94 



NA TURE 



[March 25, 1Q09 



chemical change, and be able to trace out the broad 

 outlines of the great natural cycles involved in the syn- 

 thesis of plant substances from carbon dioxide, water, 

 &c., and their decomposition in the animal system or 

 the soil with production once more of carbon dioxide, 

 water, and other bodies. He should study the factors 

 concerned in plant growth, the soil in its relation 

 to the plant, and the plant, considered as food, in 

 its relation to the animal; and, as the subject has 

 a commercial side, he must be able to interpret the 

 analysis of a feeding stuff or manure, and to make 

 simple calculations involving a knowledge of the 

 chemical composition of a few common substances. 

 The scheme of teaching must take account of the 

 rather special nature of the student. A young man 

 commonly chooses agriculture as a profession because 

 he loves the outdoor life of the farm and is of a 

 keenly practical turn of mind, and this temperament 

 is generally incompatible with systematic study of 

 a subject for its own sake; he will work, however, 

 and work hard, when his studies obviously subserve 

 a useful end and fit in with the central idea of his life. 

 The book before us shows how Mr. Ingle teaches 

 agricultural chemistr)', and the record of one teacher's 

 methods and experiences cannot fail to be interesting 

 to others who are engaged in the same work. The 

 student is supposed to have gone through a course of 

 inorganic and organic chemistry, but by way or 

 recapitulation an introductory chapter deals with 

 general chemical conceptions, and another with the 

 composition of the atmosphere. We then pass on to 

 a study of the soil, the plant, manures, feeding, and 

 dairy work. The author tells us in the preface that 

 the book was written whilst he was in touch with 

 South African agriculture, and the illustrations are 

 drawn sometimes from English, sometimes from 

 South African practices. 



The chief defect of the book is that it fails to 

 present the subject as a whole, and successive 

 chapters seem to have little connection one with the 

 other. There is no systematic discussion of the 

 relationship between one branch of the subject and 

 another, and the reader gets a sense of much detail 

 but no general principles. In the mass of detail 

 certain things have got left out which certainly ought 

 to have gone in. Chief of these is the physical 

 composition of soil as shown by mechanical analysis, 

 concerning which not a word is spoken, in spite of 

 its fundamental significance in soil work. No 

 mention is made of the loss of nitrogen from soils 

 by aerobic bacterial action. There is also, and perhaps 

 necessarily, a lack of proportion ; thus the grasses 

 get no more space than the sweet potato, notwith- 

 standing their enormously greater technical import- 

 ance. 



Indeed, the book is not so much an elementary text- 

 book as a short reference book, and from this point 

 of view it will be found very useful for class work. 

 There is a great collection of data from many sources, 

 the compilation of which must have involved an 

 enormous amount of labour, and for which the teacher 

 will have much cause to be grateful to Mr. Ingle. 



E. J. Russell. 

 NO. 2056, VOL. 80] 



TIMBER. 



Timber. By J. R. Baterden. Pp. ix + 3Si. (London: 

 Archibald Constable and Co., Ltd., 1908.) Price 

 6s. net. 



THIS popular manual undoubtedly contains in- 

 teresting and miscellaneous information about 

 the uses, preservation, and strength of timbers. 

 The author, who is an engineer, occasionally refers- 

 to useful matter in engineering publications, and 

 has compiled extensively from the reports of the 

 forest ofificers of the various British colonies and of 

 the United States. It is unfortunate, however, that 

 he has attempted to write a general treatise. He is 

 confessedly ignorant of botany; and his account of 

 the structure and origin of the numerous species 

 dealt with is usually meagre and defective, and in 

 many instances almost puerile. His frequent de- 

 scriptions of trees in the living state are out of place 

 in a small manual, the subject of which is timber, 

 and not forestry. The same remark applies to many 

 of the illustrations, which are irrelevant. Hack- 

 neyed pictures of the common oak, beech, larch, &c., 

 growing in the isolated state, only serve to show 

 (but Mr. Baterden and his publisher are unaware of 

 this) how trees ought not to be grown, if they are 

 to be regarded as producers of timber of proper 

 shape and quality. 



European timbers, which should have been fully 

 treated, on account of their great importance to the 

 home grower and consumer, are dismissed by Mr. 

 Baterden in a short chapter, which contains some 

 singular errors and omissions. The bibliography at 

 the end of the volume does not include the Quarterly 

 Journal of Forestry and the Transactions of the Scot- 

 tish Arboriciiltural .Society, journals from which much 

 useful material might have been extracted. Only 

 three lines are devoted to the cricket-bat willow, the 

 w^ood of which is the most costly produced in England. ^ 

 No allusion is made to native species, like the white- 

 beam and the service tree. A more glaring omission 

 occurs in the account of home-grown poplars, where 

 nothing whatever is said about the black Italian 

 poplar (usually referred to Populus canadensis), 

 which is the most common species in cultivation and 

 the fastest in growth. Nobody will be much the 

 wiser by reading the following article :— " Plum, 

 which is somewhat similar to pear, is also used for 

 turnery. Weight about 40 lb. per cubic foot." The 

 durmast is erroneously considered to be something 

 different from Qtiercus sessilifiora. with which it is 

 identical. The timber of the Turkey Oak, which 

 every forester knows to be of poor quality, is said 

 to be suited for the same class of work as the common 

 oak. 



The timbers of North America are dealt with at 

 great length; and Lebanon cedar appears amongst 

 them. The Atlas cedar is never mentioned, though, 

 both on account of its valuable timber in Algeria 

 and its successful cultivation in England, it deserves 

 an extended notice. The beautiful yellow cedar of 

 British Columbia and .-Maska, which may be seen 

 growing with great vigour in many of ohr parks. 



