Year: 1871

| This process consists Of an altogether special
method of preparing Sulphte of Lime. aud of
applying it in the decoloration and publication Of
canejuce and syrups


The conditions which must be fulfilled for the
utilisaton Of this process comprised therefore
in two kinds of operations, the one having refer
ence to the manufacture Of the substance itself
the other, the manner of employing it.


PREPARATION OF NoSo-suLPHrrE OF LINE.


The Mono-Sulphite of Lime, Gnsoluble sui
phte of lime, proto-sulphte CT llmel is easily
susceptible of deterioration, which renders it but
very little sensible to the action Of weak acid
contained in large liquid masses it. therefore, re-
qures to be manufactured at the very moment of
its employment and in particular manner.


In the method of its preparation resides the
success of its application to canejuice and syrups.
1t is important therefore, to follow implicitly the
following directions which, happily, are of prompt
and easy execution.


! First, however, it is necessary to say few
words as to the action of the apparatus, which
has been so adapted as to permit of the manu-
facture Of the substance employed at the very
time its use is required.


This apparatus (see note at end) by its solidity,
particular arrangement and the perfec. regularity
of its actior satisfies as nearly as is possible tie
exigencies and usages of Colonial manufacture.
] Producing, by means of the combustion of raw
sulphur, solution invariably charged with an
equal quantity of sulphurous acid, it allows Of
/ A. of Inhi of
in the place where it is constructed, and the cost
price of this substance is only that of the sulphur
and lime which enter into its combination, or in
other words, a nearly Insignificant sum.


ton Of sulphite Of lime, which contains 532
TBS. of sulphur and 932 Tbs. of Iime can not IN
fact cost, even taking into account the labor re-
quired for its production, more than from e2 l6
to e. that is to say, less than what only the
packing and freight of the same quantity of this
substance would cost if shipped from Europe.


The manufacture of the sulphte Of lime in the
sugarhouse itself has, therefore, not only the ad
vantage of permitting the employment of an
excellent substance until now never usefully ap-
| piled. but also allows 1t to be obtained at an
extremely low price, thus freeing planters from
the exigencies of foreign traders.


To function the apparatus, small quantity of
sulphur is set fire to in the furnace about b.
and when, after few minutes, the product of the
combustion disengages itselfin in abundance through
the chimney, the water reservoir is opened, and a
small stream of water allowed to fow of such
volume that when the valve which is placed at
the end of the last column Of the apparatus is
three-fourths closed the sulphur continues to
burn freely without the escape of any white va
pors through the chimney being perceptibe. In
this way, nearly the whol9 of the sulphur is
utilised, and forms itself into sulphurous acid.


This aceum1lates in the apparatus, being dissolved
in the thin shower Of water which falls slowly
INTO the cylindrical reservoir to which is attached
a discharge tap. In order to regulate the action
of the apparatus in proper manner, it is neces
sary, first, to add from time to time large hand
ful of sulphur, which is to be put in the furnace ;
second, to keep up moderate and continuous flow
of water; third to open the valve only sufficiently
to permit Of an active combustion without an ap
preciable loss of white yvpOr through the chimney


And now, the apparatus being sufficiently
charged with the suphurous solution, the follow
ing is the next step By means of eaden pipe
communicating at its upper end with the reser-
voir tap, the liquid in the apparatus is allowed to
| flow to the bottom Of circular wooden tub
such as the half of an ordinary beer cask. Be
fore, however the acid liquid is allowed to flow
into this, small quantity of common lime, or
better still, quick-lime finely sifted, must be
placed on the spot on which the liquid will fall
As soon as the liquid falls on the lime, the whole
must be stirred round, and the circular movement
thus given to the mass must be continued through
out the operation, that is until all the lime is
transformed into suIphite. This trasformation is
complete when the liquid contained in the tub
previously milky white, becomes Of a decidedly
] yellow color.


But it ia necessary and is an essential point in
the operation, that a little more Of the sulphurous
acid should be allowed to flow from the apr aratus
than is requisite to saturate the lime 10 de-
termine the quantity, there should be plunged
into the liquid contained in the tub piece Of
/ ltmus paper which should at once turn red This
acidity in the yellow mixture formed in the tub
need not be very decided, but it is indispensable ;
for, otherwise, it will not be long before the
sulphte will undergo notifications rendering it
little fit to act eificaciously upon the cane,julce
and syrups.


As lime varies in quality according to the care
taken in its preparation. it would be difficult to
determine once and for always what quantity of
this substance should be added to the suphurous
solution SO as to manufacture the Mono-Sulphite,
but preliminary experiment, easily made, will
enable anyone to do so in his individual case


Having allowed the suphurous acid to run into
the tub up to a mark indicating the volume Of
fluid intended TO be taken from the apparatus at
each operation, say 20 gallons = then 6xed
quantity of siftsd lime of the same quality as is
intended to be afterwards used say fbs.-:s to
be thrown by small portions into the liquid in The
tub until its acidity shall have nearly disappeared
All that then remains to be done is to weigh the
lime which remains in hand, so as to ascertain
the quantity required for 20 gallons Of the sui
pburous solution. Having these data it will be
easy TO have little tin vessel made which will
serve to measure very approximately the ouaatitv