From John Perkins
ALS: American Philosophical Society
Boston March 12 1770
Just as I was about inclosing my papers5 it came in my head to mention to you a notion I have sometimes had that Pit-Coal is a vegitable production as of Grass or other Herbage of which the rich and fat Soil of our fresh Marshes is form’d.6 We know that these are constantly filling up by the Annual Supplys of this kind so that perhaps many places that were formerly Boggs or Marshes are now uplands over which Travelers pass without imagining they were ever otherwise.
What gave occasion to these Thoughts at first was the accounts the Irish at their first coming among us many years Since, gave of their Boggs. They assure me that on drying the Substance of them they make tollerable Fewel and the better as the lower they digg it. The bottom parts dry blackest and yield a Sulphureous Smoke nearly approaching that of Pit-Coal.
I should like to visit the Coal-Mines to see the Nature and Circumstances of them Or to gain by Conversation with those who are well acquainted with them some further insight concerning these Subterraneous Stores. I am Sir, as ever, Your most humble Servant
Endorsed: Dr Perkins. March 12, 1770
5. See the preceding document.
6. Pit coal and sea coal were terms for coal in the modern sense, as distinct from charcoal. This letter from Perkins may well have been what first aroused BF’s interest in the subject. In 1772 he visited a mine far under the sea, and soon thereafter outlined to Barbeu-Dubourg his theory—closely akin to Perkins’—of the vegetable origin of sea coal. Jacques Barbeu-Dubourg, Œuvres de M. Franklin … (2 vols., Paris, 1773), II, 199.