154 



PART 11. 



REVIEWS. 



Art. I. Experimental Researches in Natural History. By John 

 Murray, F.S. A. F.L.S. &c. London. ]2mo,;^pp. 177. Qs. Re- 

 viewed by M. 



The author of this little work has chosen some of the most 

 remarkable phenomena in nature for description and illustra- 

 tion. His first two subjects are on the light of the glow-worm 

 and the luminosity of the sea. Both are treated with much 

 practical knowledge, gained, it would appear, from extensive 

 and patient investigation. He first speaks of the nature of 

 light, and declares himself a follower of Newton, in the opinion 

 tHat it is " material, and consisting of particles, exceedingly 

 minute, cast off from the luminous surface," and rejects the 

 idea of Descartes and others, that light is only a " mere 

 quality." 



The author next adverts to the origin of light, but which is 

 the least luminous part of his essay. Descending to his mun- 

 dane object, he considers, in his way, reflected, phosphoric, 

 electric, and spontaneous light emitted by various minerals, 

 animals, vegetables, and their combinations. 



The luminosity of the sea, afterwards fully treated of, he 

 says is caused by the presence of luminous insects, as the 

 Cancer fulgens, shining crab, &c.; and many instances of 

 spontaneous light are evolved by chemical processes and com- 

 binations, under the action of heat, as the Chlorophane 

 (chloros^ green, phaind, to shine; gives out a beautiful apple- 

 green light when placed on a heated iron ; petalite (petalon, a 

 thin plate ; laminar fracture) rubelite {rubellus, reddish ; colour), 

 tungstate of lime, anatase, &c. 



Many substances, according to Mr. Skrimshire, emit light 

 on being brought within the circuit of an electric current, as 

 alum, sugar, chalk, &c. 



Some diamonds emit light in the dark, and especially, 

 according to Boyle, if slightly heated, rubbed, or compressed. 

 *' Canton's phosphorus," not described by the author, " and 

 the Bolognian stone, are phosphorescent when heated." Of 

 this last curious substance, it has been said by naturalists, that 



