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 important points—­the superiority of the hot over the cold mode, and the necessity for great attention to the operation of tempering.  Let them take a tumbler of cane-juice and a bottle containing lime water, add the latter to the former by drops, pausing and stirring between each, and they will find that, after the addition of a certain quantity, the opaque gummy appearance of the liquor undergoes a change, and the impurities contained in it separate into flakes, which increase in size with each drop of lime added, until they become extinct, and the supernatant liquor perfectly transparent; this is the precise point at which the liquor is tempered, and each drop of lime added after this, causes the flakes to diminish rapidly in size, at last entirely to disappear (being re-dissolved), and the liquor to resume its former gummy appearance; it is, therefore, evident that there should be no such expressions as tempering high or low.