426 Chronicles of Science. [ July, 
its English form, for which we are indebted to Phihp Henry Law- 
rence ; the translation, however, being revised by the author. The 
original work of Cotta is well known. Opinions vary widely as to 
its merits, but it has passed through two German editions, and a 
third is in preparation. 
This alone speaks loudly in favour of a work which is purely 
scientific, and may be accepted as the best possible testimony to its 
general merits. Professor Cotta informs us—“ This English edition 
may 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 unin- 
terrupted steps towards new fields of discovery, and every year 
alters its aspect. Ina system of lithology, however, most of the 
names which are in use will probably remain, and one chief object 
of this book is to define these so as to render intelligible the ideas 
which each name should convey, and both author and translator are 
actuated by the desire and ambition of arriving, as far as may be 
possible, at a common ground for all nations in respect of the 
important matter of rock nomenclature.” 
A careful examination of this important work must be reserved, 
and will probably be presented to our readers on a future occasion ; 
it is sufficient now that we have directed attention to the first 
appearance in the English language of a comprehensive treatise on 
Lithology. 
The following mineralogical works have appeared during the 
quarter :—‘ Die Minerale der Schweiz,’ von Dr. Adolf Kenngott. 
Leipzig. 1866.—‘ Vorlesungen tiber Mineralogie, von Kokscharow. 
1 Band. St. Petersburg. 1865. (Received by us not until March, 
1866.)—‘ A Catalogue of Siberian Topazes, by Kokscharow. St. 
Petersburg. 1866. (Written in the Russian language.) 
Analyses of Rahtite, of Marcylite, and of Moronolite, by Mr. 
§. W. Tyler, are given in ‘Silliman’s Journal,’ by Professor Charles 
U. Shepard.* Rahtite was distinguished as a new species by Mr. 
Tyler in 1861, during a survey of the Ducktown copper-mines, 
Tennessee. It is found associated with melaconite, chalcopyrite, 
and Redruthite, in the decomposed portions of the great copper lodes 
of these mines. The colour of the mineral is a dark lead-grey, with 
a tinge of blue, not unlike some of the ores of antimony. Its 
structure is massive, though at first inspection it seems highly 
crystalline; but this deceptive appearance arises from its being 
traversed in all directions by slender prismatic cavities, imparted to 
it by some unknown mineral which has wholly disappeared. The 
walls of these cells are polished and bright. 
The analysis of Rahtite, which is so named after Captain Raht, 
* <The American Journal of Science and Art,’ No. 122. 
