Humphrey Jackson’s certificate of 30 March 1772, recommending him for membership of the Royal Society, singled him out as a chemist who had discovered a method of making isinglass from British materials and ‘likewise for his invention of preserving Naval Timber from speedy decay’ (1). And yet, shortly after Jackson’s death in 1801, the compilers of the abridged
Philosophical Transactions
dismissed him as a charlatan (2), and Thomson’s
History of the Royal Society
referred to his ‘infamous practices’ (3). This paper aims at unravelling the truth by examining his activities and writings. Humphrey Jackson, born in 1717, would seem to have been the son of Thomas Jackson of Stockton-on-Tees, from whom he inherited a considerable fortune in 1746 (4). The son was apprenticed to a Stockton apothecary and surgeon in 1735 (5). Moving to London he set up as a chemist, married Elizabeth Savory in July 1743, and acquired property in Upper East Smithfield two years later (6). Jackson wrote three books and a tract under the name of ‘H. Jackson, chemist’. A cataloguer erroneously thought the author was ‘Henry’, so that all Humphrey’s works have been attributed to Henry Jackson in the British Library’s
General Catalogue of Printed Books
. The confusion spread to other libraries in Britain and the United States, with the result that no assessment has been made of Humphrey Jackson’s output as a whole. Nevertheless, internal as well as external evidence shows the authorship to have been his alone.
