Trof, Boritshy — Bohemian Basalts and Phonolites, 35 

 I^IB "V^I IE "VST S. 



I. — Petrographische Studien an den Basaltg^steinbn Bohmens. 



pp. 294, with 8 coloured lithographic plates. 

 Petrographische Studien an den Phonolithgesteinen Bohmens. 



pp. 95, with 2 coloured lithographic plates. By Professor Dr. 



Emanuel Boricky. (Archiv fiir der naturwissenschaftliche 



Landesdurch-forschung von Bohmen, vols. ii. and iii. 1873-4.) 



THE journal in which these valuable monographs are published is 

 perhaps not so widely known among English "cultivators of the 

 natural sciences as it well deserves to be. Published in both the 

 Czech and German languages, under the direction of committees of 

 ardent and enthusiastic naturalists, having their head-quarters in 

 Prague, it contains the record of numerous original investigations on 

 the topography, geology, palaeontology, botany, and zoology of 

 Bohemia ; and we cannot but congratulate the cultivators of the 

 natural histary sciences in that country on the important contribu- 

 tions which they are making towards the progress of science, and 

 their success in illustrating the natural features of their own very 

 interesting country, to which the contents of these volumes bear such 

 ample testimony. 



The striking characters presented by the phonolites of the 

 volcanic district of Northern Bohemia have long been made familiar 

 to geologists by the descriptive writings of Eeuss, Jokely, Jensch, 

 and Hochstetter, and the analyses of Rammelsberg and other 

 chemists ; but it was reserved for Dr. Boritsky to> show that the 

 basalts of the same district, when carefully studied, are of at least 

 equal interest,, and surpass indeed the similar rocks of any other 

 area in the remarkable diversity of characters which they present. 

 It is certainly a noteworthy circumstance — to which our author draws 

 attention — that the whole of the varieties of basalt described in the 

 classical work of Zirkel on the " Basaltgesteine " are to be found in 

 Bohemia, while he has been able to detect some new and interesting 

 forms of tho rock which are quite new to petrologists. 



As exhaustive illustrations of the rocks of a particular district, 

 these monographs of Dr. Boritsky are invaluable. During his in- 

 vestigation of the basalts he has examined more than 1000 sections 

 derived from 400 different localities; and his conclusions concerning 

 the phonolites are based on the study of 300 sections of rocks de- 

 rived from 120 localities.. But a very inadequate idea of these 

 important works would be conveyed by merely noticing the micro- 

 scopical studies which they record. Dr. Boritsky, who is an accom- 

 plished mineralogist and chemist, has in every case combined his 

 microscopical with chemical and crystallographic researches, and, 

 more than all this, has sought to follow up the results of his re- 

 searches on the rocks in the laboratory by investigating their rela- 

 tions to one another in the field. 



The monograph on the Bohemian basalts commences with a dis- 

 cussion of the optical and chemical characters presented by the 



