



Polarization of Galvanic Light. '•*". 375 



In reality forming a compromise between the two, what about 

 these views is peculiar, came deductively from another independ- 

 ent source. I submit them with no wish for their adoption if 

 they do not bring us nearer to nature. If there be error in them, 

 time and criticism will eradicate it ; if truth, science will appro- 

 priate it and thus be relieved from a present reproach. Finally 

 and with regret must I own, that my mind is too much overtask- 

 ed to permit of now making that clear and full development, 

 usually and justly demanded in support of new views. 



West Point, X. Y., Feb. 9, 1849. 



Art. XXXIII. — Polarization of Galvanic Light; by Chas. 

 G. Page, M D., Prof. Chem. National Med. College, Washing- 

 ton, D. C., Examiner of Patents, P. O. U. S. A. 



Having seen it stated* upon the authority of Arago, that the 

 light of the galvanic arc, like that from incandescent gas was not 



• - _ _»*m * * mm 



polarizable, I have been induced to repeat the experiment with a 

 view of testing for my own satisfaction, a principle so important 

 in a theoretical point o[ view. The experiment was briefly per- 

 formed and only with reference to the simple fact itself. The 

 battery employed was a Grove's, of fifty pairs, platinum plates 

 four inches square and double surface of zinc. By means of a 

 Nicols prism and one reflexion from a plate of mica, the light 

 from the arc between the charcoal points was distinctly polarized. 

 Its property in this respect was much more decided when the arc 

 was first formed than when it had continued for a few seconds. 

 It may be observed, that when the electrodes are first withdrawn 

 the arc is very intense, and does not rise in the arched form im- 

 mediately ; but as soon as the charcoal points have become in- 

 tensely heated, the arc becomes elongated and rises, from the up- 

 ward current of air, and the upper portion of the arc is then 

 feeble in intensity. This upper portion did not appear at all 

 polarizable upon a single reflection, but upon two reflections 

 was decidedly so. 



* Being poorly supplied with journals and very mu»h occupied in official labors, 

 I have been obliged t<> take the statement as I find it in ral works of high repute 



upon ti subject at ^alvanisuu &c. 



Washington, Feb. 19, 1849. 



