LITHOLOGY, or a Classified Synopsis of the

Names of Rocks and Minerals, also by Mr. LAWRENCE, adapted to the present work, may be had, price 5s. or printed on one side only (interpaged blank) for use in Cabinets, price 78.

TRANSLATOR'S PREFACE.

IN presenting this work to English readers, I wish to acknowledge the kind assistance I have received from Professor Jukes and Mr. Bristow in my own country, from M. Daubrée and M. Guyerdet in France, and last, but not least, from the distinguished author, Professor Cotta himself, and from Mr. Stelzner, of Freiberg, to whose valuable assistance I owe most of what is good in the new arrangement of the Mineralogical part of the work. For the many imperfections which, in spite of much care, will probably be found, I am alone responsible. Nevertheless, I hope that this work may in some measure supply a want which has been long felt in our geological literature.

I trust that allowance will be made for the difficulties of a translator if, in some instances, terms have been used in this work in a slightly extended or even different sense from that of some English authors. This has never been done without much consideration, and what appeared to me absolute necessity in rendering the meaning of my author, and in the absence of an exact equivalent for the German term in our accepted geological language.

The juxtaposition of the English, German, and E equivalent names for each rock, although frequentl senting doubts and difficulties, will, I trust, in the meet with acceptance, in which case it cannot fail to useful.

Scientific names are the coin in which enquirer exchange their ideas; and if they can be made to spond in different countries, the gain to science great. Such correspondence is as important in i as the assimilation of currency for the operati commerce. Should this object have been in an promoted by the present work, my most sanguine tations will have been fulfilled.

I may here mention that, in furtherance of the object, I have published, separately, a catalogue names of Rocks in the three languages. This cata which is an outline of this work, may, perhaps. useful to collectors.

P. H. LAWREN

AUTHOR'S PREFACE

TO THIS EDITION.

BEFORE my friend the Translator undertook the translation of this work, I had collected materials and made certain alterations with a view to a third edition.

The Translator himself, in the course of his labour, proposed certain alterations, which were adopted with my entire concurrence.

As far as my knowledge of the language enables me to judge, after a careful perusal, the translation appears to me to be very accurate.

This English edition may therefore be considered as the third edition of my original work, although, if the appearance of a third German edition should be delayed for some time longer, there will doubtless be new matter and fresh alterations to be introduced; for Science marches with uninterrupted steps towards new fields of discovery, and every year alters its aspect.

In a system of Lithology, however, most of the names

which are in use will probably remain, and one object of this book is to define these so as to intelligible the ideas which each name should co and both Author and Translator are actuated desire and ambition of arriving, as far as may be po at a common ground for all nations in respect important matter of rock-nomenclature.

B. COT