Sir Archibald Geikie corresponded with a number of people both socially and professionally. Much of that in this series relates to issues of professional interaction, including appointments to office and academic writing. There is also much relating to geological research and surveying. A number of letters also discuss social engagements and other non-professional matters.

Geikie's relationship with both professional and educational bodies and other organisations has resulted in a significant amount of correspondence with relevant individuals in these organisations such as Thomas Lauder Brunton of the Royal Society, William Benjamin Carpenter of the University of London, Sir Robert Christison of the University of Edinburgh and William Sweetland Dallas of the Geological Society of London. There are also a sizeable number of letters from Rev William Branwhite Clarke of Sydney Australia and a number from James Croll concerning his financial situation.