Paul Villard

Paul Villard (around 1900)

Paul Ulrich Villard (born September 28, 1860 in Lyon , † January 13, 1934 in Bayonne ) was a French physicist and chemist . He discovered in 1900 during work on radium the γ-radiation as the third representative of ionizing radiation .

Life

Paul Villard began training at the École normal supérieure in Paris in 1881 , which he completed in 1884 with the Agrégation . In the following years he taught as a teacher at various state schools in Paris, Orléans , Bordeaux , Coutances , Rouen and Montpellier . With the support of Marcelin Berthelot , Villard became “Chargé de conférence” at the natural science faculty of the University of Montpellier and was able to do some experimental research there. However, he was drawn back to Paris, so he asked to be released from his teaching duties. In Paris, Villard turned to the director of the chemistry laboratories of the École normal supérieure Henri Debray (1827–1888) and asked for permission to work in his laboratory, which he was granted. He spent the remainder of his scientific career in chemistry on Rue d'Ulm. In 1904 Robert Lespieau (1864–1947) granted him his own small laboratory.

In 1904 Villard was awarded the Prix Wilde and in 1907 the Prix La Caze . On December 28, 1908, the Académie des Sciences elected him to succeed Eleuthère Mascart as a member of their Physique Générale section . He asserted himself clearly ahead of Édouard Branly and other competitors. In the vote that took place on November 23, 1908, Villard was still inferior to Edmond Bouty . Villard was also a member of the Société française de physique , the Société française des électriciens and the Société des amis des sciences , honorary member of the Société de radiologie médicale de Paris and a corresponding member of the Société industrial de l'Est .

Towards the end of his life, Villard accepted a “Pension d'honneur” from the Caisse nationale des Sciences . Due to his deteriorating health, he was forced to spend a lot of time outside Paris and died in Bayonne in early 1934 . Villard was an officer in the Légion d'Honneur .

Act

Villard's first research focus was the study of gas hydrates . In 1888, together with Robert Hippolyte de Forcrand (1856–1933), he determined the temperature dependence of hydrogen sulfide and chloromethane hydrates. In the same year he succeeded in producing hydrates of methane , ethane , ethene , ethine and nitrous oxide , whose physicochemical properties he investigated in the following years. In 1890 Villard studied the hydrates of propane and in 1896 those of argon . Between 1888 and 1896 he published nine articles on the physico-chemical properties of these hydrates in the Comptes rendus de l'Académie des sciences . This work was also the basis of his dissertation.

In 1897 Villard began using a Crookes tube to examine the X-rays that had been discovered shortly before . In a first note he reported on their effects on photo plates . Villard wanted to find out where the material from which the cathode rays are formed comes from . He noticed the reducing effect of the cathode rays when they hit plates coated with lead sulfate or copper oxide. From this, Villard drew the (incorrect) conclusion that the cathode rays consisted of hydrogen that came from the tube surface. Hydrogen particles bombard the cathode , become negatively charged there and then repelled by the cathode to form the cathode rays. Villard only revised his view in the second edition of his book Les Rayons cathodiques from 1908 and followed Joseph John Thomson's presentation that the cathode rays consist of electrons .

Villard also investigated the chemical effects of X-rays, in particular the glass discoloration they caused. When Pierre and Marie Curie reported similar effects of radium rays , Villard became interested in radioactivity . He received a few milligrams of a weakly radioactive salt and began to investigate the reflection and refraction properties of cathode rays and beta rays . To do this, Villard deflected the beta rays emitted by the radioactive source with a magnetic field and recorded them on two photo plates arranged one behind the other and separated by an aluminum foil. In doing so, he discovered a new penetrating type of radiation. His results were announced on April 9, 1900 during the meeting of the Académie des Sciences . Henri Becquerel , who was initially skeptical of Villard's observations, soon confirmed them. Villard did not name the new radiation. The designation γ-radiation goes back to Ernest Rutherford , who chose it in 1903 as a continuation of the designations α- and β-radiation introduced in 1899 .

In 1904 Villard had an almost year-round dispute with Henri Pellat (1850–1909), who believed that he had discovered that cathode rays were subjected to anisotropic friction when they passed through a magnetic field. Villard was able to demonstrate convincingly that a "magnetofriction" does not exist.

Between 1906 and 1908 Villard developed a theory about the appearance of aurora borealis. He calculated the paths that cathode rays (electrons) travel under the influence of the earth's magnetic field . On this basis he tried to explain the appearance, the geographical distribution and the movements of the northern lights.

In 1908 Villard presented his “Radiosklerometer” (radiation hardness meter), a measuring device for determining the penetration capacity (“hardness”) of X-rays based on the electrometer principle. As a new unit of measurement, he proposed the amount of X-ray radiation that is released by ionization in a volume of one cubic centimeter (1 cm³) of air under normal conditions for temperature and pressure, an electrostatic unit (1 esu , unit of charge in the cgs system ). The later unit X-ray was based on a similar definition .

The Villard circuit he invented , a one-way converter circuit with voltage doubling, which is primarily used to supply X-ray tubes , is named after him.

Fonts (selection)

Books

Les Rayons cathodiques . Scientia, 1st edition, Gauthier-Villar, Paris 1900 ( gallica , archive.org ).
Les Rayons cathodiques . 2nd edition, Gauthier-Villars, Paris 1908.

Magazine articles

Villard has contributed to Comptes rendus de l'Académie des sciences , Journal de physique , Journal le Radium , Annales de chimie et de physique , Bulletin de la Société française des électriciens , Bulletin de la Société d'Encouragement , Revue générale des sciences , among others , Revue scientifique and Bulletin de la Société française de photographie .

To chemistry

Sur l'hydrate d'hydrogène sulfuré . In: Comptes rendus de l'Académie des sciences . Volume 106, 1888, pp. 849-851 (with Robert Hippolyte de Forcrand; online )
On the formation of the hydrates de gaz . In: Comptes rendus de l'Académie des sciences . Volume 106, 1888, pp. 939-941 (with Robert Hippolyte de Forcrand; online )
Sur l'hydrate de chlorure de methyle . In: Comptes rendus de l'Académie des sciences . Volume 106, 1888, pp. 1357-1359 (with Robert Hippolyte de Forcrand; online )
On the composition of hydrates d'hydrogène sulfuré et de chlorure de méthyle . In: Comptes rendus de l'Académie des sciences . Volume 106, 1888, pp. 1402-1405 (with Robert Hippolyte de Forcrand; online )
Sur quelques nouveaux hydrates de gaz . In: Comptes rendus de l'Académie des sciences . Volume 106, 1888, pp. 1602-1603 ( online ).
Sur quelques nouveaux hydrates de gaz [Note] . In: Comptes rendus de l'Académie des sciences . Volume 111, 1890, pp. 302-305 ( online ).
About the composition et la chaleur de formation de l'hydrate de protoxyde d'azote . In: Comptes rendus de l'Académie des sciences . Volume 118, 1894, pp. 646-649 ( online ).
Sur les propriétés physiques du protoxyde d'azote pure . In: Comptes rendus de l'Académie des sciences . Volume 118, 1894, pp. 1096-1099 ( online ).
Sur l'hydrate carbonique et la composition des hydrates de gaz . In: Comptes rendus de l'Académie des sciences . Volume 119, 1894, pp. 368-371 ( online ).
Sur les propriétés des gaz très purs au voisinage du point critique . In: Journal de Physique Théorique et Appliquée . 3rd episode, volume 3, 1894, pp. 441-451 ( doi: 10.1051 / jphystap: 018940030044100 , PDF ).
Sur la dissolution des solid dans les vapeurs . In: Comptes rendus de l'Académie des sciences . Volume 120, 1895, pp. 182-184 ( online ).
Propriétés physiques de l'acétylène; hydrate d'acétylène . In: Comptes rendus de l'Académie des sciences . Volume 120, 1895, pp. 1262-1265 ( online ).
Propriétés de l'acide carbonique solid . In: Comptes rendus de l'Académie des sciences . Volume 120, 1895, pp. 1413-1416 (with R. Jarry; online ).
Combinaison de l'argon avec l'eau . In: Comptes rendus de l'Académie des sciences . Vol. 123, 1896, pp. 377-379 ( online ).
Sur les effets de mirage et les différences de densités qu'on observe dans les tubes de Natterer . In: Journal de Physique Théorique et Appliquée . 3rd episode, Volume 5, 1896, pp. 257-266 ( doi: 10.1051 / jphystap: 018960050025700 , PDF ).
Dissolution of the liquides et des solides dans les gaz . In: Journal de Physique Théorique et Appliquée . 3rd episode, Volume 5, 1896, pp. 453-461 ( doi: 10.1051 / jphystap: 018960050045301 , PDF ).
Étude des gaz liquéfiés . In: Annales de chimie et de physique . 7th Series, Volume 10, pp. 387-432 ( online ). - Part of the dissertation
Étude expérimentale des hydrates de gaz . In: Annales de chimie et de physique . 7th Series, Volume 11, 1897, pp. 289-394 ( online ). - Part of the dissertation

To physics

Sur le voile photographique en radiography . In: Comptes rendus de l'Académie des sciences . Volume 125, 1897, pp. 232-234 ( online ).
Sur la diffusion des rayons cathodiques . In: Comptes rendus de l'Académie des sciences . Volume 127, 1898, pp. 223-224 ( online ).
Sur les rayons cathodiques . In: Comptes rendus de l'Académie des sciences . 1898–1900:
- [Part 1]: Volume 126, 1898, pp. 1339-1341 ( online ).
- [Part 2]: Volume 126, 1898, pp. 1564-1566 ( online ).
- [Part 3]: Volume 127, 1898, pp. 173-175 ( online ).
- [Part 4]: Volume 130, 1900, pp. 1614-1616 ( online ).
Sur les rayons cathodiques . In: Journal de Physique Théorique et Appliquée . 3rd episode, Volume 8, 1899, pp. 5-16 ( doi: 10.1051 / jphystap: 0189900800500 , PDF ).
Sur les rayons cathodiques . In: Journal de Physique Théorique et Appliquée . 3rd episode, Volume 8, 1899, pp. 148-161 ( doi: 10.1051 / jphystap: 018990080014801 , PDF ).
Sur l'action chimique of rayons X . In: Comptes rendus de l'Académie des sciences . Volume 128, 1899, pp. 237-239 ( online ).
Redresseur cathodique pour les courants induits . In: Comptes rendus de l'Académie des sciences . Volume 128, 1899, pp. 994-996 ( online ).
Sur l'action chimique of rayons X . In: Comptes rendus de l'Académie des sciences. Volume 129, 1899, pp. 882-883 ( online ).
- On the chemical action of the X-rays . In: Philosophical Magazine . 5th episode, volume 49, number 297, 1900, p. 244 ( doi: 10.1080 / 14786440009463840 ).
About the discharge of the corps électrisés et the formation de l'ozone . In: Comptes rendus de l'Académie des sciences . Volume 130, 1900, pp. 125-127 ( online ).
Sur la discontinuité de l'émission cathodique . In: Comptes rendus de l'Académie des sciences . Volume 130, 1900, pp. 1750-1772 ( online ).
Sur la réflexion et la réfraction des rayons cathodiques et des rayons déviables du radium . In: Comptes rendus de l'Académie des sciences . Volume 130, 1900, pp. 1010-1012 ( online ).
Sur le rayonnement du radium . In: Comptes rendus de l'Académie des sciences . Volume 130, 1900, pp. 1178-1179 ( online ).
Transformateur à haut voltage. A survolteur cathodique . In: Journal de Physique Théorique et Appliquée . 4th episode, Volume 10, 1901, pp. 28-32 ( doi: 10.1051 / jphystap: 019010010002801 , PDF ).
Sur les rayons cathodiques . In: Comptes rendus de l'Académie des sciences . Volume 138, 1904, pp. 1408-1411 ( online ).
Sur les rayons cathodiques. Reply à la Note de M. Pellat . In: Comptes rendus de l'Académie des sciences . Volume 139, 1904, pp. 42-44 ( online ).
Sur les rayons cathodiques et les lois de l'Electromagnétisme . In: Comptes rendus de l'Académie des sciences . Volume 139, 1904, pp. 1200-1202 ( online ).
Sur les actions chimiques de la lumière - (Response to l'article de MA Guêbhard) . In: Journal de Physique Théorique et Appliquée . 4th episode, Volume 4, 1905, pp. 619-623 ( doi: 10.1051 / jphystap: 019050040061901 , PDF ).
Sur le mécanisme de la lumière positive . In: Comptes rendus de l'Académie des sciences . Volume 142, 1906, pp. 706-709 ( online ).
Sur l'aurore boreal . In: Comptes rendus de l'Académie des sciences .
- [Part 1]: Volume 142, 1906, pp. 1330-1333 ( online ).
- [Part 2]: Volume 143, 1906, pp. 143-145 ( online ).
Sur certains rayons cathodiques . In: Comptes rendus de l'Académie des sciences . Volume 143, 1906, pp. 674-676 ( online ).
Sur l'aurore boréale: response à la Note de M. Störmer . In: Comptes rendus de l'Académie des sciences . Volume 143, 1906, pp. 587-588 ( online ).
Sur les actions chimiques de la lumière . In: Journal de Physique Théorique et Appliquée . 4th episode, Volume 6, 1907, pp. 369-379 ( doi: 10.1051 / jphystap: 019070060036900 , PDF ).
Sur les actions chimiques de la lumière (suite) . In: Journal de Physique Théorique et Appliquée . 4th episode, Volume 6, 1907, pp. 445-457 ( doi: 10.1051 / jphystap: 019070060044501 , PDF ).
Sur l'induction unipolaire et la cause probable des aurores polaires . In: Comptes rendus de l'Académie des sciences . Volume 147, 1908, pp. 740-742 ( online ).
Instrument nouveau: Radiosclérométre . In: Archives d'électricité médicale . Volume 16, 1908, pp. 236-238.
Instruments de mesure à lecture directe pour les rayons x. Substitution de la méthode électrométrique aux autres méthodes de mesure en radiologie. Scleromètre et quantimètre . In: Archives d'électricité médicale . Volume 16, 1908, pp. 692-699.
Les rayons cathodiques et l'aurore boréale . In: Journal de Physique Théorique et Appliquée . 4th episode, Volume 7, 1908, pp. 429-453 ( doi: 10.1051 / jphystap: 019080070042901 , PDF ).
Phenomènes pseudo-photographiques . In: Journal de Physique Théorique et Appliquée . 4th episode, Volume 7, 1908, pp. 506-520 ( doi: 10.1051 / jphystap: 019080070050601 , PDF ).
Sur la lumière positive et le passage de l'électricité dans les gaz . In: Journal de Physique Théorique et Appliquée . 4th episode, Volume 7, 1908, pp. 325-361 ( doi: 10.1051 / jphystap: 019080070032500 , PDF ).
Sur un voltmètre électrostatique à lecture directe pour très hautes tensions . In: Comptes rendus de l'Académie des sciences . Volume 152, 1911, pp. 1134-1136 (with Henri Abraham ; online ).
Voltmètre électrostatique à lecture directe pour très haute tension . In: Journal de Physique Théorique et Appliquée . 5th episode, volume 1, 1911, pp. 525-529 (with Henri Abraham; doi: 10.1051 / jphystap: 0191100107052500 , PDF ).

proof

literature

Historic

A. Blondel: Paul Villard . In: Revue générale de l'électricité . Volume 35, Number 13, 1934, pp. 411-414.
Émile Borel : [ Mémoire ]: Comptes rendus de l'Académie des sciences . Volume 145, Volume 198, 1934, pp. 213-215 ( online ).
Émile Picard : La vie et l'oeuvre de Paul Villard et de Georges Gouy . In: Mémoires de l'Académie des sciences de l'Institut de France . Volume 63, Gauthier-Villars, Paris 1941, pp. 1-30 ( online ).

Modern

E. Scott Barr: Anniversaries in 1960 of Interest to Physicists . In: American Journal of Physics . Volume 28, Number 5, 1960, pp. 472-474 ( doi: 10.1119 / 1.1935838 ).
Sigalia Dostrovsky: Villard, Paul . In: Complete Dictionary of Scientific Biography . Volume 14, Charles Scribner's Sons, Detroit 2008, pp. 31-32 ( online ).
Leif Gerward, André Rassat: La découverte en 1900 des rayons gamma par Paul Villard / Paul Villard's discovery of gamma rays - A centenary . In: Comptes rendus de l'Académie des sciences 4th part, Paris 2000, Volume 1, pp. 965-973 ( doi: 10.1016 / S1296-2147 (00) 01094-5 ).
Leif Gerward: Paul Villard and his Discovery of Gamma Rays . In: Physics in Perspective . Volume 1, Number 4, 1999, pp. 367-383 ( doi: 10.1007 / s000160050028 ).
Benoit Lelong: Paul Villard, J.-J. Thomson et la composition des rayons cathodiques . In: Revue d'histoire des sciences . Volume 50, Numbers 1-2, 1997, pp. 89-130 ( online ).
Benoit Lelong: Paul Villard, JJ Thomson, and the Composition of Cathode Rays . In: Jed Z. Buchwald, Andrew Warwick (Ed.): Histories of the Electron: The Birth of Microphysics . Mit Press, 2001, ISBN 0-262-02494-2 , pp. 135-168.

Individual evidence

^ Prix Wilde . In: Comptes rendus de l'Académie des sciences . Volume 139, 1904, pp. 1122-1124 ( online ).
^ Prix La Caze . In: Comptes rendus de l'Académie des sciences . Volume 145, 1907, pp. 1002-1005 ( online ).
↑ Les membres du passé dont le nom commence par V. Académie des sciences, accessed on December 4, 2017 (French).
↑ Secret Committee . In: Comptes rendus de l'Académie des sciences . Volume 147, 1908, p. 1447 ( online ).
↑ Èlectiones . In: Comptes rendus de l'Académie des sciences . Volume 147, 1908, p. 1460 ( online ).
↑ Secret Committee . In: Comptes rendus de l'Académie des sciences . Volume 147, 1908, p. 949 ( online ).
↑ Èlectiones . In: Comptes rendus de l'Académie des sciences . Volume 147, 1908, p. 960 ( online ).
↑ ^a ^b ^c Qui est-ce? Ceux dont on parle . Éditions de la vie moderne, Paris 1934.
^ E. Dendy Sloan, Carolyn Ann Koh: Clathrate Hydrates of Natural Gases . 3rd edition, CRC Press, 2008, ISBN 978-0-8493-9078-4 , p. 4.
^ Henri Becquerel: The Radio-Activity of Matter . In: Nature . Volume 63, Number 1634, February 21, 1901, pp. 396-396 ( doi: 10.1038 / 063396d0 ).
^ Ernest Rutherford: The Magnetic and Electric Deviation of the Easily Absorbed Rays from Radium . In: Philosophical Magazine . 6th episode, volume 5, number 25, 1903, p. 177 ( doi: 10.1080 / 14786440309462912 ).
^ Ernest Rutherford: Uranium Radiation and the Electrical Conduction Produced by It . In: Philosophical Magazine . 5th episode, volume 47, number 284, 1899, p. 116 ( doi: 10.1080 / 14786449908621245 ).
↑ RF Mold: The early history of X-ray diagnosis with emphasis on the contributions of physics 1895-1915 . In: Physics in Medicine and Biology . Volume 40, 1995, pp. 1747 and 1777 ( doi: 10.1088 / 0031-9155 / 40/11/001 ).

personal data
SURNAME	Villard, Paul
ALTERNATIVE NAMES	Villard, Paul Ulrich
BRIEF DESCRIPTION	French physicist and chemist, discoverer of gamma radiation
DATE OF BIRTH	September 28, 1860
PLACE OF BIRTH	Lyon
DATE OF DEATH	January 13, 1934
Place of death	Bayonne

[1] Prix Wilde . In: Comptes rendus de l'Académie des sciences . Volume 139, 1904, pp. 1122-1124 ( online ).

[2] Prix La Caze . In: Comptes rendus de l'Académie des sciences . Volume 145, 1907, pp. 1002-1005 ( online ).

[3] Les membres du passé dont le nom commence par V. Académie des sciences, accessed on December 4, 2017 (French).

[4] Secret Committee . In: Comptes rendus de l'Académie des sciences . Volume 147, 1908, p. 1447 ( online ).

[5] Èlectiones . In: Comptes rendus de l'Académie des sciences . Volume 147, 1908, p. 1460 ( online ).

[6] Secret Committee . In: Comptes rendus de l'Académie des sciences . Volume 147, 1908, p. 949 ( online ).

[7] Èlectiones . In: Comptes rendus de l'Académie des sciences . Volume 147, 1908, p. 960 ( online ).

[Qui-8] Qui est-ce? Ceux dont on parle . Éditions de la vie moderne, Paris 1934.

[9] E. Dendy Sloan, Carolyn Ann Koh: Clathrate Hydrates of Natural Gases . 3rd edition, CRC Press, 2008, ISBN 978-0-8493-9078-4 , p. 4.

[10] Henri Becquerel: The Radio-Activity of Matter . In: Nature . Volume 63, Number 1634, February 21, 1901, pp. 396-396 ( doi: 10.1038 / 063396d0 ).

[11] Ernest Rutherford: The Magnetic and Electric Deviation of the Easily Absorbed Rays from Radium . In: Philosophical Magazine . 6th episode, volume 5, number 25, 1903, p. 177 ( doi: 10.1080 / 14786440309462912 ).

[12] Ernest Rutherford: Uranium Radiation and the Electrical Conduction Produced by It . In: Philosophical Magazine . 5th episode, volume 47, number 284, 1899, p. 116 ( doi: 10.1080 / 14786449908621245 ).

[13] RF Mold: The early history of X-ray diagnosis with emphasis on the contributions of physics 1895-1915 . In: Physics in Medicine and Biology . Volume 40, 1995, pp. 1747 and 1777 ( doi: 10.1088 / 0031-9155 / 40/11/001 ).