666 



SCIENCE 



[N. S. Vol. XXIX. No. 747 



but in the region of the Rhine and in France. 

 The sixteen beautiful pails from the cemetery 

 of Hem moor near Hanover are examples. 

 One often finds Roman motives in use, but 

 under forms scarcely recognizable. Among 

 the most remarkable specimens of this kind 

 belonging to the epoch of invasions must be 

 classed the celebrated golden horns of Gallehus 

 in Schleswig. To this period also belongs the 

 Roman silver service found at Hildesheim. 



Differences are pointed out between the re- 

 cent Celtic civilization of Germany and that 

 of Great Britain and Ireland. At the time 

 the Romans gained a foothold in England 

 local Celtic art had reached a high stage of 

 originality and development. Celtic elements 

 were even borrowed by the Romans, whose 

 political domination over the land did not 

 exercise any marked influence on the national 

 art, which continued without interruption 

 particularly in Scotland and Ireland, and 

 which culminated in the heroic and legendary 

 Celtic period of the first 500 years a.d. 



The last two chapters are devoted to the 

 closing epochs of prehistoric times in Scandi- 

 navia (500 to 1000 A.D.), and to Finland and 

 the Slavic countries. 



Miiller, who is director of the National Mu- 

 seum of Danish Antiquities, has been known 

 for years as a gifted writer on northern arche- 

 ology. The present volume maintains the 

 high standard the author set for himself in 

 earlier works. Each chapter is accompanied 

 by a selected list of references. One misses, 

 however, an index which is all but indis- 

 pensable in a work so important as this. The 

 next general work on prehistoric Europe will 

 in all probability devote more space to the 

 contributions of such men as Rutot and 

 Penck; those of the former on pre-Ghellean 

 industry and those of the latter on the anti- 

 quity of man from the standpoint of glacial 



George Geant MacCurdy 

 Yaie University 



Orundriss der EristallograpMe fur Stvdie- 

 rende und zum Selbstunierricht. Von Dr. 

 GoTTLOB LiNCK. Zweite umgearbeitete Auf- 



lage. Pp. 254, 604 figures, 3 colored plates. 



Jena, G. Fischer. 1908. 



Since the appearance of the first edition of 

 this little text-book of crystallography twelve 

 years ago it has remained the most satisfac- 

 tory elementary treatise on the subject in any 

 language. Unlike most text-books in the 

 same field, it discusses crystallography in all 

 its phases. Crystals are treated as bodies pos- 

 sessing certain well-defined properties in con- 

 sequence of their structure, rather than merely 

 as bodies characterized by distinct forms. 



Starting with a brief statement of the dif- 

 ference between typical fluids and typical 

 solids, the author develops the usual conception 

 with reference to the growth of crystals, and 

 follows this with descriptions of different kinds 

 of crystal aggregates, a discussion of the sym- 

 metry of crystal planes, and statements of 

 their simplest zone relations. The 32 classes 

 of crystal forms are then treated in detail in 

 92 pages. In the first edition this discussion 

 occupied 116 pages. The reduction is due to 

 the omission from the new edition of some 

 unnecessary explanations of figures, to the 

 condensation of such explanations as are re- 

 tained, and to a slight rearrangement in the 

 order of treatment of some features of the 

 subject. Everything essential to the under- 

 standing of the principles of geometrical 

 crystallography remains, and in addition 

 there has been introduced a most excellent 

 series of photographs of crystal forms and 

 combinations that will prove a welcome nov- 

 elty to the student. On the whole, the first 

 half of the revised edition does not differ ma- 

 terially from the corresponding portion of 

 the earlier edition. 



It is in the last half of the volume in which 

 the greatest changes are observed. This now 

 occupies 114 pages as against 93 pages in the 

 first edition. The study of the physical 

 properties of crystallized substances has ad- 

 vanced so rapidly in the past decade, and the 

 results of these studies have become of such 

 practical importance in physical and chemical 

 investigations that they merit much more 

 careful consideration than is usually given 

 them' in text-books published in the English 

 language. Indeed, there is scant reference to 



