Daily capital journal. (Salem, Oregon) 1903-1919, 1908-06-22


therefore most susceptible to attacks
from fungi. Heartwood, which can
usually be distinguished from sap
wood by its darker or more reddish
color, contains, on the other hand,
much less moisture. II is therefore
more durable than sapwood. But
because its pores are stopped up by
gums and resins It dies out much
less rapidly than the more porous
sapwood. In almost every case as
much care should be taken thor
ughly to dry out the heartwood as
In the case OF the moister sap
wood
BY pling the timber so as to per-
nit free access Of air all aronnd II
the moisture content of timbers of
certain sizes can be reduced to about
10 or Is per cent. OF course the
climate has a great influence on the
rate at which the wood dries out
and the total amount of moisture
II loses.
The moisture content OF alr-dry
wood can be still further reduced
by kiln-drying; and this Is empolyed
| to a considerable extent, but usually
for other purposes than increasing
the durability of the wood. More
| over, either air-dry or kiln-dry
wood has the power to reabsorb
moisture when exposed to the atmos-
phere in damp situations. and so the
benefits of drying, as far as dura-
bility is concerned, are only mod
crate. Yet the increased life which
II gives is, In nearly all cases. more
than sufficient to repay the added
cost OF seasoning.
| The strength OF partially seasoned
timber, other things being equal, in
crease as the amount of moisture
1t contains decreases. Thoroughly
seasoned timber of small sizes Is
sometimes three or even four times
as strong as the same timber, when
green. Moreover the process oi
drying out. important but little un
derstood changes take place in the
organic contents of the wood cells
by which the wood Is not only rend
cred less attractive to fungi, but II
made more permeable and so better
prepared for preservative teatment
All timber should be thoroughly sea
soned before being exposed to de
cay.
An exterior coating secured by
dipping q post in a thin solution o
cement or other material that vii
harden on. the post Is not an effec
tive protection, because In shrink
ing or swelling the wood form
cracks throIgh which decay enters
by Chemical Impregnation.
BY far the best method OF check
ing the growth OF fungi. however
is to deprive them of food. Thi
can be done by injecting poisonou
substances into the timber, and 81
changing the organic matter from
foods suitable for fungi into power
full funglcides. II is a mistake 4
: suppose that the germs OF decay ar
inherent in the wood, and only nee
an opportunity for development Z
bring about It's destruction. Severa
processes for the preservation o
wood have been founded on the falls
. assumption that Il Is necessary I
destroy the germs" In the interio
OF the timber. The impressio
I doubtless arose from the fact tina
? after n stick OF timber begins TO ro
Il Is impossible TO tell Just wher
r the fungus spores terminated an
. gained an enterance into the tim
4, ber. Moreover, the fact that IN
interior OF the wood may hay
reached an advanced stage OF dc
cav before there are any externa
evidences OF the flngi-such
fruiting bodies. or Aims OF myceliuI
: tends TO convince the casual ot
e server that decay starts from the II
: terror. Yet the wood-destroyin
I agencies start from the outside
D This explains the efficacy OF certai
e paints which merely form q supel
e fielal coating over the surface OF IN
! timber, but which are polsonoJ
! enough TO prevent the spores troi
2 terminating, or the hyphae OF mos
3 forms OF wood-destroying funi
r from penetrating into the unpr'
: iected wood In the interior. The al
I clients were In the habit OF paintin
their statues with oily and bitun
mons preparations TO preserve theI
from decay. The great woooe
statue OF Diana at Ephesus, whlc
was selpposed TO have descended m
raculously from heaven, was Pre-
teeted from earthly decay by oil {
nard. Pettigrew extracted the pr
seryatiye fluids from the heart
an EcyDtian mummy that had r.
sisted decay for over 5000 year
and found that decomposition In
medIately set I'm. This showed tha
n was the presence OF the antisepp'
which prevented decay, and not
| ho,,toat obanqa of the tissues