In 1788 appeared Nicholson's ‘Elements of Natural History and Chemistry, translated into English, with Notes, and an Historical Preface,’ 4 vols., a work taken from the Count de Fourcroy's ‘Leçons d'Histoire Naturelle et de Chimie,’ 1781, together with a supplement ‘On the First Principles of Chemistry,’ 1789. It was about this time that he invented an ingenious form of areometer, and patented an instrument which bore his name, and was long in use by experimental chemists in all laboratories until superseded by Beaume's hydrometer. In 1788 Jean Hyacinthe de Magellan [q. v.] entrusted to Nicholson the manuscript memoirs of the Count de Benyowsky, a Hungarian adventurer who was shot by the French in May 1786 at Foule Point in Madagascar. Nicholson wrote a long introduction to these memoirs, which were published in 1790, 2 vols. 4to. A recent edition of the first part of this work was edited by the present writer in 1893.
In scientific research Nicholson attained some important results. Like Carlile and Ritter, he discovered the chemical action of the galvanic pile; and he communicated to the Royal Society in 1789 two papers on electrical subjects: ‘A Description of an Instrument which, by the turning of a Winch, produces the two States of Electricity without Friction or Communication with the Earth’ (Phil. Trans. lxxviii. 403); and ‘Experiments and Observations on Electricity’ (ib. lxxix. 265). In the same year he reviewed the controversy which had arisen over Richard Kirwan's celebrated essay on Phlogiston, and published a translation of the adverse commentaries by the French academicians Lavoisier, Monge, Berthollet, and Guyton de Morveau, viz. ‘An Essay on Phlogiston, to which are added Notes,’ London, 1789.
Nicholson was now living in Red Lion Square, London, where he acted as a patent agent, and took out four patents for inventions of his own, in 1790, 1802, 1806, and 1812 (the last was not completed). On 29 April 1790 he patented (No. 1748) a machine for printing on linen, cotton, woollen, and other articles, by means of ‘blocks, formes, types, plates, and originals, which were to be firmly imposed upon a cylindrical surface in the same manner as common letter is imposed upon a flat stone.’ ‘From the mention of “colouring cylinder” and “paper-hangings, floorcloths, cottons, linens, woollens, leather, skin, and every other flexible material” mentioned in the specification, it would appear,’ writes Dr. Smiles, ‘as if Nicholson's invention were adapted for calico-printing and paper-hangings, as well as for the printing of books. But it was never used for any of these purposes. It contained merely the register of an idea, and that was all.’ The scheme was never in practical operation; but Bennet Woodcroft, in his introductory chapter to ‘Patents for Inventions in Printing,’ credits Nicholson's patent with producing ‘an entire revolution in the mechanism of the art.’ It was not until seventeen years afterwards that Friedrich König consulted Nicholson as a patent agent about registering his invention of a cylinder printing press for newspapers. Nicholson's next published work was a translation of Chaptal's book, ‘Elements of Chemistry,’ 3 vols., London, 1795, and he also brought out ‘A Dictionary of Chemistry, exhibiting the Present State of the Theory and Practice of that Science, its Application to Natural Philosophy, the Processes of Manufactures … with a number of Tables,’ 2 vols. 4to, London, 1795; and two years afterwards he commenced his well-known ‘Journal of Natural Philosophy, Chemistry, and the Arts, including original Papers by Eminent Writers, and Reviews of Books, illustrated with numerous Engravings,’ 1797–1802, 4to; 1802–15, 8vo.
About 1799 he opened a school in Soho for twenty pupils; but after some years it declined, owing to Nicholson's diversified interests. He concentrated much of his attention on planning the West Middlesex waterworks, and he sketched arrangements for the supply of Portsmouth and Gosport from the springs at Bedhampton and Farlington, under the Portsdown Hills. He afterwards engaged in a similar undertaking for the borough of Southwark. In 1799 he also published a work translated from the Spanish ‘On the Bleaching of Cotton Goods by Oxygenated Muriatic Acid;’ and ‘Experimental Enquiries concerning the Lateral Communication of Motion in Fluids,’ 1799, from the French of Jean Baptiste Venturi. His next publications were ‘Elements of Chemistry,’ 1800; ‘Synoptic Tables of Chemistry,’ fol., 1801; and ‘A General System of Chemical Knowledge,’ 1804, all translated, with notes, from Fourcroy's ‘Système des Connaissances Chimiques,’ &c. An account of ‘Mr. W. Nicholson's attack in his “Philosophical Journal” on Mr. Winsor and his National Light and Heat Company,’ 12mo, was published anonymously in 1807.
In 1808 he printed ‘A Dictionary of Practical and Theoretical Chemistry, with Plates,’ &c., formed on the basis of his earlier ‘Dictionary,’ but ‘an entirely new work.’ This was the foundation of Ure's ‘Dictionary,’ which was published in 1821, avowedly on ‘the basis of Mr. Nicholson's;’ a book which has been carried on in successive
