232 NATURAL SCIENCE. Marcu, 
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 TrRopicAL AGRICULTURE. H. A. A. Nicholls; M.D., F.L.S. 
8vo. Pp. xxi. and 312, with illustrations. London: Macmillan & Co, 1892. 
Price 6s. 
Tus book is the outcome of 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 ot 
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 esculenta) 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 
