April 7, 1898] 



NATURE 



545 



he calls anti-electric energy behind shadows. The papers leave 

 us a little uncertain as to M. de Heen's distinction between 

 the terms infra electric and anti-electric; " anti "-electricity, 

 we are told, includes both "infra"- and " ultra "-electricity, 

 but the latter we do not see defined, at all events, in these two 

 writings. 



From Mr, A. A. Campbell Swinton we have received a re- 

 print of his paper on adjustable X-ray tubes, read before the 

 Rontgen Society. — Part iv. (vol. vii.) of the Atti dei Lincei 

 contains two papers, one on the cryptoluminescence of metals, 

 by Prof. A. Roiti ; the other on the diffusion of Rontgen rays, 

 by Drs. R. Malagoli and C. Bonacini. According to the two 

 latter writers, (l) the two electrodes contemporaneously emit 

 ortho-kalhodic rays, but that which communicates with the 

 negative pole of the excitor develops them the most intensely ; 

 (2) from the electrodes, at a certain stage of rarefaction, there 

 seem to start two cones of radiation, one enclosed in the other 

 or partially separate, carrying opposite charges ; both are dis- 

 placed by magnets subject to the same laws ; (3) the violet anodic 

 light, like the ortho-kathodic rays, is intensely affected by 

 magnetic action, but it follows the opposite law, behaving like 

 an electric current from the anode to the anti-anode ; (4) it 

 seems to follow that the anti-anodic system of Maltezos is, 

 perhaps, only a feeble anti-kathodic system, for between the 

 two systems there is identity rather than mere analogy, and 

 that not only in their effect on the glass. — The Bulletin de la 

 Soci^te Francaise de Physique {^0%. 108, 1 11) contains abstracts 

 of two papers by M. Villard, the first dealing principally with 

 the rays which produce the hemispherical illumination of " focus " 

 tubes above the plane of the anti-kathode ; the second dealing 

 with the laws of variation of the resistance of a Crookes' tube, 

 the electric attraction and repulsion of the seat of emission, 

 the production of Goldstein's rays, and the nature of the 

 kathodic rays. From their action in reducing crystals, silicates, 

 oxides of copper, and'other substances, M. Villard suggests that 

 the kathodic rays are formed of molecules of hydrogen due to 

 the traces of moisture left in the tube. — Dr. Josef R. v. Geitler, 

 of Prague, contributes to the Wiener Berichte a paper on electric 

 and magnetic decomposition of kathodic rays. The subject has 

 been somewhat foreshadowed by Birkeland, and the investiga- 

 tion bears close analogy to one published by Prof. J. J. Thomson 

 in October 1897. Like him the author, experimenting on the 

 shadow of a wire placed in the kathodic pencil, has obtained 

 a broadening out of the shadow, which appears bordered by a 

 series of green fluorescent striae separated by dark interspaces. 

 Dr. Geitler claims, however, that his experiments are in tnany 

 respects essentially distinct from Prof. Thomson's. 



By the death recently repnirted from Allahabad of Sir Saiyid 

 Ahmad Khan, Indian Moslems have lost a leader who devoted 

 many years, with great success, to their educational welfare and 

 to the extension of scientific knowledge. He may well be de- 

 scribed as the apostle of education to the Mahomedans of India. 

 His institute at Aligarh, with its own printing-press and journal, 

 his Anglo-Oriental college at the same place, on the model of a 

 college of Oxford or Cambridge, for the education of Ma- 

 homedans of the upper classes, are splendid monuments to his 

 breadth of mind, his wisdom, and his energy. The following 

 particulars of Sir Saiyid Ahmad's career are from an article in 

 Wednesday's Times : — This great leader of his people and 

 pillar of British rule, as he has been called, was born in Delhi 

 in 1817. His ancestors, who claimed descent from the Prophet, 

 are said to have originally come from the Herat Valley, and 

 for several generations held high office in the Court of the 

 Moghul Emperors of Delhi. In 1837, after his father's death, 

 the young man entered the British service in the Court of the 

 Judge at Delhi, and from that time until he finally retired 



NO. 1484, VOL. 57] 



from the service he remained in the judicial branch. 

 It was immediately after the Mutiny also that he threw himself 

 heart and soul into the cause of Mahomedan education, and 

 one of his earliest steps was to establish a translation society 

 which should prepare suitable books, the want of which he 

 greatly felt. A few years later this useful association expanded 

 into the Scientific Society of Aligarh, with its own press, from 

 which translations of numerous works on history and various 

 modern sciences have been issued for the use of Mahomedans. It 

 was after a visit to England in 1870 that he bent his mind to the 

 great undertaking of the Anglo-Oriental College at Aligarh, 

 which was opened in 1873 by Sir William Muir, while the found- 

 ation-stone of the building now in existence was laid with much 

 ceremony by Lord Lytton in 1877. Having retired from the 

 service in 1876, Saiyid Ahmad was in 1878 appointed a member 

 of the Viceroy's Council by Lord Lytton, the appointment being 

 renewed for a further period by Lord Ripon. He has also been 

 on the Legislative Council of the North-West Provinces. In 

 1888 he was made K. C.S.I. For many years past Sir Saiyid 

 Ahmad's home at Aligarh has been the goal of the pilgrimages 

 of many of the greatest personages in India, and his reception 

 by his fellow-Mahomedans when he has gone to the Punjab or 

 to Haidarabad has been semi-regal. His last years were wholly 

 devoted to the prosperity of his college and institute, and most 

 of his journeys have been made on their behalf. Anglo-Indians 

 who knew him best are as enthusiastic in his praise as the Indian 

 Mahomedans. To the end he never changed the main article 

 of his social faith — that education was the one indispensable 

 requirement of Indian Mahomedans if they were to maintain 

 under the British Raj the high position which was their due. 



An interesting address, by Prof. Thomas Gray, on the 

 development of electrical science, in which the history of 

 electrical progress since the beginning of the seventeenth, 

 century is traced, is published in Science of March 18 and 25. 



Herr Freiherr v. Richthofen, President of the Berlin. 

 Gesellschaft fiir Erdkiinde, contributes a note to the Verhand- 

 lungen on the spelling of Chinese names. With the ordinary 

 German pronunciation, Kiautschoii represents the Chinese name 

 more correctly than Kiaotschau, Tschifu than Chefoo, Nitdsch- 

 wang than Newchwang, Futschoufu than Foochowfoo. 



The whole of the first number of the new volume of the 

 Mittkeilungen von Forschungsreisenden und Gelehrten aus den- 

 deutschen Schutzgebieten is taken up with an exhaustive account 

 of the drum language of the Duala, by Herr R. Betz This^ 

 method of conversation at a distance reaches a higher develop- 

 ment in the Duala region than in any other part of the Kameruns. 

 The paper contains no fewer than 275 examples of signs and 

 phrases. 



From an advance proof of the tables relating to the output of 

 coal and other minerals in 1897, published by the Home Office, 

 we learn that 202,119,196 tons of coal were mined in the 

 United Kingdom last year. This was an excess of nearly seven 

 million tons over the output for 1896. Next to coal, the largest 

 outputs were :— ironstone, 7,793,168 tons; fireclay, 2,682,472 

 tons ; oil shale, 2,223,757 tons. 



Prof. Dr. J. Walther contributes a further instalment of 

 his studies of deserts to the Verhandlungen of the Gesellschaft 

 fiir Erdkiinde zu Berlin. Prof. Walther made an expedition 

 into the waste regions of Transcaspia and Bokhara after the 

 Geological Congress at St. Petersburg last year, and describes 

 his observations on the erosive action of wind, of great ranges 

 of temperature, and of the saline deposits in dried-up lakes. 

 The paper forms an important addition to the author's geological 

 work in similar regions of North America and North Africa. 



