, 1875-06-16
STEWARDS SULPHURIC ACID PRO.
CESS IN THE MANUFACTURE OF
SUGAR.
From the Barbados GZ06e.)
2Sth April, 1875.

2Sth April, 1875.
Sir,-As an old member and officer of the
General Agricultural Society, I make no apollo
gy for addressing you, asits President, on a
subject which | believe to be of the highest
Importance not only to the class particularly
represented by our Society, but to the whole
community, because every inhabitant Of the
Island is sustained, directly or Indirectly, by
its staple product, and every thing which tends
to depreciate the value of our sugar, causes;an
injury which is not confined to the Planters
alone but reacts universally. Everyone, there.
fore, is interested in preventing, if possible,
any injury to our sugar manufacture, but it is
the duty of our society to endeavour to detect
mischief which may threaten-give warning of
its approach, and counsel to avoid it,
The danger to which, desire to direct YOUR a.
tention is that which may be apprehended from
the introduction of " Stewant's process for the
dgecatiOn Of canGuace By the aid of Sulphuro1s
acid gas" [ am informed that this process
has already been introduced here on "a shall
scale, and that it is about to be tried on a
larger scale on Constant estate.
The bleaching properties of the acids ind
Salts Of Sulphur have led to many at
tenpts to use them in the manufacture of SUI
gar, and the beauty of some Of the sugar thus
manufactured cheated people from time to
time into the belief that an Improvement had
been effected. The destructive action of Sulphu-
rOus acid is at first 50 feeble as scarcely to be
perceived, whilst its bleaching aud defeating
properties are at once apparent; but there the
Specious improvement ends, and it will b.
found like the apples OF the Dead Sea, to be
beautiful only at first sight the improvement
is not persistent all sugars which nav been ex-
posed during manufacture to the action of sui
phuric acids become clammy after a time, and
on reaching the home market will be found to
have lost theii brilliancy and when p~Olarized,
will be found to contain a notable proportions of
sugar of fruits, thus proclaiming their origin
and lettering Refinefs from purchasing them.
This, however, is by no means the worst fea-
ture of these processes, for although Sulphu-
rOus acid is at first feeble in it's destructive
action, it slowly changes, more rapidly at a
high temperature, to s~ulphuric acid. which has
the property of destroying cane sugar with
great rapidly the ~fructose produced by its
action, remaining and increasing in the molas-
ses, which it renders unfit for re-boiling into
sugar, and no merchant would knowingly pur-
chase. such molasses for expectation because
the Refners could not use it. Thus Stewards
process would ruin the molasses market Of
Barbados, as all mOlasSes coming from a coun-
try where sulphur acids are used, is avoided;
and as the manufacture of Rum is not extern
sively carried on, the injury would be a serious
one.
Bi-sulphite Of lime spoiled the Demerara
molasses, but it was not so important to them
as it would be to US, because although they
failed to extract a second quality of sugar even
with. the aid of the vacuum pan, they carry on
a very extensive Rum manufacture.
I will not unnecessarily %lengthen this letter
by describing the action we'll known to all
chemists, by which sulphurous acid absorbs
oxygen and becomes .%sulphurio acid. or by de-
failing the actual experiments which have been
made to show how this change goes on in su-
gar solutions, neither need I refer to the cor.
respondence which enabled me to speak with
such certainty as to the results Of the use OF
Bi-sulphite' of lime in Demerara, but as this is
an attempt which is not likely to be abandoned
tamolv hv advantnrara- whose nhioct ia IN maka