;i6 



NATURE 



[August 2, 1894 



dynamical action taking place within the sun, or in 

 connection with hurricanes in his atnosphere, or 

 anywhere near the sun outside. 



" It seems as if we may also be forced to conclude that 

 the supposed connection between mtgnetic storms and 

 sun-spots is unreal, and that the seeming agreement 

 between the periods has been a mere coincidence." 



The next year's address is on electric radiation, the ex- 

 periments of Hertz, and electric discharge in gases ; with a 

 reference to Mr. Crookes' discovery of vacuum-stresses as 

 an outcome of experimental troubles experienced in his 

 weighing of thallium, and with a characteristic foot-note 

 by Lord Kelvin to the word " troubles " : — " Tribulation, 

 not undisturbed progress, gives life and soul, and leads to 

 success when success can be reached, in the struggle for 

 natural knowledge." It is followed by the speech de- 

 livered at the unveiling of Joule's statue in Manchester 

 Town Hall on December 7, 1893, and by the Royal 

 Institution lecture on Isoperimetrical Problems ; this last 

 being an attempt at popularising the calculus of varia- 

 tions ! From how to surround a maximum acreage with 

 a given boundary subject to certain conditions, and how 

 to plan a railway route with a minimum of expense, the 

 author ascends to recent researches in the problem of 

 three bodies, and to the geometrical representation of 

 problems of dynamical stability by the method of geo- 

 detics. The most curious part of this lecture is not 

 scientific but social, viz. the treatment accorded to that 

 unfortunate hero, " Horalius Codes.'' The representation 

 of Dido as a cute Phenician adventuress successfully 

 wheedling a reasonable plot of ground out of a sarcastic 

 African chief is fair enough, but the spectacle of the stout 

 old warrior with his wounded leg scrambling after a 

 plough along a single furrow from morning till night over 

 all kinds of country, in order to secure as much of the 

 public cornland as possible at the hands of his grateful 

 countrymen, is an odd reading of the legend. That he was 

 awarded a piece of land such that it would take two oxen 

 the whole of a dayto plough it,is a statement poetic perhaps 

 in its terms but more precise in its meaning than if e.x- 

 pressed in some extinct units of measurement ; but 

 to suppose that it was to be ploughed round, and that 

 Horatius must guide the plough, and guide it with a 

 constant eye to secure the maximum of benefit for his 

 minimum of service, is hardly fair either to the memory 

 of the patriot or to the spirit of the Romans in their early 

 and wholesome days. 



It can hardly be said even now to represent the atti- 

 tude of any nation with respect to the services of its 

 military or political heroes, but it may very well be held 

 as a typical illustration of the way in which most coun- 

 tries at present attempt to reward their inventors through 

 the medium of their patent laws. 



Whether the author half intended the Horatian epi- 

 sode as a satire, or whether (as is more probable) he is 

 taking the story as a myth for whose social significance 

 or historical bearing he cares nothing, it serves as a 

 popular introduction to what else would be rather an 

 abstruse subject— a subject, indeed, which few people 

 would have ventured to use as the basis for a Friday 

 evening discourse. 



These, then, are the varied and highly readable con- 

 NO. 1292, VOL. 50J 



tents of this small book. May the author long live with 

 undiminished vigour, and give us many more of these 

 recreations of a great mind. 



Oliver J. Lodge. 



THE FLORA OF CEYLON. 

 A Handbook to the Flora of Ceylon : containing 

 Descriptions of all the Species of the Flowering Plants 

 indigenous to the Island, and Notes on their History, 

 Distribution and Uses. By Henry Trimen, M.B. 

 (Lond), F.R.S., Director of the Royal Botanic 

 Gardens, Ceylon. With an .Atlas of Plates illustrating 

 some of the more interesting Species. Part i. 

 Ranunculaceae— Anacardiacea:. Svo. pp. xvi. 327, with 

 plates i.-xxv. (410). Part ii. Connaraceas— Rubiacex>. pp. 

 392, with plates xxvi.-l. (Published under the authority 

 of the Government of Ceylon. London : Dulau and 

 Co., 1S93-94.) 



WHEN Dr. Trimen left England at the beginning 

 of 1S77 to undertake the directorate of the 

 Ceylon Gardens, he had already formed the determina- 

 tion to elaborate the flora of Ceylon, and to publish a 

 descriptive handbook of its botany. Those who knew him 

 knew that this work would only hi undertaken after due 

 preparation and without undue haste, but that it would 

 be pushed forward steadily and with all reasonable speed 

 to a satisfactory consummation: and the two instalments 

 now before us amply justify such a conclusion. 



Dr. Trimen was fortunate in having had so careful a 

 predecessor as G. H. K. Thwaites, whjse '' Enumjrat io 

 Plantarum Zeylaniae," published in 185S-64, he rightl y 

 describes as "an extremely accurate and most valuable 

 work," rendered more useful by the extensive series of 

 illustrative specimens distributed by Thwaites to the 

 principal herbaria of the world. The first work of the 

 new Director was to bring this up to date, which he did 

 in a "Systematic Catalogue," published in 1885, and 

 arranged in accordance with the " Genera Plantarum." 

 In the course of a visit to England in 1SS6, Dr. Trimet* 

 found time to examine the invaluable Ceylon Herbarium 

 of Hermann, preserved in the British.Museum, upon which 

 Linnxus based his Flora Zeylania: ; and he publishe d 

 a complete enumeration and identification of the plants 

 therein contained, with notes, in vol. xxiv. of ihc Journal 

 of the Linnean Society. Various new species have from 

 time to time been published by Dr. Trimen in the 

 Journal of Botany ; and these, with the results of the 

 rest of his work, arc embodied in the " Handbook." 



In his younger days. Dr. Trimen was known as a 

 painstaking British botanist, and the " Flora of .Middle- 

 sex," issued in 1869, for which he was mainly responsible, 

 initiated a new departure in works of the kind. It was 

 marked by thoroughness and accuracy ; every page 

 showed care and research : and these qualities are 

 abundantly manifest in this Ceylon " Handbook." A 

 careful correlation of the work of predecessors in the 

 same field is another char.acteristic shared by each book ; 

 and in each there was need for this, for .Middlesex plants 

 have been recorded since the days of William Turner, 

 while the Cingalese flora has been treated of by various 

 authors from Hermann (1717) downwards. 



