August 25, 192 1] 



NATURE 



f^3i 



Calendar of Scientific Pioneers. 



August 25, 1S14. Sir Beniamin Thompson, Count 

 von Rumford, died. — The founder of the Royal Institu- 

 tion and of the Rumford medals of the Royal Society 

 and the American Academy of Sciences, Rumford 

 devoted much time to science and its application to 

 practical purposes, and was one of the first to show 

 that heat was "a mode of motion." 



August 25, 1822. Sir William Herschel died.— Pre- 

 eminent among the astronomers of his day, Herschel 

 extended immensely the bounds of sidereal astronomy. 

 In 1781 at Bath he discovered Uranus. His great 

 telescope at Slough was one of the wonders of the 

 scientific world. He made extensive observations of 

 the moon and planets, first established the motion of 

 the sun in space, discovered many nebulae, and 

 showed that the components of double stars were 

 moving round their common centre of gravity. 



August 25, 1867. Michael Faraday died. — Unrivalled 

 as an experimental investigator and as a lecturer, 

 Faraday was the assistant to Davy and the successor 

 of Brande at the Royal Institution, and in 1833 be- 

 came the first Fullerian professor. Though his 

 investigations covered a wide range, the great work 

 of his life was his series of " Experimental Researches 

 in Electricity," to which all later students of elec- 

 tricity owe a vast debt. 



August 25, 1908. Antoine Henri Becquerel died. — 

 The son and grandson of distinguished physicists, 

 Becquerel made himself famous by his memorable 

 discovery in i8q6 of radio-activity, for which in 1903, 

 with the Curies, he was awarded the Nobel prize. 



August 26, 1723. Anton van Leeuwenhoek died. — A 

 pioneer worker with the microscope, Leeuwenhoek 

 made important discoveries in support of the circula- 

 tion of the blood, blood-corpuscles, spermatozoa, and 

 other subjects, and contributed 112 papers to the 

 Philosophical Transactions. 



August 28, 1839. William Smith died.— The " father 

 of English geology," Smith published his epoch- 

 making geological map of England in 1815. 



August 28, 1863. Eilhard Mitscherlich died.— The 

 discoverer in 1819 of isomorphism and of dimorphism, 

 Mitscherlich spent two years with Berzelius at Stock- 

 holm, and then in 182 1 succeeded Klaproth as pro- 

 fessor of chemistry in the University of Berlin. 



August 29, 1816. Johann Hieronymus Schroter 

 died. — For more than thirty years Schroter studied 

 the topography of the planets. He has been called 

 the Herschel of Germany. His observatory at Lilien- 

 thal, in which Bessel worked, was pillaged during 

 the War of 18 13. 



August 29, 1868. Christian Friedrich Schonbein 

 died. — Schonbein for many years held the chair of 

 phvsics and chemistry in the University of Basle. In 

 183Q he discovered ozone, and in 1846 made known 

 his invention of guncotton. 



August 30, 1844. Francis Baily died. — After amass- 

 ing a fortune on the Stock Exchange, Baily devoted 

 himself to astronomy. He was a founder of the 

 Roval Astronomical Society, reformed the Nautical 

 Almanac, edited a star catalogue, and during the 

 years 1838-42 repeated the Cavendish experiment for 

 determining the density of the earth. 



August 30, 1S88. - Johann Peter Griess died. — In 

 i8q8 Griess discovered the first diazo-compound, and 

 three vears later the first azo-colours, which have pro- 

 duced a revolution in the art of dyeing. 



August 31, 1900. Sir John Bennet Lawes, Bart., 

 died. — A great pioneer in the application of science 

 to agriculture, Lawes was the founder of the Rotham- 

 sted Experimental Station, where for fifty-seven years 

 Gilbert was his collaborator. E. C. S. 



NO. 2704, VOL. 107] 



Societies and Academies. 



Paris. 



Academy of Sciences, August 8. — M. L^on Guignard 

 in the chair. — A. DemouHn : Surfaces generated by 

 circles. — P. Fafou : The domains of existence of cer- 

 tain uniform functions. — M. Potron : Ihe representation 

 of the group of 27 right lines in a group of quaternary 

 coHineations. — K. Ogura : The movement of a particle 

 in the field of a charged nucleus. — L. Dunoyer : A new 

 spectrum of caesium. The metal was contained in a 

 quartz tube, with plane parallel quartz ends, and 

 surrounded with a wire spiral in which high-frequency 

 currents were produced. The whole could be heated 

 uniformly in an electric furnace. The vapour com- 

 menced to be luminous at 100° C, reaching a maxi- 

 mum luminosity at 250° C. The spectrum consists of 

 fine lines with no trace of a continuous background. 

 Measurements of more than 300 wave-lengths for the 

 low-temperature soectrum aro given. — S. Procopiu : 

 Magnetic double refraction of mixed liquids and crystal- 

 line structure. — E. Moles and F. Gonsalez : A new re- 

 vision of the density of oxygen gas. Special atten- 

 tion has been paid to varying the method of pre- 

 paring the gas, and density measurements are given 

 for oxygen prepared from potassium permanganate, 

 potassium chlorate, mercuric oxide, and silver oxide, 

 and by the electrolysis of water. The general mean is 

 1-42889. difTering only by one part in 10.000 from the 

 figure at present accepfed. 1-42905. The densities, 

 classified according to the method of preparation, 

 showed no sign of any systematic error. — A. Mailhe : 

 The preparation of a petrol from a fatty oil. Linseed 

 oil was passed over a catalyst composed of copper, 

 magnesia, and kaolin heated to 55o°-6;o° C. The 

 volatile product was further treated with hydrogen 

 and reduced nickel at 180° C. After refining, petrol 

 and kerosene fractions were obtained. The petrol con- 

 tained benzene and naphthene derivatives. — G. Vavon : 

 The velocity of the reaction in the hvdrogenation by 

 platinum black. The rapidity with which the hvdro- 

 genated body formed leaves the surface of the catalyst 

 is a sroverning factor in the velocity of the reaction. — 

 V. Yeramian : The synthesis and dehydration of 

 ethvlpropvlphenvlcarbinol. EthvlproDvlphenylcarbinol 

 was prepared by the Grignard reaction from propvl- 

 phenvlketone and ethvlmagnesium bromide. This can 

 be distilled without decomposition under low pressure 

 (25 mm.), but is readily dehydrated, producing an un- 

 saturated hydrocarbon, C,„H,p, probably 3-phenyl-3- 

 hexene. — V. Lnbimenko : The state of chlorophyll in the 

 plasts. A study of the causes of the inactivity, from 

 the point of view of photosvnthetical reactions, of 

 pure chlorophyll prepared by chemical methods. It 

 was found that treatment of the living tissue bv vari- 

 ous solvents, besides coagulating the proteid sub- 

 stances in the plasts, produces sensible changes in the 

 optical properties of the green pigment. The chloro- 

 phyll of the leaves of Asiytdistra elatior can be com- 

 pletpty removed by extraction with water. The ab- 

 sorption spectrum of the material thus extracted is 

 absolutely identical with that of the living leaf. The 

 chlorophyll is intimately related to the proteid sub- 

 stances of the plasts, and this is probably of a chemical 

 nature. — M. Romieu : The crystalline inclusions of the 

 eleocvtes of Nereis and their relations with the eosino- 

 phil £?ranulation. — C. Levaditi : Embryonic leaflets in 

 relation to oatho£?enic micro-organisms. Meso- 

 dermic infections are caused bv bacteria, fun^i, 

 spirillae, and protozoa, whilst infections of the 

 ectoderm are produced bv virus, usually invisible and 

 capable of passing filters. 



