558 Reviews — Ramsay's Geology of North Wales. 



of Mechanics at the same place. An extract from his preface will 

 give a general idea of the book : — " If a mineral is to be determined 

 by means of these Tables, the kind of lustre, degree of hardness, the 

 streak, and also the colour, when the mineral has a metallic appear- 

 ance, must be made out. If these characters are properly deter- 

 mined— and this is a very easy matter — the Tables show that the 

 choice is confined to a small number of minerals, among which the 

 right one can be fixed upon either at once, or after consulting some 

 Handbook on Mineralogy, and can nearly always easily be found out 

 if the crystalline form is plainly recognizable. If this characteristic 

 is wanting, the determination is undoubtedly more difficult, or, 

 rather, takes more time, especially if the mineral has a non-metallic 

 lustre and a colourless streak. In such a case, the number of 

 minerals suggested is sometimes very large, and it appears ad- 

 visible to make use of the supplementary Tables, in which are 

 given the behaviour of these minerals in the matrass, with water 

 and hydrochloric acid." These Tables will be useful to the student, 

 in making him pay more attention to the physical characters, for, 

 with von Kobell's tables by his side, he is apt to trust too much to the 

 chemical properties to be determined, and consequently, when called 

 upon to determine a mineral without his blowpipe and re-agents, he 

 may feel somewhat at sea. No doubt von Kobell's tables are 

 most valuable (and it is to be regretted that the English translation 

 is out of print), but, at the same time, it is well if the student 

 accustom himself to determine minerals by even simpler means. 



C. L. N. F. 



lesAT-iE-ws. 



I. — Memoirs of the Geological Survey of Great Britain, and 

 OF the Museum of Practical Geology, Vol. III. The Geology 

 OF North Wales, by A. C. Ramsay, F.R.S., with an Appendix 

 ON THE Fossils, by J. W. Salter, A.L.S., F.G.S. 8vo. pp. 381 ; 

 Plates 28. (Longmans & Co.) 



THIS long promised Work will be heartily welcomed, more espe- 

 cially by those geologists whose affections centre chiefly in 

 Paleozoic rocks, and who are perhaps of opinion that the exploration 

 of newer geological territories has of late years occupied somewhat 

 exclusive attention. At the same time, however, the work before us 

 will be scanned with interest by those who are so eager in their 

 enquiries into the causes which have given rise to the contour of the land. 

 Its appearance cannot fail to remind us of one, now alas ! no more, 

 whose ability, joined to his enthusiasm, few could rival — the late 

 Sir Hemy De le Beche. Under his direction the survey of North 

 Wales was begun, and so many years have elapsed since then, that 

 those of his associates who at that time were comparatively young as 

 geologists, have now come to rank among ovx most eminent experts. 

 Those to whom the greater share of the work in North Wales feU, 

 are Professors Eamsay and Jukes, and Messrs. Aveline and Selwyn. 



