The Hawaiian gazette. [volume] (Honolulu [Oahu, Hawaii]) 1865-1918, 1880-01-21
Complete ClarlncatIon of Cane Juice

A Complete Qualification of Cane Juice.
1t may seem strange that until the present
day, after so many years of observation and
experiment, and despite the scientific skill
that has been brought to bear on the subject,
this should remain test question on the sugar
industry That this is 50, we have only to see
the extreme care and attention that is given to
the Ginning" in all the better managed es-
tates in the colonies; how variation in the
quantity of lime is thought often to be scru-
pulously necessary with every variation in
locality from which the canes may be brought,
| &c. The processes and notifications of pro-
cesses that have been patented and practised
with this end in view are too numerous to
mention; too much has been attempted and
too much left undone through sheer scientific
ignorance.
For some years back, as a chemist, 1 have
made study of the sugar question, more es-
pecially as it is represented by the raw and
refined articles, and always take great inter-
est in its welfare. Recently, during a visit to
the colonies, 1 have had opportunities of ex-
tending my knowledge and experience on the
subject, and was induced then, as now. to re-
commend the following as among the least ex-
pensive and most effective methods of produc-
ing complete Qualification of cane Juice.
claim nothing new or original in the materials
used, as these have been employed and dis
carded over and over again; but the method of
application embodies its success. and so far as
it has been tried has been attended with graft
flying results.
The juice is defeated in the usual manner,
but with this difference and one on which l
| place great Importance: that instead of SO lin
ing under as is usually practiced, about 2lbs
extra lime over and above the usual quantity
is to be added the heating, cracking, and
Swimming to be conducted as formerly, then
to this alkaline juice, which must be allowed
to settle well, from l to 3 per cent of pure
bisulphite of lime, of specific gravity 1860 . :,
is slowly added as the liquor runs to the wall ;
this is effectively done by placing the required
quantity in tub above the gutter which con-
veys the juice to the "wal -" and, by means
of a plug in the bottom, it can be so arranged
as to empty itself in the same time as the
CHARTERS, and thus become distributed through
out the whole mass. At this stage it will be
observed that the liquor on the wall is slightly
acid to test paper; but, as it begins to boil,
this acid becomes volatilized, leaving, if pro-
perly manipulated, perfectly neutral syrup
of pale transparent yellow color, on which
any further addition of lime or bisulphite of
lime should produce no effect, that is TO say,
the lime should produce no precipitation of or
further bleaching acting,-any colors that
still remain being beyond the power of bisul-
phite of lime of sulphurous acid to remove.
The sugar produced from such syrup is
not up TO the standard of that prepared by
adding vitriOl to the pan before striking out,
but, maintain, that by working in this way,
with slight excess of lime and subsequent
naturalization of this excess by the inert sui
phurous acid, that it has produced all that has
been claimed for it, viz, the complete re-
moval from the juice of all organic bodies
having prejiducial effect on the yield of
cane sugar. ANY impurities that still remain
| consist of mineral matters and coloring matter
of an organic nature allied to chlorophylle,
and this has been done without iIverting any
cane sugar, and, l doubt not, that if syrup as
it runs from the subsiders to the vacuum pan
was treated with pure sulphurous acid, either
in the gaseous or liquid state, class of sugars
could be prepared that would compare favor
ably with the best, without in any way de-
creasing the yield, and would certainly pro-
duce better yield of moasses sugar.
very noticeable feature in the process'is
the beautiful appearance the liquor presents
in the wall, where it is so transparent and
light colored that the bottom of the teche can
almost be seen through the mass of liquid,
and the scum that usually requires so much
sweeping TO remove is conspicuous by its
absence.
popular error exists as to the injurious
effect on cane juice of any excess of lime, that
this is the case is contrary to fact, at least so
far as the cane sugar of the juice is concerned,
on which it has no action. Any prejudicial
effect which it may possess only exists when
it is allowed to pass through every stage of
the process to completion in free and uncom-
bined stage, when it would tend to dissolve,
in part, the precipitated albuminous matter,
and to combine with the glucose forming dark
coored products, only in a secondary sense
effecting the yield but not actually destroying
the cane sugar. By adopting my process this
alkalinity is neutralized at an early stage of
the process, and after it has fulfilled its func-
ton to the utmost. JOHN Y MCCLELLAN.
Glasgow, 18th November, 1879.