This paper has as its object the preliminary work required for a proposed investigation of the vibrational spectra. The main body of the paper is divided into three sections. The first is an outline of the theory of normal vibrations. The second is the application of the theory to tetragonal white tin. The third is a summary of results. In its most modern form, the theory is to be found in a paper of Born and Begbie, Applications of the theory to various solids are to be found in papers of Eellermann, Smith and Curien. Other papers of particular interest include those of Blackman, Montroll, Houston and Kroll. The series of papers by Blackman deserve special study since his work provided the first quantitative measure of the defect in the Debeye continuum theory. Houston's paper proposed a method of approximating the frequency distribution. The interesting work of Montroll and of Kroll treat the problem by taking the specific heat as a given function and solving an integral equation for the frequency distribution.