NA TURE 



72, 



A 



THURSDAY, MAY 24, 1906. 



ADOLF VON BAEYER'S COLLECTED WORKS. 

 Aclctlj von Baeyer's gesainmelle M'erke. Herausjre- 



i,'-cbpn zur Feier des siebzicjsten Geburtstages des 



Autors von seinen Schiilcrn und Frciindcn. Erster 



Band, pp. cxxxii + 990. Zweiter Band, pp. 1194. 



(BriinswicU : F. Vieweg und Sohn, 1905.) 

 S we examine these two splendid volumes we 

 cannot but feel that no better way of com- 

 memorating the seventieth birthday of Adolf von 

 Baeyer could possibly have been found than that of 

 collecting together his researches and publishing them 

 so that they might be studied in their entirety by all 

 students of chemistry. 



The publication of the complete researches of an 

 investigator who has had a profound influence on the 

 scientilic thought of his time has much to recommend 

 it, since the collected works form not only a memorial 

 to the investigator, but also enable others to gain an 

 insight into the train of thought which preceded the 

 gradual development of each important discovery. 



The present volumes have, moreover, a special 

 interest since they have been produced under the 

 personal supervision of Baeyer himself, with the 

 result that the vast amount of work which he has 

 accumulated during the fifty years of his active life is 

 arranged in the manner which he himself wished and 

 lliought most suitable. 



These volumes contain as frontispiece a strikingly 

 lifelike portrait of Baeyer. The introduction contains 

 a most interesting sketch of Baeyer's life (1835-1905) 

 from his own pen, which enables the reader to form a 

 verv vivid idea of the difficulties Baeyer had to en- 

 counter in the earlier days of his scientific career. Not 

 only were the schools of chemistry which existed at 

 that time few in number and the appliances even in 

 the best of them only of a very elementary kind, but 

 research in organic chemistry was still quite in its 

 infancy, and therefore every new development was 

 cl the nature of pioneer work. 



Although in his grandfather's house Baeyer was in 

 hi; early years brought into contact with Paul Hfeyse, 

 Geibel, Fontane, and other literary giants of the time, 

 ho showed no inclination towards literature, and soon 

 began to develop a love for science by taking a keen 

 interest in chemistry, botany, physics, and mathe- 

 matics. 



In 1S56 he decided to devote himself seriously to 

 chemistry, and became a student in Bunsen's labora- 

 tory at Heidelberg at a time when Roscoe, Pebal, 

 Lieben, Beilstein, Lothar Meyer, and others were work- 

 ing in the laboratory, and when Bunsen's reputation 

 as a teacher and investigator was at its highest. His 

 first original investigation was a continuation of the 

 work of Bunsen and Roscoe on the combination of 

 hydrogen and chlorine, and this, as well as his next 

 research, on methyl chloride, w-ere suggested by Bunsen. 

 After this Baeyer worked entirely on his own initiative, 

 and gradually laid the foundations upon which the 

 great edifice of his life-work was subsequently raised. 



The papers collected together in the two volumes 



NO. 1908, VOL. 74] 



before us have been grouped bv Baeyer under 

 the following headings : — (i) The organic arsenic 

 compounds; (2) the uric acid group; (3) indigo; (4) 

 papers arising from the researches on indigo; (5) 

 pyrrol and pyridine bases ; (6) experiments on the 

 elimination of water and on condensation ; (7) the 

 phthaleins ; (8) the chemistry of the hydroaromatic 

 compounds; (9) the terpenes ; (10) nitroso-compounds ; 

 (11) furfurol; (12) acetylene compounds and the 

 " Spannung's Theoric"; (13) peroxides; (14) the 

 basic properties of oxygen; (15) dibenzalacetone and 

 triphenylmethane; (16) various researches in the aro- 

 matic series; (17) various researches in the aliphatic 

 series; (18) nomenclature; (19) diversa. 



The titles alone will serve to convey some idea of 

 the immense range of subjects which have claimed 

 the attention of Baeyer, and as we study each of these 

 sections we meet always the same characteristics — 

 great skill in overcoming experimental difficulties 

 (often necessitating the working out of entirely new 

 methods of attack), and great ability in deducing the 

 correct theoretical explanation from the results of 

 experiment. 



Within the necessarily limited space of this review- 

 it is, of course, impossible to discuss in any detail even 

 the most far-reaching of Baeyer's discoveries or to 

 attempt to follow their historical development. 



Attention may, however, be briefly directed to some 

 characteristics of Baeyer's work which will probablv 

 strike the reader most as he studies the successive 

 sections into which these researches are divided. 



The researches on uric acid, which date from i860, 

 are marvels of experimental skill, including, as they 

 do, the discovery and characterisation of barbituric 

 acid, violuric acid, and many other new members of 

 this important group, and this at a time when the 

 structure and relationship of the more important 

 members of this section of organic chemistry were 

 little understood. Baeyer was naturally interested in 

 the problem of the synthesis of uric acid, and in 

 1863 he endeavoured to accomplish this by combining 

 uramil with potassium cyanate, when he obtained 

 pseudo-uric acid, an acid which contains one molecule 

 of water more than uric acid itself. The synthesis 

 was completed in 1S95, when E. Fischer and L. Ach 

 showed that pseudo-uric acid is converted into uric 

 acid when it is melted with anhydrous oxalic acid. 



Of great interest, not only from a purely scientific, 

 but also from the commercial point of view, are the 

 sections on the phthaleins and on indigo. The 

 researches on the phthaleins must have required ex- 

 ceptional skill, ingenuity and patience, because it must 

 be remembered that this work was absolutely new, and, 

 moreover, the substances belonging to this class are, 

 at the present day, some of the most difficult to deal 

 with experimentally. 



The well-known papers on indigo should be read 

 in connection with a most interesting sketch of their 

 historical development (p. xxxviii) which Baeyer him- 

 self has contributed. 



The labour entailed in carrying out these researches 

 must have been very great, and it is instructive to 

 read that, after a certain time, Baeyer became so 



E 



