May 12, 1904] 



NATURE 



Zl 



physical infirmity made it increasingly difficult for him 

 to keep himself informed. At the same time the very 

 limitation of his physical powers, his partial paralysis, 

 and his poor eyesight, probably conduced to his 

 ' iiiinence as a speculative thinker. He was gifted with 

 a strong logical mind, and was an acute reasoner, and 

 a clear, vigorous, and independent thinker, capable of 

 broad and striking generalisation. Knowledge, we 

 know, dwells in heads replete with thoughts of other 

 men, wisdom in minds attentive to their own. 

 Kxcept by personal contact, Williamson was largely 

 debarred from the knowledge of other men's thoughts; 

 by the very circumstances to which allusion has been 

 made he became more attentive to his own. Like 

 most original thinkers he was somewhat tenacious of 

 opinions, and apt to be dogmatic in their utterance. 

 His beliefs were too hardly won to be lightly discarded. 

 But although at times impatient of contradiction, he 

 had too strong a regard for truth, was too sincere and 

 broad-minded a man to persist in any opinion, if ils 

 unreasonableness was made clear to him. Like 

 Carlyle, his philosophy was largely swayed by his 

 emotions, and like Carlyle's, his judgments on men 

 and things were apt to be tinctured by the mood of the 

 moment — a fact which may serve to account for seem- 

 ing inconsistencies in their expression. 



He had a high sense of duty, and of the responsi- 

 bilities of his position as a representative man of 

 science. Although, like many strong men, fond of 

 power, he was in no sense a self-seeking man, and 

 was contemptuous of the artifices by which smaller and 

 more ambitious men seek to gain preferment. 



Williamson was born at Wandsworth on May i, 

 1824; hence he had just completed his eightieth year at 

 the time of his death. Much of his early life was 

 spent on the Continent. He began the study of 

 chemistry under Gmelin at Heidelberg, in the old 

 cloisters which formerly did duty as class rooms and 

 laboratory, but soon joined Liebig at Giessen. Whilst 

 at Giessen he published, so far back as 1845, his first 

 paper on " The Decomposition of Oxides and Salts by 

 Chlorine," in which he determined the conditions of 

 production of hypochlorous and chloric acids, and the 

 cause of the difference in the mode of action of chlorine 

 upon alkalis and alkaline earths, and upon salts. The 

 main outcome of this paper has long since been worked 

 into the text-books. It is of interest as throwing light 

 upon the theory of the action of bleaching solutions. 

 The experimental material for a short paper on 

 " Ozone " was likewise accumulated at Giessen. In 

 this paper, which also appeared in 1845, Williamson 

 concluded that the peculiar properties belonging to the 

 oxygen set free by the agency of the electric current 

 are produced by the admixture of a peroxide or acid of 

 hydrogen, whereas by the action of phosphorus on 

 atmospheric air the same substance is not produced. 

 His surmise that a compound of hydrogen 

 and oxygen existed possessing some of the charac- 

 teristic properties of ozone but dissimilar from 

 Th^nard's hydrogen peroxide has not been established 

 by subsequent investigation. 



.■\t about this time Williamson took his degree, and 

 in 1S46, whilst still at Giessen, published an important 

 paper on " The Blue Compounds of Cyanogen and 

 Iron," which probably contains more determinative 

 analytical work than any other of his memoirs. In 

 it he describes the formation of prussian blue in 

 different circumstances, and the influence which these 

 exercise on its composition, giving particular atten- 

 tion to the presence of potassium, which materially 

 affects the colour and dyeing power of the product. 



These, with two short papers, one relating to the 

 theory of ozone, and another on the constitution of 



NO. 1802, VOL. 70] 



oenanthol, which he published in Liebig's Annalen, 

 comprise the outcome of the Giessen period. He then 

 passed on to Paris, where he came under the influence 

 of Comte. It is hardly to be supposed that a man of 

 his temperament, and in such surroundings, 

 could remain wholly unaffected by the events of 1848. 

 His position, however, was made secure by Graham, 

 who came over to Paris to offer him the chair of 

 practical chemistry in LIniversity College, to which he 

 was appointed in 1849, and where he continued to 

 teach for thirty-eight years. 



In 1850 Williamson published his epoch-making 

 paper on the " Theory of /^itherification." It was first 

 read to the chemical section of the British .•\ssociation 

 at the Edinburgh meeting of August, 1850, and in its 

 original form as " communicated by the author " 

 occupies about seven pages of the Philosophical Maga- 

 zine. Certainly no chemical paper of equal length 

 ever exercised so profound an influence on contem- 

 porary thought. This memoir, although frequently- 

 referred to, is probably seldom read by the chemical 

 student. And yet written more than half a century 

 ago there is scarcely a term in it which needs alteration 

 to bring it into harmony with modern chemical termin- 

 ology or present day doctrine. It is a model of concise 

 reasoning, founded upon happily devised experiment. 

 Williamson clearly traces for us the genesis of the idea; 

 which led him to his capital discovery. His original 

 intention was not to elucidate the theory of the manu- 

 facture of ether ; he says his object in commencing his 

 experiments was to obtain new alcohols by substi- 

 tuting carburetted hydrogen for hydrogen in a known 

 alcohol, and for this purpose he acted upon sodium 

 ethylate with the iodide of the carburetted hydrogen 

 which was to be introduced in the place of that 

 hydrogen — an expedient which he says he hopes may 

 render valuable services on similar occasions. To his 

 astonishment the compound thus formed had none of 

 the properties of an alcohol — it was nothing else thani 

 common ether, C,H,„0. This simple observation 

 threw a flood of light upon the relations of alcohol and 

 ether, which Williamson proceeded to develop by a 

 train of reasoning, and to prove by a series of experi- 

 ments which are now among the commonplace observ- 

 ations of every lecturer in organic chemistry wherever 

 the science is taught. Williamson not only illustrated 

 these relations by arguments and proofs which are 

 absolutely unassailable, but by a course of reasoning 

 which instantly riveted the attention and secured the 

 adhesion of the whole chemical world, he demonstrated 

 the true process of etherification, and thereby reconciled 

 the teaching of apparently irreconcilable facts. It 

 must have been with a special gratification that the 

 young man of twentj'-six penned the following lines, 

 which happily summarise the position he had attained. 



" Innovations in science frequently gain ground 

 only by displacing the conceptions which preceded 

 them, and which served more or less directly as their 

 foundation ; but, if the view which I have here pre- 

 sented be considered a step in our understanding of the 

 subject, I must beg leave to disclaim for it the title of 

 innovation ; for my conclusion consists in establishing 

 the connection and showing the compatibility of views 

 which have hitherto been considered contrary ; and the 

 best possible justification of the eminent philosophers 

 who advocated either one of the two contending 

 theories, is thus afforded by my reconciling their argu- 

 ments with those of their equally illustrious opponents."' 

 -An observation no less tactful than true. 



The paper is epoch-making in more senses than one. 

 In it U'illiamson not only foreshadowed his adherence 

 to the doctrine of types which in his subsequent teach- 

 ing he did so much to elucidate and extend, but he 



