402 Scientific Intelligence. 



12. Einfilhrung in die Gesteinslehre : Ein Leitfaden filr den 

 akademischen Unterricht und zum Selbststudium von A. vox 

 Lasaulx. 215 pp. 8vo. Breslau, (Edward Trewendt). — This 

 little work, like another by Hussak, recently published, is espe- 

 cially adapted for the instruction of those who are commenc- 

 ing their petrographical studies. The author assumes that they 

 have made themselves familiar with the now fully developed 

 methods of modern petrography, mechanical, microscopic, micro- 

 chemical, and goes on to describe the kinds of structure in rocks, 

 the most important rock-forming minerals, and the classification 

 and description of the different kinds of rocks. The author's idea 

 of leading students to go direct to original papers for information 

 is a good one, and with this end in view the literature of the sub- 

 ject is given very fully in an appendix. 



13. Pyrargyrite and Proustite. — Dr. Ernst Rethwisch has 

 published, as an inaugural dissertation at the University of Gott- 

 ingen, an admirably thorough discussion of the crystallbgraphic 

 and chemical characters of the two ruby silver ores. Such a 

 review, especially on the crystallographic side, has long been a 

 desideratum in mineralogical literature. The complexity of the 

 subject may be gathered from the fact that the total number of 

 planes identified in the two species amounts to one hundred and 

 eight. 



14. The Marble Border of Western New England: its geology 

 and marble development in the present century. (Middlebury His- 

 torical Society, vol. i, part II, Middlebury, Vt., 1885). — This 

 pamphlet contains a short paper on the geological features of the 

 Marble belt, by Professor Ezra Brainerd, and another on the Mar- 

 ble Fields and Marble Industry, by Professor H. M. Seely of 

 Middlebury, Vermont. The marble belt is for the most part the 

 belt of the Stockbridge limestone, the great limestone of Emmons's 

 " Taconic System." The subject is treated from an economical 

 and historical point of view, as indicated in the title. 



15. Die Meteor iten-Sammlung des Jc. k. miner alogischen Hof- 

 Eabinetes in Wien am 1. Mai 1885, von Dr. Aristides Brez- 

 ina. From the Jahrb. der k. k. geol. Reichsanstalt, 1885, pp. 

 151-276; with four plates. — The collection of meteorites of the 

 Vienna Museum has long been recognized as ranking among the 

 most important in the world. Of late years the increase has been 

 very rapid and the present catalogue includes 358 numbers. Dr. 

 Brezina, however, has done much more than merely give a his- 

 tory of the collection and a list of localities with dates, weights 

 and so on. He discusses also at some length the origin of the 

 peculiar structure of meteoric stones, and the systems of classifica- 

 tion proposed. The work is therefore an important contribution 

 to a most interesting subject. 



16. Botany of the Challenger Expedition. Vol. I, 1885. — This 

 bulky and well-illustrated quarto volume is devoted to the deeply 

 interesting subject of Insular Floras, namely, of the Bermudas, of 

 the Southern Atlantic Islands, with St. Helena, etc., of Juan 



