into consideration, Prof Goret ven
lures to differ from the conclusions of the
hygienic congress, and strongly recommends
the planting of trees in streets and squares.
But they must be planted with judgment,
They should be two to three meters apart,
and the branches should not be allowed to
come in contact with the buildings near
which they grow. The sorts best adopted
for street planting are those which grow to
considerable height and spread out their
branches The fashion that prevails in
some continental cities of cutting trees
down to uniform size is highly objection
able. The branches of trees so situated
become so compacted together as to be i'm
pervious to light, and the shade they give
deep, is too circumscribed to be
of much use.-Gencca (S,citzerkand) Car.
London Times.