Abstracts of Technical Articles from Bell System Sources (01 October 1930)

In answer to the first question emphasis is laid on the virtual identity between Laplace's generating function and the Cauchy-Poincaire characteristic function, on the close approach of Laplace's analysis to the form of the Fourier reciprocal equations and to the explicit presentation by Laplace of the Hermite polynomials and related Gram-Charlier expansion. In answer to the second question, the author submits Laplace's contributions to the probability of causes and points out the distinction drawn by Laplace between the meaning of the word limit when used outside the domain of probability theory and its meaning when the word is attached to the observed frequency with which an event happens. As evidence that the Theorie Analytique is in advance of much recent literature, and on account of its great practical value, the Laplacian method of dealing with integrands involving factors raised to high powers is outlined. 

In this connection attention is called to a Laplacian differential equation which contains, as a special case, the differential equation from which Karl Pearson has derived his famous system of frequency curves. Method, of Enhancing the Sensitiveness of Alkali Metal Photoelectric Cells.3 A. R. OLPIN . A technique is described for sensitizing alkali metal photoelectric cells to light by introducing onto the metal surface small amounts of dielectrics, as oxygen, water vapor, sulphur vapor, sulphur dioxide, hydrogen sulphide, air, sodium bisulphite, carbon bisulphide, etc., or some organic compound as methyl alcohol, acetic acid, benzene, nitrobenzene, acetone, etc., or some organic dye as tropaeolin, rosaniline base, eosin, cyanine, kryptocyanine, dicyanine, neocyanine, etc.