The letters concern Dewar's work on the low-temperature thermoelectric properties of bismuth; detection of impurities in bismuth; the writing of joint papers with Liveing, especially on their investigation of CN band spectra; unfavourable comments on Crookes's and Ramsay's work on the argon spectrum; his own and his wife's poor health. One letter, dated 18th June 1907, states Dewar's need for radium bromide.

There are five letters in total, each written on the Royal Institution of Great Britain embossed notepaper.