Copy letter from James Hopwood Jeans, Secretary of the Royal Society; [John Cunningham] McLennan, FRS Returns Grayson Smith's paper 'The band spectrum of potassium' [not enclosed] and states that measures are being taken to ensure the amended version of 'The Ultra-violet spark spectra of some of the elements' by R. J. Lang is published, including forwarding the letters Lang sent to John Cunningham McLennan to the referees. 8 April 1924