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is not known。
The chemicals employed in both of these processes
compel a separation of the resinous matters from the
cell tissues or cellulose。 These products are then
treated in the manufacturing of paper with few variations；
the same as the ordinary rag pulp。
These now perfected processes are the results of long
and continuing experimentations made by many inventors。
The following paper was read before the London
Society of Arts by Mr。 Alfred Glyde； in May； 1850；
and is equally applicable to some of the wood paper
of the present day：
〃Owing to the imperfections formerly existing
in the microscope； little was known of the real nature
of the plants called fungi until within the last
few years； but since the improvements in that instrument
the subject of the development； growth；
and offices of the fungi has received much attention。
They compose； with the algae and lichens；
the class of thallogens （Lindley）； the algae existing
in water； the other two in air only。 A fungus
is a cellular flowerless plant； fructifying solely by
spores； by which it is propagated； and the methods
of attachment of which are singularly various and
beautiful。 The fungi differs from the lichens and
algae in deriving their nourishment from the
substances on which they grow； instead of from the
media in which they live。 They contain a larger
quantity of nitrogen in their constitution than vegetables
generally do； and the substance called 'fungine'
has a near resemblance to animal matter。
Their spores are inconceivably numerous and minute；
and are diffused very widely； developing
themselves wherever they find organic matter in a
fit state。 The principal conditions required for
their growth are moisture； heat； and the presence
of oxygen and electricity。 No decomposition or
development of fungi takes place in dry organic
matter； a fact illustrated by the high state of
preservation in which timber has been found after the
lapse of centuries； as well as by the condition of
mummy…cases； bandages； etc。； kept dry in the hot
climate of Egypt。 Decay will not take place in a
temperature below that of the freezing point of
water； nor without oxygen； by excluding which； is
contained in the air； meat and vegetables may be
kept fresh and sweet for many years。
〃The action which takes place when moist vegetable
substances are exposed to oxygen is that of
slow combustion （'eremacausis'）； the oxygen
uniting with the wood and liberating a volume of
carbonic acid equal to itself； and another portion
combining with the hydrogen of the wood to form
water。 Decomposition takes place on contact with
a body already undergoing the same change； in the
same manner that yeast causes fermentation。 Animal
matter enters into combination with oxygen in
precisely the same way as vegetable matter； but as；
in addition to carbon and hydrogen； it contains nitrogen；
the products of the eremacausis are more
numerous； being carbon and nitrate of ammonia；
carburetted and sulphuretted hydrogen； and water；
and these ammoniacal salts greatly favor the growth
of fungi。 Now paper consists essentially of woody
fibre； having animal matter as size on its surface。
The first microscopic symptom of decay in paper is
irregularity of surface； with a slight change of color；
indicating the commencement of the process just
noticed； during which； in addition to carbonic acid；
certain organic acids are formed； as crenic and ulmic
acids； which； if the paper has been stained by
a coloring matter； will form spots of red on the
surface。 The same process of decay goes on in
parchment as in paper； only with more rapidity；
from the presence of nitrogen in its composition。
When this decay has begun to take place； fungi are
produced； the most common species being
Penicilium glaucum。 They insinuate themselves between
the fibre； causing a freer admission of air； and
consequently hasten the decay。 The substances most
successfully used as preventives of decay are the
salts of mercury； copper； and zinc。 Bichloride of
mercury （corrosive sublimate） is the material employed
in the kyanization of timber； the probable
mode of action being its combination with the albumen
of the wood； to form an insoluble compound
not susceptible of spontaneous decomposition； and
therefore incapable of exciting fermentation。 The
antiseptic power of corrosive sublimate may be
easily tested by mixing a little of it with flour
paste； the decay of which； and the appearance of
fungi； are quite prevented by it。 Next to corrosive
sublimate in antiseptic value stand the salts of
copper and zinc。 For use in the preservation of
paper the sulphate of zinc is better than the chloride；
which is to a certain extent delinquescent。〃
There are numerous paper tests which include the
matter of sizing； direction of the grain； absorbing
powers； character of ingredients； etc。 A few of them
are cited。
SIZING。The everyday tests as to hardness of
sizing answer every ordinary purpose： Moisten with
the tongue； and if the paper is slack…sized you can
detect it often by the instant drawing or absorption
of the moisture。 Watch the spot moistened； and the
longer it remains wet the better the paper is sized。
Look through the spot dampenedthe poorer the
sizing the more transparent is the paper where it is
wet。 If thoroughly sized no difference will be apparent
between the spot dampened and the balance
of the sheet。 When there is a question as to whether
a paper is tub or engine sized； it can be usually decided
by wetting the forefinger and thumb and pressing
the sheet between them。 If tub…sized； the glue
which is applied to the surface will perceptibly cling
to the fingers。
TO TEST THE INK RESISTING QUALITY OF PAPER。
Draw a heavy ink line across the sheet。 If the paper
is poorly sized； a feathery edge will appear； caused
by spreading of the ink。 Slack…sized paper will be
penetrated by the ink； which will plainly appear on
the reverse side of the sheet。
TO DETERMINE THE DIRECTION OF THE GRAIN。
An easy but sure test to determine the direction of
the grain in a sheet of paper； which will be found
useful and worth remembering； is as follows：
For instance； the size of sheet is 17x22 inches。
Cut out a circular piece as nearly round as the eye
can judge； before entirely detaching from the sheet；
mark on the circle the 17…inch way and the 22…inch
way； then float the cut out piece on water for a few
seconds； then place on the palm of the hand； taking
care not to let the edges stick to the hand； and the
paper will curl until it forms a cone； the grain of the
paper runs the opposite way from which the paper
curls。
ABSORBING POWERS OF BLOTTING PAPER。Comparative
tests as to absorbing powers of blotting
can be made between sheets of same weight per
ream by allowing the pointed corner of a sheet to
touch the surface of a drop of ink。 Repeat with e