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_ Preservatives are applied to timber for one or more of several 
objects, i.e., to render it less susceptible to attacks from para- 
sitic fungi; to make it as far as possible waterproof; to preserve 
it and at the same time improve its appearance; to prevent or 
check the ravages of boring insects and other forms of animal 
life and to render it less inflammable. 
me instances one application may suffice for two or. more 
of these objects, for chemicals are available that are poisonous 
alike to fungi and insects, or which possess both antiseptic and 
water-proofing properties. 
The chief danger to unprotected wood in temperate countries 
must be anticipated from parasitic fungi for mycelium of certain 
species may be present in the timber when it is felled or pur- 
chased ; whether or not, there are always spores floating about in 
the atmosphere which are a source of danger to wood upon which 
they may fall. For some time the presence of spores or mycelium 
may pass unnoticed, but directly conditions arise which favour 
development, growth becomes active and signs of decay or break- 
ing up of the wood tissues are soon seen. If, however, the 
conditions are unfavourable to fungus growth, the spores and 
attacks by the application of an agent which is poisonous to such 
lowly forms of plant life 
and other purposes. Sheds and farm buildings constructed of 
preserved timber are yearly becoming more popular, but it 
appears that a good deal more preserved timber might be used 
for such work. 
Fence timber deserves special attention and no post ought to 
be placed jn the ground that has not had at least the lower part 
treated with an antiseptic. The weakest part of a post is that 
about the ground line or, roughly, the portion occurring 9 in. 
above and 9 in. below the ground level, a point often described 
as “‘ between wind and water.’’ This section is constantl 
exposed to moisture from the soil and to the drying effects o 
the air but can never become as dry as the more exposed parts, 
