NA TURE 



[December 17, 190b 



■O. Z. Bianco, of the Royal University of Turin, now sends 

 us a quotation from Scliopenliauer's dissertation " Ueber 

 den Willen in der Natur " to show that the German meta- 

 physician accepted Herschel's speculation as to the cause 

 of motion of inorganic matter under the influence of 

 gravitation. Dr. Bianco deals with the same subject in a 

 paper entitled " Schopenauer e la gravitazione universale," 

 published in the Rivisia FHosofica in 1906. 



The Physical Review for October contains a paper by 

 Prof. E. F. Nichols and Dr. \V. S. Day on new groups 

 of residual rays in the long wave spectrum. The sub- 

 stances tested were rock salt, ammonium chloride, 

 witherite (barium carbonate), and strontianite (strontium 

 carbonate). The radiation from a group of Nernst 

 burners was reflected in succession from five plane sur- 

 faces of one of these materials, and, after passing through 

 a spectrometer composed of concave silvered mirrors and 

 a wire difTraction grating, fell on a Nicholls radiometer, 

 the deflection of which could be observed. The residual 

 wave-lengths . found are : — for rock salt, 52-3 ; for 

 ammonium chloride, 51-4; for witherite, 460; and for 

 strontianite, 43-2x10-° centimetre. 



A LARGE part of the November number of the 

 Physikalischc Zcilschrift is devoted to the papers read at 

 the Versammlung deutscher Naturforscher und Aerzte at 

 "Cologne in September. .Amongst a number of interesting 

 communications, we note one from Dr. J. Classen, of 

 Hamburg, on the value of the quotient electric charge by 

 mass for the kathode rays. His method is that of Kauf- 

 niann, in which the velocity of the electron is taken to 

 be that due to its passage through the electric field between 

 kathode and anode, and the elTeot of a magnetic field on 

 the path of the electron is measured. In Dr. Classen's 

 experiments a Wehnelt kathode is situated a millimetre 

 in front of a large anode with a hole a millimetre diameter 

 at its centre, and the discharge tube is placed in a mag- 

 netic field due to two large coils arranged in the Helmholtz 

 manner. The deflections of the rays are determined photo- 

 graphically. The value of the quotient obtained is 

 I-77XIO', i.e. considerably loss than the 1.86x10" obtained 

 by Kaufmann. 



We have received a copy of the ", Guide-annuaire de 

 Madagascar et DiSpendances " for the year 1908. This 

 official publication contains a complete list of Government 

 officials in the various provinces of Madagascar, and much 

 valii-'ble statistical information. 



We have received from Messrs.. John \A'heldon and Co., 

 of Great Queen .Street, London, a copy of a catalogue of 

 800 books and papers on cryptogamic botany which they 

 ■offer for sale. The books are catalogued alphabetically by 

 authors' names under the headings algre, fungi, lichens, 

 musci and hepaticas, Alices, and general. 



Messrs. Spottiswoode and Co. have sent us a copy of 

 the autobiography of the late Sir Edward Frankland, which 

 was edited and concluded by his two daughters, and 

 printed for private circulation in 1902, under the title 

 " Sketches from the Life of Edward Frankland." Copies 

 of this interesting volume may now be obtained from 

 Messrs. Spottiswoode at the prcc of 3,'!. 6rf. net. 



The first two numbers have reached us of Patlwlogica, 

 a new bi-monthly journal devoted to pathology, and having 

 a strong editorial committee. The journal includes 

 original articles, abstracts of recent publications, and 

 reviews of bculis ; it is published by Luigi Grifiini, Genoa. 

 NO. 2042, VOL. 79] 



OUR ASTRONOMICAL COLUMN. 



Water \'.\roLR in the Atmosphere of Mars. — A tele- 

 gram from Prof. Lowell, published as Circular No. luo 

 of the Kiel Centralstelle, reads as follows : — " Quantitative- 

 measures by \'ery, with his new spectral comparator, of 

 Slipher's spectrograms Mars mmron (?), show little a 

 water vapor band twenty-two per cent, stronger in Mars 

 spectrum than in our own air. Solar lines C equal. — 

 Lowell." 



Our readers will remember that early in the present 

 year Mr. Sliphcr photographed the spectrum of Mars in 

 which the a water-vapour band was considerably stronger, 

 relatively, than in a similar spectrum of the moon, both 

 spectra being taken when the objects were at about the 

 same altitude (see Nature, vol. Ixxvii., No. 2002. 

 .March 12, p. 442). It is to these photographs, presumably, 

 that the above message refers, the queried word probably 

 meaning " moon." 



AcCEI.ERAnON OF MATTER IN THE TaIL OF MoREHOUSE's 



Co.met. — In a paper published in No. 22 of the Comptes 

 rcndus (November 30, p. 1033), MM. Baldet and Qu(Snisset 

 give further details concerning the accelerating velocities 

 of the agglomerations seen, on their photographs, in the 

 tail of comet igoSc. 



Between September 17 and November 6 ninety-six photo- 

 graphs were obtained, with six different cameras, at the 

 Juvisy Observatory, and, on e.xamining these, it is quite 

 possible to recognise the same features of the tail on 

 photographs taken at different times on the same night 

 and also on those taken on successive nights. 



The photographs taken on October 15 and 16, with an 

 interval of nineteen hours, afford a good example. Measures 

 made on that of October 15 showed that a luminous 

 mass, then some 580,000 km. from the head, was travelling 

 at a velocity of about 14 km. per sec. The same mass 

 was easily recognisable on the photograph of October 16, 

 and the measures showed that it was then about 

 2,200,000 km. from the head, that is to say, it had 

 travelled 1,600,000 km. during the interval; had 14 km. 

 been maintained as a uniform velocity, the distance covered 

 would have been- only 960,000 km. Measures made on 

 two plates taken on CJctober 15, with an interval between 

 the exposures of ih. 40m., showed that another similar 

 luminous mass was travelling at the velocity of 58 km. 

 per sec. 



Other peculiarities in the tail are also noted, and in one 

 of the two photographs which accompany the paper there 

 is a remarkable deflection in the tail, not far from the 

 head, which seems to indicate that the ejected matter had 

 encountered some such obstructing medium as would be 

 provided by meteoritic debris. 



The peculiar changes of the comet's appearance are also 

 reviewed by Prof. Barnard in No. 4, vol. xxviii., of the 

 A.itrophysical Journal (p. 292, November). With three 

 cameras, Prof. Barnard secured 190 negatives, which show 

 very strikingly how rapidly the enormous changes in the 

 comet's appearance took place. Two photographs repro- 

 duced with the paper were taken on September 30 and 

 October i respectively, the interval between the exposures 

 being barely twenty-four hours ; yet the general appear- 

 ance of the tail was utterly transformed during that 

 interval. 



Characteristics of the Suferior (IC^) Layer of the 

 Sun's .\tmospiiere- — In a paper published in No. 22 of the 

 Comptes rendiis (November 30, p. 1016), M. Deslandres 

 states that by employing a large spectroheliograph of a 

 special type he has succeeded in obtaining photographs 

 with the pure radiation (K,) of the highest layer of the 

 sun's atmosphere. In previous work the calcium radia- 

 tion, K, — the central dark reversal of the calcium K line — 

 has always been mixed with varying proportions of the 

 bright (K,) reversals which bound it on either side, con- 

 sequently the photographs have shown the integrated 

 phenomena of the highest layer and the layer immediately 

 below it ; but in the new photographs those phenomena 

 peculiar to the upper layer are shown alone. The favour- 

 able weather of the last four months has permitted a fine 

 set of such photographs, extending over four rotations of 

 the sun, to be obtained. 



