140 



SCIENCE. 



[N. S. Vol. II. No. 31. 



Frank H. Bigelow upon the 'Earth as a 

 Magnetic Shell.' This is an investigation, 

 largely theoretical, upon lines already fol- 

 lowed by the author in earlier publications. 

 In discussing the modes of transference of 

 energy from the sun to the earth, he as- 

 sumes, in addition to the electro-magnetic 

 radiation emanating from the sun in all 

 directions in straight lines, also a magnetic 

 radiation belonging to the ' magnetic field,' 

 which near to the earth is at right angles 

 to the ecliptic. In this iuagnetic radiation 

 are found the explanation of several sets of 

 phenomena, as the aurora, magnetic dis- 

 turbances, earth currents and meteorolog- 

 ical periodic variations . This subj ect is dis- 

 cussed at length with the aid of a number 

 of diagrams. The author concludes from 

 the values obtained for the vectors of the 

 polar magnetic field at the earth that there 

 is an exfleded system around the poles and 

 an inflected system in the tropical belts. 

 Further, he shows that the outer stratum, 

 or shell, of the earth is permeable to ex- 

 ternal magnetic forces, while the nucleus is 

 is not; assuming that /i = 2, the radius 

 of the nucleus is calculated to be 3170 miles. 

 The effect of the magnetic radiation ai-gued 

 for is discussed with reference to the several 

 sets of phenomena mentioned, and it is also 

 suggested that certain deviations from the 

 Newtonian law of gravitation noted in the 

 secular motions of the sun and the planets 

 may find their explanation in a mechanical 

 stress called out by this ' magnetic radia- 

 tion.' Another physical article is by J. 

 Trowbridge and W. Duane, who continue 

 their discussion of the results obtained in the 

 Jefferson Physical Laboratory in the experi- 

 mental determination of the velocity of 

 electric waves. The essential features of 

 the methods employed have been earlier 

 (April, 1895) described, but they are here 

 improved upon. The final result for the 

 velocity obtained is 3.0024 x lOi", and the 

 conclusion is reached that the velocity of 



short electric waves traveling along two 

 parallel wires differs from the velocity of 

 light by less than two per cent. L. A. 

 Bauer takes up anew the discussion of the 

 distribution and secular variation of ter- 

 restrial magnetism — a subject treated by 

 him in the thesis noticed in Science, Vol. 

 I., No. 25 — and reaches some important re- 

 sults to be extended in a following article ; 

 they maj^ be more definitely spoken of later 

 in connection with this. Two articles upon 

 analytical chemistry come from the labora- 

 tory of F. A. Gooch at New Haven; the 

 first, by Gooch and Phelps, is a discussion 

 of a new method of determining carbon 

 dioxide ; the second, by Kr eider, describes 

 some new devices (as a hot filter, a valve, 

 etc.) convenient in the laboratory. In the 

 department of mineralogy, W. M. Foote 

 describes leadhillite pseudomorphs from 

 Graubj"^, Mo.; W. H. Hobbs describes cerus- 

 site crystals irom Missoula, Montana, barite 

 and manganite from Negaunee, Michigan, 

 chloritoid from Michigamme, Mich.; "W. F. 

 Hillebrand gives analyses of calaverite 

 from Cripple Creek, Colorado. In petrol- 

 ogy, L. V. Pirsson discusses the subject of 

 complementary rocks and radial dikes. 

 In the department of botany, B. L. Robin- 

 son and J. M. Greenman present a long 

 article (42 pages, forming contribution No. 

 IX., N. S.), from the Gray Herbarium, 

 and containing descriptions of many new 

 species. This consists of four parts, viz.: 



I. On the Flora of the Galapagos Islands, 

 as shown by the collection of Dr. G. Baur ; 



II. New and Noteworthy Plants, chiefly 

 from Oaxaca, collected by Messrs. C. G. 

 Pringle, L. C. Smith and E. W. Nelson; 



III. A Synoptic Revision of the Genus 

 Lamourouxia ; IV. Miscellaneous New 

 Species. The number (108 pages) con- 

 cludes with a notice of Professor Thomas 

 H. Huxley by O. C. Marsh, and likewise 

 one of Professor Daniel C. Eaton by W. H. 

 Brewer. 



