1835.] Scientific Intelligence. 317 



have a shadow. Now, the fact is, that when sound passes very 

 rapidly we have a kind of shadow of sound. When two tuning 

 forks are set differently, we have one sound ascending and the other 

 descending, affordingja strong similarity to the interference of undula- 

 tions. When light is polarized, as by Iceland spar, if we cause two 

 portions to act upon the same plane, alternations of dark and light 

 colours are obtained, shewing interference of waves, but when these 

 portions act at right angles no such interference takes place. When 

 light passes through a gas, and when we examine the spectrum, we 

 observe dark spaces, which may be occasioned by one wave interfering 

 with another. Light from the sun does not possess polarized pro- 

 perties which light from a hot iron does, shewing that light is derived 

 from the sun's atmosphere, and not from the substance of that lumi- 

 nary, because, in the latter case, there would be a gradual diminution 

 of its size. A strong argument in favour of the undulatory theory 

 is derived from a recent experiment of Mr. Faraday, who found, by 

 the action of electricity, that as much light was given out from a 

 copper wire in the course of a few days as could be emitted from the 

 sun in a year. Is it possible to suppose that this enormous quantity 

 of light existed pent up in a substantial form in the wire ? Dr. Ritchie 

 gives his decided negative to such an opinion, but is inclined to infer 

 that the light which enables us to see exists within ourselves, as the 

 heat which warms us is contained within us. 



6th February. — Dr. Faraday exhibited some very beautiful expe- 

 riments illustrative of his new researches in electricity, an account 

 of which was read the previous night at the meeting of the Royal 

 Society. They referred to the phenomena of induction, which con- 

 stitute the facts from which Dr. Faraday has raised a new branch of 

 science. He shewed that the electric spark and shock may be obtained 

 by means of a helix connected with a voltaic pile and a long train of 

 wire, leading into a bason of mercury, the instant that the current is 

 broken ; proving that the effect is produced by the agency of the 

 induced current. The same phenomena do not occur when short 

 wires are employed. He exhibited likewise the electro-magnetic- 

 machine, in which the electricity developed in a coil of wire is beau- 

 tifully elicited by means of a magnet rotating in contact with mer- 

 cury. This instrument forms an excellent means for procuring an 

 instantaneous light, as the spark is capable of igniting combustible 

 bodies, as candles, lamps, &c. We shall take the earliest opportu- 

 nity of presenting our readers with an analysis of Dr. Faraday's 

 papers. 



13^ February. — Mr. Landseer read a very learned disquisition 

 on a monument, of which a cast was brought to this country by Mr. 

 Joseph Benomi, who has recently published travels in the East. The 

 original of this ancient relic exists along with nine others on the sea 

 shore near the river Lycus, two hours journey from Bayrroot. With 

 the exception of this one of which the cast was exhibited to the meet • 

 ing, by permission of Lord Prudhoe, the monuments are much de- 

 faced. 



They were probably seen by Herodotus, for he describes similar 

 relics in Ionia. Maundrell saw them in 17^7> and describes them 

 with great accuracy. Benomi is the only other modern traveller who 



