IT is difficult, without a tedious accuracy, or without full illustration, to express the complete relations of crystalline structure, which dispose minerals to take, at different times, fibrous, massive, or foliated forms; and I am afraid this chapter will be generally skipped by the reader: yet the arrangement itself will be found useful, if kept broadly in mind; and the transitions of state are of the highest interest, if the subject is entered upon with any earnestness. It would have been vain to add to the scheme of this little volume any account of the geometrical forms of crystals an available one, though still far too difficult and too copious, has been arranged by the Rev. Mr. Mitchell, for Orr's "Circle of the Sciences;" and, I believe, the "nets" of crystals, which are therein given to be cut out with scissors and put prettily together, will be found more conquerable by young ladies than by other students. They should also, when an opportunity occurs, be shown, at any public library, the diagram of the crystallization of quartz referred to poles, at p. 8 of Cloizaux's "Manuel de Mineralogie;" that they may know what work is; and what the subject is. With a view to more careful examination of the nascent states of silica, I have made no allusion in this volume to the influence of mere segregation, as connected with the crystalline power. It has only been recently, during the study of the breccias alluded to in page 186, that I have fully seen the extent to which this singular force often modifies rocks in which at first its influence might hardly have been suspected; many apparent conglomerates being in reality formed chiefly by segregation, combined with mysterious brokenly-zoned structures, like those of some malachites. I hope some day to know more of these and several other mineral phenomena (especially of those connected with the relative sizes of crystals), which otherwise I should have endeavored to describe in this volume. NOTE V. Page 168. "St. Barbara." I WOULD have given the legends of St. Barbara, and St. Thomas, if I had thought it always well for young readers to have everything at once told them which they may wish to know. They will remember the stories better after taking some trouble to find them; and the text is intelligible enough as it stands. The idea of St. Barbara, as there given, is founded partly on her legend in Peter de Natahbus, partly on the beautiful photograph of Van Eyck's picture of her at Antwerp: which was some time since published at Lille. NOTE VI. Page 227. "King of the Valley of Diamonds." ISABEL interrupted the Lecturer here, and was briefly bid to hold her tongue; which gave rise to some talk, apart, afterwards, between L. and Sibyl, of which a word or two may be perhaps advisably set down.