Contemporaneous Notes on Elements and Technology = "ELT/TECH"

Contemporaneous Developments in Organic Chemistry and Biochemistry = "Org/Bio"

GENERAL/ANALYTICAL CHEMISTRY	DECADE	PHYSICAL CHEMISTRY
1791: GALVANI discovers "animal electricity." ( VOLTA ) 1792-4: J. RICHTER: "ANFANGSGRUNDEN DER STOICHIOMETRIE." ("Basics of Stoichiometry") Determines constant combining proportions and "equivalents," especially of acids and alkalies.	1790 Return to top ELT/TECH	-
1800: VOLTA shows that "animal electricity" is not of animal origin but from contact of metals. Produces "current electricity." Is this due to chemical action or to mere contact of metals? ( Voltaic Pile ) 1800: The Voltaic Pile. NICHOLSON and CARLISLE produce hydrogen and oxygen by electrolysis of water. 1803-1807: BERZELIUS and HISINGER. Decomposition of salts by electrolysis. DAVY identifies electricity with chemical affinity; ( BERZELIUS' DUALISTIC THEORY. ) 1805: GROTTHUSS' theory of electrolysis. DAVY isolates the alkali metals by electrolysis, supposing them at first to be hydrogen compounds; establishes (1810) the elementary nature of chlorine. Controversy between PROUST and BERTHOLLET over the Law of Constant Proportions.     PROUST finally establishes its truth. { WOLLASTON confirms experimentally the Law of Multiple Proportions, determining many "equivalent weights." > BERZELIUS and combining weights. 1808: GAY-LUSSAC'S Law of Combining Volumes. Gases combine in volume proportions of whole numbers. } AVOGADRO'S HYPOTHESIS. DALTON proposes THE ATOMIC THEORY (Announced in T. THOMSON'S "SYSTEM OF CHEMISTRY" (1807) and in DALTON'S "NEW SYSTEM OF CHEMICAL PHILOSOPHY" (1808): 1. Every element consists of homogeneous atoms, all of which have the same constant weight. 2. Compounds are formed by union of atoms of different elements in simple proportions. Leads to PROUT'S Hypothesis.	1800 Return to top ELT/TECH Org/Bio	1803: BERTHOLLET: "ESSAE DE STATIQUE CHIMIQUE" HENRY'S Law.
1811: AVOGADRO'S HYPOTHESIS: Equal volumes of gases contain equal numbers of "molecules." The physical atom (molecule) of an elementary gas is not the same as a chemical atom. The former may consist of several of the latter. Same principle announced independently by AMPÉRE in 1814. THE VOLUME THEORY OF ATOMS (see below) Connections of Avogadro to DUMAS, FARADAY and LAURENT and GERHARDT. PROUT'S Hypothesis: Atomic Weights are multiples of hydrogen. Connected to Dalton's (prior) atomic theory. DALTON unsuccessful in determining atomic weights. Used arbitrary symbols for atoms (Greek letters, circled "+", etc.); modern system of symbols and notation was introduced by BERZELIUS later in this decade. DALTON rejects the idea that gas densities are proportional to atomic weights. Many doubt the possibility of determining which multiples represent the true atomic weights. Possiblity of solving this problem suggested by DULONG and PETIT'S Law of Atomic Heats (1819) and MITSCHERLICH'S Law of Isomorphism. Laurent and Gerhardt's atomic weights.(~1845) BERZELIUS makes many careful determinations of combining weights, confirming WOLLASTON'S Law of Multiple Proportions. THE VOLUME THEORY OF ATOMS BERZELIUS' DUALISTIC THEORY: All compounds, organic and inorganic, consist of a positive and a negative part. Elements are either electropositive or electronegative. BERZELIUS' ideas lead to DUMAS' Etherin Theory and THE RADICAL THEORY. Earlier in this decade, GAY-LUSSAC and THENARD on iodine and cyanogen (First compound "radical").	1810 Return to top ELT/TECH Org/Bio	(1818: GROTTHUSS' Photochemical Absorption Law (leads to work by DRAPER and BUNSEN.)
BERZELIUS' greatest work was in the substantiation of the Atomic Theory.     He determined many atomic weights by study of composition, reactions, by analogy, etc. DUMAS' method for vapor density determination. Unsuccessful in fixing atomic weights. DÖBEREINER'S Triads. (Developed from Prout's hypothesis and Dalton's Atomic Theory.)	1820 Return to top ELT/TECH Org/Bio	1823: FARADAY and DAVY on liquefaction of gases. 1824: CARNOT: Second law of thermodynamics. "Brownian movement" observed.
GRAHAM discovers polybasic nature of phosphoric acid and the relation of water and nonmetal oxide in acids. LIEBIG and WÖHLER extend Graham's observations of polybasic acids to the polybasic organic acids. Downfall of Oxygen Theory of Acids. 1834: FARADAY'S Law. Electrochemical equivalent. idea of "valence" (1852)	1830 Return to top ELT/TECH Org/Bio	GRAHAM on diffusion of gases. "Adsorption" of hydrogen by platinum---- FARADAY
DOWNFALL OF OXYGEN THEORY OF ACIDS (as espoused earlier by LAVOISIER). New concept: An acid contains hydrogen which can be replaced by a metal. STAS' accurate work on atomic weights, extending over many years, establishes the exactness of laws of chemical combination and of conservation of mass. 1843: DUMAS: Combining proportions of hydrogen and oxygen. LAURENT and GERHARDT define atomic weights in terms of twice the volume of the unit weight of hydrogen. Distinguish among atom, molecule and equivalent.	1840 Return to top ELT/TECH Org/Bio	DRAPER'S photochemical work based on that of GROTTHUSS (1818). Leads to work by BUNSEN and ROSCOE. 1840: Law of HESS. Beginning of thermochemistry. 1849: GRAHAM on diffusion of liquids. 1849: FRANKLAND: Metal alkyls. idea of "valence" (1852)

1851: WILLIAMSON: "ON THE CONSTITUTION OF SALTS." Substitution of atoms. Distinguishes between atom and molecule of an element. { 1852: First idea of VALENCE (or "Saturation Capacity"), based on observations of Faraday (1834) and Frankland (1849). Further discussion. } 1855: ODLING: Atoms have "replacement" or substitution values. KEKULÉ (quadrivalence of carbon and formation of carbon chains, 1858) Graphic formulas----KEKULÉ and COUPER MODERN CONCEPTION OF VALENCE AND MOLECULAR STRUCTURE Kekulé's benzene ring. GERHARDT (~1855): Formulas can only express reactions and relations of compounds. Atomic arrangement is impossible to determine.	1850 Return to top ELT/TECH Org/Bio	1852: BUNSEN and ROSCOE'S photochemical work. (based on DRAPER'S 1840 work.) BUNSEN and G. R. KIRCHHOFF: Spectroscopic analysis. identification of rubidium and cesium and helium. HITTORF: Migration of ions and transference numbers. KINETIC THEORY OF GASES developed by KRÖNIG (1856) CLAUSIUS (1857) G. R. KIRCHHOFF (1857) DEVILLE: high temperature reactions (e.g., decomposition of water) effects on equilibria. CLAUSIUS: Equilibrium of ions and molecules. ( Arrhenius' Theory of Electrolytic Dissociation (~1888).
1860: Karlsruhe meeting. CANNIZZARO explains how to fix values for atomic weights. (based upon previous work of Avogadro, Döbereiner and Laurent and Gerhardt) MODERN CONCEPTION OF VALENCE AND MOLECULAR STRUCTURE 1861: GRAHAM: Dialysis and distinction between colloids and crystalloids. (based upon earlier work by Graham (1849). DE CHANCOURTOIS NEWLANDS' (1865) Law of Octaves > 1869: THE PERIODIC LAW: MENDELEEV and L MEYER Vicinity of the "Periodic Law" in the "Mallinckrodt Outline of the History of Chemistry".	1860 Return to top ELT/TECH Org/Bio	PHYSICAL CHEMISTRY 1863: GULDBERG and WAAGE: Law of Mass Action (based in part on by Berthelot and De St. Gilles.) ( VAN'T HOFF(1884) on equilibrium and Ostwald Dilution Law. 1869: GOLDSTEIN: Discovery of cathode rays. 1869: BERTHELOT'S thermochemical studies. ( 1879 Law of Maximum Work)
1874: VAN'T HOFF and LE BEL: independently establish the foundations of STEREOCHEMISTRY based in part upon work of Pasteur. CROOKES' Cathode rays are negatively charged particles. Stoney, et al.	1870 Return to top ELT/TECH Org/Bio	ANDREWS: Conception of critical temperature and pressure. The CLARK standard cell. 1873: VAN DER WAALS'S equation. 1876: KOHLRAUSCH: relative migration velocities (based on work of Hittorf and Clausius. GIBBS' Phase Rule. Chemical thermodynamics. 1877: PFEFFER'S measurements of osmotic pressure. ( Raoult) 1878: VICTOR MEYER'S work on vapor densities. Dissociation of iodine. 1879: Law of Maximum Work
1886: GOLDSTEIN: Discovery of "canal rays." 1887:WISLICENUS: "DIE LAGERUNG DER ATOME IM RAUME" ("THE ARRANGEMENT OF ATOMS IN SPACE") 1888: LE CHATELIER'S Principle.	1880 Return to top ELT/TECH	HELMHOLTZ applies thermodynamics to electrochemistry. 1881: RAOULT: Freezing and Boiling Point Laws. VAN'T HOFF applies gas laws to solutions. ( Arrhenius) 1882: THOMSEN thermochemical studies. 1884: VAN'T HOFF on equilibrium. 1885: OSTWALD Dilution Law. NERNST'S osmotic theory of electrochemical action. THEORY OF ELECTROLYTIC DISSOCIATION ---- ARRHENIUS ( Sutherland) Vicinity of the "Theory of Electrolytic Dissociation" in the "Mallinckrodt Outline of the History of Chemistry". 1889: NERNST: Concept of Solubility Product.
1891: Term "electron" ---- STONEY. 1892: WERNER: The metal ammonia complexes. Inorganic stereoisomerism. Co-ordination numbers. OSTWALD: theory of indicators. ( HANTZSCH ) 1895: Completion of MORLEY'S work on the combining ratio of oxygen and hydrogen. 1895: RÖNTGEN: X-rays. 1896: WILSON: First cloud chamber. 1896: BECQUEREL: Radioactivity of uranium. 1897: WIECHART and J. J. THOMSON: "Radiant matter" ---- negative corpuscles from breakdown of atoms ( Thomson atom and Electron theory of valence.) ( Bohr atom) Vicinity of the Bohr atom, etc., in the "Mallinckrodt Outline of the History of Chemistry". 1899: E. RUTHERFORD: α and β rays. 1899: THIELE'S partial valence theory.	1890 Return to top ELT/TECH Org/Bio	The WESTON standard cell.
Tautomeric theory of indicators (HANTZSCH, based on Ostwald's work) Liquifaction of hydrogen Onnes { 1900: BECQUEREL: β rays = cathode rays. VILLARD: Discovery of α rays. 1902: E. RUTHERFORD and SODDY: Radioactivity and atomic disintegration. 1903: RAMSAY and SODDY: Helium from uranium. } The J. J. THOMSON atom. Electronic theory of valence. ( Debye) nuclear atom. 1903: RICHARDS and pupils on revision of atomic weight values. 1904: KIPPING: investigation of silanes, which was basis for later development of silicone industry. 1905: EINSTEIN: Photoelectrical theory. Special theory of relativity. MASS-ENERGY EQUIVALENCE. E = mc2 1909: E. RUTHERFORD: α rays are helium (ions).	1900 Return to top ELT/TECH Org/Bio	1900: PLANCK: The Quantum Theory. SUTHERLAND: Theory of complete ionization. BJERRUM. Debye and Hückel. 1906: NERNST: Heat Theorem. Third Law of Thermodynamics. 1907: LEWIS introduces the concept of "activity." 1907: MORSE and FRAZER'S measurements of osmotic pressure. Use of "pH" --- SØRENSEN
ONNES: Liquifaction of Helium. 1911: E. RUTHERFORD: Discovery of nuclear atom. Bohr atom. Vicinity of the Bohr atom in the "Mallinckrodt Outline of the History of Chemistry". EINSTEIN: Law of Photochemical Equivalence. "Active" nitrogen ----- STRUTT. J. J. THOMSON: Positive Rays. "Meta-neon." Moseley and Aston. 1911: WILSON: Expansion cloud chamber---ionization tract. Aston. 1913:BOHR ATOM. Theory of stationary states. SOMMERFELD: Quantum Numbers. ATOMIC NUMBERS ---- MOSELEY Aston. Scroll down to 1910 to view the vicinity of Atomic Numbers in the "Mallinckrodt Outline of the History of Chemistry". 1913: SODDY, FAJANS, RUSSELL: Group displacement law. 1913: SODDY: Isotope concept. "LAUE'S Spots." BRAGG and BRAGG: Crystal structure. Moseley 1914: RICHARDS and LEMBERT: "Isotopic lead." 1915: BRAGG Fourier series. ( Robertson) {1916: LEWIS and 1919: LANGMUIR} Theory of Atomic Structure Electronic formulas Lewis' electronic theory of acids and bases. 1917: LANGMUIR: unimolecular film. 1919: E. RUTHERFORD: Artificial transmutation. Atom Nucleus.   α particle bombardment of light elements. GAMOW Cockcroft.	1910 Return to top ELT/TECH Org/Bio	1911: DONNAN: Law of Membrane Equilibrium. 1912: DEBYE: theory of dipole moments. Polar and non-polar compounds. RICHARDS: Compressibility of atoms. 1916: FREUNDLICH and LANGMUIR: Adsorption isotherm. ( Willstätter) 1919: ASTON: Mass Spectrograph. Isotopic elements. Whole Number Rule.
1920: KRATZER--- Molecular spectra. CZERNY --- rotation, vibration infrared spectroscopy Structure. 1923: SMEKAL--- light scatter frequency characteristic of liquids. SMEKAL-RAMAN effect. Structure MILLIKAN: Cosmic rays. COMPTON effect. BRØNSTED and HEVESY: mercury isotopes. HARKINS et al.: chlorine isotopes. ( HEVESY ---- 212Pb ) E. RUTHERFORD { HARKINS element "neutron" CHADWICK (discovery of the neutron) } beta ray emission Pauli. 1923: BRØNSTED theory. LEWIS (Electronic theory of acids and bases) and SIDGWICK (Covalency Rule) Pauling. 1925: HEYROVSKÝ: Polarography. G. P. THOMSON et al.: crystal analysis ( elucidation of Structure. Related work by LONSDALE	1920 Return to top ELT/TECH Org/Bio	LEWIS and RANDALL--- ionic activity (, c) 1923: DE BROGLIE: electron diffraction. DEBYE and HÜCKEL DEBYE-HÜCKEL-ONSAGER Equation.
PAULI: Neutrino Hypothesis FERMI: β-Decay Theory neutrino (1950's) DIRAC > C. D. ANDERSON: Positron. PAULING--- Resonance --(culmination of previous spectroscopy, x-ray and electron diffraction, crystal analysis and bonding theories by Lewis, et al.), and HOUWINK'S study of physical properties and structure. STRUCTURE. 1933: ROBERTSON: X-ray analysis structure. 1933: RABI 1935: BORN: Optical rotary power Chemical bond and atom orientation. ( infrared spectroscopy, in 1940's). JOLIOT-CURIE: Artificial Radioactivity 1934: FERMI: neutron bombardment. FERMI: "Transuranium elements" Thermal neutrons. HAHN and STRASSMANN MEITNER and FRISCH Nuclear Fission.	1930 Return to top ELT/TECH Org/Bio	YUKAWA Prediction of Meson. Cosmic rays C. D. ANDERSON: Meson. light meson PAULI Neutrino Hypothesis. FERMI β-Decay Theory. COCKCROFT and WALTON: Nuclear transmutation. Artif. accel. particles. PARTICLE ACCELERATORS LAWRENCE----Cyclotron. Electrostatic Generators Betatron (1940's) Linear Accelerators
NUCLEAR FISSION SPALLATION > FERMI: ATOMIC PILE (first self-maintaining Nuclear Chain Reaction) (given U235 and Pu239) ATOMIC BOMB and NUCLEAR REACTORS in which regeneration of fuel can occur . ATOMIC BOMB Nuclear Fusion (see below) ION EXCHANGE: applied to separation of radioisotopes. Linear Accelerators > Synchrotron Principle > Electron Synchrotron Synchro-Cyclotron (1950's)Cosmotron Infrared spectroscopy and Nuclear Magnetic Resonance ORGANIC SYNTHESIS Quinine Morphine Oxytocin Strychnine Cortisone Biotin, etc. Electron Paramagnetic Resonance Molecular Orbital Theory	1940 Return to top ELT/TECH Org/Bio	NONEQUILIBRIUM THERMODYNAMICS (PRIGOGINE) Light Mesons heavy mesons Hyperons(1950's)
LIBBY: C14 DATING tritium dating NUCLEAR FUSION (H2 and H3) --- HYDROGEN BOMB Carbon cycle and proton-proton chain Pinch Effect Eventual expected utilization of fusion energy Geochemistry and Magnetochemistry Complexes and Crystal Field Theory Neutrino and antineutrino (based upon Fermi's Beta-Decay Theory) Parity Laws (mentioned at right ) Cosmotron Bevatron (~1960) Alternating Gradient Synchrotron	1950 Return to top ELT/TECH Org/Bio	Hyperons (and neutrino/antineutrino) LEE and YANG: Parity laws.
1962: BARTLETT: first noble gas (xenon) compounds	1960 Return to top ELT/TECH Org/Bio	Beginnings of Computational Chemistry
-	1970 Return to top ELT/TECH Org/Bio	-
1985 - KROTO and WALTON: C60 (fullerene) 1988 - Scanning Tunnelling Microscope images a benzene molecule	1980 Return to top ELT/TECH Org/Bio	-
-	1990 Return to top ELT/TECH Org/Bio	-