TRANSACTIONS OF SECTION A. 549 



extent by iodides. Whether the sulphides also belong here is harder to say, but 

 is not unlikely. 



Tt has long been admitted as one of the most vulnerable points in the theories 

 of dissociation and the capillary electric phenomena that the values computed for 

 such cells as Hg- | KCl | Na^S | Ilg by the use of these methods for the terminal 

 E.M.F.'s and Planck's equations for the liquid contact (KCl | Na,S) do not agree 

 with the values obtained by direct measurement of the cell as a whole. The 

 tendency seems to have been to regard the contact Na^S | Hg as the disturb- 

 ing element ; but the views here presented point to the discrepancy really lying 

 in the determination of the value lor Hg | KOI. This, of course, has a direct and 

 important bearing ou the value for the standard electrodes now in common use. 



The same considerations serve to clear up some of the discrepancies between 

 theory and experiment in the phenomena of galvanic polarisation in general. 



The present paper is merely intended to indicate the line of reasoning which 

 has led up to, and act as a preliminary notice for, a series of experiments aimed at 

 a clearer separation and measurement of the individual components of these 

 phenomena which the author has at present in hand, and expects soon to bring 

 forward as basis for a more thorough and conclusive treatment of the v/hole 

 subject. 



9. Effect of Ron- Electrolytes on the Zippma7i7i Electrometer Curve, 



By J. A. Craw. 



10. Determination of the Surface Tension of Mercury by the 

 Method of Hippies. ByJ.A.Cnxw. 



11. 2'he Potential Differences of Allotropic Silver. 

 By J. A. Craw. 



MONDAY, SEPTEMBER 16. 

 The Section was divided into two Departments. 



Department I. — Mathematics. 

 The following Report and Papers were read : — 



1. Report on Tables of certain Mathematical Functions. 

 See Reports, p. 54. 



2. A Criterion for the Recognition of the Irregular Points of Analytic 

 Functions. By Professor Mittag-Leffler, Foreign Member R.S. 



Let c,3 + e,(.r — «) + a,(.r — «)■-+.. . be a lower series, and let us make the 

 analytical continuation of this series along the line L, which starts from a. The 

 paper dealt with the problem of finding a criterion which will determine the 

 first singular point x upon L, which is found on proceeding from a towards 

 infinity. 



The condition found was as follows : — 



_ Denote by e and 6 two positive quantities less than unity, and by 



(tt) (II) (in 



1901. 



