442 



NA TURE 



[March io, 1892 



Kopp's scientific papers dealing with his laboratoiy 

 labours mainly appeared in Poggendorff's Annalen der 

 Physik und Chetnie, and latterly in Liebig's Annalen 

 der Cheinie. One or two of his contributions appeared 

 in the Philosophical Magazine^ and the Chemical Society 

 published his elaborate memoir on the specific heats of 

 compound substances, in which he sought to develop and 

 extend Naumann's law. But, compared with those of his 

 contemporaries, Liebig and Wohler, his papers are com- 

 paratively few in number. This is largely accounted for 

 by the very character of his investigations. His com- 

 munications were, for the most part, records of measure- 

 ment, often troublesome and tedious in their nature, and 

 followed by long and wearisome calculations ; and in 

 many cases the substances with which he experimented 

 ■could only be prepared in a state of purity by long- 

 continued operations. It is only those who have engaged 

 in work of this kind that can properly appreciate the 

 amount of labour thus involved. The nature of the 

 relations which he strove to elucidate necessitated the de- 

 termination of the particular physical constants of some 

 scores of substances ; indeed, to Kopp, their number was 

 only limited by the extent of his knowledge of the exist- 

 ence of their isomerides and homologues. Much of this 

 work was necessarily of a pioneer character. It stands, in 

 fact, to our later knowledge much in the same way as 

 does the work of Boyle, Mariotte, and Gay-Lussac to the 

 fuller development of the gaseous laws which we have 

 witnessed during the past few years. Kopp, indeed, was 

 among the earliest to venture into a province of which 

 he actually was the first to recognize the exceeding fruit- 

 fulness. Its soil, however, is not of that nature which, 

 tickled with a hoe, laughs with a harvest ; it is only with 

 much tillage and patient toil — the conjoint work of phy- 

 sicists and chemists — that it can be made to yield its 

 riches. It is, however, by such work that the supreme 

 secret— the true nature of the form of force with which 

 the chemist is mainly concerned, the real nature of 

 chemical affinity — will be revealed. 



Kopp is known to the literary world mainly by his 

 great work on the "History of Chemistry" (Bruns- 

 wick, 1843-47, 4 vols.). The amount of labour and re- 

 search involved in the preparation of this work was 

 simply stupendous. It is not many men of twenty-five 

 who would have either the skill or the patience to attack 

 the mass of literature which embalms the chemical lore 

 of the ancient peoples of the East, or who would devote 

 years to extracting what there is of science or philosophy 

 from the jargon of the alchemists, or the mystical writings 

 of the Rosicrucians. It is hardly to be wondered at 

 that nearly every subsequent writer on the history of 

 chemistry has been content to take his facts from Kopp : 

 their works, so far as they relate to the early history of 

 the science, are based, and, for the most part, avowedly 

 so, on his researches. From time to time Kopp pub- 

 lished supplementary volumes on the same subject. In 

 1869-75 appeared his " Beitrage zur Geschichte der 

 Chemie" (Brunswick, three parts); in 1871-73 the 

 " Entwicklung der Chemie in neuerer Zeit"; and, in 

 1886, "Die Alchemie in alterer und neuerer Zeit" 

 (Heidelberg, 2 vols.). In 1849 appeared his " Einleitung 

 in die Krystallographie " (Brunswick; 2nd ed., 1862) ; 

 and in conjunction with his Giessen colleagues. Buff and 

 Zamminer, he published his " Lehrbuch der physikal. 

 und theoretischen Chemie" (Brunswick, 1857; 2nd ed., 

 1863), which constitutes a portion of the well-known 

 Graham-Otto's " Lehrbuch der Chemie," one of the 

 standard text-books in Germany and Austria. 



In 1848, Kopp joined Liebig in the production of the 

 Jahresbericht iiber die Fortschritte der Clieniie, which he 

 continued to edit, latterly with Heinrich Will, down to 

 1862. In 1 85 1 he became the acting editor of the An- 

 nalen der Chemie, and although, with increasing years 

 and failing health, he was obliged to relinquish the re- 



NO. I 167, VOL. 45] 



sponsible management, he continued to the last to take a 

 lively interest in the fortunes of the periodical. 



Kopp's services to chemical science were recognized by 

 our own Chemical Society as far back as 1849 ! ^^^1 with 

 the exceptions of Bunsen, who is the Doyen of the Forty, 

 and who celebrates his jubilee as a Foreign Member this 

 year, and of Fresenius, who was elected in 1844, he was 

 the oldest Foreign Member of the Society. He was made 

 an honorary member of the German Chemical Society in 

 1869, and in 1888 he was elected a Foreign Member of 

 the Royal Society. 



Kopp was a good linguist and an omnivorous reader, 

 not only of matters scientific, but also of history and con- 

 temporary politics. He was remarkably catholic in his 

 tastes and wide in his sympathies. Indeed, no man 

 could be further removed than he in this respect from 

 the conventional idea of the German professor. He was 

 a constant reader of Nature, and hence was well in- 

 formed of the march of events, scientific and educational, 

 in this country. The writer of this notice, who counts it 

 a great privilege to be able to number himself among 

 his pupils, when visiting him in Heidelberg last spring 

 was astonished to find how fully and accurately he had 

 grasped the details and bearings of the projected scheme 

 for the new University in London, as it was at 

 that time understood. He was much interested, too, 

 in the great experiment which the County Councils have 

 undertaken in relation to secondary education, but of 

 the result of that experiment in its present form he ex- 

 pressed himself as not very hopeful. His extraordinary 

 range of information, his wonderfully retentive memory, 

 his geniality, his keen sense of humour, his fund of 

 anecdote, and exceptional conversational powers, made 

 him one of the most delightful of companions. Even in 

 the pages of the Jahresbericht, the evidences of Kopp's 

 humour are to be found. In abstracting the well-known 

 paper by Playfair and Joule on the Specific Volume of 

 Hydrated Salts, he is constrained to remark : — 



" Die Verfasser dieser Abhandlung sind anerkannte 

 Forscher, aber das hebt die Unbegreiflichkeit nicht auf, 

 dass in dem phosphorsauren Natron, welches wir vor 

 uns sehen, es nur das Wasser sein soil, welches den Raum 

 erfiillt, neither acid ?wr base occupy space. Wie durch 

 Zauberei kommen die letztern erst bei dem Erhitzen 

 raumlich zum Vorschein. — Siiure und Basis nehmen hier 

 keinen Raum ein, iveil die Annahme, das Wasser sei 

 hier mit dem spec. Volum des Eises vorhanden, gemacht 

 worden ist, und nach ihr fur Saure und Basis Nichts 

 iibrig bleibt. Jene Katze wurde von ihrem Herrn vermisst, 

 obgleich er sie unter Handen hielt, weil er die Annahme 

 gemacht hatte, sie habe das Fleisch gefressen. An diese 

 merkwiirdige Begebenheit wird man sehr oft in den 

 Naturwissenschaften erinnert. Ein Mann supponirte, 

 seine Katze habe Fleisch gefressen ; er wog sie, und da 

 sie grade so viel wog als das abhanden gekommene 

 Fleisch, sagte er verwundert : ' hier ist mein Fleisch ; 

 wo bleibt meine Katze ? ' " 



As Mr. Oscar Wilde has just reminded us, we are far 

 too serious nowadays ; our Jahresberichte, Bcrichte, and 

 Chemical Society Journals have grown to be fat, unwieldy 

 tomes, and the printers' bills grow steadily year by year ; 

 otherwise some of us would not be greatly shocked to 

 find our scientific reading occasionally lightened a httle 

 in this way. For it was the saying of an ancient sage 

 that humour is the only test of gravity ; and gravity, of 

 humour. 



By no one will Kopp's departure be more keenly felt 

 than by Bunsen, his friend and colleague for more than 

 a quarter of a century. The strollers along the Anlage 

 will miss the quaint little figure on its way to the daily 

 visit to the old veteran, who, rich in honour and in years, 

 is now the last of that famous triumvirate — Bunsen, 

 Kirchhofif, and Kopp— the memory of whose services the 

 world will not willingly let die. T. E. THORPE. 



