50 The Manufacture of Paper. 
finer. The samples compared were taken from a paddock 
near Malvern. The difference may be accounted for by the 
difference of rainfall during these two years, and would tend 
to show that the manufacturer should collect the OTASSES 
from the driest localities. As I have stated, these grasses 
are the best Victorian material for a substitute for esparto 
that has come under my notice. Under ordinary circum- 
stances the grasses may be collected without pith. The 
resinous coating is easily got rid of by an alkaline solution, 
and at the same time the colouring matter is rendered 
soluble. The per centage of pulp is fully equal to esparto, 
and the fibre as applied to paper making quite as strong: 
Another point greatly in their favour is, that they have no 
other uses and are at present valueless. 
It may be interesting to go over the present methods used 
in converting raw material into paper. The number pro- 
posed and patented is very great, but all have one object in 
view, the destruction of the silicious and resinous coating, © 
which, besides rendering the fibre brittle, protects the 
colouring matter from the action of the bleaching solution. 
It has been proposed to crush the fibre between rollers, and 
then to destroy this coating by means of an acid, either 
hydrochloric, sulphuric, or nitric may be used. This has 
been found to answer in the case of sugar-canes, but for 
materials having a fine fibre it does not answer well, as the 
acid invariably acts on the fibre, rendering it weak and 
harsh. Others digest the crushed fibre in vats for from ten 
to eighteen hours with an alkaline solution heated by steam — 
pipes. This works well with some fibres, but as in the case 
of the acids, the fibre is to some extent damaged. I believe 
no method has succeeded so well as that in which the un- 
crushed material is placed in a rotary high-pressure boiler, 
with a solution of lime or dilute alkali, after which the 
aperture is closed and high pressure steam introduced 
through a pipe passing through the axle upon which the 
boiler revolves, and the pressure maintained at about 100 lbs. 
per square inch for from five to fourteen hours. When the 
fibre is removed from the boiler, the coating is either dis- 
solved or rendered lose so that it may be easily removed in 
the process of washing in a beating machine, and at the 
same time the greater. part of the coleuring matter, which 
has been rendered soluble by the action of the alkaline 
solution, 1s washed awa 
The expense of this method is not much greater than when 
