232 NATURAL SCIENCE. March. 



and similar matters. There are many illustrations, and the book 

 is interesting not only to the manufacturer but to the general 

 reader. 



A Text-Book of Tropical Agriculture. H. A. A. Nicholls, M.D., F.L.S. 

 8vo. Pp. xxi. and 312, with illustrations. London : Macmillan & Co., 1892. 

 Price 6s. 



This book is the outcome ol a competition. The Jamaica Govern- 

 ment offered a premium for the best Text-book of Tropical Agri- 

 cuture specially adapted for the use of colleges and higher schools 

 in that colony, and the author having sent in the manuscript of part 

 of the book before us, it was awarded the prize on condition that 

 some chapters were added treating of most of the cultivated tropical 

 plants not noticed in the original. This was done, and in 1891 the 

 Government of Jamaica published the book, of which Messrs. 

 Macmillan have just issued the London edition, of the convenient 

 size, general excellence of production, and with the bright scarlet 

 cover of their other manuals for students. 



The work has already passed the test of practical experience in 

 Jamaica, and is now being adopted by the Governments of other 

 colonies. 



The author hopes to serve not only scholastic institutions, but 

 peasant proprietors, owners of small estates, and intending settlers 

 in tropical countries, and the fact, as stated in the preface, and 

 evident from the merest glance at the text, that we have here 

 " not a mere compilation, but the record of experience gained 

 by study, observation, and experimental cultivations," should ensure 

 it success. 



The book is divided into two parts. Part I. — " Elements of 

 Agriculture " — is a capital introduction to the science, occupying 85 

 pages, well arranged in thirteen chapters. The first is brief and 

 introductory, the [second and third give a concise account of Soils, 

 how they are formed by atmospheric and other action, their con- 

 stituents, classification, and properties. Chapters 4 and 5, on Plant 

 Life, tell in about 20 pages of the parts of a plant, its nutrition, 

 composition, and reproduction by seed or vegetative processes. A 

 short chapter follows on Climate, " the greater or less degree of heat, 

 light, and moisture," and the influence thereon of elevation, forest, 

 aspect, or soil. Then under manures is considered the restoration or 

 fertility to an exhausted soil, or the improvement of a poor one, and 

 the most important "general" and "special" manures, their pre- 

 paration, use, and effect, are described. 



Chapter 8, " Rotation of Crops," follows, and is, unfortunately, 

 necessarily short, very little attention, as the author remarks, having 

 been given to working out a proper system of rotation in the 

 West Indies, as has been done in Europe and North America. The 

 importance of experiments is urged, and a course of rotation sug- 

 gested, viz., yams or tanias (the rhizome of Colocasia escuknta) the 

 first year, maize the second, sweet potatoes the third, and castor- 

 oil or a similar crop for the fourth. Stress is also laid on the bene- 

 ficial mechanical effect on the soil, from the necessary frequent 

 turning over and consequent exposure to the chemical action of 

 the atmosphere, while the rotting of roots of former crops make 

 channels in all directions for water and air. Moreover, a proper 

 system of rotation prevents blight and keeps away destructive insects 



