The sixth volume of Faraday's correspondence contains letters from the end of 1860 to his death in 1867. The dominant topic of the 1860s is Faraday's involvement with the lighthouse service relating to his advice to Trinity House and the Board of Trade on matters such as electric light and the controversial issue of fog signals.

The letters in this volume concern Faraday's work on topics such as terrestrial and atmospheric magnetism, the electrification of lighthouses and the theory of telegraphic retardation, as well as advice to the Government on the war with Russia, his exclusion from the Sandemanian Church and his views on table turning.

Almost 75% of the letters in Volume 3 were previously unpublished. During this period (1841-1848) he discovered the magneto-optical effect and diamagnetism, allowing him to argue for his views on the nature of matter.

Volume 2 covers the 1830s, a period when Faraday pursued the consequences of his discovery of electromagnetic induction and revised entirely the theories of electrochemistry and the nature of electricity. His correspondents include scientists of the day as well as antiquaries, military men, artists and politicians.