236 Tlic hish Nat'H7-alist. December, 19 13. 
Dipper in County Longford. 
In a letter in the Mornins; Post, last September, Rev. Sir George R. 
Fetherston records the occurrence of the Dipper at Ardagh, Co. Longford. 
Longford and Westmeath are the only two counties in Ireland from which, 
according to the " Birds of Ireland," Mr. Ussher had no record for this 
bird. 
REVIEW. 
ROCK-FORMING MINERALS. 
Outlines of Mineralogy for Geological Students. By Grenville A. J. 
Cole. 8vo., pp. 339 and 124 illustrations. London : Longmans, 
Green & Co., 191 3. Price 5s. net. 
Professor Cole's old students and geological students generally will be 
glad to read this latest product of his pen. The book is divided into two 
parts. Part I. deals with the characters of minerals, while in Part 11. 
we have a descriptive account of those most com-monl)' found. Chapter i. 
discusses the nature of a mineral, and the student is led by a simple 
method of elimination and illustration to the important characters of 
definite chemical composition and characteristic crj^stalline form. The 
physical characters of minerals and common features of crystals are 
dealt with in chapters ii. and iii., respectively, and lead on naturally 
to a consideration of the underlying elements of symmetry and the 
essential features of the seven crystallographic systems into which crystals 
are divided. In chapter iv. we have a description of the thirty-two 
classes of symmetry, the various forms in each being given in a clear 
and concise manner . Twinning and cleavage occupy chapter v., and 
in chapter vi. is a very good exposition of that most thorny of all problems 
for the ordinary student — the optical characters. In chapter vii. further 
physical features such as fluorescence and radioactivity are treated of, 
and in chapter vii. the student is introduced to simple methods of blow- 
pipe analysis of minerals. In the descriptive part of the book the 
minerals are arranged by the fundamental element in each, and these are 
taken in the order of Mendelief's table. Thus iron, nickel, cobalt and 
platinum are considered in the tenth chapter, and under the head " Iron " 
we have Native Iron, Pyrite, Marcaoite, Pyrrhotite, Haematite, &c. 
The book is excellently written throughout, and it should prove of even 
greater value to the student of geology than the " Aids in Practical 
Geology " which is everywhere highly spoken of. 
I SW.MN. 
