Mary.  Pure!  Does that mean clear—­transparent?

L. No; unless in the case of a transparent substance.  You cannot have a transparent crystal of gold; but you may have a perfectly pure one.

Isabel.  But you said it was the shape that made things be crystals; therefore, oughtn’t their shape to be their first virtue, not their second?

L. Right, you troublesome mousie.  But I call their shape only their second virtue, because it depends on time and accident, and things which the crystal cannot help.  If it is cooled too quickly, or shaken, it must take what shape it can; but it seems as if, even then, it had in itself the power of rejecting impurity, if it has crystalline life enough.  Here is a crystal of quartz, well enough shaped in its way; but it seems to have been languid and sick at heart; and some white milky substance has got into it, and mixed itself up with it, all through.  It makes the quartz quite yellow, if you hold it up to the light, and milky blue on the surface.  Here is another, broken into a thousand separate facets and out of all traceable shape; but as pure as a mountain spring.  I like this one best.

The audience.  So do I—­and I—­and I.

Mary.  Would a crystallographer?

L. I think so.  He would find many more laws curiously exemplified in the irregularly grouped but pure crystal.  But it is a futile question, this of first or second.  Purity is in most cases a prior, if not a nobler, virtue; at all events it is most convenient to think about it first.

Mary.  But what ought we to think about it?  Is there much to be thought—­I mean, much to puzzle one?

L. I don’t know what you call “much.”  It is a long time since I met with anything in which there was little.  There’s not much in this, perhaps.  The crystal must be either dirty or clean,—­and there’s an end.  So it is with one’s hands, and with one’s heart—­ only you can wash your hands without changing them, but not hearts, nor crystals.  On the whole, while you are young, it will be as well to take care that your hearts don’t want much washing; for they may perhaps need wringing also, when they do.

(Audience doubtful and uncomfortable.  Lucilla at last takes courage.)

Lucilla.  Oh! but surely, sir, we cannot make our hearts clean?

L. Not easily, Lucilla; so you had better keep them so, when they are.

Lucilla.  When they are!  But, sir—­

L. Well?

Lucilla.  Sir—­surely—­are we not told that they are all evil?