L. When they are dissolved, or uncrystallized, they are really separated from each other, like a swarm of gnats in the air, or like a shoal of fish in the sea;—generally at about equal distances. In currents of solutions, or at different depths of them, one part may be more full of the dissolved atoms than another; but on the whole, you may think of them as equidistant, like the spots in the print of your gown. If they are separated by force of heat only, the substance is said to be melted; if they are separated by any other substance, as particles of sugar by water, they are said to be "dissolved." Note this distinction carefully, all of you.
DORA. I will be very particular. When next you tell me there isn't sugar enough in your tea, I will say, "It is not yet dissolved, sir."
L. I tell you what shall be dissolved, Miss Dora; and that's the present parliament, if the members get too saucy.
(DORA folds her hands and casts down her eyes.)
L. (proceeds in state). Now, Miss Mary, you know already, I believe, that nearly everything will melt, under a sufficient heat, like wax. Limestone melts (under pressure); sand melts; granite melts; the lava of a volcano is a mixed mass of many kinds of rocks, melted: and any melted substance nearly always, if not always, crystallizes as it cools; the more slowly the more perfectly. Water melts at what we call the freezing, but might just as wisely, though not as conveniently, call the melting, point; and radiates as it cools into the most beautiful of all known crystals. Glass melts at a greater heat, and will crystallize, if you let it cool slowly enough, in stars, much like snow. Gold needs more heat to melt it, but crystallizes also exquisitely, as I will presently show you. Arsenic and sulphur crystallize from their vapors. Now in any of these cases, either of melted, dissolved, or vaporous bodies, the particles are usually separated from each other, either by heat, or by an intermediate substance; and in crystallizing they are both brought nearer to each other, and packed, so as to fit as closely as possible: the essential part of the business being not the bringing together, but the packing. Who packed your trunk for you, last holidays, Isabel?
ISABEL. Lily does, always.
L. And how much can you allow for Lily's good packing, in guessing what will go into the trunk?
ISABEL. Oh! I bring twice as much as the trunk holds. Lily always gets everything in.
LILY. Ah! but, Isey, if you only knew what a time it takes! and since you've had those great hard buttons on your frocks, I can't do anything with them. Buttons won't go anywhere, you know.
L. Yes, Lily, it would be well if she only knew what a time it takes; and I wish any of us knew what a time crystallization takes, for that is consummately fine packing. The particles of the rock are thrown down, just as Isabel brings her things—in a heap; and innumerable Lilies, not of the valley, but of the rock, come to pack them. But it takes such a time!