322 



NA TURE 



[February i, 1900 



liisaged mother, entered the hall, followed by the various 

 Tiiembers of his family. The proceedings were opened 

 by an address from the Mayor of Rotterdam, whose 

 words, however, like those of some of the following 

 speakers, being Dutch, were only intelligible to a limited 

 number of the audience. Suffice to say that van't Hoflf 

 was the recipient of a series of memorials and con- 

 gratulatory addresses from various scientific corporations. 

 The University of Utrecht, van 't Hoff's alma mater^ sent 

 a deputation, and the chemical students of Amsterdam, 

 where van't Hoff till recently occupied the chair of 

 chemistry, were also officially represented. The after- 

 noon's programme concluded with the presentation to 

 the professor of his own biography by Dr. Ernst Cohen, 

 and of the before-mentioned jubilee volume on behalf of 

 former students by Dr. Meyerhoffisr. To each of the 

 speakers van't Hoff replied in a few words, expressing 

 his thanks for the honour accorded to him, in simple and 

 unaffected language. 



In the evening a highly successful dinner took place. 

 It was interrupted by continual bursts of applause, as 

 congratulatory telegrams arrived from almost all parts of 

 the civilised world. To the series of toasts proposed in 

 his honour, van "t Hoff replied in his native tongue, 

 making, however, a graceful variation in excellent Eng- 

 lish to acknowledge his appreciation of the presence 

 of a guest from England at a time of national em- 

 bitterment. 



An account of the jubilee celebration at Rotterdam 

 would scarcely be complete without a reference to the 

 life and work of the man in whose honour it was held. 

 For a complete and extremely interesting account readers 

 are referred to Cohen's biography,^ which has been con- 

 sulted by the present writer in this connection. 



Jacobus Henricus van 't Hoff was born on August 30, 

 1852, at Rotterdam, where his father still practises as a 

 medical man. While at school he showed an intense 

 interest for natural science ; many of his leisure hours 

 were spent in carrying out simple chemical experiments 

 at home. After passing through the Hoogere Burger- 

 school in Rotterdam, his parents decided that he should 

 have a technical training, and for this purpose he was 

 sent to the technical school at Delft. Two years' study 

 at Delft sufficed for him to pass his technical examination, 

 whereupon he proceeded to Leyden, devoting most of his 

 time io the study of mathematics and physics. Remain- 

 ing but one year at the latter University, he was attracted 

 by Kekule to Bonn, then at the height of its fame as the 

 school of structural chemistry. Later, in the same year, 

 we find him in Wiirtz's laboratory in Paris. 



In Septemberofthefollowingyear(i874)van 'tHoffpub- 

 lished in Utrecht a pamphlet, the contents of which form 

 the foundation of our present stereochemistry. The proud 

 structure built up on the ideas first expressed in this 

 modest publication is one of the greatest chemical 

 achievements of modem times. The adverse criticisms 

 of Kolbeand other then existing authorities on structural 

 chemistry are historical, but after twenty-five years' sub- 

 jection to the crucial test of experiment, we can assert 

 that the theory of the asymmetric carbon atom is one of 

 the most firmly established in chemical science. 



In December 1874, three months after the publication 

 lews on chemical structure, van't Hoff graduated 



of his 



as doctor of mathematics and physics at Utrecht, the 

 title of his thesis being " Contributions to our knowledge 

 of cyanacetic and malonic acids." 



That the path of fortune has not always run smoothly 

 for him appears from his experiences during the months 

 following graduation. Repeated attempts to obtain a 

 post as teacher failed, and finally leaving home, he de- 

 parted to Utrecht with the intention of giving private 



1 " J.-icobus Henricus vai 

 Portriit und Bibliographic. 

 Engelmaiin.) 



■t Hoff." 

 Price M. 



Von Ernst Cohen. Mit einem 

 1.60. (Leipzig : Verlag von W. 



NO. 1579, VOL 61] 



instruction. During this period he devoted his spare 

 hours to writing " La Chimie dans I'Espace." Finally, 

 in 1876, the desire to devote himself to teaching was 

 gratified by his appointment as lecturer at the Royal 

 Veterinary School at Utrecht. 



In October 1877, on the elevation of the old Amsterdam 

 Athenjeum to the status of a University, van 't Hoff ob- 

 tained the post of lecturer on theoretical chemistry, and 

 scarcely a year had elapsed before he was appointed 

 professor of chemistry, mineralogy and geology, a chair 

 he held until the commencement of 1896. 



The activity he showed during his connection with the 

 University of Amsterdam is well known. Notwithstand- 

 ing very onerous routine duties, he continuously produced 

 work of first class importance, and by his inspiration 

 created a distinguished school of chemists. 



" Physicam chemiae adjunxit" is the maxim which 

 characterises the life work of van't Hoff. His endeavours 

 to fill up the gap in our knowledge of the connection 

 between constitution and chemical properties led to the 

 production of his " Etudes de Dynamique Chimique," 

 to the setting up of a most important theory of equi- 

 librium, and to the overthrow of Berthelot's principle of 

 maximum work. 



Closely bordering on the theory of equilibrium the 

 problem of affinity next attracted his attention, and the 

 application of thermodynamics to Pfeffer's osmotic ex- 

 periments brought forth his great theory of solutions, 

 according to which the physical laws (Boyle's, Gay- 

 Lussac's, Avogadro's) holding for the gaseous state, 

 apply equally well to dilute solutions. The most im- 

 mediate result of this theory was the formulation by 

 Arrhenius of the theory of electrolytic dissociation. 

 The changes thus brought about in the nature of our 

 chemical conceptions have been enormous, and the 

 rapid development of electrochemistry in recent years 

 stands in direct connection with the establishment of 

 van't Hoff's laws of solutions. In 1890 the extension of 

 his theory of solutions to the case of solids enabled him 

 to show the existence of simple laws in solid aggregates, 

 and much of our present knowledge with regard to the 

 solid state of matter dates from this discovery. 



In spite of seductive offers on the part of another 

 Dutch University in 1893, and of two German Uni- 

 versities in 1887 and 1894, van't Hoff remained true to 

 Amsterdam until 1895, when the Prussian Academy of 

 Sciences made him a most brilliant offer. Not only was 

 he elected a Member of the Academy, but at the instance 

 of the latter, the Prussian Government placed at its 

 disposal the necessary funds whereby van 't Hoff is 

 enabled to devote himself entirely to his work as in- 

 vestigator. In this way a foreign Government has 

 recognised his services to science and provided the 

 means for his searching genius to exert itself to its 

 fullest extent. 



During the past few years van't Hoff's attention has 

 been chiefly turned to that province of physical chemistry 

 dealing with transition phenomena, double-salt formation 

 and double decomposition, and his present goal is the 

 explanation of the formation of oceanic salt deposits on 

 the basis of such investigations. Already a great deal 

 has been accomplished, and especially for geologists 

 most important results have been brought to light. 

 From a politico-economic point of view the importance 

 of such research for the great Stassfurt salt industry is 

 obvious. 



Prof, van 'tHoff 's laboratory is situated in Wilmersdorf, 

 a suburb of Berlin. It consists of some four or five 

 small rooms forming the ground story of an ordinary 

 house. Here van 't Hoff works with at most three or four 

 students. He is in the happy position of a professor not 

 obliged to lecture more than once a week, and not ex- 

 pected to do more than extend the bounds of human 

 knowledge. H. M. Dawson 



