Buchanan, John Young

(b. Glasgow, Scotland, 20 February 1844; d. London, England, 16 October 1925)

oceanography, chemistry.

After graduating from the University of Glasgow in 1863, Buchanan studied chemistry at Marburg, Bonn, Leipzig, and Paris. He was appointed chemist, physicist, and geologist of the pioneering oceanographic expedition of the Challenger (1872–1876), under the leadership of Charles Wyville Thomson. He continued his oceanographic studies in his private laboratory in Edinburgh and on ocean cruises. Among his few long-time scientific associates was Prince Albert of Monaco.

Buchanan’s participation in the Challenger expedition shaped his scientific career. His work dealt mainly with the design and improvement of oceanographic instruments and observational methods, and with data collection—essential aspects of a young science. His research, always original and based on observations, was carried out with the utmost thoroughness and precision.

Certain of Buchanan’s publications contain important generalizations. He prepared the first reliable surface salinity map of the oceans. His analysis of spatial and seasonal distributions of salinity and temperature contradicted the widely adopted thermal circulation theory originated by Humboldt. Buchanan’s observations and speculations (1877, 1886) on thermohaline circulations in vertical planes were utilized and confirmed—at least for the subtropics—by J. W. Sandström in 1908 and A. Merz in 1925. Buchanan demonstrated that vertical currents from submarine sources supplied the cold surface water that is generally observed along the western shores of continents. He produced many valuable and meticulous studies on the physical and chemical properties of seawater and sea ice, and on the constitution, formation, and distribution of concretionary deposits of iron and manganese oxides discovered by the Challenger. He received much attention for his demonstration of the inorganic nature of the gelatinous deep-sea deposit that leading naturalists had thought to be a protoplasmic slime. Buchanan’s studies in limnology helped to establish the generality of the temperature stratification of temperate lakes and the concept of the thermocline (1886), and he pioneered in quantitative studies of seasonal variations in heat content of lakes. Buchanan seems to have worked purely for his own satisfaction, accomplishing more than his publications would indicate.

BIBLIOGRAPHY

I. Original Works. Buchanan collected most of his publications in four volumes: Experimental Researches on the Specific Gravity and the Displacement of Some Saline Solutions (Edinburgh, 1912); Scientific Papers, Vol. 1 (Cambridge, 1913); Comptes rendus of Observation and Reasoning (Cambridge, 1917); and Accounts Rendered of Work Done and Things Seen (Cambridge, 1919). Most of his papers published in scientific journals (more than 100) are listed in the Royal Society of London’s Catalogue of Scientific Papers (London, 1867–1925), VII, 291; IX, 386–387; XIII, 885. Some of Buchanan’s more important papers are “On the Distribution of Salt in the Ocean, as Indicated by the Specific Gravity of Its Waters,” in Journal of the Geographical Society (London), 47 (1877), 72–86; “On the Distribution of Temperature in Loch Lomond During the Autumn of 1885,” in Proceedings of the Royal Society of Edinburgh, 13 (1886), 403–428; and “On Similarities in the Physical Geography of the Great Oceans,” in Proceedings of the Geographical Society (London), 8 (1886), 753–768.

II. Secondary Literature. Information on Buchanan’s life may be found in two obituaries: in Proceedings of the Royal Society of London, 110A (1926), xii-xiii; and Proceedings of the Royal Society of Edinburgh, 45 (1925), 364–367.

Gisela Kutzbach