He was the son of Captain Reinhold Seehl (d. 1721), a German volunteer who worked his way through the ranks in the Swedish army.[citation needed] He settled in England and was naturalised as a British subject by Act of Parliament introduced in 1783 (23 Geo c. 8).[3]
Seehl occurs in a London subscription list in 1757.[4] He was one of just three people with addresses in Poplar and Blackwall to be found in Thomas Mortimer's Universal Director of 1763. There his entry reads "Seehl, Ephraim Rinhold, Copperas Merchant, Blackwall; or at the Bank Coffee-house, Threadneedlestreet." At this time he was leasing the Copperas Works in Bromley from his brother-in-law, the shipwrightJohn Perry of Blackwall Yard.[5][6]
Seehl worked on the compounds of sulphur. The distinction of its acids, and sulphur dioxide, was not clarified at this point. The preparation of sulphuric acid was known by the beginning of the 17th century. With Augustus Sala, Nicolas Lemery and J. C. Bernhardt, Seehl is mentioned as one of those working on methods for its production.[7] The method of making it by heating sulphur with saltpetre has been attributed to him.[8]
A new improvement in the art of making the true volatile spirit of sulphur (1744). Seehl was mentioned for this work in Johann Friedrich Gmelin's Geschichte der Chemie.[11]
A short treatise upon the art and mystery of making of copperas (1768)
^Ephraim Rinhold Seehl, An Easy Method of Procuring the Volatile Acid of Sulphur, by Ephraim Rinhold Seehl; Addressed in a Letter to the President and Fellows of the Royal Society, Philosophical Transactions Vol. 43, (1744 - 1745), pp. 1-9. Published by: The Royal Society. Stable URL: https://www.jstor.org/stable/104402