914 



SCIENCE. 



[N. S. Vol. IX. No. 284. 



MODERN VIEWS OP MATTER. 



Professor Oliver Lodge in the International 

 Monthly for May reviews the modern views of 

 matter touching more particularly upon J. J. 

 Thomson's electro-corpuscular theory, and upon 

 Johnstone Stoney's electron theory. It has 

 been known since Maxwell's time that a mov- 

 ing electric charge stores kinetic energy so 

 that work is required to set it in motion and it 

 does work when it is stopped, that is, an elec- 

 trical charge is endowed with that most per- 

 plexing property of matter inertia. Johnstone 

 Stoney's theory is that atoms of matter are ag- 

 gregrates of electrons, an electron being, as it 

 were, a stretched spot in the ether or a very 

 small electric charge. J. J. Thomson's cor- 

 puscular theory is more or less similar to the 

 electron theory only that J. J. Thomson has 

 pretty clearly shown by experiment that what 

 he calls a corpuscle exists, that its mass (inertia) 

 is about 1/500 of the mass of the hydrogen atom 

 and that it carries a definite negative electric 

 charge. 



In a very interesting communication to Nature, 

 May 10, J. J. Thomson shows that many phys- 

 ical phenomena can be interpreted in terms of 

 his corpuscular theory ; for example the pro- 

 portionality of thermal and electric conduc- 

 tivity, and the variation of electrical conduc- 

 tivity with temperature. 



W. S. F. 



NOTE ON A NEW ABYSSAL LI3IPET. 



Under the name of Bathysciadium conicum 

 Dautzenberg and H. Fischer have described* a 

 new deep water limpet which combines some 

 curious characters. The specimens are simply 

 conical with radiating riblets and an almost 

 membranaceous shell, and have a diameter of 

 1.5 mm. and a height of 0.9 mm. Some ana- 

 tomical details are given by Dr. Pelseneer in a 

 note appended to the description. The animal 

 was obtained from the beak of a cuttlefish 

 dredged by the Prince of Monaco off the Azores 

 in 843 fathoms. 



Like Lepeta it is without eyes or ctenidia, 

 the respiration being carried on by the surface 

 of the mantle. The muzzle appears to be 

 without lappets, the right tentacle has an ap- 



* Bull. Soc. Zool. de France, xxiv., p. 207. 



pendix like that of Cocculina (supposed to be a 

 degenerate verge), there are no posterior fila- 

 ments ; an unpaired mandible and long radula 

 are present, the nervous system is that of the 

 Docoglossa and the otoliths are single. 



Dr. Pelseneer regards the genital gland 

 (otherwise strictly docoglossate) as hermaph- 

 rodite, a condition so exceptional, and, con- 

 sidering the minute size of the animal, so diffi- 

 cult to determine, that judgment may fairly be 

 suspended pending further confirmation of it. 

 The radula as figured leads to the belief that 

 except in the absence of the rhachidian tooth 

 (often degenerate in abyssal limpets) the teeth 

 are like those of Lepetella; the major lateral 

 being broken into three pieces which have 

 been taken for three separate teeth by the 

 author cited. If this suspicion be correct the 

 formula is 1 + 2-0-2 + 1, for a transverse series 

 of the radula. The creature will be the first 

 true limpet (Docoglossa) to show any trace of a 

 verge, and if really hermaphrodite, the first to 

 exhibit this character. The single otolith is 

 very likely correlated with the small size of 

 the animal. The genus will stand next to 

 Lepetella among the Abranchiate Docoglossa. 

 Wm. H. Dall. 



THE PLANET EEOS. 



A letter from the Arequipa Station of the 

 Harvard College Observatory of June 1, 1900, 

 gives details concerning four photographs of 

 Eros taken there in April with the Bruce tele- 

 scope, by Dr. Delisle Stewart. An adjacent 

 star was followed in an eye piece and by means 

 of a micrometer screw the photographic plate 

 was moved with regard to it by an amount and 

 in a direction equal to the motion of Eros. 

 The stars thus appeared as trails and Eros 

 as a point. Approximate positions were deter- 

 mined from the plates at Arequipa with the 

 results given below. Paper prints of two of 

 these plates were sent to Cambridge and meas- 

 ures of them are also given. The negatives 

 are now on their way to Cambridge, and as soon 

 as received accurate positions will be derived 

 from them. 



These appear to be the first observations of 

 Eros since its conjunction with the Sun. The 



