412 



NATURE 



[May 26, 192 1 



Calendar of Scientific Pioneers. 



May 27, 1914. Sir Joseph Wilson Swan died.— A 



partner in a firm of chemical manufacturers at New- 

 castle, Swan became famous by his invention of the 

 carbon process in photography and by his pioneering 

 work on the incandescent electric lamp. His first 

 carbon filament lamp was shown at Newcastle in 

 1879. He received many honours, and in 1898-99 was 

 president of the Institution of Electrical Engineers. 



May 28, 1893. Charles Pritchard died. — Graduating 

 as a Wrangler in 1830, Pritchard from 1834 to 1862 

 was headmaster of a successful grammar school at 

 Clapham. In 1870, at the age of sixty-three, he 

 became Savilian professor of astronomy at Oxford. 

 He was a pioneer in the photographic measurement 

 of stellar parallax, invented the wedge photometer, 

 and in 1885 published his " Uranometria Nova 

 Oxoniensis. " 



May 28, 1906. Rudolf Knietsch died.— A native of 

 Silesia, Knietsch in 1884 became a director of the 

 Badische Anilin- & Soda-Fabrik at Mannheim, where 

 he played an important part in the manufacture of 

 artificial indigo and in that of sulphuric acid by the 

 contact process. 



May 29, 1829. Sir Humphry Davy died.— Already 

 famous for his discovery of nitrous oxide, in 1801 at 

 the age of twenty-three, and at a salary of looL a 

 vear, Davy became the first professor of chemistry 

 at the Royal Institution. His great discoveries of 

 sodium and potassium were made there in 1807. In 

 1815 he invented his miners' safety-lamp. Knighted 

 in 18 18, he was president of the Royal Society from 

 1820 to 1827. His death occurred at Geneva. 



May 29, 1896. Gabriel Auguste Daubree died.— 

 Trained in Paris as a mining engineer, Daubree be- 

 came professor of geology in the Mus^e d'Histoire 

 Naturelle and Director of the School of Mines. He 

 carried out an important series of experimental re- 

 searches in geology. 



May 29, 1897. Julius von Sachs died.— Professor 

 of botany at Wiirzburg from 1868, Sachs contributed 

 to all branches of botany, and especially to plant 

 physiology. His well-known text-book was published 

 in^865 and his "History of Botany " ten years later. 



May 29, 1898. Sir Lyon Playfair, first Baron Playfair 

 of St. Andrews, died. — Chemist to the Geological Survey 

 and the School of Mines, Playfair from 1856 to 1869 

 was professor of chemistry at Edinburgh. He entered 

 Parliament, held public office, and did much to further 

 the study and application of science. He was knighted 

 in 1883 and raised to the peerage in 1892. 



May 31, 1867. Theophile Jules Pelouze died.— Joint 

 author with Fr^my of an important treatise on 

 chemistry, Pelouze made researches in organic chemis- 

 try, lectured at the College de France and the Ecole 

 Polvtechnique, and became President of the Mint. 



June 1, 1812. Richard Kirwan died.— Of indepen- 

 dent means and possessing many accomplishments, 

 Kirwan was the correspondent of many scientific men, 

 and in 1799 became president of the Royal Irish 

 Academy. His " Elements of Mineralogy " _ (1784) 

 was the first svstematic treatise on that subject in 

 English, and his essay on Phlogiston (1787) was 

 one of the last attempts to defend Stahl's theories. 

 Kirwan acknowledged his conversion to Lavoisier's 

 views four vears later. 



June 1, 1903. J. Peter Lesley died.— Born at Phila- 

 delphia and educated for the ministry, Lesley as- 

 sisted in geological work and ultimately became pro- 

 fessor of geologv in the University of Pennsylvania, 

 and from 1874 to 1893 directed the Geological Survey 

 of that State. 



E. C. S. 



NO. 2691, VOL. 107] 



Societies and Academies. 



London. 

 Royal Society, May 12. — Prof. C. S, Sherrington, 

 president, in the chair. — G. W. Walker : The problem 

 of finite focal depth revealed by seismometers. Ob- 

 servations of the emergence angle of P waves at 

 Pulkovo suggest that the depth of focus is of order 

 one-fifth of the earth's radius. Important modifica- 

 tions are necessary in the interpretation of seismo- 

 grams and in the attempt to determine how speed of 

 propagation depends on depth. A test of the accuracy 

 of the Pulkovo values can be made by a scrutiny of 

 seismograms for distances > 11,000 kilometres. 

 Corresponding measures of the angle of emergence of 

 S waves by means of three component seismometers 

 are required. — E. A. GriflBths : A liquid oxygen 

 vaporiser. The liquid oxygen is contained in a metal 

 vacuum vessel. The emission of gas is governed by 

 bringing a flexible portion of the outer wall into 

 contact with the inner ; the degree of contact deter- 

 mines the rate of transmission of heat. Any desired 

 rate of gas evolution can be obtained up to 10 litres 

 per minute, and the delivery remains constant. — 

 Dorothy M. Palmer and W. ,G! Palmer: Some experi- 

 ments on the catalytic reduction of ethylene to ethane. 

 The hydrogenation of ethylene in the presence of 

 nickel has been quantitatively examined. The mixture 

 of ethylene and hydrogen was brought into contact 

 with nickel in motion in an electrically heated tube. 

 The rate of hydrogenation was measured by the rate 

 at which a mixture of ethylene and hydrogen in equal 

 proportions by volume had to be passed into the tube 

 to maintain the gas therein at constant pressure. The 

 effects of varying conditions were studied. The curves 

 showing rate of reaction against time display "induc- 

 tion " periods during which no hydrogenation took 

 place, varying in duration from a few seconds to many 

 hours, according to the conditions of the experiment. 

 Then the rate of reaction increases rapidly to a sharp 

 maximum, and decreases less rapidly to a lower value, 

 which decreases slowlv. A theorv is advanced to 

 account for these efjects.— W. 'G. ' Palmer : The 

 catalytic activity of copper. Part ii. The activity of 

 copper when prepared from oxide by reduction with 

 carbon monoxide and methyl alcohol vapour is dis- 

 cussed. Constant-boiling mixtures of several alcohols 

 with water were used as reactants. Water acts as a 

 positive, and hydrogen as a negative, auxiliary catalyst 

 when adsorbed on the copper. The activity-tempera- 

 ture curves for a catalyst prepared bv carbon monoxide 

 obey a simple exponential law. Between 270° and 

 280° C. the activity curves generally undergo a sudden 

 change of direction corresponding to a great reduction 

 of the temperature coefficient. This is attributed to 

 the diminution in the thickness of the adsorbed alcohol 

 layer to at most two molecular diameters. The 

 activitv of the catalyst does not increase continuously, 

 as the temperature' of its preparation from oxide is 

 lowered.— Prof. C. F. Jenkin and D. N. Shorthose : 

 The total heat of liquid carbonic acid. The total heat 

 of carbonic acid between temperatures of -I- 10° C. 

 and +100° C. and between pressures of 900 lb. and 

 1800 lb. per square inch was measured. The values 

 hitherto accepted, based on the assumption that the 

 specific heat at constant volume does not change over 

 this range, require sligtit correction. — Dr. A. O. 

 Rankine : The viscosity and molecular dimensions of 

 gaseous cyanogen. The viscosity of gaseous cyanogen 

 has been measured at 15° C. and 100° C, the values 

 obtained being, respectively, 0-980 x to-'' and 

 1-264x10-'' C.G.S. units. Assuming Sutherland's 

 law of temperature variation, the data have been used 



