26o 



Reviews and Book Notices. 



Mineralogy: an Introduction to the Scientifc Study of Minerals. 

 By Henry A. Miers, D.Sc, M.A., F.R.S., etc. 8vo., pp. xviii. +585; 

 with two coloured plates and 716 illustrations in the text. London : 

 Macmillan & Co. 1902. Price 25s. 



In this handsome volume Pro- 

 fessor Miers offers to the student of 

 mineralogfy a text-book of a kind 

 which has longf been a desideratum, 

 and we do not doubt that it will be 

 heartily welcomed by students and 

 teachers alike. The author points 

 out in his preface that certain im- 

 portant branches of mineralog-y, 

 viz., those dealing- with the origin, 

 occurrence, associations, and geo- 

 log-ical relations of minerals, have 

 been excluded ; and accounts for 

 their omission by the consideration 

 that they are of sufficient mag-nitude 

 to deserve a separate volume. We 

 hope that we may reg-ard this not 

 merely as an apology, but as a 

 promise. Apart from this the work 

 is admirable as a text-book almost 



Witherite from Hexham. 



Aragonite from Cumberland. 



as much for what it omits as for 

 what it includes. The judgment 

 shown in this respect marks it as 

 the production of one who is a 

 successful teacher no less than a 

 practised mineralogist. 



The principal bulk of the volume 

 divides into two nearly equal parts ; 

 the one devoted to the properties of 

 minerals in general, the other deal- 

 ing with the more important mineral 

 species severally. The general part 

 begins with a discussion of crystal- 

 line form and an account of the six 

 crystallographic systems, and pro- 

 ceeds to the conjunctions of crystals, 

 twinning, vicinal faces, and the 

 measurement of crystals on the 

 g^oniometer. This covers the geo- 

 metrical properties of crystals. 

 The next section treats of the 

 crystallophysical properties, such 

 as elasticity', cohesion, etc., and 

 especially the optical characters. 

 These are described lucidly and 

 sufficiently fully, the author prefer- 

 ring to make use of the ' indicatrix,' 

 though he does not entireh' discard 

 Fresnel's ellipsoid. There remains 

 those properties, such as specific 

 gravity and specific heat, which are 

 not specially related to crystal form, 

 and the chemical properties of 

 minerals, of which a useful summary 

 is given. Particularly acceptable is 

 the chapter devoted to isomorphism, 

 vicarious replacement, etc., contain- 

 ing much material which the student 



Naturalist, 



