20 REVIEWS. 



As we have not reviewed the first edition, our readers will readily excuse 

 our entering in some detail upon the portions of this work which are un- 

 altered, as well as upon the portions which are to be considered as addi- 

 tions to the first edition. 



PHYSICAL GEOGRAPHY. 



The first two chapters of the Physical geography are occupied with an 

 account of Chemical and Physical phenomena, which, in our opinion, ought 

 to have been worked up with much more care, or altogether omitted. For 

 example, in the table of Elements, page 9, there are many inaccuracies, 

 several of which are chargeable on the author, and not to be transferred to 

 the printer. We take, at random, Copper, Chrome, and Silver. 



Copper is said by Professor Ansted to occur ordinarily as Copper Pyrites, 

 which is quite correct ; but he proceeds to add, that Copper Pyrites i3 

 formed of three atoms of copper and one of sulphur, which is completely 

 erroneous. 



Chrome is described as commonly occurring in a compound of four 

 atoms of protoxide of chrome, iron, magnesium, and alumina, known as 

 Chrome iron ; a view which is not taken of that mineral by any mineralo- 

 gist, as it is well known to have the same formula as Magnetic iron, with 

 replacement of isomorphous elements. 



Again, Hornsilver is described as a bichloride of silver. We subjoin 

 the correct formula for each of these cases : — 



In the third chapter, which is one of the most valuable in the book, 

 there are numerous tables of Areas of River Drainage, Relative areas of land 

 and water, &c, &c, for which our author is principally indebted to John- 

 ston's Physical Atlas. 



He has also introduced some of the newest information relative to these 

 subjects from Lieutenant Maury's well-known work on the Physical Geo- 

 graphy of the Sea. We extract the following relative to the Atlantic : — 



" The form and physical features of the ocean bottom of the Atlantic, between 

 the northern part of South America and the latitude of London, are now known 

 with sufficient accuracy to admit of general description. Down to latitude 15° 

 north, and parallel to the European coast, is a large north and south tract from 



