XXXV111 



of the several classes of vital powers and their mutual relations, and point- 

 ing out the necessity of distinguishing, more carefully than had been done 

 oy early inquirers, between physical and final causes. In 1844 Dr. Roget 

 again travelled abroad, revisited Geneva, and took the opportunity of 

 attending the Meeting of the Italian Scientific Association held that year 

 at Milan. 



In other respects his public life during his long term of office as Secretary 

 was intimately associated with the annals of the Royal Society. In the 

 course of that time changes had been introduced which rendered the duties 

 of the Senior Secretary exceedingly laborious. Not only did the task of 

 editing the Proceedings both of the Society and of the Council fall to his 

 share, but also that of making and preparing for publication the Abstracts 

 of Papers read. This labour was performed by Dr. Roget from November 

 1827 until his retirement from office in 1848. Ever devoted to the inte- 

 rests of the Society and to his own important duties, he at times found his 

 position one of great delicacy, and his name had occasionally to appear in 

 the front rank of polemical warfare. On these occasions he maintained his 

 position by firmness and forbearance, wdiile sometimes smarting under un- 

 deserved attacks. On the 7th of November, 1836, a vote of thanks was 

 accorded to him by the Society. 



On retiring from office, although in his seventieth year, he at once em- 

 barked in a laborious undertaking which he had projected many years be- 

 fore. As long ago as the year 1805 he had formed, for his own use in 

 literary composition, a small classed catalogue of words, which vocabulary 

 had often proved of great service to him in his writings. This he deter- 

 mined to expand into a work of general utility, and after three or four 

 years of labour he published, as its result, the now well-known ' Thesaurus 

 of English Words and Phrases, classified and arranged so as to facilitate 

 the expression of ideas, and assist in Literary Composition.' The appre- 

 ciation which the work has received may be inferred from the fact that it 

 has reached a twenty-eighth edition. It first appeared in 1852, and after 

 running through two editions, was reduced to a more portable form, and 

 stereotyped. Not the least remarkable part of the work is the arrange- 

 ment, at once philosophical and practical, of the Ideas, which forms the 

 basis of the classification. The book may be shortly described as the con- 

 verse of an ordinary dictionary. A dictionary sets forth the idea belonging 

 to a given expression ; the * Thesaurus ' supplies the expression to a given 

 idea. A French ' Thesaurus,' in which the author, Mr. T. Robertson, 

 adopted in all its details Dr. Roget's arrangement, was published in Paris 

 in 1859, with the title " Dictionnaire Idcologique. Recueil des Mots, des 

 Phrases, des Idiotismcs, et des Proverbes de la Langue Franeaise classes 

 selon l'ordre des Idees." An imitation of the original work, but omitting all 

 the phrases from the classification, was also produced in America. 



With the publication of the 'Thesaurus,' Dr. Roget's public career may 

 be said to have closed. He had for many years retired from practice, and 



