February 5, 1903] 



NA TURE 



o'o 



In conclusion, we congratulate the author on having 

 carried out so formidable a task as the compilation of 

 these tables apparently single-handed. Should a second 

 edition be necessary, revision of some parts and con- 

 densation to two-thirds its present bulk would make it 

 a decidedly useful work. J. A. H. 



OUR BOOK SHELF. 



Natural and Artificial Sewage Treatment. By 

 Jones and Roechling. Pp. vii + 96. (London : Spon, 

 1902.) 



The authors state that they are making public in the 

 above treatise information which they have already 

 brought before different societies of professional men, 

 but they claim that while putting the matter forward in 

 a new form, they have also brought it up to date. This 

 is doubtless the case with the statements concerning 

 treatment of sewage on the land, but the treatment 

 by bacteria beds is not so satisfactorily brought up to the 

 date of publication. In fact, the impression produced by 

 a careful perusal of the book is that the presentation of 

 the two methods of treatment by land and by bacteria 

 tanks and beds is such as to indicate a very considerable 

 predilection for the sewage farm. This impression is 

 caused, not by an overstatement of the results of sewage 

 farming, but by an understatement of the permanency 

 and advantages of an artificial bacterial installation. The 

 authors do not lay stress, as they should in fairness do, 

 on the fact that what they term the "artificial" bacterial 

 treatment is the bacterial treatment of the sewage farm 

 carried out under regulated and controlled conditions 

 which add much to the precision, uniformity and regu- 

 larity of the process of purification. When they place 

 to the advantage of land treatment that it removes 

 pathogenic germs, they are on doubtful ground ; and 

 when they speak of the entire loss of manurial value and 

 the production of larger volume of effluent by the artificial 

 bacterial process as disadvantageous, they apparently 

 forget that bacterial effluents are not infrequently directly 

 or indirectly used in certain parts of the year for irriga- 

 tion, and further, that a larger volume of good effluent 

 turned into a watercourse is usually of direct advantage. 



Some statements are, moreover, open to serious ques- 

 tion and have not been decided in the sense stated. Such 

 is the oft-repeated one that treatment of ordinary 

 sewage causes bacteria beds rapidly to silt up and that 

 their material requires renewal, that their capacity is not 

 permanently increased by resting, that they are peculiar 

 in requiring careful management and that a covering of 

 scum is necessary to the action in the so-called "septic 

 tank." It should have been stated that beds which silt 

 up are either improperly constructed, are being im- 

 properly treated or are receiving abnormal sewage, and 

 that bacterial treatment, whether effected on land or in 

 artificially constructed spaces, is identical in its cause and 

 its nature and requires similar considerate management. 

 Both processes have frequently failed because they have 

 been inconsiderately provided for and dealt with. 



If the above considerations are borne in mind, "dis- 

 trict councillors, sanitarians and all interested in this 

 complicated process " may with advantage peruse the 

 little book, and they will find that, in the second part more 

 especially, information of real value is presented in a 

 lucid and intelligible form. 



It might have been anticipated from the title of the 

 book that chemical processes of treatment received no- 

 tice. It is satisfactory to find that they are not dealt 

 with, and that the terms "natural and artificial," as ap- 

 plied to sewage treatment, are intended to refer to land 

 treatment and to so-called bacterial treatment re- 



spectively. It should be remembered that both these 

 treatments are "naturally " effected in the main by the 

 bacteria present in the sewage itself, and that the laying 

 out of a sewage farm is as truly artificial as the provision 

 of beds of flints, pebbles or other materials for so-called 

 contact treatment. 



Thomson's Gardeners Assistant. New Edition. 



Pp. viii + 607. (London : The Gresham Publishing 



Company, 1900-1902). Six Vols., Ss. each. 

 This important horticultural work, revised and entirely 

 remodelled under the able direction and general editor- 

 ship of Mr. \V. Watson, Curator, Royal Gardens, Kew, 

 has now been completed. It has been published in six 

 divisional volumes, or in two volumes of 656 and 607 

 pages respectively. Many specialists have contributed 

 to the work, and a glance at a list of their names with 

 the articles for which they are severally responsible is 

 sufficient to prove the value of this great addition to the 

 literature of gardening. 



Divisional vol. i. contains about forty pages on 

 "Plant Structure," an epitome of such portions of 

 botanical science as are of most interest to the gardener, 

 by Dr. M. T. Masters. " Insect and other Plant 

 Enemies," as also an article on "Garden Friends," are 

 well treated by Mr. J. Fraser. Mr. G. Massee, our 

 greatest authority, writes on " Plant Diseases caused by 

 Fungi." All these articles are well illustrated and clearly 

 and pleasantly written. Soils and manures are treated at 

 length by Mr. Willis. Tools and instruments and garden 

 structures are thoroughly dealt with, described and, when 

 desirable, illustrated — the underlying principles being 

 explained in a concise and lucid manner. 



Divisional vol. ii. has articles, all well illustrated, • 

 on heating, propagation, transplanting, pruning, flower- 

 garden and pleasure-grounds, hardy ornamental trees 

 and shrubs, hardy herbaceous perennials, aquatic and 

 bog plants, hardy and half-hardy annuals and popular 

 garden plants. 



Divisional vol. iii. treats on the greenhouse and 

 conservatory, gives a select list of desirable stove and 

 greenhouse plants with full cultural details. The orchids 

 are fully treated by Mr. J. O'Brien, a descriptive list of 

 the more important ones from a garden standpoint being 

 given, together with full particulars as to their require- 

 ments and cultivation ; plans of orchid houses even are 

 given. Other special articles are those on ferns, palms 

 and cycads, succulent plants, summer bedding, the sub- 

 tropical garden, floral decorations, &c. 



The remaining three divisional volumes deal fully and 

 carefully with the fruit and kitchen garden. Lists of the 

 best varieties are in each case given, and in some 

 instances, under "Asparagus," for instance, the methods 

 pursued by present-day market cultivators near London, 

 and also about Paris, are described pretty fully. 



Calendarial directions for each department of the 

 garden for each month are contained towards the close 

 of the last volume, in which are also treated the best 

 methods of collecting, packing and storing vegetables, 

 &c. 



We think that, taken altogether, the present edition of 

 " Thomson's Gardener's Assistant " may fairly be re- 

 garded as the standard book on British gardening. 



G. N. 



Proceedings of the Aristotelian Society. New Series. 



Vol. ii. Pp. 240. (London : Williams and Norgate, 



1902.) 

 This collection of papers read before the Aristotelian 

 Society during the session 1901-2 maintains the 

 decidedly high level reached by previous volumes. For 

 the professed metaphysician there will be special interest 

 in the essays of Dr. G. F. Stout and Mr. H. W. Carr, 

 who both take up, though on rather diverging lines, 



NO. 1736, VOL. 67] 



