i 



March 2, 1922] 



NATURE 



>63 



extent of their implication in matters of great 

 ntific and practical importance. 

 The work under notice now tells the whole tale in 

 form which leaves nothing to be desired, and adds 

 at least one new chapter. It is not difficult to under- 

 stand how much it must have cost of resolution and 

 hard labour to bring to its present form the vast 

 amount of material that had accumulated in Sir 

 George Beilby's hands, and we must all be grateful 

 to Sir Herbert Jackson, whose persuasiveness brought 

 Sir George Beilby to the point of setting out on his 

 task, and whose help, along with that of Mr. W. D. 

 llaigh, is very gratefully acknowledged by the author. 

 ■ I unhesitatingly say," he states, " that without his 



Fig. 2. — Cr>'stalline antimony polished by emery and rouge and etched with potassium cyanide, 

 showing fikn of flowed metal covering pits. From "Aggregation and Flow of Solids." 



(Mr. Haigh's) constructive skill and insight the work 

 would not have been accomplished." And we may 

 add that no one more than Sir Herbert Jackson was in 

 a position to appreciate the importance of Sir George 

 Beilby's work. 



The letterpress extends over some 250 pages, clearly 

 printed and in every respect easily readable. The 

 concluding part consists of thirty-four beautiful re- 

 productions of a series of figures, nearly all photo- 

 graphic. Not one of them is uninteresting, and most 

 of them are remarkable. In the letterpress the topics 

 dealt with in sequence are the following : Microscopic 

 methods and measurements ; surface tension films in 

 liquids and solids ; the varied ways in which aggrega- 

 tion takes place ; cohesion among minute solid 

 particles and between these particles and fiat surfaces ; 

 polish, the result of surface flow ; the crystalline and 

 vitreous states in solids ; influence of the crystalline 

 NO. 2731, VOL. 109] 



and vitreous states on the physical and mechanical 

 properties of ductile metals ; influence of the crystal- 

 line, mobile, and vitreous states on the flow of rocks 

 and ice ; molecular pulsation cells : a tentative hypo- 

 thesis ; extension of Faraday's work on the optical 

 and other characteristics of thin metal leaves ; phos- 

 phorescence of crystals effected by the change from 

 the crystalline to the vitreous state. 



The general nature of Sir George Beilby's work 

 can probably be best understood by thinking of the 

 conditions under which it was carried out. We have 

 to picture a man of scientific taste and talent, whose 

 lot has been cast in the industrial world, eager to 

 devote his leisure to the advancement of fundamental 

 knowledge and compelled to select a 

 topic that can be cultivated experi- 

 mentally under home conditions, that 

 do not give any very exceptional 

 facilities for experimental work. 

 Under these limits, what better than 

 to take up the study of some topic 

 of micro-chemistry or micro-physical 

 chemistry } Able to provide himself 

 with the best appliances for his pur- 

 pose, and skilled in the manipulative 

 art of the chemist, he develops a 

 highly special technique, and with all 

 these resources applies himself to 

 particular problems of his subject. The 

 result is a series of refined observations 

 and delicate manipulations which has 

 disclosed many things never seen before 

 and established many new facts about 

 the structure and behaviour of solids. 

 It is really very difficult to give a 

 summary of what is contained in this 

 book. It would be rather like writing a short para- 

 graph summarising the incidents of an Antarctic ex- 

 plorer's voyage of discovery. No doubt it is possible 

 to say, in a word, that the centre of Sir George 

 Beilby's doctrine is the vitreous film of solids, but 

 the great interest of the book lies in the record 

 of successive experimental steps by which the facts 

 have been estabhshed and amplified. To the 

 student of molecular physics, the metallurgist and 

 engineer, the geologist, the fine artificers of glass and 

 metal, the records have something of first-rate im- 

 portance to say. 



The present writer is probably not singular in 

 having felt surprise on first learning that the final 

 perfect polish of glass or metal was produced by the 

 use of an abrading agent. One could understand the 

 finer and finer scratches of grinding giving a greater 

 and greater smoothness, and it was possible in the 



