1 54 Imperial Institute of France. 



summated the purification of the Sta2;e, fostering imagina- 

 tion without oflVnding nature, and tiisplaving character 

 without polluting it by personality, ]t was in the midst of 

 this gradual refinement of the Athenian Stage that Me- 

 nander rose to form a purer mi)del of chaste and delicate 

 comedy. A few fragments of his works, saved from the 

 tooth of time, are the only specimens of his style that have 

 reached our age; hut these are sufficient to confirm the loss 

 which morality and taste have sufTcrcd by the ainiihilation 

 of the rest. 



[To be continued.] 



IMPERIAt, INSTITUTE OF FRANCE, 

 [Continued from vol. xxxix. p. 401.] 



OPTICS. 



New Inquiries of Messrs. Malus and Ar a go. 



A direct ray of light, as is well known, possesses the pro- 

 perty of dividing itself into two distinct bundles in its pas- 

 sage through a rhomboid of Iceland spar, whatever in othei* 

 respects may be its position in relation to the principal sec- 

 tion of the rhomboid. 



If we subject the hght of which one of these bundles 

 is composed to the action of a second rhomboid, we find 

 that it differs essentially Irom the direct light, since, in cer- 

 tain positions of the principal section of the second cry- 

 stal, it no longer undergoes double refraction : 'for the dis- 

 covery of this beautiiul property we are indebted to Huy- 

 ghens. 



When endeavouring to account for this experiment, 

 Newton rentarks, in one of the questions which he has 

 placed at the end of his treatise on Optics, that it is neces- 

 sary to admit that the molecules of which the luminous rays 

 are composed must have sides endowed with different pro- 

 perties : iliese oides, which some authors have designated by 

 the appellation of poles, ate fliainetricallv opposite to each 

 other, and in two directions re3|)ectivcly icciangnlar. 



This being yranfed, in a rav of ordinary light, the poles 

 of the molecuh'S will not affect any particular position, and 

 will be uiuhjrmly directed towards all the points of the 

 space; whereas a polarized rav will be composed of mole- 

 cules, the siniilar poles of which will have the same situa- 

 tion: this last ray will be distinguished from a ray of direct 

 light, in so far as the latter is always divided into two fas- 

 ciculi in its passage through a rhomboid of carbonate of 

 lime; while the polarized ray experiences only a single re- 

 fraction 



