598 



NATURE 



[Mar. 2 1, 1872 



superintendent of the " Nautical Almanack" and secre- 

 tary of the Board of Longitude, and in 1827, on the 

 resignation of Sir Humphry Davy, v.-as spoken of as a 

 probable successor to his office of President of the Royal 

 Society, Davies Gilbert, however, being chosen. He 

 died in 1S29, at the age of 56, and his character was thus 

 drawn by his intimate friend Sir Humphry Davy : — " A 

 man of universal erudition and almost universal accom- 

 plishments. Had he limited himself to any one depart- 

 ment of knowledge, he must have been first in that 

 department. But as a mathematician, a scholar, and a 

 hieroglyphist, he was eminent ; and he knew so much 

 that it was difficult to say what he did not know." 



Sir Humphry Davy's brilliant career, and especially 

 that portion of it which contributed so greatly to the fame 

 and success of the Institution with which he was con- 

 nected, is drawn in detail by his biographer ; and the 

 faihngs in his character and in his life which obscured its 

 lustre to his contemporaries' are in no way concealed. 

 The following contrast of the characters of Davy and of his 

 pupil and successor, Faraday, will be read Avith interest : 

 — " Whenever a true comparison between these two nobles 

 of the Institution can be made, it will probably be seen 

 that the genius of Davy has been hid by the perfection 

 of Faraday. Incomparably superior as Faraday was in 

 unselfishness, f xactness, and perseverance, and in many 

 other respects also, yet certainly in originaHty and in elo- 

 quence he was interior to Davy, and in love of research 

 he was by no means his superior." As early as 1804, when 

 Davy was only twenty-si.\. Dr. Dalton consulted him as 

 to the best mode of preparing his lectures, and described 

 him as "a very agreeable and intelligent young man, the 

 principal failing in whose character as a philosopher is 

 that he does not smoke ;" and within two or three years 

 from that time he had made the discoveries which have 

 immortalised his name. 



Dr. Bence Jones does not carry down the history of 

 the Royal Institution beyond 18 14, when it became as 

 closely associated with Faraday's career as it had pre- 

 viously been with Davy's. We have seen what were the 

 primary objects for the promotion of which the Institution 

 was founded ; and we know also the great work which 

 it effected during the first ten years of its existence. 

 These special purposes soon gave way to the eft'ort, as 

 our author expresses it, after striving to be fashion- 

 able ; and the fashionable element has continued to be 

 the most prominent feature in its subsequent life to the 

 present day. Something is, no doubt, gained by making 

 scientific subjects one of the ordinary topics of conversa- 

 tion in West End salons ; the continuation of the History 

 of the Royal Institution, which will have to be written 

 twenty years hence, will show whether this object is com- 

 patible with the carrying on of original investigations 

 which will add to the sum of our knowledge of the laws 

 of Nature. 



OUR BOOK SHELF 



Une ExpA-ience relative d la Question de la Vapejir 



Vesiculaire. Par M. J. Plateau. (Brussels : F. Hayez.) 

 The elder Saussure, and after him De Luc, considered it 

 to be an established fact that clouds are formed of little 

 hollow globules, which Saussure designated vesicular 



vapours, or vesicles. These vesicles, having a structure 

 similar to the soap bubble, were assumed to be capable of 

 floating in the atmosphere and of remaining suspended 

 in it so long as their physical condition was unaltered. 

 When they became resolved into drops of water they 

 formed rain. The same structure was assigned to the 

 cloud formed by the condensation of the vapour ol boiling 

 water in air colder than itself. M. Plateau has endea- 

 voured to put this view of the vesicular constitution of 

 vapour to the test of experiment. With this view he has 

 taken advantage of a method devised by M. Duprez, for 

 inverting a wide tube (20mm. in diameter) full of water, 

 so that the water may remain suspended in the tube. By 

 means of a narrow tube drawn out at one end, so as to 

 present an orifice of o'4mm. in diameter, he succeeded 

 in obtaining small hollow globules of water of less than a 

 millimetre in diameter, and tiMnsporting them under the 

 free surface of the water, suspended in the wide tube. As 

 soon as contact was established with that surface, the 

 little bubble became detached, and the air which it con- 

 tained penetrating into the liquid, mounted through it. 

 The experiment, on being several times repeated, gave 

 always the same result. M. Plateau has applied this 

 method to the cloud formed when water is boiled in free 

 air. " Let us imagine," he s tys, " that at a certain distance 

 from the surface of the water suspended in the wide tube, 

 a current of visible vapour of water arise?. If this vapour 

 is composed of vesicles, each of them which comes into 

 contact with the liquid surface must introduce into the 

 water a microscopic bubble of air, which will immediately 

 begin to ascend, so that the whole will form in the water 

 of the tube a cloud which will rise slowly in it, and alter 

 its transparency." In making the experiment, no cloud 

 was produced, and M. Plateau concludes, in conformity 

 with the view now generally held by physicists, that the 

 vesicular state of vapour has no real existence. He dis- 

 cusses objections which may be raised to his experiment, 

 such as the possible solution of the bubbles of air in the 

 water, the bursting of the bubbles at the surface of the 

 water and the escape of the air contained in them, or 

 their rolling under the surface of the water till they reach 

 the margin of the tube and thus get away ; and shows 

 satisfactorily that these objections do not invalidate the 

 result at which he has arrived. 



Clicinical Notes for the Lecture Room, on Heat, Laws of 

 Chemical Combination, and Chemistry of non-Metallic 

 Elements. By Thomas Wood, PhD,, F.C.S. Pp. i8l. 

 (London : Longmans, Green, and Co.) 

 On reading this volume the author's intention is plainly 

 manifest ; the book has been written principally for the 

 use of students preparing for the matriculation examina- 

 tion at the University of London. It has been written as 

 concisely as possible, rendering the task of '' cramming " 

 the subject more easy of attainment. For such a purpose 

 we certainly can recommend this book ; but for beginners 

 who wish to study chemistry we think it has several ' 

 faults. One of them is that such a comparatively large 

 amount of the book is devoted to the subsidiarv subject, ; 

 Heat, almost a quarter of the text being thus occupied. , 

 The article on thermometers, for instance, occupies no . 

 less than nine pages, which strikes us as being rather out ■ 

 of proportion to the remainder of the book. A second ■ 

 fault is the almost complete absence of any such details ; 

 as would enable a student to repeat the experiments men- 

 tioned in the te.xt. This we think is a fault which would 

 tend to make the beginner get up his subject parrot-like, ' 

 a method which is certainly not to be desired. The , 

 chemistry of the non-metallic elements only occupies ' 

 eighty-five pages of this volume ; the definitions and laws • 

 of chemical combination occupy another thirty-eight ^ 

 pages. The explanations, in the majority of instances, are , 

 clearly expressed, the f.icts of the case being stated in as 

 few words as possible. A few of the definitions can 

 scarcely be considered good ; one, in particular, is "that 



