The white of egg is, perhaps, the best substance that can be employed
in clarifying jelly, as well as some other fluids, for the reason that
when albumen (and the white of egg is nearly pure albumen) is put into
a liquid that is muddy, from substances suspended in it, on boiling
coagulates in a flocculent manner, and, entangling with the
impurities, rises with them to the surface as a scum, or sinks to the
bottom, according to their weight.