22 



NATURE 



[March 8, 19 17 



Treadwell. According to the translator, W. T. 

 Hall, the original has been so thoroughly revised 

 and so largely rewritten that it is no longer fair 

 to publish the book as a literal translation, and 

 though the general plan has been kept, greater 

 stress has been laid upon the theoretical side of 

 the subject. The introductory chapter deals with 

 such general principles as are usually included in 

 text-books on physical chemistry, viz. electrolytic 

 dissociation, electromotive series, solubility 

 product, mass law, etc., subjects which not 

 only come well within the scope, but are 

 essential to the thorough grasp, of analytical 

 methods. 



The book is, in short, not the ordinary type of 

 examination vaie mecum. It is rather in the 

 nature of a philosophical treatise on analysis in 

 which the subject is treated with the thoroughness 

 demanded by a highly important and dignified 

 branch of chemical science. A special feature of 

 the new edition is the use of ionic equations, 

 which often appear side by side with the more 

 usual form. In this way the student is, without 

 much effort, familiarised with both methods of 

 representing reactions. 



(2) The procedure adopted by Dr. Mulliken for 

 the identification of pure organic compounds (in 

 vol. ii.) by means of tables follows very closely 

 that of vol. i. Vol. ii. contains what are termed 

 compounds of Order II., which includes those 

 of the three elements, carbon, hydrogen, and 

 oxygen, of vol. i., with the additional element, 

 nitrogen. 



The tables are divided into suborders of colour- 

 less and coloured compounds, these again into 

 genera comprising acidic, basic, and neutral com- 

 pounds, and these again into divisions A and B 

 of solid and liquid species. 



An illustrative example of the application of the 

 tables is given, and the author claims that the 

 method of identification is much more rapid than 

 that which would have been required to arrive at 

 an equally certain result by the use of the method 

 of empirical formulae. This may be true of a sub- 

 stance with no previous history which is thrust 

 into the hands of a chemist for rapid identifica- 

 tion. But the writer is by no means convinced 

 that, however valuable the data, the arrangement 

 for research purposes is the most satisfactory that 

 could be devised. 



Although it may be true that the scheme of 

 species, genera, suborders, and orders may help 

 one, like a botanical key, to track down an un- 

 known compound more quickly than by means 

 of a combustion, one has to remember that 

 it is rarely that a chemist engaged on re- 

 search is entirely ignorant of the possible nature 

 of the substance he has obtained. It is not a 

 question of one of a possible 4000 compounds 

 described in these tables, but more probably one 

 of half a dozen. 



The molecular formulae and Richter's lexicon 

 will soon put the chemist on the track of a refer- 

 ence ; and if, in addition, he has tables of specific 

 reactions arranged according to molecular 

 NO. 2471, VOL. 99] 



formulae, he will rapidly orient his compound^ 

 provided it has been described before. 



The present arrangement is too mechanical, and 

 makes too little appeal to the previous sequence 

 of chemical events to be entirely satisfactory. At 

 the same time one would not wish to depreciate 

 the value or trustworthiness of the vast and varied 

 data which Dr. Mulliken has compiled with so- 

 much care and discrimination. There are distinct, 

 if restricted, uses for such tables. 



It may be added in conclusion that not the least 

 important section in the book is chap, iii., giving a 

 list of reagents, their preparation and uses, which 

 many organic chemists often overlook. 



J. B. C. 



GARDEN AND FIELD. 



(i) The Standard Cyclopaedia of Horticulture. By 

 L. H. Bailey. Vol. iii., F — K. Pp. v+1201— 

 1760. Vol. iv., L — O. Pp. V. + 1761-242 1,. 

 (New York : The Macmillan Co. ; London : 

 Macmillan and Co., Ltd., 191 5-16.) Price 255. 

 net each vol. 

 (2) The Small Grains. By M. A. Carleton, 

 Pp. xxxii + 699. (New York : The Macmillan 

 Co.; London: Macmillan and Co., Ltd., 1916.) 

 Price 75. 6d. net. 

 (i) LJ ORTICULTURE has been well served hy 

 ^ -^ its encyclopaedists. In this country we 

 possess Nicholson's Dictionary and "The Gar- 

 dener's Assistant," both admirable works of their 

 kind. But unfortunately, and in spite of the ever- 

 increasing popularity of gardening, no new edition 

 of either of these works has appeared in recent 

 years. One, we know, is under revision, and but 

 for the war a new edition would have appeared 

 before now. No less admirable than these in- 

 digenous productions is Bailey's "Standard Cyclo- 

 paedia of Horticulture," now appearing in a 

 greatly enlarged form. This "cyclopaedia" is 

 indispensable to horticulturists if only for the fact 

 that it contains descriptions of the many new- 

 garden plants which are of recent introduction,, 

 particularly from China. Although this country 

 led the way in the systematic horticultural explora- 

 tion of that wonderful country, America has made 

 notable contributions thereto, and the many intro>- 

 ductions due to Wilson, Forrest, Purdom, Ward,, 

 and Farrer are now coming into general cultiva- 

 tion both in the States and here. Not a few of 

 these acquisitions are described in the pages of 

 Dr. Bailey's work. 



As is to be expected from the provenance of 

 this work, the sections treating of tools and 

 machinery are particularly well done, the article 

 on machinery and implements extending over 

 upwards of twenty closely printed pages, and 

 beginning with the just claim that "the American 

 is known by his tools and machinery." 



Of great interest to British horticulturists alsa 

 is the comprehensive account eiven of horti- 

 culture in the North American States, to which 

 more than 100 pages of vol. iv. are devoted. The 



