November 8, 191 7] 



NATURE 



189 



I 



be said that these test-tubes, after the usual wash, 

 were subjected to a further cleaningf, first with 

 alcohol, and then with distilled water. Baeyer 

 always insisted that the occurrence of a chemical 

 chang-e can be more easily observed and its course 

 more closely followed with small quantities of 

 material and the aid of a test-tube and glass rod 

 than by the employment of a hundred grams of 

 substance and larg-e flasks or beakers. That this 

 view was undoubtedly correct is demonstrated not 

 only by the brilliant results which Baeyer himself 

 achieved with such simple means, but even more 

 conclusively by the fact that his pupils, if perhaps 

 reluctantly at first, all ultimately adopted his 

 method of work. There can be no doubt that the 

 discovery and careful characterisation of so many 

 substances, and the publication of so much im- 

 portant work covering- such a wide field, would 

 not have been possible had not Baeyer early 

 acquired the habit of working with small quanti- 

 ties of material. 



Baeyer's immense power of work is shown by 

 the fact that, until his eig-htieth birthday, he 

 delivered his usual lectures on five mornings of 

 each week and continued to experiment in his 

 laboratory with his usual unflagging energy. Had 

 the war not robbed him of his private assistant 

 and laboratory staff, it is probable that he would 

 have gone on even longer. He confided to one of 

 his intimate friends that /work in the laboratory 

 gave him as much pleasure after fifty years' toil 

 as at any time during his career, and to the last 

 he took the greatest interest in any developments 

 in the domain of natural science which were 

 brought to his notice. It is well known that he 

 viewed with disfavour and apprehension the grow- 

 ing domination of military power in Berlin and 

 Prussia generally, and it was mainly, no doubt, 

 for this reason that he refused to accept the invita- 

 tion to Berlin on the death of Hofmann. 



Adolf Baeyer was born on October 31, 1835, in 

 Berlin, and he spent his early life in the house 

 (242 Friedrichstrasse) of his grandfather, which at 

 that time was a centre of the fiterary life of Berlin, 

 and it thus came about that Baeyer was brought 

 up in a literary atmosphere. He always referred 

 to this early intimate contact with literature with 

 pleasure, and considered that the love for litera- 

 ture which he acquired in those days was of great 

 service to him throughout his later career. 

 Baeyer's chief interest in these early days seems 

 to have been for botany and in living things 

 generally, and his first contact with chemistry was 

 on his ninth birthday, when his father gave him 

 a copy of Stockhardt's " Schule der Chemie." 



In his " Erinnerungen aus meinem Leben," 

 which he wrote for the celebrations organised in 

 connection with his seventieth birthday, he tells 

 us that he converted a passage in the house into 

 a small laboratory, and there carried out the usual 

 dangerous and unpleasant experiments associated 

 with early youth. It was during this time that he 

 made his first discoverv. that of the double salt, 

 CuC03,NaoC03,H20. The activity of the small 

 laboratory does not seem to have been altogether 

 NO. 2506, VOL. 100] 



appreciated, and the poet, Paul Heyse, who was 

 a frequent visitor at the house, had reason to 

 protest : 



Es stinkt in diesem Haus gar sehr 

 Das kommt vom Adolf Baej^er her. 



When he entered the university Baeyer seems 

 at first to have entirely forsaken his chemical 

 experiments and to have devoted himself to physics 

 and mathematics ; but the interest in chemistry 

 soon returned, and in 1856 he entered Bunsen's 

 laboratory at Heidelberg. After studying the 

 methods of analysis in this famous laboratory for 

 a year, he came under the influence of Kekul6, 

 whom he afterwards followed to Ghent, and whom 

 he always considered was his real teacher. 



Baeyer obtained the Ph.D. degree in 1858; his 

 dissertation, "De arsenici cum methylo conjunc- 

 tionibus," presented and printed in Latin, was a 

 difficult and important piece of accurate work and 

 a great achievement for so young an investigator, 

 especially as it was commenced and carried out 

 entirely on his own initiative. In the spring of 

 i860 Baeyer returned to Berlin and became Privat- 

 dozent at that university, but in the same year he 

 was appointed teacher in organic chemistry in the 

 Gewerbe Institut, an institution which later de- 

 veloped into the Berliner Technische Hochschule. 

 The foundations of many of Baeyer's most im- 

 portant researches were laid during the next few 

 years, for we find him publishing papers on the 

 uric acid group, mellitic acid, isatin and indigo, 

 the reduction of benzene carboxylic acids, acetylene 

 derivatives, etc., subjects which later developed 

 into the classical memoirs with which his name is 

 so intimately associated. Among the distinguished 

 workers who were attracted to Baeyer's laboratory 

 during this time we find the names of Graebe, 

 Liebermann, Nencki, 'and Victor Meyer, and it 

 .was in 1866 (Annalen, cxl. , 295) that the method 

 of reduction by distillation with zinc dust was 

 elaborated which enabled Graebe and Liebermann 

 to demonstrate that alizarin is a derivative of 

 anthracene, and thus to proceed with the synthesis 

 of this important colouring matter. 



The next stage in Baeyer's career began in 1872, 

 when he was appointed professor of chemistry in 

 Strasburg-, and it was here that he numbered 

 among his pupils Emil and Otto Fischer and 

 H. Caro, and produced many papers, of which 

 those dealing with the phthaleins are probably the 

 most important. Baeyer stayed in Strasburg for 

 three years, and then proceeded in 1875 to Munich, 

 where he remained for forty years, and it was in 

 the Munich laboratories that most of his famous 

 researches reached maturity. 



It is impossible to mention even the titles of 

 the long series of papers which appeared with 

 such regularity during this long period, and are 

 so well known to every student of chemistry. 

 Mention may, however, be made of his researches 

 on the phthaleins, the reduction of the phthalic 

 acids, the constitution of benzene, indigo and its 

 derivatives, and last, but not least, the researches 

 on the polyacetylene derivatives, which arc marvels 



