PROGRESS REPORT OF THE FLAX COMMISSIONERS, 13

My experience is that from three to four hours is the best time to allow the fibre to remain in the
water. The best test is tasting it, for, as soon as there is no bitter taste on chewing a portion of the
tissue still remaining on the fibre, the soaking has proceeded long enough. Less than three hours will
scarcely remove the whole of the bitter principle, while twelve hours' soaking takes the gloss off some
kinds of flax, and gives it a dull appearance; but I prefer leaving the flax that has been run through
the machines for the last two hours of the day, in the water all night, to taking it out of soak too soon.
The water in which flax is soaked should be clear and free from iron, or the flax will turn black;
for this reason water running from swamps is inadmissible. Running water is certainly the best, the
clear rapid current of the Waikato being admirably adapted for the purpose. I have not tried whether
a slight current running through tanks or ponds would be sufficient to remove the colouring matter;
but, judging from the large quantity that escapes, I should fancy that the current ought to be strong
enough to change the whole of the water in them every five or ten minutes. Of course, loss of weight
is experienced by soaking, but the quality of the fibre will be so much improved that this loss will be
well repaid.

The beneficial effects of soaking may readily be made apparent, by boiling in water portions of
soaked and ordinary hand-washed or rinsed fibre. The former will be found to yield a perfectly clear
fluid, of a pale yellow colour, and without smell or taste, while the latter will yield a liquor of the
colour of the mucilage or liquid gum sold in shops, of a slightly bitter taste, and smelling when hot
something like barley-water. This would be a good test for purchasers.

Besides the bitter principle, a green fluid also escapes while washing or soaking. This, on being
examined by a powerful microscope, is seen to be water, coloured by minute granules of chlorophyll
(the substance that colours leaves green) floating in it. These granules are so small as to pass through
filter-paper, but they are precipitated by chloride of tin and by acetate of lead, the solution in both
cases being left clear and colourless. These granules have escaped out of the cells broken by the
machine, and this has led Mr. Nottidge, of Canterbury, to object to the Auckland machines, as he sup-
poses that when "the leaf is broken and bruised, the cellular tissue is completely broken up, the fluid
contents of the cells set free, and, by the same cause, openings would be forced in the tubular cells of
the fibre, whether those cells contained fluid or air, and if they contained fluid some of that fluid would
be forced out. The result is obvious-the fluid juices would be drawn into the tubular fibres, and into
the minute canals between the ultimate fibres, by capillary attraction, and the tubes being so minute the
capillary attraction would act very rapidly and with great force."- Trans. N.Z. Inst., Vol. II. p. 110.)
I cannot, however, agree with these opinions, for the following reasons: If a leaf is carefully examined
with a microscope immediately after having been passed through the machine, the bundles of fibres will
be found quite white and unbroken, if the machine is doing its work properly. Small particles of
green tissue will be seen scattered loosely through the leaf, and others will be seen sticking to the
bundles. I have often closely examined the ultimate fibres, to see if they contained any chlorophyll,
or other colouring matter, and I have cut quite dry dressed fibre across, and plunged the ends into the
green fluid, but I have always found the ultimate fibres quite empty, except when broken, in which
case they generally contain water. As chlorophyll generally exists in small grains, and always in a
semi-solid or viscous state, it could not possibly penetrate through the sides of the fibres; but if the
machine was "cutting" it might certainly be possible for small portions to penetrate into the cut
fibres; but, as we have seen that these fibres do not average more than half an inch in length, that
would be the limit to which it could penetrate. As for the minute canals between the ultimate fibres,
I have always failed to see them, and have already suggested (Trans. N.Z. Inst., Vol. II. p. 112) that
they do not exist in the leaf, but were made by the knife of the observer when cutting fine sections. If
a portion of stained fibre is taken and boiled in water, or in a dilute solution of soda, until the ultimate
fibres can be separated as fluff, they will be found to be quite white, although those parts of the fibrous
bundles that have not been separated still keep their colour. This shows that it is the cement which
binds the ultimate fibres together that is stained by the juices of the plant, and not the ultimate fibres
themselves. The fact, also, that no precipitate is produced when neutral acetate of lead is added to
the liquor obtained by boiling soaked fibre in water, shows that little or none of the green fluid and
mucilage has remained in or on the fibres. I think, therefore, that this objection to the Auckland
machines is unfounded, but I agree with Mr. Nottidge that passing a stream of water through the
machine is beneficial to the fibre.

Not having experimented myself with steaming flax, nor with iron or india-rubber rollers, I shall
say nothing about them, but shall leave it to others to give us their experience.

RETTING.

Nothing is more likely to lead to mistakes than to assume, without inquiry, that those processes
which have been proved to be best for one manufacture must necessarily be the best for another similar,
but not identical, manufacture; and as many people are now advocating the retting of New Zealand
flax after it has passed through the machines, I think it may be advisable to make a few remarks on
the subject.

Dr. Hector and Mr. W. Skey, in their paper already referred to, describe several experiments that
they made on retting, and speak very highly of them; indeed, they say that there can be no doubt as
to the success of the process. Although hesitating to express an opinion against such high authorities,
I am bound to confess that the few experiments I have made are not at all favourable, for in all cases
I found the fibre so discoloured that its value would be greatly deteriorated. I found that pond
retting not only blackens the fibre, but that the ultimate fibres rotted as quickly as the cement, so that
when broken the ultimate fibres broke off short, and did not pull out, as is the case when the cement is
dissolved by an alkali. In fact, the ultimate fibres seemed to get rotten before the retting was
sufficiently advanced to produce any useful result. Schenk's process I have not tried, owing to the
expense; but I find that any action of hot or warm water on the cement turns it gray; and although
Schenk's process may offer advantages over pond retting, I do not think that either can be introduced,
unless some means are found for preserving the colour of the fibre. Indeed, a priori reasons lead me to
think that retting will never be applied to Phormium fibre with the same success as it has been to