112 



NATURE 



[Dec. 9, 1875 



Prussian blue, he fancied he had settled the grand and 

 difficult problems connected with the colouring matter of 

 leaves. While the isolated position of Fusinieri, and the 

 want of contact with better scientific minds than his own, 

 will account for this, we must not forget that the abject 

 poUtical condition of the land and the narrow jealousy of 

 its multiplied rulers made it difficult for a man to work 

 intellectually or to teach properly, so that we may well 

 express our admiration that one so hampered has 

 achieved so much, and set so good an example to his 

 more fortunate countrymen. May their scientific efforts 



prosper 



C. T. 



SCIENCE IN GERMANY 

 {From a German Correspondenf) 



HERR W. SIEMENS has recently made the following 

 interesting communication to the Academy of 

 Sciences of Berlin : — 



It has been shown by Willoughby Smith and by 

 Sale that crystalline selenium conducts electricity better 

 when illuminated than when in darkness. The specific 

 conductivity, however, of selenium rendered crystal- 

 line by heating from 100° to 150° C. is very small and 

 extremely variable ; and also the increase of the con- 

 ductivity through illumination is very inconstant, so that 

 it is impossible to establish a determinate dependence of 

 the conductivity on the illumination. 



Herr Siemens has succeeded, by continuous heating of 

 amorphous selenium to a temperature of 210"^, as also by 

 cooling of melted selenium to 210"^ (at which temperature, 

 long continued, the selenium passes into a coarse-grained 

 crystalline state), in producing another modification of the 

 crystalline selenium, which has considerably greater con- 

 ductivity, and retains it, and conducts electricity metalli- 

 cally, so that with increase of temperature the conduc- 

 tivity decreases. The action of light on this modification 

 of crystalline selenium is much greater, and apparently 

 quite constant. By fusing in two flat spirals of wire, 

 about I millimetre apart, between two leaves of mica in 

 coarsely crystalline selenium, he has obtained an exceed- 

 ingly sensitive measure of light. Dark heat rays are 

 ■without direct influence on the conductivity, and heating 

 of the selenium, as already mentioned, diminishes the 

 same. Diffuse daylight even doubles the conductivity of 

 this light-measure, and direct sunlight increases it some- 

 times more than tettfold. The increase of conductivity 

 of the coarse-grained selenium through illumination takes 

 place very quickly. And similarly, the diminution of it, 

 on shutting off the light, occurs, apparently, at once ; but 

 a longer time is required before the state corresponding 

 to darkness is again fully established. The increase of 

 the conductivity is not proportional to the light intensity, 

 but a function of it, which comes near the proportion of 

 the square root of the light intensities. 



Herr Siemens hopes this interesting property of sele- 

 nium may be utilised for construction of a reliable photo- 

 meter. W. 



NOTES 

 Every one will hear with genuine regret of the proposed re- 

 signation by Prof. Max Miiller of the Chair of Comparative 

 Philology in Oxford University. He has resolved to take this 

 step on the ground that he begins to feel the need of rest, 

 and that he wishes to be able to devote all his attention to the 

 ancient language and literature of India. He has just finished, 

 be says, the work of his life, the Editio Princeps of the text and 

 commentary of the oldest of the sacred books of the Brahmans, 

 the oldest of the Aryan world. It was this which first brought 

 him to England in 1846, and it was in order to be able to stay in 

 England that he accepted the duties of professor. Dr. Miiller 



was appointed to the Chair of Natural Philology in 1868, in 

 which year it was founded and endowed. " I have," he justly 

 states, "satisfaction that I leave the new science of language, to 

 which my work as Professor has been mainly devoted, firmly 

 established in the system of academic studies, and that the Uni- 

 versity will find among my pupils several quite able to fill my 

 place." It will not be an easy matter, we fear, to find a worthy 

 successor. 



There has just been placed in Westminster Abbey a marble 



scroll bearing an appropriate inscription to the memory of 



Jeremiah Ilorrocks. The movement for such a memorial was 



commenced some time ago, and is referred to in Nature, 



vol. X. p. 190, and xi. p. 31. The scroll is affixed to the 



pedestal of the monument of John Conduitt, nephew of Sir 



Isaac Newton, which is situated at the extreme west end of the 



north side of the nave, and exactly opposite that of Newton, at 



the extreme east end. The inscription is as follows : — 



In Memory of 



Jeremiah Horrocks, 



Curate of Hoole, in Lancashire, 



Who died on the 3d of January, 1641, in or near his 22d year ; 



Having in so short a life 



Detected the long inequality in the mean motion of Jupiter and Saturn ; 



Discovered the orbit of the Moon to be an ellipse ; 



Determined the motion of the lunar apse ; 



Suggested the physical caiise of its revolution ; 



And predicted from his own observations the Transit of Venus, 



Which was seen by hims«lf and his friend William Crabtree 



On Sunday the 24th of November (O.S ) 1639 : 



This Tablet, facing the Monument af Newton, 



Was raised after the lapse of more than two centuries, December 9, 1874. 



The friends of Horrocks are indebted for the inscription to the 



joint labour of the Dean of Westminster and Prof H. J. S. 



Smith. It is a simple act of justice to state that the idea of this 



tablet was suggested by two ladies, Mrs. Orme and Mrs. 



Patmore, and that upon the latter has fallen the burden and 



heat of the day so far as the correspondence with subscribers 



is concerned. 



M. Le Verrier, as President of the Scientific Association of 

 France, has received the handsome sum of 2,300 francs from 

 M. P. Bischoffsheim to meet the balance of the expense incurred 

 during the important and refined experiments conducted by M. 

 Cornu, towards determining with great precision the velocity of 

 light, an expense which otherwise must have been borne by the 

 eminent savant who directed the experiments. 



Considerable dissatisfaction is felt among the Fellows of the 

 Linnean Society at the delay in the publication of the zoological 

 papers communicated to it. The zoological paper last published 

 in the Journal is dated Dec. 17, 1874, and that in the Transac- 

 tions, Nov. 19, 1874. It is said that there are at least a dozen 

 awaiting publication, and the number is likely to be increased. 

 There is reason to fear that no zoological paper communicated 

 during the present year will appear before the end of it. 



A REPORT is widely circulating in Oxford University to the 

 effect that Lord Salisbury, its Chancellor, is endeavouring to 

 obtain the issue of a Commission for inquiring into the question 

 of University Reform. Another form of the report is that the 

 Commission will have an executive character. A third rumour 

 names Mr. Gladstone as one of the Commissioners. But nothing 

 certain is known upon the subject at Oxford. 



The January number of the Practitioner will contain a memoir 

 of the late Dr. Francis E. Anstie, by Dr. Buzzard, with a 

 portrait engraved on steel. This number will also contain some 

 of Dr. Anstie's unpublished researches on alcohol. 



Dr. Burdon Sanderson announces that the first of hia 

 annual course of Lectures on Comparative Pathology will be 

 given at the University of London, on Wednesday next, Dec. 15* 

 Subject — The Pathology of Inflammation. 



