Reynolds, James Emerson (1844–1920), chemist, was born 8 January 1844 at 5 Booterstown Avenue, Blackrock, Co. Dublin, son of James Reynolds, doctor, and his wife (née Campbell), from England. He was named after his great-uncle, Capt. Emerson, RN. His father had literary interests and was the author of two plays, which were moderately successful. His sister was a dressmaker. From a young age he helped his father in his apothecaries’ hall in Booterstown, becoming his assistant after leaving school. Here he developed his interest in chemistry and experimentation and set up a small chemical laboratory at home. At the age of seventeen he published his first two papers, ‘On the oleaginous matter formed on dissolving different kinds of iron in dilute acids’ in Chemical News (1861) and ‘On a new process for photographic printing’ in the British Journal of Photography (1861). At that time he was assistant chemist in the Dublin Chemical Society, and closely followed developments in contemporary science. Over the next three years he published a number of papers in Chemical News and the Journal of the Royal Dublin Society on a range of subjects, which, while not generally ground-breaking, were remarkable as the work of a self-taught young chemist on areas of current interest. He continued his researches in photography and made several contributions (1861–5) to the British Journal of Photography, mostly on chemical subjects relating to photographic processes, such as the properties of albumen as a vehicle for the silver salts in printing paper, chemical tests for removal of hyposulphite of soda, and the manufacture of ammonium sulphocyanide (to be used as a substitute for ‘hypo’ in fixing). In 1864 he was editor of the British Journal Photographic Almanac.
Encouraged by his father he studied medicine at the Royal College of Physicians and Surgeons, Edinburgh, obtaining his licentiate 1865. He returned to Dublin and practised for a short time, but after his father's death abandoned medicine to follow his first love, chemistry. Devoting himself full-time to his experiments, despite his lack of formal training in theoretical or practical chemistry, he was offered, at the age of 23, the position of keeper of minerals (1867) to the RDS (then situated in Leinster House). For the first time he had access to a fully equipped professional laboratory. The following year (1868) he became chemical analyst to the RDS and made one of his most important contributions to organic chemistry, the isolation of thiourea (thiocarbamide), a sulphur equivalent of urea, which was known from theory but which notable chemists had failed to isolate. He published his findings in the Journal of the Chemical Society of London (1869) and established his reputation. Over the next few years he produced many new substitution products of urea and over sixteen derivatives of silicon, a subject he continued researching for the rest of his life. In 1871 he described the preparation of a compound of acetone with mercuric oxide, which became the basis of ‘Reynolds's test’ for acetone.
As well as pursuing his own research interests, his analytic work for the RDS included investigating artificial fertilisers and cattle food for adulteration, analysing the gas supply to the RDS, and testing the purity of whiskey from various distilleries around the country. A new spectroscope (1870), manufactured by the Grubb firm in Dublin, facilitated his investigations. Continuing the RDS tradition of public lectures, he contributed to scientific meetings on a variety of topics, including ozone, the chemical action of light, and absorption spectra. In 1872, at his own request, he was given the title of professor of analytic chemistry, the first such title given to anyone in an institute or university in Ireland or Britain. He was also professor of chemistry and physics at the RCSI (1870–75) and had a considerable practice as a consultant and public analyst. Interested in medical chemistry and hygiene, he was one of four authors of a Manual of public health in Ireland (1875) and was also responsible for the analysis of the Vartry water supply to Dublin. Like many others he was interested in investigating the potential uses of Irish peat.
In 1875 he accepted the position of professor of chemistry at the University of Dublin (TCD), resigning from his two other positions. The university awarded him an honorary MD degree (1876). He began teaching in earnest, finding plenty of scope for his drive and organisational ability, updating teaching, and improving the accommodation of his classes. An excellent lecturer, he was renowned for the strict discipline maintained in his classes. A pioneer in the use of periodic tables in lectures, he assigned beryllium its correct place in the periodic table, and emphasised the importance of teaching chemistry through practical experience, publishing a four-volume textbook, Experimental chemistry for junior students (1882), which ran to several editions and was translated into German. His innovative approach to the teaching of chemistry became universally adopted. He also introduced separate examination papers for organic, inorganic, and practical chemistry. From the beginning he campaigned with other staff members, including George Francis Fitzgerald (qv), for greater recognition of science in the university. He proposed (1888) several reforms including longer curricula, scholarships, studentships in pure and applied science, and degrees in science, including research and postgraduate degrees. According to McDowell & Webb, he lacked the diplomatic ability to improve the status of chemistry in the university, though three years later studentships and a D.Sc. were introduced. He was one of the first to receive the higher degree of D.Sc. (1891) from Dublin University. His complaints of inadequate pay eventually led to his resignation in 1903, aged 59. Moving to London, he continued his private research at the Davy-Faraday laboratory (1903–11) and in a small laboratory at his home. His last work, ‘On the synthesis of silicalcyanide and of a feldspar’, was published in the Proceedings of the Royal Society in 1913.
Recognised as a chemist of international standing, Reynolds was an active member of several institutions: the Institute of Chemistry of Great Britain and Ireland (founding and council member 1877–81, 1885–7, 1898–9; vice-president 1882–4, 1892–5), the Society of Chemical Industry (fellow 1873, president 1892, vice-president 1892–4), the Chemical Society (member 1873, vice-president; 1881–4, 1889–92, 1897–1900, president 1901–3), the British Association for the Advancement of Science (president of chemical section, Nottingham meeting 1893), and the Royal Society (fellow 1880, council member 1900–02, vice-president 1901–2), a unique feat considering that he lived outside London for most of that time.
He married (1875) Janet Elizabeth, daughter of John Finlayson, prebendary of Christ Church cathedral, Dublin; they had one son and a daughter. He had a serious accident in 1919, followed by a stroke from which he never fully recovered. He died 18 February 1920 at his home in Kensington, aged 76. His original specimen of thiourea is displayed in the chemistry department, TCD.