(b. Edinburgh, Scotland, 3 November 1749; d. Edinburgh, 15 December 1819) chemistry.
An uncle of Sir Walter Scott’s, Rutherford is mentioned frequently in works devoted to the life and letters of the famous novelist; his place in the history of chemistry depends solely on his discovery of nitrogen. He was a son of John Rutherford, professor of medicine at the University of Edinburgh from 1726 to 1765, and his second wife, Anne Mackay: Scott’s mother was Daniel Rutherford’s stepsister.
A pupil of William Cullen and Joseph Black at Edinburgh, Rutherford traveled in Europe for about three years after obtaining his M.D. and before beginning practice at Edinburgh in 1775. Shortly afterward he became a member of the Philosophical Society of Edinburgh (later the Royal Society of Edinburgh), and in 1786 succeeded John Hope, father of Thomas Charles Hope, as regius professor of botany at the university. In the same year he married Harriet Mitchelson: they had two sons and three daughters.
Rutherford’s M.D. dissertation, dated 12 September 1772, was devoted mainly to the discoveries regarding the gas that Black had called “fixed air” (carbon dioxide), but which Rutherford preferred to call “mephitic air”. About two-thirds of the way through the work he wrote that, having dealt with the air from calcareous bodies, he would say something of the air rendered malignant by animal respiration. He noted the contraction of air in which animals had been confined, and said that by their respiration good air became in part “mephitic” but also suffered a further change: the separation of the mephitic air by means of a caustic alkaline solution did not render the remaining air wholesome. Although it gave no precipitate with limewater, it nonetheless extinguished flame and life.
This is the earliest published account of the awareness of a gas (nitrogen) that, although unable to support life and combustion, was clearly not Black’s “fixed air.” There can be little doubt about Rutherford’s priority of publication, but priority of discovery seems attributable to Cavendish, Priestley, or Scheele. Cavendish, in a manuscript published thirty years after his death by W.V. Harcourt (Report of the British Association for the Advancement of Science, 1839 , 64–65), wrote: “Air which has passed thro’a charcoal fire contains a great deal of fixed air... but... consists principally of common air, which has suffered a change in its nature from the fire.” He removed fixed air from air in which charcoal had been burned and found the remaining air unfit for combustion and of a density slightly less than that of common air.
The paper was undated but was marked “communicated to Dr. Priestley.” The latter gave an inaccurate account of it in his classical paper “Observations on Different Kinds of Air,” read (over four meetings) to the Royal Society in March 1772 (Philosophical Transactions of the Royal Society62 , , 147–252, see 225; the volume was not published until 1773). A few pages earlier in the same paper Priestley described how, in one of his own experiments, air in which moist iron filings and sulfur had been confined had decreased in volume by approximately a quarter; the remaining air gave no precipitate with limewater and was less dense than common air. Scheele’s observation that air consisted of two gases, his names for which are usually translated as “vitiated air” (nitrogen) and “fire air” (oxygen), was not published until 1777 but may have been made as early as 1771.
I. Original Works. Rutherford’s Dissertatio inauguralis de aere fixo dicto, aut mephitico (Edinburgh, 1772) is his only work of importance. An English translation by A. Crum Brown (communicated by L. Dobbin) is “Daniel Rutherford’s Inaugural Dissertation,” in Journal of Chemical Education, 12 (1935), 370–375. Rutherford also published a short account of a maximum and minimum thermometer, the design of which has been attributed to him but which he clearly attributes to his father, in “A Description of an Improved Thermometer,” in Transactions of the Royal Society of Edinburgh, 3 (1794), 247–249. The authorship of two works ascribed to Rutherford by M.E. Weeks is uncertain.
II. Secondary Literature. M.E. Weeks, “Daniel Rutherford and the Discovery of Nitrogen,” in Journal of Chemical Education, 11 (1935), 101–107, repr. with additions in M.E. Weeks and H.M. Leicester, Discovery of the Elements, 7th ed. (Easton, Pa., 1968), 191–205, gives numerous references of Rutherford in the literature about Sir Walter Scott. D. McKie, “Daniel Rutherford and the Discovery of Nitrogen,” in Science Progress, 29 (1935), 650–660, gives a translation of the relevant sections of the dissertation.