of Light laithin Solid and Fluid Bodies. 409 



Tliis insulation of the bluer rays greatly increased the beauty 

 of the phaenomenon, and promiseil to throw some light upon 

 its cause. I was therefore anxious to ascertain their state of 

 polarization, which was not indicated by the analysing rhomb. 



With this view I transmitted through the solution a strong 

 beam of polarized light, and was surprised to find that the blue 

 beam, which it yielded by dispersion, retained the same in- 

 tensity in every position of the analysing prism, and therefore 

 possesses a quaquaveisiis polarization, such as that which light 

 receives when transmitted through a congeries of minute 

 doubly refracting crystals, having their axes in all possible 

 directions. 



Jn making the same experiment with otherdispersing fluids 

 and solids, I found some in which the whole beam was com- 

 pletely polarized in the plane of reflexion, and others in which 

 it exhibited solely a quaqiiaversus polarization ; but as these 

 experiments indicate new processes in the decomposition and 

 polarization of light, which require a more extended analysis, 

 I shall resume the subject in a separate communication, con- 

 tenting myself at present with a general account of the more 

 important facts, and the results to which they lead. 



Having transmitted a condensed beam of light through an 

 alcoholic solution of the leaves of the common laurel, or of 

 tea, either green or black, I found that the bfight red beam 

 which it dispersed, possessed, like the blue one in the quini- 

 ferous solution, a quaquaversus polarization, a small portion 

 of the light being polarized in the plane of reflexion. The 

 green beam dispersed by the preparation of orcine has the same 

 properties, the white portion of it disappearing and reappearing 

 during the revolution of the analysing rhomb. In the aqueous 

 solution ofesctdine*, the dispersed pencil consists of two finely- 

 contrasted pencils ; the one ro/iiiis/i and polarized in the plane 

 of reflexion, and the other a voy deep blue, having quaqiia- 

 versus polarization. The xvJiite pencil is more intense than 

 the blue one, which is the very reverse of what takes place in 

 the solution of quinine. The alcoholic solution of the seeds 

 of the Colchicum autumuale gives a bright and copious gree?i 

 beam of dispersed light, which consists of two pencils, one 

 whitish and polarized in the plane of reflexion, and the other 

 bright green, with a quaquaversus polarization. The same 

 property is possessed by a solution oi' guaiacum in alcohol, 

 which disperses, by the stratum chiefly near its surface, a 

 beautful violet light; and also by an alcoholic solution of std- 

 ])/ia/e (fstnjc/itiine, which disperses a green light, after it has 



* In the :ilcoholic solution of esciiline, thc/ain^6/utf approaches to violet. 

 The polarization is like that in quinine. 



