772 



NATURE 



[August i8, 192 i 



error is outlined by Mr. Wedel with a wealth of 

 learning and an aptness of illustration that are a 

 credit to American scholarship. His little volume 

 betrays an enormous amount of research presented 

 in an attractive and succinct manner that is a 

 model for work of this kind. Especially praise- 

 worthy is the logical and efficient distinction be- 

 tween material necessary for his narrative and 

 the equally important material, needed by the 

 specialist for verification and reference, that is 

 rightly relegated to his ample notes ; it is a dis- 

 tinction which is all too rarely made. Mr. Wedel 

 is to be congratulated on a very able and read- 

 able contribution to the embryology of science. 



(2) A much more difficult, though perhaps less 

 thankful, task has been performed by Mr. Robert 

 Steele. His edition of the version of the pseudo- 

 Aristotelian " Secretum Secretorum " used by 

 Roger Bacon, with notes by the father of English 

 science himself, is a definitive contribution to our 

 knowledge of the medieval attitude towards 

 phenomena. This volume forms the fifth and 

 largest fascicule of Mr. Steele's fundamental and 

 valuable series of the hitherto unedited works of 

 Roger Bacon. These works appeal perhaps to 

 few readers, yet they are of permanent value as 

 among the earliest documents of the re-birth of 

 science. 



With our present standards of historical 

 and textual criticism it is at first incomprehensible 

 that a great intellect like Bacon's could have 

 taken this debased Arabian work for a treatise 

 of Aristotle. With our standards of scientific 

 verification it is equally incredible that such data 

 as this work presents could make any appeal save 

 to a confused and obfuscated intellect. Yet an 

 appeal it did make, and for precisely that reason 

 the work is of great interest, for by studying it and 

 works like it we may reasonably hope to learn 

 something of the mental processes with which 

 "science" in our sense made its appearance in 

 the modern world. These notes of Bacon were 

 made at the turning point of his career, just before 

 he passed from the pre-scientific to the scientific 

 stage. He never freed himself from his belief in 

 astrology, nor could any man entirely reject this 

 doctrine while the geocentric theory held full 

 sway. But Roger enunciated principles of ob- 

 servation and experiment which, in other hands, 

 ultimately rendered astrological theory untenable. 

 He never developed an adequate standard of 

 textual criticism, but he made a strong appeal for 

 the systematic study of languages, he formulated 

 methods for such study, and he made remarkable 

 and interesting attempts at grammatical analyses. 

 These efforts of his, in other and more fortunate 

 NO. 2703, VOL. 107] 



hands, led to a scientific treatment of languages 

 and of texts. 



Roger Bacon stands as one of the heralds of the 

 dawn of science, yet he has suffered much, and still 

 suffers, from misunderstanding and neglect. Some 

 of his most interesting works are still unprinted, 

 and their publication is one of the several im- 

 portant pieces of work that must be achieved 

 before any adequate and continuous history of 

 science can be written. Yet the editing of such 

 works is by no means easy, for it requires, on 

 the one hand a very special training, and on 

 the other a wide range of different kinds of 

 knowledge that are very rarely combined in one 

 individual. It further demands a degree of patient 

 endurance of toil that is rare even among pro- 

 fessional scholars ; and, lastly, it calls for an in- 

 difference to the material reward for such pro- 

 longed labours that is perhaps rarest of alL 

 Every one of these qualities the editor of this 

 fascicule exhibits in abundant measure ; his intro- 

 duction and notes are scarcely less valuable than 

 the text itself. We can but hope that Mr, Steele 

 will be spared to complete the task that he has 

 undertaken — a task for which very few besides 

 himself are properly equipped. 



It would be ungracious not to mention also the 

 valuable translation from the Arabic text by Mr. 

 Fulton with which the volume is enriched. The 

 book is a peculiarly fine example of the skilful, 

 accurate, and scholarly printing which the Claren- 

 don Press has taught us to expect from it. 



Charles Singer. 



Physical Chemistry, Pure and Applied. 



(1) A System of Physical Chemistry. By Prof. 

 W. C. McC. Lewis. (In three vols.) Vol. ii,. 

 Thermodynamics. Third edition. (Text-books 

 of Physical Chemistry.) Pp. viii + 454. (Lon- 

 don: Longmans, Green, and Co., 1920.) 155. 

 net. 



(2) The Determination of Hydrogen Ions. By 

 Dr. W. Mansfield Clark. Pp. 317. (Baltimore: 

 Williams and Wilkins Co., 1920.) 5.50 dollars. 



(3) The Physico-Chemical Properties of Steel. By 

 Prof. C. A, Edwards. Second edition, thor- 

 oughly revised. Pp. xii + 281. (London: 

 Charles Griffin and Co., Ltd., 1920.) 21s. net. 



(4) Die Reaktionen des freien Stickstoffs. By Prof. 

 W. Moldenhauer. Pp. viii+178. (Berlin: 

 Gebriider Borntraeger, 1920.) 26 marks. 



(i) pROF. LEWIS'S "System of Physical 



J7 Chemistry" has been reviewed in these 



columns on two previous occasions, in September,. 



1916, and in May, 1919. Only a brief notice is 



