476 



NATURE 



[June 9, 192 1 



Calendar of Scientific Pioneers. 



June 9, 1875. Gerard Paul Deshayes died. — A 



founder of the Geological Societ\- of France, Deshayes 

 was distinguished for his study of the fossil mollusca 

 of the Paris basin. He assisted Lyell in the classifica- 

 tion of the Tertiary system into Eocene, Miocene, and 

 Pliocene. 



June 10, 1836. Andre Marie Ampere died. — A 

 teacher first at Bourg and Lyons, Ampere in 1805 

 "became a professor at the Ecole Polytechnique, and 

 in 1824 was appointed to the chair of experimental 

 physics in the College de France. Like Oersted, 

 Faraday, and Henry, he was a pioneer in the science 

 of electrodynamics, which he developed with 

 mathematical skill. His " Observations Electro- 

 •dynamiques " appeared in 1822 and his "Th^orie des 

 Ph^nom^nes Electro-dynamiques " in 1830. 



June 10, 1858. Robert Brown died.— Beginning life 

 as an assistant surgeon in a Scottish regiment, through 

 Banks Brown in 1801 went to Australia with Flinders 

 in the Investigator, and four vears later returned with 

 a collection of 4000 plants. He was afterwards placed 

 in charge of Banks's collections and became botanical 

 keeper at the British Museum. The foremost botanist 

 •of his day, his works embrace not only systematic 

 botany, but also plant anatomy and physiology. Hum- 

 boldt called him "facile princeps botanicorum." 



June 10, 1903. Luigi Cremona died. — Distinguished 

 for his work in synthetic geometry, Cremona for 

 thirty years was professor of higher mathematics in 

 the University of Rome. He reorganised the mathe- 

 matical instruction in Italy, and for a time was 

 Minister of Education. 



June 11, 1875. Joseph Winlock died. — For some 

 years superintendent of the American "Nautical Al- 

 manac," Winlock in 1865 succeeded G. P. Bond as 

 professor of astronomy and director of the observatory 

 at Harvard. 



June 11, 1897. Karl Remegius Fresenius died. — A 

 student at Bonn and then assistant to Liebig, 

 Fresenius from 1845 onwards was professor of 

 chemistry and technology at the Agricultural Institute 

 at Wiesbaden. He made manv analytical researches, 

 wrote standard text-books, and in 1862 founded the 

 Zeitschrift fiir analytische Cheniie. 



June 12, 1885. Henry Charles Fleeming Jenkin 

 died.— The assistant of Lord Kelvin in his important 

 experiments on the resistance and insulation and the 

 making of electric cables, Jenkin afterwards occupied 

 the chairs of engineering in University College, London 

 (186;), and in Edinburgh University (1868). 



June 13, 1844. Thomas Charles Hope died. — Hope 

 in i7qq succeeded Black as professor of chemistry in 

 Edinburgh University. Unrivalled as a popular 

 teacher, more than 16,000 students attended his lec- 

 tures. To him we owe the demonstration that water 

 attains its maximum density at 4° C. 



June 14, 1746. Colin Maclaurin died. — Born in 1698, 

 Maclaurin at the age of nineteen became professor of 

 mathematics at Aberdeen. In 1725 he was appointed 

 to the similar chair at Edinburgh. After Newton's 

 death he was recognised as the foremost British 

 mathematician. He died at York, his death being 

 due to his exertions during the Rebellion of '41;. 



June 14, 1S75. Heinrich Louis D'Arrest died. — Of 

 Huguenot descent, D'Arrest was born and educated 

 at Berlin. He assisted Encke, held the chair of mathe- 

 matics and astronomy at Leipzig, and In 1857 became 

 director of Copenhagen Observatory. 



June 14, 1903. Karl Gegenbaur died. — Famous for 

 his work In comparative anatomy, Gegenbaur held the 

 chairs of anatomy at Jena and Heidelberg. His " Ele- 

 ments of Comparative Anatomy " appeared In 1874. 



E. C. S. 

 NO. 2693, VOL. 107] 



Societies and Academies. 



London. 



Royal Society, June 2.— Prof. C. S. Sherrington, 

 president, in the chair.— Bakerian lecture by Dr. 

 T. M. Lowry and Dr. C. P. Austin : Optical rotatory 

 dispersion. Although no case is known in which 

 Blot's law of inverse squares, a = k/\-, is accurately 

 true, the rotatory dispersion in a very large number 

 of organic compounds can be expressed by the simple 

 dispersion formula, o = fe/(A'-A„"), which differs from 

 Blot's formula only in the introduction of a "disper- 

 sion constant " A„^ This formula is a special case of 

 the general formula a = 2fe„/(A=-A„=) introduced by 

 Drude as an approximation based upon the electronic 

 theory of radiation and absorption of light. Sub- 

 stances which require more than one term of this 

 equation are said to show complex rotatory dispersion. 

 Tartaric acid and its esters give dispersion curves 

 which frequently show an inflexion, a maximum, and 

 a change of sign; they are described as cases of 

 anomalous rotatory dispersion. These can be repre- 

 sented by two terms of Drude's equation, while the 

 rotatory dispersion in quartz was represented by a 

 similar equation, in which the dispersion-constant of 

 the negative term was negligible. In order to express 

 recent measurements it is necessary to assume finite 

 values for both dispersion-constants and to Introduce 

 a term to express the influence of the infra-red absorp- 

 tions ; this can be taken as a constant. The anomalous 

 dispersion of tartaric acid was attributed by Arndtsen 

 in i8s8 to the presence of two modifications of the 

 acid differing in the sign of their rotations and in the 

 magnitude of their dispersions. This view has been 

 confirmed (i) by the proof that the complex rotator>' 

 dispersion of the acid and its derivatives can be ex- 

 pressed as the sum of two simple dispersions, and 

 (2) bv the discovery of certain "fixed " derivatives of 

 tartaric acid which exhibit simple rotatory dispersion. 

 -Attention Is directed to some analogies between tar- 

 taric acid and nitrocamphor, which give two isomeric 

 compounds in solution. 



Zoological Society, May 24.— Prof. E. W. MacBride 

 vice-president, in the chair.— Dr. C. W. Andrews :' 

 The skull of Dinotherium giganteum in the British 

 Museum.— Dr. C. F. Sonntag : (i) The comparative 

 anatomy of the tongues of the Mammalia, Families 3 

 and 4, Cebidae and Hapalidas. (2) Some points in the 

 anatomy of the tongues of the Lemuroidea.— Prof. R. 

 Broom : Some new genera and species of anomodont 

 reptiles from the Karroo beds of South Africa.— R. J. 

 Pocock : The external characters of some species of 

 Lutnnae (otters). 



Geological Society, Mav 2^;.— Mr. R. D. Oldham 

 president, in the chair.- G. "W. Lamplugh : The jund 

 don of Gault and Lower Greensand near Leighton 

 Buzzard (Bedfordshire). The paper, a continuation 

 of one by the author and the late J. F. Walker pub- 

 lished in 1903, describes about twenty sections ex- 

 hibiting the base of the Gault in excavations around 

 Leighton Buzzard. The variable "Basement Beds" 

 of the Gault are "condensed" deposits, falling mainly 

 within the "zone of Ammonites mammillatus " as 

 recognised in northern France. The evidence bears 

 out Jukes-Browne's suggestion of the occurrence of 

 a current-swept strait in this quarter during late 

 Lower Cretaceous times. During the accumulation of 

 the "Basement Beds " a shoal in this strait north of 

 Leighton formed a reef, while the deeper water to the 

 southward gathered a stratum of gritty glauconitic 

 loam and clay with fosslliferous phosphatic nodules. 

 The transitional stages are visible in the sections. 

 The dark clays above the " Basement Beds " belong 

 to^ the Lower Gault, here reduced to about half its 

 thickness at Folkestone. They rest sharply on the 



