128 



NATURE 



[June 9, 1898 



From what has preceded, it may be concluded that the 

 atmosphere contains a hitherto undiscovered gas with a 

 characteristic spectrum, heavier than argon, and less 

 volatile than nitrogen, oxygen, and argon ; the ratio of 

 its specific heats would lead to the inference that it is 

 monatomic, and therefore an element. If this conclusion 

 turns out to be well substantiated, we propose to call it 

 "krypton," or "concealed." Its symbol would then be 

 Kr. 



It is, of course, impossible to state positively what 

 position in the periodic table this new constituent of our 

 atmosphere will occupy. The number 22-51 must be 

 taken as a minimum density. If we may hazard a con- 

 jecture, it is that krypton will turn out to have the density 

 40, with a corresponding atomic weight 80, and will be 

 found to belong to the helium series, as is, indeed rendered 

 probable by its withstanding the action of red-hot mag- 

 nesium and calcium on the one hand, and on the other of 

 oxygen in presence of caustic soda, under the influence 

 of electric sparks. We shall procure a larger supply of 

 the gas, and endeavour to separate it more completely 

 from argon by fractional distillation. 



It may be remarked in passing that Messrs. Kayser 

 and Friedlander, who supposed that they had observed 

 D3 in the argon of the atmosphere, have probably been 

 misled by the close proximity of the brilliant yellow line 

 of krypton to the helium line. 



On the assumption of the truth of Dr. Johnstone 

 Stoney's hypothesis that gases of a higher density than 

 ammonia will be found in our atmosphere, it is by no 

 means improbable that a gas lighter than nitrogen will 

 also be found in air. We have already spent several 

 months in preparation for a search for it, and will 

 be able to state ere long whether the supposition is well 

 founded. 



LYON PLAYFAIR. 



TT is now fifty-three years since I first met Playfair. 

 ■'■ He was President of the Chemical Section of the 

 British Association in 1855 at Glasgow. Frankland and 

 I were the Secretaries. Liebig attended the meeting, 

 and stayed with his friend Walter Crum, and it was 

 appropriate that Playfair, who was one of Liebig's most 

 promising English pupils, should preside over a meeting 

 of chemists at which his German master was present. 

 Playfair then was in the height of his activity. His 

 addresses in 1855, and again thirty years later, when he 

 was President of the Association, although not containing 

 much of striking originality, were clear, luminous ex- 

 positions, as indeed were his speeches in the House of 

 Commons, and latterly in the House of Lords. 



In the year 1834, when he was fifteen years of age, he 

 began to study chemistry under Graham, who was then 

 professor at the Andersonian at Glasgow. After a short 

 visit to his parents in India, where his father was Chief 

 Inspector-General of Hospitals in Bengal, he followed 

 Graham to London, and in 1838 went to Giessen to study 

 under Liebig, then the rising star in the chemical firma- 

 ment. There he became not only Liebig's pupil, but his 

 friend ; he worked at organic chemistry, publishing in 

 1 841 his first paper on a new fatty acid contained in 

 the butter of nutmegs, and in the following year he pub- 

 lished an abstract of Liebig's report on organic chemistry 

 as applied to chemistry and pathology. On his return 

 to England, through Liebig's influence with James 

 Thomson, a man who even in those early days saw the 

 value of science as applied to industry, Playfair was 

 appointed as chemist to the well-known calico print- 

 works at Clitheroe. After a few years he exchanged 

 this position for a more suitable one in the Royal In- 

 stitution, Manchester, where he found more congenial 

 society in the friendship of Dalton and Joule. It was 



NO. 1493, VOL. 58] 



whilst he was in Manchester that Playfair induced 

 Bunsen, who had just perfected his process of gas 

 analysis, to come over to Alfreton to collect the gases 

 of the blast furnace. The results of this visit furnished 

 the first evidence concerning the chemical changes oc- 

 curring in the blast furnace, and were published in the 

 British Association Reports for 1845. 



It was in conjunction with Joule that Playfair's name 

 is best known as an investigator, several memoirs on 

 atomic volume and specific gravity appearing in their 

 joint names in the Chemical Society's Journal^ the most 

 important result of which was the discovery of the well- 

 known laws relating to the disappearance of the volume 

 of the acid and of the base of crystals of hydrated salts. 

 If Playfair had remained under the influence of Dalton 

 and Joule, his record of original work would probably 

 have been much longer than it is, but his activity was 

 destined to be turned into other channels. Sir Robert 

 Peel, who had heard of Playfair and formed a high 

 opinion of his powers, appointed him on a Commission to 

 inquire into the sanitary condition of large towns, and 

 such matters he found more to his taste than purely 

 scientific research. In recognition of the services which 

 he performed on this Commission, he was appointed 

 chemist to the Museum of Practical Geology. It was 

 here that he carried out his best-known research, namely 

 that on the nitro-prussides, a new class of salts 

 characterised by giving a splendid purple colour with 

 alkaline sulphides. A year or two later preparations 

 were being made for the first great exhibition of 1851, 

 and Lyon Playfair was chosen as a competent man to 

 visit the manufacturing districts to secure the co-oper- 

 ation of persons interested in manufactures and com- 

 merce. This somewhat difficult task he accomplished 

 with tact and success, and later on he took a leading part 

 in the classification and arrangement of the exhibits, and 

 the appointment of the juries was mainly left in his 

 hands. A good story is told of his savoir /aire at the 

 opening of the exhibition, where it was of course desirable 

 to have all nations represented. A very gaily-dressed 

 Chinaman found himself in the procession side by side 

 with the Archbishop of Canterbury, and was about to be 

 removed to some less conspicuous position when the 

 Prince Consort desired he might be left where he was. 

 Playfair's efforts had been successful in obtaining the 

 recognition of China, for, in the absence of any yellow- 

 jacketed mandarin as ambassador, Playfair had got 

 hold of a Chinese ticket-collector of a junk then being 

 exhibited in the docks. Not only during the existence 

 of the exhibition, but even up to the present time, 

 Playfair left his mark on the results of that exhibition, 

 for he was the guiding hand in the numerous and 

 complicated transactions which have taken place since 

 the purchase of the South Kensington Estate by the 

 Royal Commissioners. The foundation of the Science 

 Scholarships, which are now proving such a boon to 

 the aspirants to scientific fame, was entirely Playfair's 

 idea. Working in connection with the exhibition 

 of 185 1 brought him into personal contact with the 

 late Prince Consort, in whose household he accepted a 

 post, and it was to Playfair that the Prince was much in- 

 debted in his various schemes of land improvement and 

 other scientific matters. A few years later, when the 

 Science and Art Department was put upon a new foot- 

 ing, Playfair was appointed joint secretary with Sir 

 Henry Cole ; this partnership, as might be foreseen from 

 the character of the two men, did not last long, and Play- 

 fair became Inspector-General of Government Museums 

 and Schools of Science. A more permanent and satis- 

 factory position was, however, now open to him. In 1856 

 he succeeded Gregory as Professor of Chemistry in the 

 University of Edinburgh, and in this position he remained 

 for thirteen years, and the wags said that he was the only 

 Scotchman who, having tasted the flesh-pots of Egypt, 



