474 Heviews — Pocket Handbook of Minerals. 



teaching. Numbering about 25,000 specimens, it includes all the 

 important mineral species, South Australian minerals being, of course, 

 well represented. The species are classified according to the 

 arrangement adopted by Dana in the sixth edition of the " System 

 of Mineralogy," and the information contained in the Catalogue 

 comprises the registered number of each specimen, its locality when 

 known, the source through which it was obtained, and occasional 

 remarks of general interest. 



II. — A Pocket Handbook of Minerals. By G. Montague Butler. 

 pp. ix + 298, with 89 figures in the text. Kew York : John 

 Wiley & Sons, 1908. Price 12«. 6d. net. 



TO those who have to arrive at a rapid determination of mineral 

 specimens — for instance, prospectors and other workers in the 

 field — the convenient handbook prepared by Professor Butler will 

 prove welcome. In it he gives for each species the physical characters, 

 such as the colour, lustre, hardness, and streak, that are observable 

 almost by mere handling of the specimen, and the reactions that may 

 be determined by means of the ordinary blowpipe and simple reagents 

 included in any prospector's outfit, the more important and decisive 

 tests being emphasized by a judicious use of heavy type. The various 

 characters are summarised in tables printed at the end of the book 

 on folding sheets of paper, an inconvenient arrangement that would 

 probably not stand the wear and tear of constant use. Ample space 

 is left for the addition of notes that experience may suggest, and the 

 book is well illustrated with sketches of characteristic crystals and 

 pictures of typical specimens. The additional chapters dealing 

 respectively with the commercially important ores of the various 

 metals and with the average retail prices of gem-stones and minerals 

 will be valuable to the prospector, and the ample glossary will be 

 useful to those not conversant with the technical terms in vogue 

 among mineralogists. The arrangement of the mineral species 

 follows closely Dana's well-known treatise, from which, indeed, the 

 information given has been mainly culled. 



The value of the book would have been greatly increased by the 

 addition of numerical data, such as the specific gravity, which is given 

 only in cases where it is an obviously distinctive character, and the 

 refractive constants. Methylene iodide has been so much reduced in 

 price of late years that an ounce or so is no serious addition to the 

 expense of an outfit; even without a dilutant it may after a little 

 experience be employed to give valuable information. jS'ow that 

 portable refractometers are available it is possible to determine in 

 the case of most transparent substances the refractive indices, often 

 a satisfactorily decisive test. 



III. — Brief Notices. 

 1. Plumbago. — It is singular to find how little one knows about the 

 most ordinary things, and Dr. J. W. Evans must be congratulated in 

 having, at the instance of Dr. Murray, cleared up the history of the 



