Presidential address to the chemical society

1930 ◽  
Vol 49 (13) ◽  
pp. 251-258
Author(s):  
J. F. Thorpe
Keyword(s):  
Presidential Address ◽  
Chemical Society

scholarly journals A hypothesis of molecular configuration in three dimensions of space

1916 ◽  
Vol 92 (642) ◽  
pp. 451-462 ◽  
Keyword(s):  
Negative Charge ◽  
Presidential Address ◽  
Chemical Society ◽  
Negative Sign ◽  
Three Dimensions ◽  
Molecular Configuration ◽  
Mental Picture ◽  
Chemical Combination ◽  
The Moment ◽  
Dimensions Of Space

It is now almost universally acknowledged that the valency of an element is due to its being associated with one or more electrons. The mechanism of chemical combination was sketched by me in the Presidential Address to the Chemical Society in the sentence:— "If it be conceded that a salt differs from its solution only in so far as the mobility of the solution permits of transfer of ions, the transfer of an electron from the sodium to the chlorine must take place at the moment of combination. Symbolised, if we write E for electron and simplify the reaction, dealing for the moment with an atom and not with a molecule of chlorine, we have ENa + Cl = NaECl. Here the electron serves as the bond of union between the sodium and the chlorine. . . . If it be desired to form a mental picture of what occurs, let me suggest a fanciful analogy which may serve the purpose: it is that an electron is an amœba-like structure, and that ENa may be conceived as an orange of sodium surrounded by a rind of electron; that on combination the rind separates from the orange and forms a layer or cushion between the Na and the Cl, and that on solution an electron attaches itself to the chlorine in some similar fashion, forming an ion of chlorine. It will be noticed that the E fills the place usually occupied by a bond; thus Na—Cl. It happens providentially that the bond and the negative sign are practically the same; Na—Cl may be supposed to ionise thus, Na(—Cl), the negative charge or electron remaining with the chlorine."

XXIX.—The First Chemical Society, the First Chemical Journal, and the Chemical Revolution (Part II)

1952 ◽  
Vol 63 (4) ◽  
pp. 385-400 ◽  
Author(s):  
James Kendall
Keyword(s):  
Special Interest ◽  
Presidential Address ◽  
Chemical Society ◽  
Complete List ◽  
Supplementary Information ◽  
Chemical Revolution ◽  
In The Beginning ◽  
Revolutionary Period

Since the delivery of my presidential address (1) in July I have assembled an amount of supplementary information regarding “the Chemical Society instituted in the beginning of the Year 1785”. This, together with a brief description of some other chemical societies of the revolutionary period, forms the basis of the present paper.First of all, it will be expedient to furnish a complete list of the dissertations read before the Society during 1785–86 and included in the first volume of its Proceedings, appending short comments with respect to the communicators or their topics when anything of special interest arises.

Chemical translators: Pauling, Wheland and their strategies for teaching the theory of resonance

1999 ◽  
Vol 32 (1) ◽  
pp. 21-46 ◽  
Author(s):  
BUHM SOON PARK
Keyword(s):  
Quantum Mechanics ◽  
Presidential Address ◽  
Three Dimensional ◽  
Chemical Society ◽  
Orbital Theory ◽  
Resonance Theory ◽  
X Ray Crystallography ◽  
Transmission Of Knowledge ◽  
Chemical Concepts ◽  
Scientific Truth

It was well said by Clerk Maxwell: ‘For the sake of persons of different types of mind scientific truth should be presented in different forms, and should be regarded as equally scientific whether it appears in the robust form and colouring of a physical illustration, or in the tenuity and paleness of a symbolical expression.’From N. V. Sidgwick's Presidential Address to the Chemical Society, London, 1937During the years between 1930 and 1950, chemistry underwent a transformation that affected both research and education. New subdisciplines like chemical physics and physical organic chemistry emerged, encouraging an influx of ideas and experimental techniques from physics. X-ray crystallography and other spectroscopic methods became indispensable for determining structures of atoms, molecules and crystals; such chemical concepts as valence and bond were refined within a new explanatory framework based on principles of physics; and the study of reaction mechanisms and rates became closely intertwined with that of structures and properties of chemical compounds. In conjunction with these changes, introductory chemical textbooks began to shift their emphasis from thermodynamic equations and solution theories to three-dimensional arrangements of atoms in molecules and types of chemical bonds. There is no doubt that the most important impetus behind this transformation was the development of quantum mechanics in the mid-1920s, and the most prominent among those who applied it to chemistry was Linus Pauling. And in Pauling's view, ‘the principal contribution of quantum mechanics to chemistry’ was the concept of resonance.The entry of resonance into chemistry, or the reception of the theory of resonance in the chemical community, has drawn considerable attention from historians of science. In particular, they have noted Pauling's flamboyant yet effective style of exposition, which became a factor in the early popularity of the resonance theory in comparison to the molecular orbital theory, another way of applying quantum mechanics to chemical problems. To be sure, the non-mathematical presentation of the resonance theory by Pauling and his collaborator, George Wheland, helped to facilitate the reception; but this presentation was vulnerable to the confusion that arose among chemists owing to the similarity between resonance and tautomerism, or between foreign and indigenous concepts. The reception occurred at the expense of serious misunderstandings about resonance. This paper investigates the ways in which Pauling and Wheland taught, and taught about, the theory of resonance, especially their ways of coping with the difficulties of translating a quantum-mechanical concept into chemical language. Their different strategies for teaching resonance theory deserve a thorough examination, not only because the strategies had to do with their solutions of the philosophical question whether resonance is a real phenomenon or not, and whether the theory of resonance is a chemical theory or a mathematical method of approximation, but also because this examination will illuminate the role of chemical translators in the transmission of knowledge across disciplinary boundaries.

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