they have served their purpose, though it is a pity that a few copies of
the worst of them could not be printed on permanent paper for
preservation in libraries so that future generations could congratulate
themselves on their progress in civilization.

But in our absorption in the printed page we must not forget the other
uses of paper. The paper clothing, so often prophesied, has not yet
arrived. Even paper collars have gone out of fashion--if they ever were
in. In Germany during the war paper was used for socks, shirts and shoes
as well as handkerchiefs and napkins but it could not stand wear and
washing. Our sanitary engineers have set us to drinking out of
sharp-edged paper cups and we blot our faces instead of wiping them.
Twine is spun of paper and furniture made of the twine, a rival of
rattan. Cloth and matting woven of paper yarn are being used for burlap
and grass in the making of bags and suitcases.

Here, however, we are not so much interested in manufactures of
cellulose itself, that is, wood, paper and cotton, as we are in its
chemical derivatives. Cellulose, as we can see from the symbol,
C_{6}H_{10}O_{5}, is composed of the three elements of carbon, hydrogen
and oxygen. These are present in the same proportion as in starch
(C_{6}H_{10}O_{5}), while glucose or grape sugar (C_{6}H_{12}O_{6}) has
one molecule of water more. But glucose is soluble in cold water and
starch is soluble in hot, while cellulose is soluble in neither.
Consequently cellulose cannot serve us for food, although some of the
vegetarian animals, notably the goat, have a digestive apparatus that
can handle it. In Finland and Germany birch wood pulp and straw were
used not only as an ingredient of cattle food but also put into war
bread. It is not likely, however, that the human stomach even under the
pressure of famine is able to get much nutriment out of sawdust. But by