!8o 



NATURE 



[July i8, 1907 



kind that the " movement is produced in the sthenometer 

 by some unknown force emanating from the right and left 

 hands that can move a straw over a very considerable arc." 

 It was shown, however, by Messrs. F. J. M. Stratlon and 

 P. Phillips in the Journal of the Society for Psychical 

 Research for December, 1906, that heat radiated from 

 the hand is the cause of the motion of the balanced straw 

 of the sthenometer. Hot objects were observed to produce 

 the same effects, and the extent of the motion was found 

 to increase with the heat radiated from the hand as 

 indicated by a thermopile. With the results of these 

 experiments before us, and also a note by Mr. Stratton in 

 the March number of the Journal of the society, it is 

 difficult to understand why the effect described should be 

 supposed to be produced by an unknown force. Much 

 more substantial evidence will be required than that 

 adduced in the article in the Contemporary Review before 

 any firm foundation can be secured for the position taken 

 up by Dr. .Schofield. 



The three official articles, on the work done at the 

 Physikalisch-Technische Reichsanstalt during the year 

 1906, which appeared in the April, May, and June numbers 

 of the Zeitschrift fiir Instrumentenkundc , have now been 

 issued as a separate pamphlet. In addition to statistics 

 showing how the work of the institution is growing, short 

 summaries of the principal conclusions arrived at during 

 the course of the year's work are given, and greatly 

 enhance the interest and value of the publication. As 

 typical examples may be mentioned the paragraphs on the 

 expansion of bodies at very high and at very low tempera- 

 tures, on the comparison of the various temperature scales 

 at high temperatures, on the self-inductance of lead- 

 covered and other cables, and those on the comparison of 

 the methods of testing magnetic materials. Apart, how- 

 ever, from its scientific value, there is one feature of the 

 report which teaches us an important lesson, that is, the 

 close contact which exists between the institution and the 

 manufacturers of Germany. Almost every official, from 

 the president downwards, has spent some time during the 

 year in visiting the works of clients of the institution, 

 " um personlich Fuhlung mit der Industrie zu nehmen," 

 to quote the words of the report. How long will it take 

 us to learn this lesson? 



An important series of determinations of fundamental 

 atomic weights is described by Prof. T. \V. Richards, in 

 conjunction with several of his students, in No. 69 of the 

 Publications of the Carnegie Institution. The atomic 

 weight of potassium was re-dctermined by ascertaining the 

 ratio of the weight of potassium chloride to that of the 

 silver chloride it produces when precipitated by means of 

 almost exactly the theoretical quantity of silver nitrate. 

 By using a Gooch crucible with a matting of platinum 

 sponge the w^eight of the silver haloid formed could be 

 determined with a high degree of accuracy, a correction 

 being introduced for the minute quantities of silver chloride 

 retained in the mother liquors. A similar series of deter- 

 minations was also made with potassium bromide by con- 

 verting the latter into silver bromide. In both series 

 exactly the same value, 39-114, for the atomic weight of 

 potassium was obtained (£1 = 35-473, Br = 79-953). Deter- 

 minations were also made, introducing many new refine- 

 ments, of the weight of silver nitrate formed from a known 

 weight of silver; the results are of especial interest, 

 inasmuch as they are incompatible with the low value 

 recently advocated for the atomic weight of nitrogen if 

 the atomic weight of silver be taken as 107-93 ; assuming 

 this value, 111? atomic weight of nitrogen becomes 14037. 

 NO. 1968, VOL. 76] 



The atomic weight of sulphur was also determined by a 

 new method based on the conversion of silver sulphate 

 in a quartz tube into silver chloride by means of gaseous 

 hydrogen chloride. The change takes place in a manner 

 very favourable to accurate results, and gives a value 

 32.113 for the atomic weight of sulphur (Ag= 107-93), which 

 is considerably higher than that accepted hitherto. An 

 interesting account of the general principles underlying 

 recent determinations of atomic weights was given by 

 Prof. Richards in a lecture delivered before the German 

 Chemical Society, and printed in the current number of 

 the Berichte. 



The Board of Agriculture has published colour-printed 

 geological maps of Worms Head (Sheet 246). The map is 

 issued in two editions (price is. 6J. each), on one of 

 which (the solid edition) glacial deposits are omitted, while 

 on the other (the drift edition) such deposits are indicated 

 by colour. The scale is 1 inch to the mile. 



The latest list issued by Messrs. Voigtlander and Son, t I 

 12 Charterhouse Street, E.C., is a handsome production. 

 It contains numerous examples of photographs taken with 

 various types of lenses made by this firm, and is in addition 

 provided with an excellent introduction by Dr. H. Harting 

 on the selection of photographic lenses and cameras. 



The Livingstone College Year-book for 1907 contains 

 the annual report, extracts from letters from old students, 

 hints on diet and hygiene in the tropics, &c. The college 

 gives a training in elementary medicine and surgery to 

 missionaries, and is doing much good work. 



Dr. M. Moszkowski has translated into German Prof. 

 T. H. Morgan's work on " Regeneration," and the volume 

 is published by Mr. W. Engelmann, Leipzig, at the price 

 of twelve marks. Prof. Morgan has provided his trans-^ 

 lator with new material relating to facts and theories of 

 scientific importance published since the fiirst or English 

 edition appeared in 1901, and this has been incorporated 

 in the German edition. At the end of the chapter on the 

 theories of regeneration, Prof. Morgan states the views 

 he now holds concerning some questions of fundamental 

 interest. 



OUR ASTRONOMICAL COLUMN. 



Comet I907d (D.amel). — Several observations of this 

 comet are recorded in No. 4188 of the Astronomische 

 Nachrichten (p. 207, July 4). Observing at Kremsmiinster 

 on June 24, Prof. Fr. Schwab saw a nebulous body of 

 about 2' diameter w-ith a bright nucleus; the comet disap- 

 peared in the dawn simultaneously with stars of the ninth 

 magnitude. Herrn van Biesbroeck, with the 15-inch re- 

 fractor at Uccle, found the magnitude to be 8-5 for the 

 whole comet, on June 19, this being decidedly brighter 

 than on the previous day. On June 27 Prof. Hartwig saw 

 a bright centrally-placed condensation. On July 4, Dr. 

 Lappa, observing at Rome, found the magnitude of the 

 nucleus to be between 6.0 and 7-0. 



This object now rises about midnight, about four hours 

 before the sun, and may be seen with a good field-glass. 



Comet 1907c (GI.^cOBI^■I). — Dr. StriJmgren continues his 

 daily ephemeris for comet 1907c in No. 4189 (p. 223, July 6) 

 of the Astronomische Nachrichten, and carries it forward 

 to July 31. This object is now travelling in a south- 

 easterly direction through the constellation Virgo, and its 

 brightness is only about half that at the time of discovery. 

 its magnitude then being 130. 



The Orbit of a Ce.nt.iuri. — Finding that his second set 

 of elements does not represent the angles measured ai 

 poriastron passage, and having many more observational 

 results on which to base his calculations. Prof. Doberck 

 has re-investigated the orbit of o Centauri, and publishes 



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