lUNK 6, I 901] 



NA TURE 



SOME SCIENTIFIC CENTRES. 



I. — The Leipzk; Chemical Laboratorn'. 



T EIPZIG is a city which boasts many traditions ; it is 

 •*-^ associated with some of the most distinguished 

 names in nearly every department of intellectual life ; and 

 its University justly takes a place among the leading 

 schools of Europe. To us there is a sense of fitness in 

 the thought that the school which produced a Wagner and 

 a Goethe should have numbered among its teachers two 

 men who have left a mark in the history of the develop- 

 ment of organic chemistry. These men are Hermann 

 Kolbe and Johannes Wislicenus ; both of them famous as 

 teachers and experimenters, and each of them associated 

 with a theory the importance of the effect of which 

 on the growth of their science it would be difficult to 

 overestimate. 



Wislicenus succeeded Kolbe in the chair at the Univer- 

 sity of Leipzig, and Wislicenus still works in the labora- 

 tory which was made famous by his predecessor ; he is 

 the oldest survivor of that generation of workers who 

 laid the foundations of organic chemistry, and as such and 

 as a mark of esteem by one of his old pupils, his labora- 

 tory has been chosen as the first of the present series. 



The laboratory in Liebig Strasse, which has been the 

 scene of so many classical researches, was built by Kolbe, 

 who commenced to work there in the autumn of 1868. 



His name was already famous in connection with his 

 earlier work on the determmation of the nature and chemical 

 constitution of organic radicles, in which he was materially 

 assisted by the researches of Frankland. But it was in 

 Leipzig that his most brilliant experimental work was 

 carried out ; it was there there that, in conjunction with 

 Drechsel, he synthesised oxalic acid from carbon dioxide 

 and potassium, and, assisted by BasarofF, obtained carb- 

 amide by the interaction of carbon dioxide and ammonia. 

 Among the early achievements which have invested the 

 present laboratory with such historic interest, and entitle 

 Kolbe to a place among the " wahre Bearbeiter," of Ber- 

 zelius — to whom, indeed, as well as to Liebig, Wohler 

 and Bunsen, he used to ascribe his inspiration — must be 

 mentioned the synthesis of isosuccinic acid, the produc- 

 tion of nitromethane from chloracetic acid, and the famous 

 reaction for obtaining salicylicacidby the action of carbon 

 dioxide upon sodium phenate, in which he disclosed the 

 singular fact that the use of potassium phenate resulted 

 in the formation of the isomeric para-hydroxybenzoate. 



Kolbe died on November 24, 1884. He was not 

 mourned by all who knew him, for his pen had made him 

 not a few enemies ; his violent attacks on the " Structur- 

 chemiker," and his description of Kekule's theory of the 

 benzene ring as " wilde Phantasien ohne reelle Basis,'' 

 have become part of the history of chemistry ; while his, 

 allusion to the since illustrious van 't Hofif in the words 

 " Ein Dr. J. H.van't Hoff, findet wie es scheint, an 

 exakter chemischer Forschung keinen Geschmack. Er 

 hat es bequemer erachtet, den Pegasus zu besteigen, und 

 in seiner ' La Chimie dans I'espace ' zu verkiinden, wie 

 ihm auf dem durch ki.ihnen Flug erklommenen chem- 

 ischen Parnass die Atome im Weltraume gelagert 

 erschienen sind," was almost worthy of Swift himself 



Wislicenus was appointed director of the laboratory in 

 October, 18S5, and effected several alterations in its in- 

 terior to increase the facilities for work. The number of 

 students rapidly increased till it reached the maximum 

 that the building could accommodate ; and in spite of the 

 counter attractions of the Physical Chemistry Institute, 

 which was opened in 1S71, the popularity of the first 

 laboratory never waned. At the present time there are 

 174 students working there, of whom 50 are engaged in 

 carrying on research under the direction of Prof. Wisli- 

 cenus and his assistants. 



Before going on to describe the researches which have 

 maintained the traditions of the laboratory, a brief glance 

 NO. 1649, VOL. 64] 



at the career of Johannes Wislicenus will assist us in 

 forming some idea of the nature and variety of his 

 experience. 



Born in 1835 in Saxony, the son of a pastor, he 

 received his education first at a school in Halle, and then 

 in 1853 at the University of the same town, where he 

 commenced to study science. But those were the years 

 of revolutions, and in the following autumn his father was 

 forced, on account of his political opinions, to fly to 

 America ; there the young Johannes obtained an appoint- 

 ment as assistant to Prof Horsford at Harvard University, 

 and one year later was made lecturer at the Mechanics' 

 Institute, New York, with a laboratory at his disposal. 



In 1856 he returned with his family to Europe, re- 

 sumed his interrupted studies at the University of 

 Zurich, and later on at Halle : in i860, he " promovirte, 

 and was appointed ' Privat-docent ' at the Zurich Poly- 

 technic." In 1865 he was called to the chair of chemistry 

 at Zurich Universitj-, and six years later became 

 director of the Polytechnic. The years 1872-1885 were 

 spent as professor at Wurzburg, where he succeeded Ad. 

 Strecker. On the death of Kolbe the vacant chair at 

 Leipzig was offered him and accepted ; and there is a 

 curious irony in the thought that his first work there 

 should have been directed towards the extension of the 

 theory of that van 't Hoff whom his predecessor had 

 regarded with such contempt. 



The work of Wislicenus has been confined almost 

 entirely to the domain of organic chemistry. He entered 

 the field when the " Radical Theory " of Kolbe and 

 Frankland had taken a firm hold on the minds of the 

 newer school of chemists. . 



One of the first problems he attacked was the constitu- 

 tion of lactic acid ; while still at Zurich he effected its 

 preparation artificially from propionic acid as well as 

 from aldehyde {Liebig' s Ann. 1863, cxxviii, 11 ; cxxxiii, 

 257 ; and cxlvi, 145). Later on he succeeded in estab- 

 lishing the identity of structure for the two different 

 substances fermentation- and para-lactic acids {Liebig's 

 Ann. Clicin. 1872, clxvi, 3 ; and clxvii, 302). The 

 structural theory alone was thus insufficient to explain 

 such cases of metamerism. He was impelled, therefore, 

 even as early as 1873, 'o the conclusion that the cause of 

 the difference between the two acids must be looked for 

 in the spacial relations of the atoms in the molecule. 



But his attention was for a time diverted from this 

 topic by the classical researches which he was carrying out 

 on acetoacetic ether ; his chief papers on the subject ap- 

 peared in 1877 {Ann. Clieni. Liebig, clxxxvi, 163 ; cxc, 257; 

 1881, ccvi, 308). He studied in detail its reactions, 

 mode of preparation and decomposition, and showed it 

 to be the most valuable synthetic agent then known. 

 His work was of the utmost value in throwing light on 

 the still debated constitution of the substance ; in it he 

 was assisted by several English students who have since 

 attained eminence. 



Wislicenus was now the occupant of the Leipzig chair ; 

 after several papers of lesser importance had appeared, 

 he challenged the attention of the world by the publica- 

 tion, in 1887, of the famous memoir : " Uber die raiim- 

 liche Anordnung der Atome in organischen Moleculen." 

 In this he put forward an explanation of what he termed 

 geometrical isomerism, which was an extension of the 

 hypothesis formulated independently by Le Bel and 

 van 't Hoff in 1874. According to this hypothesis "the 

 centre of gravity of a carbon atom was regarded as 

 situated in the centre of a tetrahedron, and its four affini- 

 ties at the four corners." When two atoms were linked 

 together, van't Hoff, and after him Wislicenus, assumed 

 that both were capable of rotating in opposite directions 

 about a common axis ; this possibility ceased, however, 

 with a double or treble linking of the carbon atoms. 

 Wislicenus further called into play the action of certain 

 " specially directed forces, the affinity energies," which 



