[ 319 ] 
The Capacity for Heat of Metals at Low Temperatures. 
By E. H. Griffiths, Sc.I)., F. R.S., and Ezer Griffiths, M.Sc., Fellow of the 
University of Wales. 
Received June 16,—Read June 25, 1914. 
Contents. 
PART I. 
Experimental Methods and Results. 
Page 
Introduction.320 
(1) Description of the apparatus.320 
(2) Construction of the sodium block.322 
(3) Measurement of mass, time, electromotive force, &c.324 
(4) Measurement of temperature.325 
(5) Details of the standardisation of the thermometers.327 
(6) Heat capacity of subsidiary substances.329 
(7) Method of experiment.329 
(8) Experimental results. 332 
(9) Nernst’s method and results.337 
(10) Discussion of the experimental values of the atomic heats C p and the difference between 
G p and C„.* ... 339 
PART II. 
Comparison of the Experimental Results with those Deduced from Formula 
Based on the. “ Quantum ” Theory. 
(1) Theoretical formulae for C„.343 
(a) Einstein’s formula.343 
(b) Nernst and Lindemann’s formula. 344 
(c) Debye’s formula.344 
(2) Comparison of Debye’s formula with the experimental results when the limit frequency 
inserted is such that the locus coincides with the atomic heat curve over the lowest 
portion of the temperature range.347 
(3) Comparison of Einstein’s, Nernst and Lindemann’s, and Debye’s formulae with the 
experimental results when the frequencies inserted give coincidence at a temperature of 
about 125° C. abs.349 
(4) The frequencies inserted in the formulae compared with the values calculated from the 
physical constants.352 
(5) Theories of atomic heat which are not based on the quantum theory; with a note by 
Prof. Callendar.353 
YOL CCXIY._A 518. Published separately, October 1,1914. 
