f tempering and clarifying cane juice, and the action of lime on
the various substances contained therein. The expression "tempering"
has, I presume, been, adopted in consequence of the use of tempered
lime for the purpose of precipitating the feculencies, held in
solution in the cane juice, into a state of suspension; and
clarification is the process by which we afterwards clear the liquor
of these and other foreign matter. Now, as I before observed,
"fermentation should be most strictly guarded against;" our first
efforts should be directed to free the cane juice from those
substances most conducive to that process; and on inquiry we find
these to be albumen and gluten; so far, however, from getting rid of
them in cold tempering, we adopt a course which retains them
permanently in solution, as lime has the power of rendering them
permanently soluble, and of forming soapy compounds with resin, wax,
and chlorophyle, or the green coloring matter of leaves, forming an
insoluble compound with and precipitating only the starch, and
converting at the same time the green color of the chlorophyle (which
is, in all probability, attached to the resin), into a dark brown, of
a greater or less intensity, according to the composition of the cane
juice, and, consequently, the quantity of lime required; it follows,
therefore, as a matter of course, that if juice be tempered before
these substances have been removed, they must be permanently retained,
and they have all the power of preventing granulation.

Albumen, and gluten are both coagulable by heat; if, therefore, we
raise the liquor to the boiling point prior to applying the lime,
taking care to remove the scum as soon as it shows signs of breaking,
and continuing the boiling until the scum thrown to the surface
becomes inconsiderable, we shall find that the albumen and gluten, in
coagulating and rising, have carried with them the small particles of
woody fibre, the wax, and a large proportion of the coloring matter,
and that the lime will now throw down the starch, and any other little
impurities remaining in suspension in the liquor, leaving it perfectly
clear and bright. Tempering is an exceedingly delicate chemical
operation, and I have no hesitation in saying, that on its proper
performance depends the quality of the produce. The following simple
experiments, which all have it in their power to try, will, if they
give themselves the trouble, fully satisfy them of two import