522 



NATURE 



[February i6, 191 i 



a special grant for the investigation of processes for pro- 

 •ducing zinc. In this connection, attention may be directed 

 to an advance chapter of the annual report on the mineral 

 production of Canada during 1909, which has been re- 

 ceived from the department, dealing with structural 

 materials and clay products. The chapter is by Mr. J. 

 McLeish, chief of the division of mineral resources and 

 •statistics. The subjects considered are cement, clay pro- 

 <lucts, lime, sand-lime brick, sands and gravels, slate and 

 •stone for building. It appears that 1909 was one of 

 record activity in the building trades. The value of 

 •cement sales in 1909 showed an increase of 44 per cent, 

 over 1908, clay products 43 per cent., and lime 58-8 per 

 • cent. The total value of the increase in production 

 amounted to well over a million pounds sterling. 



The Bryn Mawr College Monographs continue to show 

 the activity of the institution in scientific research. Vol. 

 \\\\. of the reprint series contains sixteen mathematical 

 .and two physical papers. Miss C. A. Scott contributes an 

 elegant note on the construction of certain regular poly- 

 :gons with the help of an auxiliary hyperbola ; and among 

 the numerous papers by Mr. J. E. Wright, those on differ- 

 ential invariants may be mentioned as spxecially interesting. 

 The physical papers (both by ladies) are on the spectra of 

 sulphur dioxide and on the electric spark in a magnetic 

 field. 



In his presidential address to Section A of the South 

 African Association for the Advancement of Science, 



■delivered on November 2, 1910, Prof. J. C. Beattie gives 

 an historical account of the growth of our knowledge of 

 terrestrial magnetism, dealing more especially with the 

 magnetic elements in Africa. Prof. Beattie regards the 



•establishment of one or more fixed magnetic observatories 

 in South Africa as an object of great scientific import- 

 ance, and in this he undoubtedly has the support of all 

 the leading magneticians of Europe. An appendix deals 

 •with terrestrial lines of declination, dip, and horizontal 

 Intensity for South Africa, based on the recent survey by 

 Profs. Beattie and Morrison, and contains a chart for 

 each of the three elements. 



The December (1910) number of Terrestrial Magnetism 

 and Atmospheric Electricity contains a report of the Berlin 

 meeting of the Commission on Terrestrial Magnetism and 

 Atmospheric Electricity, and a useful reprint of the whole 

 of the resolutions passed by the commission since the 

 Munich meeting in 189 1. Many of these refer to the steps 

 .to be taken to facilitate the comparison of the results 

 .obtained at different observatories. For this purj>ose, it is 

 ■xiesired that the curves of variation of declination be re- 

 produced to the scale of i minute of arc to i millimetre, 

 those of horizontal and vertical intensities to the scale of 

 0-00005 C.G.S. unit to I millimetre, and that for disturb- 

 ances the time scale be i hour to 15 millimetres. The 

 "importance of regular and frequent comparisons of the 

 Instruments used at the various observatories is insisted 

 on. So far, nothing appears to have been done to carry 

 :OUt the suggestion of the commission that magnetic 

 observatories be established along the magnetic meridian 

 passing through the centre of Africa. 



Separate copies have been received of two communica- 

 "'ions made by Dr. F. Jentzsch, of Wetzlar, to the meet- 

 ing of the German Naturforscher und Arzte at Konigs- 

 3erg in September last, which have appeared in the 

 ferhandhingen- der Deutschen Physikalischen Gesellschaft. 

 I'hey deal with appliances designed by the author for 

 improving the ultramicroscope. It will be remembered 

 ^hat in the ultramicroscope as used hitherto the light has 



NO.. 2 I 55, VOL. 85] 



impinged on one side only of the object. Dr. Jentzsch's 

 concentric condenser and ultracondenser receive the light 

 along the axis of the microscope. It is reflected by a 

 surface underneath the object, and, after further reflection, 

 crosses the axis at right angles at the point at which the 

 object is placed. An intense beam of light is thus pro- 

 duced, and the arrangement has the advantage that it 

 can be fitted to an ordinary microscof>e. 



According to a circular issued by the Bureau of 

 Standards at Washington in December, 1910, the Bureau 

 on January 1 adopted the value 1-0183 international 

 volts for the electromotive force of the Weston normal cell 

 at 20° C. This is equivalent to an increase of 008 per 

 cent, in the value of the international volt as used by thr 

 Bureau. The above value has been arrived at by an inter- 

 national investigation carried out at the Bureau of 

 Standards by representatives of the Bureau, the National 

 Physical Laboratory, the Reichsanstalt, and the Labora- 

 toire Central, and is to be adopted by all these institutions 

 so soon as the various Governments pass the necessary 

 legislation (see p. 508). The international ohm, our 

 readers will remember, is the resistance of a mercury 

 column at 0° C, 106-3 centimetres long, of uniform cross- 

 section, and of mass 14-4521 grams, and the international 

 ampere deposits o-ooiii8 gram of silver per second. 



In a paper read at the February evening meeting of the 

 Pharmaceutical Society, Dr. W. H. Martindale suggested 

 that rounded-off atomic weights should be adopted in the 

 new " Pharmacopoeia." The atomic weights of elements 

 emploj'ed in the pharmacopoeias of different nations show 

 considerable variation in magnitude, especially with regard 

 to the first, second, and third place of decimals. The 

 figures for such important elements as arsenic, bismuth, 

 bromine, chlorine, iodine, lithium, silver, and sodium vary 

 particularly, and the variations are not accounted for by 

 the fact that the oxygen standard is adopted by some and 

 the hydrogen standard by others. Dr. Martindale 's opinion 

 is that, with the exception of the weights for chlorine, 

 copper, and strontium, it might be better to do away \v!;'.i 

 the decimal proportions altogether, and that a rounded-off 

 series of figures like those in the French "Pharmaco- 

 poeia " would be sufficiently accurate for pharmaceutical 

 purposes. If rounded-off international standards could be 

 arranged, so much the better. 



The Journal of the Chemical Society for January con- 

 tains the reply of Prof. Komppa, of Helsingfors, to tli 

 criticisms of Messrs. "Leblanc and J. F. Thorpe on h: 

 synthesis of camphoric acid. The critical point in th 

 synthesis depends upon the point of attachment of th 

 last methyl-group introduced into the molecule, whic 

 Komppa regards as attached to carbon (as in camphor: 

 acid), whilst Leblanc and Thorpe have urged that its reao> 

 removal by alkalies proves it 10 be attached to oxygen. 

 The original proof that the methyl-group was attached to 

 carbon was based very largely on the fact that camphoric 

 acid was actually prepared from the methylated compound, 

 but it is now shown, further, (i) that the ester contair 

 the group — CO — CO—, because it forms a colourin, 

 matter with o-phenylene diamine, resembling in this 

 respect the whole series of ortho-quinones, but contrasting 

 sharply with an isomeric ester in which the grouping 

 changed in the manner suggested by Leblanc and Thorp 

 to —CO— C(OCH3)=, and (2) that the Zeisel method o 

 analysis indicates the presence of only two — OCH, group 

 in the ester, although the isomeric ester actually gives th 

 three — OCH3 groups postulated by Leblanc and Thorp- 

 So much interest has attached to this synthesis, as settling 



