Abstract
I tried every microscopy accompanied by physical and chemical tests on the fibre of pure Kozo-paper for books manufactured during 1688-1868.
Comparing these with the up-to-date goods, I can conclude as follows :
(1) No external change is found by the lapse of years, but polymerisation of fibre is lessened, which enormously effects upon the strength of paper
(2) Astringency is considerably weakened.
(3) Bursting strength, tensile strength and extention are now remarkably feeb
(4) Folding endurance still remains almost unchanged.
