September 2, 1904.] 



SCIENCE. 



307 



together varioiis views of psychology that 

 may be gained from a university stand- 

 point: The enlargement of the portion of 

 university appropriation devoted to this 

 science ; the broadening interest and in- 

 creasing specialization within the depart- 

 ment of psychology itself; the advanced 

 position attained in the university facul- 

 ties ; and the growing favor among students 

 and among scientific investigators. In the 

 history of this institutional development 

 the psychologists themselves deserve much 

 credit. They have continually justified 

 the confidence placed in them by intensi- 

 fying their instruction and by increasing 

 the merit of their literary and research 

 eontribiitions, until to-day these rank with 

 the best of any nation. 



Burt G. Minbe. 

 UjiiVEK.siTy OF Ilijs^ois. 



SCIENTIFIC BOOKS. 

 Gems and Gem Minerals. By Dr. Oliver 

 CcMMESTGS Farrington, Curator of Geology, 

 Field Columbian Museum, Chicago, HI. 

 Chicago, A. "W. Mumford. 1903. Imperial 

 8vo. Pp. xii + 229, with plates in color and 

 black and white. 



This work is a popular and comprehensive 

 book on the subject of precious stones, treating 

 of their finding, cutting, history and chemical 

 composition. It is intended to supply a long- 

 felt want for an inexpensive popular treatise 

 adapted alike to the mineralogist, the jeweler 

 and the general reader; and the work is one 

 full both of illustrations and information. 

 The nature of the leading gems, their occur- 

 rence, their mining, their color, luster, hard- 

 ness and specific gravity; their optical proper- 

 ties, their crystalline form, their cutting, and 

 the various superstitions connected with them, 

 are treated in successive chapters in the order 

 named. The rainor gems follow in their nat- 

 ural sequence, a chapter or part of a page 

 being devoted to each of the principal species 

 and varieties. The volume is printed on good 

 paper, and in large clear type. The illustra- 

 tions are of two kinds, in colors and in black 



and white, the latter giving maps of gem 

 regions, methods of mining and the various 

 forms of natural and cut stones, most of the 

 maps being made by half-tone processes and 

 many of them very exact. The special feature 

 of the work, however, is found in the numer- 

 ous plates produced by the three-color process, 

 and in most cases direct from the objects them- 

 selves. The application of this method makes 

 possible a vivid presentation of most of the 

 varieties of precious and semiprecious stones, 

 almost exactly true to nature, a result which 

 of course could not be attained by any black- 

 and-white process. 



Some of the plates prepared for this book 

 have already appeared in that excellent and 

 instructive popular publication, ' Birds in 

 Nature,' issued by the same publisher, whose 

 reprints of birds and other natural objects 

 have been adopted by many educational insti- 

 tutions for use in teaching, in so much that 

 more than 100,000 plates have been ordered 

 by a single school committee. Others of the 

 plates are reproduced from the great work, 

 ' Edelsteinkunde,' by Dr. Max Bauer, who 

 was one of the first to utilize the three-color 

 method with success. 



Dr. Parrington has had peculiar advantages 

 in preparing such a work, from his position in 

 charge of a great reference collection. This is 

 based on the Tiffany collection of gems gath- 

 ered for the Columbian Exposition at Chicago 

 in 1893, and subsequently purchased for the 

 Pield Columbian Museum, where it is now 

 installed in Higinbotham Hall. It is the best 

 book published up to the preseiit time as re- 

 gards text, illustration and exact facts for a 

 low price and useful to every raineralogist or 

 collector of gems. 



The color work in the gem plates compares 

 remarkably well with the three-color work of 

 Ives, who has attained excellent results, more 

 particularly, however, with porcelains, enamels, 

 pottery, etc., and is somewhat in the line of 

 the plate illustrating ISTorth American gems 

 issued by the TJ. S. Department of Mining 

 Statistics in its report for 1899. 



The Heliotype Company, of Boston, Mass., 

 also, have printed (unpublished) a most re- 



