REVIEWS OF BOOKS. 



537 



ground required. Only a student who had already had a good training 

 in chemical manipulation, and had gained a good knowledge of the 

 use of chemical apparatus, could undertake the bulk of the work, and, 

 for him, the opening chapters on these points appear somewhat super- 

 fluous ; and perhaps a little of the space occupied by them might have 

 been devoted with profit to lengthening the directions for the carrying 

 out of the special manipulations further on in the book. A few 

 points will require revision in a second edition. For example, on p. 51 

 the student is told that a normal solution of sulphuric acid contains 

 49 grammes of the acid to 100 c.c. of water ; while on p. 63 directions 

 for the estimation of water in soils are given under the heading 

 " Reaction," the mode of ascertaining the reaction of the soil being 

 altogether omitted. These slight errors, however, the student sufficiently 

 advanced to undertake the work would at once detect. A large number 

 of useful tables are given at the end of the book, and add considerably 

 to its value. 



" Physiography." By Rollin D. Salisbury. 8vo., 770 pp. (John 

 Murray, London.) 21s. 



Though written by an American for American students, and having — 

 as it should — practically all its illustrations drawn from America, yet the 

 work is so excellent, and the principles of the science are so clearly 

 enunciated, that the English reader is bound to profit greatly by its 

 perusal. At first sight, perhaps, the subject matter of the book would 

 appear to have little to do with horticulture — and certainly much it 

 contains touches horticulture directly but very little — but it is equally 

 certain that if every landscape gardener, and every builder of a rock 

 garden, gave the attention to the subject that it deserves, there would 

 occur fewer incongruities in his work. Physiography includes the 

 study of all those forces that have worked towards the sculpturing 

 of the earth's surface in large areas and in small, and all are dealt 

 with in this work in a masterly way, and illustrated by numerous 

 maps, diagrams, and reproductions from photographs of various places, 

 mostly in North America. Nearly half the book is taken up with a 

 consideration of the work of the atmosphere, of ground and running 

 water, and of snow and ice in moulding the earth's surface ; then follows 

 a consideration of lakes and shores, of volcanoes and allied phenomena, 

 of movements of the earth's crust, and so on. A chapter is also devoted 

 to the consideration of the relation of the earth to other parts of the 

 solar system, while the third part is devoted to another factor upon which 

 the horticulturist's successes and failures so much depend — the weather 

 and the climate. The last part deals with the ocean. The publisher has 

 done his work well ; the book is well printed on good paper with an ample 

 margin, the numerous illustrations and maps are admirably reproduced, 

 and a full index greatly enhances the value of the work. 



" Agricultural Geology." By J. E. Marr, M.A., P.B.S. 8vo., 818 pp. 

 (Methnen & Co., London.) 6s. net. 



One of the subjects required to be studied by candidates for the 

 International Diploma of Agriculture is geology, and this little work 



