BOOK EEVIEWS. 



651 



tions alone make the book valuable as a lesson in the arrangement of 

 pot plants. Compare this with the stodgy " groups " in many 

 "conservatories," drawing-rooms, and stuffy flower-show tents. The 

 larger villa gardens depend more for their charm on rampant sub- 

 tropical luxuriance and colour, than on coherent premeditated design. 

 For this reason Miss Florence Du Gane is to be congratulated upon 

 having accomplished the somewhat difficult task of writing an 

 interesting book on gardens, which, at first sight, offer nothing but 

 natural luxuriance. But she succeeds in describing their beauty and 

 making it interesting. She gives lists, readable lists, of the plants 

 they contain, and she gives useful cultural details. The last chapter 

 of the book deals with the history of the island. 



All who have visited Madeira, if only for a few hours from a mail 

 steamer, should certainly buy this book, and all who buy the book 

 will certainly want to visit Madeira. 



"Agricultural Bacteriology: Theoretical and Practical." By J. 

 Percival, M.A., F.L.S. 8vo., x + 408 pp. (Duckworth, London, 

 1910.) 7s. Qd. net. 



Of books dealing with bacteriology as applied to the problems of 

 agriculture and horticulture there are few in the English language. 

 Two or three of considerable merit written in America, and the excel- 

 lent translation of Dr. Lafar's " Technical Mycology " by Mr. Ohas. 

 T. 0. Salter, are practically the only ones available, and the last is 

 almost too technical for any but the very advanced student. There 

 are, of course, many dealing with bacteriological methods, and several 

 dealing particularly with the bacteriology of dairying, but no others 

 cover the wider field of soil bacteriology and the fermentation of 

 manures, and so on. 



Professor Percival has attempted to combine a book of instruction 

 in bacteriological study with a text-book of bacteriology as applied t 

 agriculture, and, we venture to think, not unsuccessfully. 



The first part of the book deals with the form and life of bacteria 

 and with methods of isolation and study. The action of enzymes and 

 fermentation are then dealt with, and then the special bacteriology 

 of the soil, nitrification, denitrification, the fixation of atmospheric 

 nitrogen by the agency of bacteria, and the nature of the fermentations 

 which take place during the ** curing " of manure. From p. 232 to 

 the end describes the part played by bacteria in the dairy, and this 

 portion need not detain us further. 



The directions for the experimental work are for the most part 

 very clear and accurate, though we do not think the author is right 

 in recommending an acid medium (p. 46) for the cultivation of bacteria ; 

 our own experience is in favour of a very slightly alkaline medium for 

 general work, using as a rule an acid medium for the cultivation of 

 fungi. 



The chapters on soil bacteriology are very clearly written, and the 

 practical application of the lessons to be learned from the knowledge 



