WILLIAM D. HARKINS 177 



A = Lambda, equivalent conductance 

 M = Mass 



w = Molality, or concentration in mols per 1,000 gm. of solvent 

 /x = Mu, ionic strength (respectively, a unit of length = io-^ cm.) 

 iV = Number of mols (respectively, number of electronic charges on a particle) 

 1^ = Frequency of vibration = 6"/X 

 P = Potential 

 p = Pressure 

 i?= Gas constant 



= 8.317X10' ergs per degree per molecule 

 = 1.9885 calories per degree per molecule 

 /' = Radius 



p = Rho, density (respectively, electrical density) 

 5 = Spreading coefficient 



r = Temperature on the Kelvin (absolute) scale 

 Tc — Critical temperature 

 T^A^a + = Transference number of the sodium ion 

 I) = Volume 



= Phi, electrical potential at a phase boundary 

 IF = Work (respectively, weight) 

 Wa = Work of adhesion 

 Wc = Work of cohesion 

 X = Field strength in electrostatic units 

 Z = Valence of an ion 



BIBLIOGRAPHY 



CRYSTAL STRUCTURE 



1. Bragg, Sir W.: Concerning the Nature of Things. New York: Harper & Bros., 1925. 



2. Bragg, W. H. and W. L.: X-Rays and Crystal Structure. New York: Harcourt, Bruce & 

 Co., 1924. 



3. Clark, G. L.: Applied XRays. New York: McGraw-Hill, 1927. 



ATOMIC STRUCTURE 



1. Andrade, E. N. da C: The Structure of the Atom. London: G. Bell & Sons, 1927. 



2. Lewis, G. N.: Valence and the Structure of Atoms and Molecidcs. New York: Chemical 

 Catalog Co., 1923. 



3. Harkins, W. D.: "The Stability of Atom Nuclei, the Separation of lostopes, and the 

 Whole Number Rule," /. Frankl. Inst., August, 1922, to April, 1923. 



4. Born, M.: Probleme der Atommechanic. Berlin: Springer, 1926. 



5. Schroedinger, E.: "Quantisierung als Eigenwert Problem," Ann. d. Phys., 79, 361, 489. 

 1926; 80, 437. 1926; 81, 109. 1926. 



IONIZATION OF SALTS IN SOLUTION AND THE ACTIVITY COEFFICIENT 



1. Lewis, G. N., and Randall, M.: Thermodynamics. New York: McGraw-Hill, 1923. 



2. Eucken, A., Jette, E. R., and la Mer, V. K.: Physical Chemistry. New York: McGraw- 

 Hill, 1925. 



3. Debye, P., and Hiickel, E.: Physikal. Ztschr., 24, 185, 305. 1923. 



