September 15, 19.21] 



NATURE 



lO' 



Calendar of Scientific Pioneers. 



September 15, 1883. Joseph Antoine Ferdinand 

 Plateau died. — A valuable contributor to physiological 

 optics and molecular physics, Plateau was trained 

 under Quetelet, and from 1835 to 1871 held the chair 

 of ph3'sics at Ghent. From 1843 he was totally blind. 

 September 16, 1736. Gabriel Daniel Fahrenheit died. 

 — German by birth, Fahrenheit became an instrument- 

 maker at Amsterdam. His improvements in thermo- 

 meters consisted in the use of mercury, the introduc- 

 tion of the Fahrenheit scale, and the substitution of 

 elongated bulbs for round ones. 



September 16, 1869. Thomas Graham died. — Distin- 

 guished mainly for his investigations in physical 

 chemistry, Graham from 1837 to 1855 held the chair 

 of chemistry in University College, London, and was 

 the first president of the Chemical Society. He dis- 

 covered the law of the diffusion of gases, and to him 

 we owe the terms "'crystalloid," "colloid," "dialysis," 

 and "atmolysis." 



September 17, 1783. Leonhard Euler died.— Though 

 born in Basle and trained in mathematics by Jean 

 Bernoulli, Euler passed most of his life at St. Peters- 

 burg and Berlin. One of the greatest mathematicians 

 and physicists of the eighteenth century, his works 

 have been described as a perfect storehouse of inves- 

 tigations on every branch of algebraical and 

 mechanical science. 



September 17, 1836. Antoine Laurent de Jussieu 

 died. — Carefully trained in medicine and botanv by 

 his uncle Bernard, de Jussieu in 1789 published his 

 ■"Genera Plantarum," a volume which formed the 

 basis of modern botanical classification. The Mus^e 

 d'Histoire Naturelle was reorganised bv him in 1793. 

 September 17, 1877. William Henry Fox Talbot 

 died. — A graduate of Trinity College, Cambridge, 

 Talbot from 1822 contributed scientific papers to the 

 Royal Society, but is most famous for his pioneering 

 work in photography. He was the first to produce 

 positives from negatives, and invented the " Calo- 

 type " process. His apparatus has recently been 

 given to the Royal Photographic Society, and it is 

 proposed to set up a memorial to him at Lavcock 

 Abbey, Wiltshire. 



September 18, 1896. Armand Hippolyte Louis Fizeau 

 died. — An early worker on photography, Fizeau also 

 made many investigations on light and heat, and in 

 1849 determined the velocity of light by measuring the 

 time it took to travel between Suresnes and Mont- 

 martre, a distance of 28,334 ft. He was awarded the 

 Rumford medal in 1866, and from 1878 was a member 

 of the Bureau des Longitudes. 



September 19, 1710. Ole Rbmer died.— The dis- 

 coverer of the finite velocity of light, Romer was born 

 in Jutland, became a pupil of Erasmus Bartholin, 

 worked with Picard, and spent the years 1672 to 1681 

 in Paris. He made known his great discoveries to 

 the Paris Academy of Sciences in 1675. Returning to 

 Copenhagen as a professor of mathematics and 

 astronomy, he there set up the first modern transit 

 instrument. Practically all his manuscripts and in- 

 struments were destroved' bv fire in 1728. 



September 19, 1761. Pieter van Musschenbroek 

 died. — A well-known Dutch experimental philosopher, 

 IMusschenbroek held chairs at Duisburg, Utrecht, and 

 Leyden. and added greatly to the knowledge of the 

 phvsical. properties of bodies. 



Septenitber 21, 1576. Girolamo Cardano died.— One 

 of the most interesting figures connected with the 

 revival of science in Europe, Cardano was a pl\vsician, 

 astrologer, and mathematician, and held positions at 

 Pavia, Milan, and Bo'ogna. His chief mathematical 

 work is his "Ars Magna," published at Nuremberg 

 in 1545. E. C. S. 



NO. 2707, VOL. 108] 



Societies and Academies. 



Paris. 

 Academy of Sciences, August 29. — M. L^on Guignard 

 in the chair. — M. de Seguier : The primitive quaternary 

 group of collineations of order 25920 and the Hessian 

 group. — J. Chazy : Curves defined by differential 

 equations of the second order. — S. Carrus : Triple 

 orthogonal systems. — G. Bertrand : Newton's law and 

 Einstein's formula for the perihelion of the planets. — 

 L. Gentil : The phenomenon of mounds {rideaux) 

 and solifluction. These mounds are frequent in the 

 region between the Somme and the Bresle, and have 

 been attributed by the author to superficial slipping of 

 siliceous clay softened by rain. The frane of R. 

 Almagia and the solifluction of J. G. Anderson are 

 considered as particular cases of a phenomenon which 

 in France leads to the formation of rideaux. — E. 

 Zaepffel : Mobile starch and geotropism. It was proved 

 experimentally that in an apparatus containing the 

 substances present in the plant-cell (water, amylase, 

 sugars, and starch) the concentration of the sugar 

 became unequal, with a maximum in the immediate 

 neighbourhood of the starch grains. In the plant-cell, 

 with the starch grains resting on the semi-permeable 

 protoplasmic membrane, this change of concentration 

 in sugar causes modifications in the osmotic relations 

 between the different cells which explain the move- 

 ments of the tissues. — J. Pettier : Observations on the 

 chromatic masses of the cytoplasm of the oosphere in 

 Mnium undidatum and M. punctatum. — W. Kos- 

 kowski and E. Maigre : The peripheral origin of the 

 hyperthermia produced by methylene-blue. — W. 

 Kopaczewski : Surface tension and the suppression of 

 shock by sodium hyposulphite. Details of experiments 

 proving that sodium hyposulphite reduces the increase 

 of surface tension caused by the addition of distilled 

 water to serum. — G. Bourguignon : Modification of 

 the chrdnaxy of the motor nerves and muscles by 

 reflex repercussion. 



Sydney. 

 Linnean Society of New South Wales, Julv 27. — Mr. 

 G. A. Waterhouse, president, in the chair. — Dr. R. J. 

 Tillyard : Mesozoic insects of Queensland. No. 8. 

 Hemiptera Homoptera (continued). The genus Meso- 

 gereon, with a discussion of its relationship with the 

 Jurassic Palaeontinidae. Additional material compris- 

 ing three forewings and fragments of two hindwings 

 has been found. In addition to the single species of 

 Mesogereon already known, four species are described 

 as new. It is concluded that Handlirsch was wrong 

 in considering the Palaeontinidae to belong to the 

 L^pidoptera, and that the general build of the insects, 

 the venational scheme, the armature of the wing, and 

 the structures of the margin show that the Palaeon- 

 tinidae are closely related to the genus Mesogereon, 

 and that both have a less close connection with the 

 recent Cicadidae. — G. D. Osborne and W. R. Browne : 

 Note on a glacially striated pavement in the Kut- 

 tung series of theMaitland District. The striated 

 pavement described provides evidence of the presence 

 of land-ice which previously had been indicated solely 

 bv the presence of glacial conglomerates and varves. 

 The direction of the striae is N. 13° W.-S. 13° E., the 

 ice having moved in a northerly direction. The floor 

 over which the ice moved is composed of a biotite- 

 dacite, and is overlain by well-laminated varve-rock.^ 

 T. Steel : The occurrence of calcium oxalate in the 

 Gidgee wattle. Acacia Cambagei. The bark of this 

 tree contains 188 per cent, (dry) of calcium oxalate, 

 the highest amount recorded for any plant. The 

 timber contained an average of ^-77 per cent. The 

 barks of a number of other species of Acacia were 



