December 15, 1921] 



NATURE 



5»5 



Calendar of Scientific Pioneers, 



December 15, 1890. James Croll died. — Known for 

 his writings on physical geology, such as his " Climate 

 and Time," 1875, Croll was successively a joiner, an 

 insurance agent, an assistant at the Andersonian 

 College, Glasgow, and keeper of maps in the Geo- 

 logical Survey of Scotland. 



December 16, 1798. Thomas Pennant died. — The 

 authcM- of "British Zoology" (1766), "British Quad- 

 rupeds" (1781), and "Arctic Zoology" (1785), Pen- 

 nant, who was the friend of Linnaeus, Buffon, and 

 Voltaire, was one of the leading British zoologists 

 of his time. 



December 16, 1809. Antoine Francois Comte de 

 Fourcroy died. — A teacher and organiser with a talent 

 for oratory-, Fourcroy did much to popularise the 

 doctrines of Lavoisier among his countrymen, and 

 with Lavoisier, Guy ton de Morveau, and Berthollet 

 published the '" Methode de Nomenclature Chimique," 

 1787. 



December 17, 1907. Sir William Thomson, Baron 

 Kelvin of Largs, died. — The son of James Thomson, 

 professor of mathematics at Belfast and Glasgow, 

 Kelvin was born in Belfast, June 26, 1824. .\fter 

 studying at Glasgow and Cambridge, and at Paris, 

 where he came under the influence of Liouville and 

 Regnault, in 1846 he was appointed to the chair of 

 natural philosophy at Glasgow, a post he held with 

 great distinction until 1899. Kelvin was pre- 

 eminent in the realm not only of theory, but also of 

 practical application. In pure science he did im- 

 portant work in thermodynamics, magnetism and 

 electricity, hydrodynamics, and the theory of the 

 aether. Besides co-operating 'with Tait in their 

 famous treatise on natural philosophv, he wrote 

 several hundred papers. As an inventor of delicate 

 scientific instruments he was unrivalled. To him are 

 due electrical measuring instruments of all kinds, the 

 mirror galvanometer, siphon recorder, standard com- 

 pass, and sounding and tide-predicting machines. He 

 was president of the Royal Society from 1890 to 1894 

 and in 1892 was raised to the peerage. He is buried 

 beside Newton in Westminster Abbey. 



December 18, 1829. Jean Baptiste Pierre Antoine 

 Wonet de Lamarck died. — Lamarck is regarded as the 

 founder of invertebrate zoology. His " Philosophie 

 Zoologique " appeared in 1809, his " Histoire des Ani- 

 maux Sans Vertebres " in 1815-22. He put forward 

 views on evolution and enunciated the doctrine of the 

 transmission of acquired characters. 



December 18, 1892. Sir Richard Owen died.— The 

 first Hunterian professor of comparative anatomy, and 

 later superintendent of the natural history collection 

 of the British Museum, Owen was one of the greatest 

 contemporaries of Darwin and Huxlev. His ana- 

 tomical and palaeontological researches refer to 

 every class of animal from protozoa to man. 



December 19, 1887. Balfour Stewart died.— A 

 meteorologist and magnetician, Balfour Stewart made 

 important researches on radiant heat and spectrum 

 analysis. He was director of Kew Observatory and 

 then professor of natural philosophy in Owen's 

 College, Manchester. 



December 20, 1913. Julius Scheiner died. — An 

 assistant to Schonfeld at Bonn, Scheiner. in 188;, 

 joined Vogel at Potsdam, where he carried out a 

 great variety of investigations in astrophysics. 



December 21, 1912. Paul A. Gordan died.— A con- 

 tributor to the study of the calculus of invariants and 

 co-invariants, Gordan for many years held the chair 

 of mathematics at Erlangen. E. C. S. 



NO. 2720, VOL. 108] 



Societies and Academies. 



London. 



Association of Economic Biologists, November 18. — Sir 

 David Prain, president, in the chair. — E. J. Butler: 

 •Meteorological conditions and disease. The meteoro- 

 logical conditions known to influence diseases of 

 plants are chiefly temperature, humidity, and radia- 

 tion. The influences are most marked in Continental 

 climates, as the amplitude and duration of the varia- 

 tions are greater than in countries like England. 

 They act both on the host-plant and the parasite, but 

 to judge of their full effect it is often necessary to 

 test them on the host-parasite complex, since the in- 

 fluence on either host or parasite alone may not give 

 a true picture of what occurs in the interaction of the 

 two which constitutes disease. Small variations, 

 amounting to not more than 5 per cent, in relative 

 humidity or 10° C. in temperature, if prolonged, may 

 be sufficient to determine whether a parasite will 

 cause nearly 100 per cent, infection or none at all. 

 In India the author has found that several diseases 

 are so sharply restricted in their distribution by these 

 factors that it is possible to demarcate the areas in 

 which thev cannot occur, and also those in which they 

 occur only in special conditions arising in exceptional 

 years, from those in which they normally occur every 

 year. The same is true in the United States. Exact 

 evaluation of the factors concerned is possible by 

 rigidly controlled experimental methods, but not by 

 field observation alone. 



Faraday Society, November 28.— Prof. A. W. Porter, 

 president, in the chair. — J. N. Greenwood : The effect 

 of cold work on commercial cadmium. Chill-cast 

 commercial cadmium undergoes spontaneous re- 

 crjstallisation at the ordinary temperature without the 

 application of cold work. Deformation hastens this 

 change. Deformation at 20° C. softens chill-cast 

 cadmium, and during the subsequent annealing 

 further softening occurs. It is concluded that two 

 forms of cadmium are being dealt with, and that the 

 quick cooling has suppressed the transformation. 

 Recr}-stalIisation and hardness experiments indicate 

 the position of the allotropic change to be in the neigh- 

 bourhood of 60° C. This accords with Cohen's trans- 

 formation Cda — >-Cd|3. Spontaneous recrystallisation 

 of cast unworked cadmium takes place suddenly after 

 about twelve days, and the hardness falls continuously 

 during the same period. This would appear to indi- 

 cate a gradual change from Cd/j to Cda- A third 

 modification has sometimes been obtained, but its 

 range of existence has not been determined. — J. N. 

 Pring and E. O. Ransome : Reaction between cathodic 

 hydrogen and nitrogen at high pressures. The elec- 

 trode potentials with metals during electrolysis indi- 

 cate that an accumulation of gas at verv high pres- 

 sures occurs at, or immediately within, the surface of 

 the electrode. When cathodic hydrogen is liberated 

 in contact with nitrogen, particularly at high pres- 

 sures, the conditions appear to be favourable to the 

 synthesis of ammonia. With nitrogen at atmospheric 

 pressure the mean percentage current yield of am- 

 monia by direct union of the elements amounted to 

 004 per cent. At pressures of from 60 to 104 atmo- 

 spheres it was 009 per cent. Experiments at from 300 

 to 500 atmospheres showed a loss of aciditv, but no 

 ammonia was indicated. The small quantity of 

 ammonia formed at lower pressures is ascribed to a 

 thermal action of the heated conductors. The results 

 indicate that no reaction takes place between nitrogen 

 and hydrogen liberated at the cathode. — F. H 



