L. I used the word clay for shortness. In both, the enemy is really limestone; but in the first, disordered, and mixed with true clay; while, here, it is nearly pure, and crystallizes into its own primitive form, the oblique six-sided one, which you know: and out of these it makes regiments; and then squares of the regiments, and so charges the rock crystal, literally in square against column. ISABEL. Please, please, let me see. And what does the rock crystal do? L. The rock crystal seems able to do nothing. The calcite cuts it through at every charge. Look here,--and here! The loveliest crystal in the whole group is hewn fairly into two pieces. ISABEL. Oh, dear; but is the calcite harder than the crystal then? L. No, softer. Very much softer. MARY. But then, how can it possibly cut the crystal? L. It did not really cut it, though it passes through it. The two were formed together, as I told you but no one knows how. Still, it is strange that this hard quartz has in all cases a good- natured way with it, of yielding to everything else. All sorts of soft things make nests for themselves in it; and it never makes a nest for itself in anything. It has all the rough outside work; and every sort of cowardly and weak mineral can shelter itself within it. Look; these are hexagonal plates of mica; if they were outside of this crystal they would break, like burnt paper; but they are inside of it,--nothing can hurt them,--the crystal has taken them into its very heart, keeping all their delicate edges as sharp as if they were under water, instead of bathed in rock. Here is a piece of branched silver: you can bend it with a touch of your finger, but the stamp of its every fiber is on the rock in which it lay, as if the quartz had been as soft as wool. LILY. Oh, the good, good quartz! But does it never get inside of anything? L. As it is a little Irish girl who asks, I may perhaps answer, without being laughed at, that it gets inside of itself sometimes. But I don't remember seeing quartz make a nest for itself in anything else. ISABEL. Please, there as something I heard you talking about, last time, with Miss Mary. I was at my lessons, but I heard something about nests; and I thought it was birds' nests; and I couldn't help listening; and then, I remember, it was about "nests of quartz in granite." I remember, because I was so disappointed! L. Yes, mousie, you remember quite rightly; but I can't tell you about those nests to-day, nor perhaps to-morrow: but there's no contradiction between my saying then, and now; I will show you that there is not, some day. Will you trust me meanwhile? ISABEL. Won't I!