In later life he formed half of the successful Edinburgh publishing business Edmonston & Douglas.
In 1847 he formed a partnership to create Edmonston and Douglas, based at 87 Princes Street,[2] which lasted 30 years.
Douglas & Foulis appear to have operated a popular circulating library in the early 20th century, which, for a cost of one guinea per year, a member could borrow one book per month, and for ten guineas per year 30 books per month could be borrowed.
[6] In these final years he moved from his earlier more intellectual and historical focus to the republishing of American novels in Britain as cheap editions.
[9] His daughter, Sarah Wyse Douglas (d.1886), married the oceanographer, Sir William Abbott Herdman.