464 



KNOWLEDGE. 



December. 1910. 



the world as a chemi.st who has alwaxs been 

 in the highest degree accessible to new ideas. 

 No one has done more than he to champion the 

 modern development of Chemical Theor\- : and the 

 words which Sir James Dewar spoke of him twelve 

 years ago are as true to-dav. "Ever_vone must admit,"" 

 said Sir James Dewar. "the debt of gratitude we owe 

 him for his iconoclastic labours in clearing out old 

 and vague notions, and for the courageous manner in 

 w hich he has supported the newer ideas of his time."' 



Sir Henry Roscoe"s fame as a teacher of chemistry 

 is world-wide. His tenure of the Professorship of 

 Chemistry at Owens College, Manchester, did more 

 than anything else to ele\'ate that institution, and the 

 University of Manchester by which it was succeeded, 

 to its present position as the foremost School of 

 Chemistry in Great Britain. Sir Henr\- has alwaxs 

 laboured to establish what we may jierhaps describe 

 as the official recognition of Chemistr\- : his bene- 

 factions to Chemical Institutions — and not least to 

 the Chemical Society and its Librarv — have been 

 great and numerous. His work on the relation of 

 Chemistry to Public Health, and his researches on 

 the .Atomic Weight of Carbon, on \'anadium, and in 

 Spectrum analysis have given him a place of the 

 highest rank among chemists. 



Sir \\'illiam Crookes. O.M., Foreign Secretar\- of 

 the Koyal Society, is a chemist whose work has 

 extended tmm the domains of pure chemistr\- and 

 industrial chemistry to that of physical chemistrw 

 and has been of the greatest significance to physics 

 and the fundamental physical conceptions of matter. 

 It is sufficient to enumerate some of his investigations 

 to indicate the range of his work. His discover\- of 

 Thallium, in 1861, was one of the first-fruits of the 

 then new science, spectrum anah'sis: his researches 

 in the rare earths and the genesis of the elements 

 have followed in logical sequence. Phxsics will 

 always commemorate him for the "radiant matter,'" 

 the " fourth state of matter," to which he was the 

 first to give these cognomens ; and his " Radiometer " 

 and " Spinthariscope." toys though they have been 

 said to be, have none the less furnished material 

 illustrations of the fundamental relations of matter 

 and energv. 



Dr. Hugo Muller was the only one of the five 

 guests who was not born a Londoner. He was born 

 at Tirschenreuth in Bavaria, and he is one of 

 several great Anglo-German chemists whose dis- 

 coveries have been at the service of his adopted 

 country. His early researches on the replacement 

 of hydrogen and chlorine are the basis of much of 

 the modern synthetic methods. His work on 

 cellulose and on other subjects produced bv plants 

 is of the highest importance. It has been said 

 of him that what he does not know regarding 

 the chemistry of ])aper is not worth knowing. 

 He is even better known as a mineralogist 

 than as a chemist, and some of his modes of 

 extracting, from minerals, products \aluable in 

 medicine are models of simjjlicit}- and accurac}- — as 



in the extraction ol litliiuni s dts from triplnlline. 



Dr. A. G. \'ernoii Harcourt is well known to Oxford 

 men as one of the most enthusiastic teachers of 

 Chemistry who ever laboured in that Universit\', and 

 his researches on the rate of chemical change marked 

 an epoch in ])hilosophical chemistrv. In more 

 utilitarian fields, his publications on Chemistry, on 

 Education, on Coal Gas, and Photometr\-, on 

 Chloroform and its anah'sis, and its safe administra- 

 tion as an anaesthetic have added to the fame of the 

 Oxford School of Chemistrw as well as to his 

 individual reputation. 



l)Ut that, perhaps, which is most imi)ressi\'e and 

 conspicuous at a banquet of this kind is less indixidual 

 achievement than the conception of the accumulated 

 knowledge during the period w hich has been covered 

 by the work of the chemists. In the sixt\' vears of 

 their joint exjierience the faces of chemical theory and 

 of chemical practice have alike been changed. It 

 would be impossible in the space of one article to 

 summarise with e\en approximate adequacy the 

 features of chemical progress in sixtx' vears: but a 

 very brief sketch of the change has been tentatively 

 furnished bv Professor Odling himself. The 

 greatest change of all has been in the advance of 

 the theories of chemical constitution. Following 

 on the acce[ited theories of Dalton came the 

 doubts awakened b\- newer in\'estigations. and the 

 assumptions which had to be made to reconcile 

 theor\' with iinestigations. Laurent and Gerhardt 

 working at the relative reacting unit weights of 

 bodies ; Liebig w ith his compound radicles : the 

 work of Dumas in chlorine solutions : Graham's 

 researches on the pohacidic acids : Williamson on 

 the compound ethers : \^'urtz and Hoffman on the 

 compound ammonias : and the extension by Caniz- 

 zaro of the work of Wurt/. were all steps in the 

 stairwav which led to a clearer comprehension of the 

 units of chemical constitutions and their types. 

 Thereafter the air w as further cleared by Frankland's 

 pol\-combinations and Gerhardt's tj-pes of dissocia- 

 tion. The re\-ision of the atomic w eights led through 

 Newland to Mendeleef — and to Mendeleef's concep- 

 tion of the table of the elements. Lyon Playfair 

 and Kekule carried the work on till Lebel and Van 

 t' Hoff furmulated the doctrines of isomerism and 

 rotating polymerisation. . . . Each of these men is 

 a link in a great chain ; but the work they do is 

 never-ending, and on it can never be written the 

 word "Finis." 



That is true ot an\ chemical researches: yet. if we 

 were to seek in a review of chemical progress over 

 sixtv vears for positi\e features they would be easil}' 

 found in the work done by those who — from 

 Berthelot to Emil Fischer — ha\-e pursued the syn- 

 thesis of organic bodies: and in the great branches of 

 knowledge which have sprung from the parent growth 

 of chemical dissociation — such as the fundamental 

 doctrines of Ampere and Avogadro : the theory of 

 solutions; electroh'sis; and the state of matter at high 

 temperatures with its corollar\' of spectrum analysis. 



