September i8, 19 19] 



NATIJfHE 



65 



stings is a further question ; the active irritant has 

 been regarded by one investigator as being probably 

 not formic acid, but an enzyme. 



The cause of the colours of " Blue John " and other 

 varieties of fluorite has long been a matter of doubt 

 and controversy. During the last two years Messrs. 

 B. Blount and J. H. Sequeira have carried out an 

 interesting investigation of the problem, and their 

 results are now briefly described in the Transactions 

 of the Chemical Society (vol. cxv., p. 705, 1919)- 

 They have carefully analysed blue and white varieties 

 of the mineral, tested the powdered material by ex- 

 traction with organic solvents, examined the gases 

 occluded by " Blue John," and subjected several types 

 of fluorite to "raying" by exposure to radium and 

 X-rays. They conclude from their experiments that 

 there is no substantial difference between white flyorite 

 and the blue, green, and amethystine varieties, except 

 in the presence of a small amount of organic matter 

 to which the colours are ascribed. The state of dis- 

 persion of the organic matter is not discussed. It 

 is already ascertained that the blue colour of certain 

 varieties of rock-salt is due to a colloidal dispersion 

 of sodium in sodium chloride, and the blue colours 

 of sodalite and ultramarine are almost certainly due 

 to a similar cause. To correlate the colours of fluorite 

 with the presence of different amounts of organic 

 matter therefore still leaves the core of the problem 

 unsettled; and it is to be hoped that the authors 

 will continue their work by applying methods of 

 X-ray analysis and ultra-microscopy in the hope of 

 demonstrating the degree of dispersion of the organic 

 matter, molecular or colloidal, in each of the varieties 

 of fluorite on which their present work has been 

 conducted. 



The Union of Technical Men (Bund technischer 

 Berufsstdnde), which has recently changed its name to 

 the Imperial League for German Technology (Reichs- 

 bund deutscher Technik) is now publishing a regular 

 weekly periodical, which reflects the opinions of the 

 leaders of technical thought in the country. Questions 

 affecting, in particular, the work of reconstruction find 

 an important place in the journal. It is interesting to 

 note that already more than one great conference or 

 Technical Parf^ament has been held, and energetic 

 measures are being taken with a view to ensure the 

 adequate representation of scientific and technical 

 thought on all public bodies. An announcement in the 

 publications of the League states that a daily paper 

 i' {Die Arbeit) will make its app>earance as soon as the 

 [ difficulties connected with the release of paper supplies 

 are overcome. 



We have received recently a copy of 'Hie Chemical 

 Technology, a monthly journal devoted to chemistry 

 and chemical technology, published in Tokyo. It is 

 printed chiefly in the Japanese language, but contains 

 a section of about eight pages in English. This con- 

 sists mainly of commercial notes upon chemical pro- 

 ducts, such as dyestuffs, alkaloids, wax, menthol, and 

 peppermint oil. The Japanese columns contain a 

 number of articles upon branches of technological 

 chemistry, and some of a more general nature, includ- 

 ing one on "Science and its Future," by Mr. S. 

 Oguri. Judging by their titles, the articles cover a 

 wide range of subjects, and indicate that chemists in 

 Japan are quite awake to the importance of their 

 science to the nation's industries. It may be noted, 

 in passing, that the journal contains several .American 

 advertisements, but not a solitary British one. 



From the director of the Wellcome chemical 

 research laboratories we have received copies of 

 sixteen scientific papers published during the last few 



NO. 2603, VOL. 104] 



years by the institution in question. They are chiefl , 

 accounts of investigations upon materials likely to l>e 

 of value in medicine. On one hand, plants used as 

 official or domestic remedies have been examined more 

 thoroughly than hitherto; and, on the other, active 

 constituents of drugs, such as alkaloids, have been 

 investigated with the view of determining their con- 

 stitution and facilitating the possible synthesis of 

 similar therapeutic agents. The distribution of thes'e 

 memoirs to scientific institutions, formerly made 

 periodicallv, was suspended during the period of the 

 war, and is now being resumed. The results of the 

 investigations, however, have already appeared in the 

 Transactions of the Chemical Society and the Pharma- 

 ceutical Journal, so that thev need not be mentioned 

 here in detail. It will suffice to say that they form 

 an important contributiori to our knowledge of the 

 medicinal plants examined, and are a testimony to the 

 excellence of the work done at the laboratories. 



The importance of having a thoroughly trustworthy 

 instrument for detecting and measuring the amount 

 of any combustible gas present in the air at any time 

 has led the Bureau of Standards at Washington to 

 investigate the working of existing instruments agid to 

 design a further instrument depending on a new 

 principle, which appears to have a great future before 

 it. It depends on the combustion which takes place 

 about a platinum wire in the mixture when an elec- 

 tric current is sent through the wire so as to heat it 

 sufficiently. Three methods of measurement are 

 adopted. The wire mav form one arm of a resistance 

 bridge and indicate the ,'imount of gas by the rise cf 

 temperature, and therefore of resistance of the wire. 

 Or the current in the wire may be increased until 

 the wire just glows, the increase required being less 

 as the amount of combustible ^as increases. Or the 

 heat generated bv the combustion may be used to 

 heat a bimetallic strip, the bending of which increases 

 as the heat generated, and therefore as the amount 

 of gas present. Full details of the instruments, with 

 drawings, are contained in Scientific Paper No. 334, 

 by Messrs. E. R. Weaver and E. E. Weibel, of the 

 Bureau. 



Vol. iii. of the Memoirs of the College of Science, 

 Kvoto Imperial University, contains an account of a 

 series of researches on the electrical resolution of 

 spectral lines {Stark effect). The method employed 

 was that originated by Lo Surdo, in which the mtense 

 electric field in the cathode dark space of a vacuum 

 tube is utilised. The elements studied include H, He, 

 Li, Ca, Mg, A, N, and O, and a number of new 

 and interesting results have been obtained. The 

 observations on the helium spectrum are particularly 

 complete, and are summarised diagrammatically in a 

 manner which brings out clearly most of the charac- 

 teristic features of the effect. Special attention is 

 given to the phenomenon of "isolated components," 

 which only exist in sufficiently strong fields, and seem 

 to be exclusivelv associated with a diffuse type of series. 

 This latter property, together with other features of 

 their observed behaviour, w^ould suggest that it mav 

 be legitimate to regard them as a special class of 

 satellite. Another observation of much interest refers 

 to certain combination series lines which make their 

 appearance only in intense electric fields. The 

 examination of the secondarv spectrum of hydrogen 

 yielded fiftv-four affected lines; these results, in con- 

 junction w-ith the Zeeman effects already on record, 

 should be of material assistance in elucidating the 

 structure of this spectrum. Among other conclusions 

 of general interest mav be mentioned the confirmation 

 of the view, which previously rested on somewhat 

 fragmentary evidence, that arc lines are affected by 



