When brown or raw sugar is refined it forms the white crystalline
product known as loaf sugar. The process involves many ingenious
arrangements in its detail, but the essential object to be obtained
is the separation of all coloring matter from the raw material
without producing any more by the process, which is a greater
difficulty than would at first appear, for all solutions of sugar
evaporated in the open air become to a great extent colored, and the
longer the exposure, and the higher the temperature, the worse the
product; a substance forming called “caramel,” which discolors it.