Transactions of the Wisconsin Academy of Sciences, Arts and Letters
volume IV (1876-1877)
Davies, J. E.
Report on recent progress in theoretical physics, pp. 241-264 PDF (6.7 MB)
Recent Progress inr Theoretical Physics. rotation of 900, we know that the difference of phase is then one- half an undulation. If A denote the length of the longer undula- tion, and 2', that of the shorter, then-- 6=m2 (m + )!'; or 2A m M _ 27n+1 2' n - 2m As - =m, and A may be determined by experiments in ref rac- tion, the value of m is known when 0 is measured. By pursuing this method, Mr. Babinet found the value of = 1.00003; a value which, small as it is, is the largest known for [non-magnetic] rotatory polarization." The first mathematical explanation of rotatory polarization as it occurs in quartz, appears to have been given by MacCullagh, in 1836 (Trans. R. Irish Acad., XVII). He succeeded perfectly in explaining the phenomena as they occur in uniaxial crystals, by introducing into the ordinary equations of vibratory motion in fluids, terms of the form c d±. So that the equations become: (1Z3 = b2 d 2+ Cd3~ dt2 de2 dz d b2 dz dze d.t2= d* cd Cauchy also appears to have furnished similar equations to M. Jamin, at the request of the latter, who compared them carefully with experiments, and found a perfect agreement so far as uniaxial crystals are concerned (Verdet-Lecons D'Optique Physique, Vol. II, p. 323). For biaxial crystals Verdet says: "La methode de MJac~Zullagh est tres remarquable: c'est un bel exemple de ce qu' on peutfaire quand on est re'duit a de simples conjectures." The matter has since been treated by M. Briot in an " Essai sur la theorie mathernatique de la lnmiere." He supposes a forced distribution of the ether in rotatory crystals, so that the lines of ethereal molecules are arranged in elliptic helices. This supposi- - tion introduces into the differential equations of vibratory move rn ent, differential coefficients of odd orders, the presence of which indicates the rotatory power. Airy has suggested similar equations for the rotation produced 253
Based on date of publication, this material is presumed to be in the public domain.| For information on re-use, see http://digital.library.wisc.edu/1711.dl/Copyright