1054 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1954 



24. Gait, Yaser and Merritt, Phys. Rev., 93, j). 1119, 1954. A more detailed de- 



scription of this work is in preparation. 



25. Yager, Gait, Merritt and Wood, Phys. Rev., 80, p. 744, 1950. See Equation 



(A-6). The X of the present paper is equal to y a M, in the notation of this 

 reference. 



26. N. Bloembergen and S. Wang, Phvs. Rev., 93, p. 72, 1954. 



27. D. W. Healy, Jr., Phvs. Rev., 86, p. 1009, 1952. 



28. G. T. Rado and J. R. Weertman, Phys. Rev., 94, p. 1386, 1954. 



29. Gait, Matthias and Remeika, Phys. Rev., 79, p. 391, 1950. 



