June 21, 1888] 



NATURE 



171 



last sixteen years only serve as a basis for future work. 

 Much has yet to be done regarding the physiological 

 action of these bodies ; and no progress can be made in 

 this respect until the alkaloids have been extracted in a 

 pure state. It is almost useless, in the interests of science, 

 to speak of the action of alkaloids extracted by various 

 reagents ; though, in certain cases of poisoning, the in- 

 vestigation of such an action may be of immediate utility. 

 Dr. Brown has devoted much space to the consideration 

 of the part played by the vital alkaloids in physiological 

 or pathological conditions. In his account he has closely 

 followed the views of M. Gautier, whose researches have 

 thrown great light on the subject. 



Dr. Brown's work may be recommended as giving a 

 general account of the present state of our knowledge 

 regarding these alkaloids. S. H. C. M. 



PRACTICAL FORESTRY. 



Practical Forestry : its Bearing on the Improvement of 

 Estates. By Charles E. Curtis, F.S.T., F.S.S., Pro- 

 fessor of Forestry, Surveying, and General Estate 

 Management at the College of Agriculture, &c. (Lon- 

 don : Land Agent's Record Office, 1888.) 



THE present work is described, as a reprint of a series 

 of papers on " Practical Forestry," which appeared 

 in the Land Agent's Record, and the author's object in 

 republishing his ideas on practical forestry is to pro- 

 mote and encourage the study of true forestry among the 

 British land-owners and land agents, and especially to 

 impress upon students the necessity of acquiring a sound 

 practical knowledge of a branch of land economy so long 

 neglected and ignored. So far so good ; but when the 

 author says, " I trust this publication will be the means of 

 spreading this object more widely " (sic), we fear that he 

 will be grievously disappointed. 



To begin with : the book is written in doubtful English. 

 Though the correct use of the English language is not 

 absolutely essential, yet in order to be a really useful 

 work, a book should be written in language which com- 

 plies with the ordinary grammatical rules, and which is 

 also intelligible to the class of readers expected to profit 

 by its perusal. The whole book is conceived in a very 

 narrow spirit, and the expressed views of the author 

 are frequently open to question. Take for instance the 

 following passage (p. 40) : — 



" The great and true principle of thinning is to en- 

 courage the growth of those trees which are left, and not 

 to secure a financial present return. This, though im- 

 portant, is quite a secondary consideration, and should 

 at all times be ignored." 



We beg to say that the great and true principle of 

 thinning is nothing of the kind. In every instance the 

 owner, or his manager, must consider what the objects 

 of his management are. They may be : — 



(1) To produce material of a certain description. 



(2) To produce the greatest possible number of cubic 

 feet per acre and year. 



(3) To secure the highest possible money return from 

 the property. 



(4) To secure the highest possible interest on the 

 invested capital. 



(5) To improve the landscape, or to affect the 

 climate, &c. 



In each of these cases the method of thinning will 

 be different. 



Again, the descriptiongiven of a true forester (p. 12) is 

 somewhat illusory. If the author thinks that a man who 

 has studied botany, vegetable physiology, geology, entomo- 

 logy, &c, is also able to wield the axe, and use with 

 skill the pruning saw or knife, he is likely to be dis- 

 appointed in nine cases out of ten. Such ideas are 

 theoretical speculations, and not the result of practical 

 experience. 



The chapter on " Soil and Site " is of a very hazy descrip- 

 tion whenever the author attempts to rise above ordinary 

 platitudes. He promises to describe clearly in future 

 sections the nature of the soils and sites in which the 

 individual trees most delight, but, as far as we can see, 

 he has got' over the difficulty by omitting to redeem his 

 promise. 



To sum up, the book is not likely to further the- object 

 which the author seems to ' have at heart. The ex- 

 perienced forester will find nothing new in it, and the 

 beginner will only meet with badly arranged statements 

 which are frequently not in accordance with the teaching 

 of science or of practice. Sw. 



OUR BOOK SHELF. 



Tropical Africa. By Henry Drummond. (London : 

 Hodder and Stoughton, 1888.) 



This is a brightly-written and most interesting sketch of 

 Mr. Drummond's experiences during a recent journey in 

 East Central Africa. He has no very surprising or 

 exciting adventures to describe, but in the course of his 

 narrative, which is written with a vigour and grace 

 unusual in books of travel, he contrives to convey a 

 remarkably vivid impression of the country through 

 which he passed. Going up the valley of the Shire" 

 River, he visited Lake Shirwa, of which little has hitherto 

 been known ; then he went on to Lake Nyassa, and to 

 the plateau between Lake Nyassa and Lake Tanganyika. 

 During the whole of his journey he was a close observer, 

 not only of the physical features of the districts he 

 visited, but of the various classes of phenomena which 

 interested him as a geologist, an ethnographer, and a 

 student of natural history. In one admirable chapter he 

 gives a full and striking account of the white ant, which 

 he had frequent opportunities of studying ; in another he 

 brings together many curious illustrations of the well- 

 known fact that among numerous species of animals 

 mimicry is one of the means of self-protection. Before 

 going to Africa, Mr. Drummond had mentally resolved 

 not to be taken in by " mimetic frauds," yet he was 

 "completely stultified and beaten" by the first mimetic 

 form he met. This was an insect — one of the family of 

 the Phasmidce— exactly like a wisp of hay. Another 

 insect, which he often saw, closely resembles a bird- 

 dropping, and the consequence is that "it lies fearlessly 

 exposed on the bare stones, during the brightest hours of 

 the tropical day, a time when almost every other animal 

 is skulking out of sight." Mr. Drummond has of course 

 much to say about the chances of a great future for 

 Africa, and in this connection he presents a good deal of 

 valuable information as to the capacity of the natives for 

 work and as to the wrongs inflicted upon them by vile 

 gangs of slave-traders. 



