The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1896-10-19
AGAINST WOOD V |
EUROPEAN DOCTORS on MERITS OF
WOOD, ASPHALT AND GRANITE.
Interesting Experiments Showing
Number of Microbes That Are
Found at Various Depths.
Euronean Edition New York Herald.

European Edition New York Herald.
People are examining now the question of
the preference to be given to the different
substances generally used in paving streets.
granite, asphalt and wood. All depends
evidently on the aim to be attained. II it is
desired to avoid noise a wood pavement is
best, and next come asphalt and granite.
As regards cleanliness. asphalt comes first,
then granite. and wood last. From an eco
nomical point of view granite leads, fol-
lowed by wood. with asphalt last.
Asphalt can be more easily repaired than
wood, which in turn is preferable to gran
lite IN that respect. Granite lasts longer
than asphalt, and asphalt than wood. Gran
lite is better for horse-cars than wood, and
much more SO than asphalt. To prevent
horses falling, wood leads, and then comes
asphalt. From a hygienic point of view
asphalt deserves the preference, wood be-
ing the least desirable. In making an aver
age, then, we find that asphalt holds the
first rank, with granite second and wood
third; but as regards noise, safety and re-
pairs, the advantages of wood give it the
preference whenever hygiene and cleanli-
ness are not of paramount Importance.
These opinions, which are based on obser-
walton in the different large towns in Eng
land, seem to me, at any rate, as far as
concerns the hygienic part, to be decidedly
open to question. From a hygienic point of
view wooden pavements have fervent advo-
Gates and irreconcilable adverSarieS, who
both bring forth arguments which are the
more contradictory in that they are based
on the same experiments. 1t is, therefore,,
difficult for the outsider to form an opin-
ion.
A number of hygienists and contractors
for municipal work claim that wooden pave
ments give rise to an impalpable dust COM
posed of pulveriZed fibers, which is taken
up into the respiratory tract; that they abb
sorb the mixture of rain and manure which
fall on their surface and thereby rot; that
they allow this liquid to filter through the
cracks between the blocks of wood and to
accumulat on the surface of the cement
on which the blocks are laid, thus giving
rise to a permanent focus of putrefaction.
"A French military Engineer, Nj. PetSche,
guided by the experience he has acquired
through the steadily increasing amount of
and particularly in Paris and London, an
increase due to the demand of the people
into the streets by the method of paving.
claims that with two or three big waShings
a week, good sweeping and two or three
distinctions q day at cab or omnibus sta
lions wooden pavements give no odor. How
ever, as these precautions are not carried
out anywhere that L am aware OF, the con-
clusion is that NJ. Petsche admits that
wooden pavements smell.
AS. regards the dust, NJ. Petsche denies
absolutely the assertion that wooden pave
m cause a greater ar, amount than
ny III IdCt tlldl inc WOOocll plOChS Oflly
wear down two or three millimetres a year
in most streets, four or five millimetres a
year IN streets with average traffic and
one centimetre at most in very busy
thoroughfareS.
AS regards the penetration of liquids
through the cracks between the blocks NJ.
Petsche claims that this is not possible,
owing to the swelling of the blocks through
the action of water. He says that so far
as Paris is concerned no one has ever
found ~stagnating liquids on the cement
basis on which the wood is laid down.
AC poa n In nhCnrnttnn Of ronn
liquids by the blocks of wood, experimental
ton only was capable of settling the ques-
mated with microbian infection. However
may have been the results of the
of sydhey. W MSo IN Ry 1 Mi M fai1ed Ga to fn Smith an1
p~athogenic organism in a block of paving
wood that had seen eleven years service,
the street department of Paris requested
Nj. MIGUEL to undertake new experiments
to confirm or upset the results of those
that the result of these experiments showed
clearly that wooden are
not as culpable as the advocates of other
sorts of would like to make us
believe.
In testing the penetration of microbes
into the wooden blocks NJ. Miguel removed
a decigramme of sawdust from the bottom
of a hole bored in a block with a drill ster-
lliZed by heat. He then diluted his sawdust
in ten cubic centimeters of sterilized water.
soWed IL on nutritive gelatine and counted
the number of colonies after thirty days
incubation at a temperature of from 20 to
% degrees centigrade.
With new blocks of wood the sample of
taken at a depth of three cent?
meters gave $50 bacteria per gramme Of
sawdust-that is. less than one per milli-
gramme. For old blocks that had seen six,
or min years of service a layer one
or two millimeters thick was first taken
off the surface. which had become incrust-
ed with earth and sand.
These results, seemed to show that wood
en- pavements are not penetrated by mi
crobeS, which remain adherent to the SUI
layer containing from one million
to one and a half million per gramme of
ga wdust. Unfortunately this conclusion is
In complete contradiction with that arrived
at by MN. Rodet and Nicholas, of Lyons,
In similar experiments.
These two men set out to verify the accu-
racy of NJ. MiouePs work-that is to say,
they made the quantitative analysis of the
microbes contained in paving blocks at diff
ferent depths. In doing so they followed
a somewhat different method, which gave
them an extremely fine powder of the wood
they took at different depths, and 1t is
probable that this will account very largely
for the difference between the results. The
Paris pavements, after three or four years
use, showed on the surface. after washing,
more than 10000, 900 bacteria; there were
"a, 2l0 at one centimeter, 43. 100 at three cent?
meters and 81 100 at five centimeterS.