203 



SCIENTIFIC SIDE-LIGHTS 



Jements 



ated by the friction, and Sir William Arm- 

 strong's hydro-electric machine is con- 

 structed on this principle. Every volcano in 

 violent eruption is a very efficient hydro- 

 electric machine, and the up-rushing column 

 is in a condition of intense electrical excita- 

 tion. This result is probably aided by the 

 friction of the solid particles as they are 

 propelled upwards and fall back into the 

 crater. The restoration of the condition of 

 electrical stability between this column and 

 the surrounding atmosphere is attended 

 with the production of frequent lightning- 

 flashes and thunderclaps, the sound of the 

 latter being usually, however, drowned in 

 the still louder roar of the up-rushing 

 steam-column. JUDD Volcanoes, ch. 2, p. 29. 

 (A., 1899.) 



990. ELECTRICITY GIVES NEW 

 PRODUCTS Carborundum. The produc- 

 tion of electricity in such enormous quanti- 

 ties as are generated at Niagara Falls has 

 led to many discoveries and will lead to 

 many more. Products that at one time ex- 

 isted only in the chemical laboratory for 

 experimental purposes have been so cheap- 

 ened by utilizing electrical energy in their 

 manufacture as to bring them into the play 

 of every-day life. Still other products have 

 only been discovered since the advent of 

 heavy electrical currents. A substance called 

 carborundum, which was discovered as late 

 as 1891, has now become the basis of an in- 

 dustry of no small importance. It is a sub- 

 stance not unlike a diamond in hardness, 

 and not very unlike it in its composition. 

 The chief use to which it is put is for grind- 

 ing metals and all sorts of abrasive work. 

 It is manufactured into wheels, in structure 

 like the emery-wheel, and serves the same 

 purpose. It is much more expensive than 

 the emery-wheel, but it is claimed that it 

 will do enough more and better work to 

 make it fully as economical. ELISHA GRAY 

 Nature's Miracles, vol. iii, ch. 25, p. 209. 

 (F. H. & H., 1900.) 



991. ELECTRICITY IN ANIMALS 



Battery of the Electric Ray Scientific 

 Structure in Living Organism. The electric 

 ray, or torpedo, has been provided with a 

 battery closely resembling, but greatly ex- 

 ceeding in the beauty and compactness of its 

 structure, the batteries whereby man has 

 now learned to make the laws of electricity 

 subservient to his will. There are no less 

 than 940 hexagonal columns in this battery 

 like those of a bee's comb, and each of these 

 is subdivided by a series of horizontal 

 plates, which appear to be analogous to the 

 plates of the voltaic pile. The whole is 

 supplied with an enormous amount of nerv- 

 ous matter, four great branches of which 

 are as large as the animal's spinal cord, 

 and these spread out in a multitude of 

 threadlike filaments round the prismatic 

 columns, and finally pass into all the cells. 

 This, again, seems to suggest an analogy 

 with the arrangement by which an electric 



current, passing through a coil and round a 

 magnet, is used to intensify the magnetic 

 force. A complete knowledge of all the mys- 

 teries which have been gradually unfolded 

 from the days of Galvani to those of Fara- 

 day, and of many others which are still in- 

 scrutable to us, is exhibited in this struc- 

 ture. ARGYLL Reign of Law, ch. 2, p. 61. 

 (Burt.) 



992. ELECTRICITY IN MEDICINE 



Electric Lamps for Pathological Investiga- 

 tion Dentistry Aided Submarine Boats. 

 Small incandescent lamps are now used for 

 examinations of the larynx and in dentistry, 

 and a lamp has even been introduced into 

 the stomach by which the condition of that 

 organ can be examined. For this last pur- 

 pose numerous ingenious arrangements have 

 to be made to prevent possible injury, and 

 by means of prisms at the bends of the tube 

 the operator can inspect the interior of the 

 organ under a brilliant light. Other inter- 

 nal organs have been explored in a similar 

 manner, and many new applications in this 

 direction will no doubt be made. In illu- 

 minating submarine boats and exploring the 

 interiors of sunken vessels it does what 

 could hardly be effected by any other means. 

 WALLACE The Wonderful Century, ch. 4, 

 p. 29. (D. M. & Co., 1899.) 



993. ELEMENTS, CHEMICAL, MAY 

 BE COMPOUNDS Perhaps Resolvable on 

 the Sun and Stars The " Dissociation The- 

 ory." Professor Lockyer's view [of the 

 separation or dissociation of chemical ele- 

 ments on the sun] has the argument from 

 continuity in its favor. It only asks us to 

 believe that processes which we know to 

 take place on the earth under certain condi- 

 tions, are carried further in the sun, where 

 the same conditions are, it may be pre- 

 sumed, vastly exalted. We find that the 

 bodies we call " compound " split asunder at 

 fixed degrees of heat within the range of our 

 resources. Why should we hesitate to ad- 

 mit that the bodies we call " simple " do 

 likewise at degrees of heat without the 

 range of our resources ? The term " ele- 

 ment " simply expresses terrestrial incapa- 

 bility of reduction. That, in celestial labo- 

 ratories, the means and their effect here 

 absent should be present, would be an in- 

 ference challenging, in itself, no expression 

 of incredulity. 



Yet it is, in point of fact, a revolutionary 

 one, and its acceptance will involve the re- 

 construction of more than one fair edifice of 

 scientific thought. CLERKE History of As- 

 tronomy, pt. ii, ch. 4, p. 259. (Bl., 1893.) 



994. ELEMENTS IN OTHER SUNS 

 Spectrum* of Sirius. The spectrum of this 

 brilliant white star [Sirius] is very intense; 

 but seen at its small altitude above the hori- 

 zon, even when it is most favorably situated, 

 the observation of the finest lines is rendered 

 very difficult by the motions of the atmos- 

 phere. Three, if not four, elementary bodies 

 show spectra in which the lines coincide 



