paper-making value of the more promising plant materials before a
critical situation arises. To be of substantial value the investigations
should include not only a determination of the quality and quantity of
pulp and paper which the material is capable of producing, but should
embrace a consideration of such relevant factors as agricultural
conditions, farm practice, assembling conditions, transportation, and
probable future supply.

Certain cultivated plants seem particularly promising, because in the
harvesting of the regular crop that portion which might be utilized for
paper manufacture necessarily is either wholly or partially assembled.
To this class of plants belong corn, broom corn, sorghum, sugar cane,
bagasse, flax, hemp, and the cereal straws.[1]

[Footnote 1: For descriptions of investigations of some of these crops,
see the list of publications at the end of this bulletin.]

It is generally conceded that the employment of different raw materials
would probably yield products of a somewhat different quality than those
now prevailing in the markets, but the qualities of papers and the
public demands are so diversified and numerous that this possible
objection should not be serious. Ten years ago sulphite manufacturers
would not accept consignments of spruce logs if they contained over 5
per cent of fir, while to-day many manufacturers tolerate 50 per cent.
Rope papers are found to contain not only jute, but when this raw
material is not plentiful, chemical pulp of various kinds. "Linen paper"
is often no more than a trade term. Not long ago printing papers were
made entirely from chemical wood pulp, but to-day if it is desired to
secure paper which is free from ground wood the specifications must so
stipulate. Writing papers, formerly made entirely from rags, now are