TRANSACTIONS OF SECTION B. 557 



Section B.— CHEMISTRY. 



President of the Section — Professor Edward Divers, M D 



F.R.S., V.P.C.S. ' ■' 



THURSDAY, SEPTEMBER U. 

 The President delivered the followino: Address: — 



"o 



The Atomic Theory without Hypothesis. 



In opening the Chemical Section of the British Association in this city and in the 

 halls of the Queen's College my first words must be those of reverence for the 

 memory of Thomas Andrews, for so many years the Professor of Chemistry in 

 this College, whose investigations into the properties of gases— above all, those 

 •which resulted in the recognition and determination of the critical pressure 

 and temperature of carbonic anhydride— have become a part of the foundation of 

 the Kinetic Theory of Gases. At the Meeting of the British Association bore 

 in 1852 Andrews was President of this Section, and again at the Meeting in 

 Edinburgh in 1871. 



Since the Meeting last year another distinguished chemist, formerly professor 

 in one of the Queen's Colleges, Maxwell Simpson, has also passed away. He, too, 

 acted as President of this Section— namely, at the Meeting in Dublin in 1878, 

 The work by which Simpson's name will ever be recalled is more especially that 

 upon the synthesis of polybasic organic acids. 



One other name must not be left unmentioned in this Address : it is that of a 

 long-time Fellow of the Chemical Society who has been intimately connected with 

 the British Association — I mean that of George Griffith, the genial and most 

 effective Assistant General Secretary of the Association for so many years, who 

 died four months ago. He had visited Belfast in the spring and made the pre- 

 liminary arrangements with the Local Committee for this Meeting. He joined 

 the Chemical Society in 1859 — ^just one year before I did — and remained a Fellow 

 until his death. 



It is now almost a century ago since John Dalton made known to the world 

 his theory of the nature of chemical combination by the publication of a table of 

 atomic weights. He had been occupying himself for some years with the study 

 of the physical properties and atomic constitution of gases before he was led to 

 extend the notion of the atom to chemical phenomena, and thus to form that 

 conception which was to become celebrated as the atomic theory. In his labora- 

 tory note-books, preserved from 1802 onwards, the publication and analysis of 

 which we owe to Sir Henry Roscoe and Dr. Harden, no reference is made to the 

 theory till 1803, but we may well believe with Henry that it was already in 

 Dalton's mind just a hundred years ago. But however that may have been, it seems 

 fitting in a year so closely approaching the centennial of its publication as the 

 present that the occupier of this Chair should address his audience on a subject of 

 such general interest and importance as the atomic theory, if indeed there remains 

 anything to be said on a subject which has so long and so fully engaged attention. 



