1. R. C. Mackenzie, Talanta, 16 (1969) 1227.
2. F. Szabadváry, ‘History of Analytical Chemistry’. Pergamon Press, Oxford 1966, Chapters I & II.
3. The authors are indebted to Mr W. E. Carrington, late of the Division of Materials Applications, National Physical Laboratory (NPL), Teddington, Middx, U.K., for providing information on early electric furnaces from the NPL archives.
4. W. E. K. Middleton, ‘A History of the Thermometer and its use in Meteorology’, Johns Hopkins, Maryland 1966.
5. J. Prinsep, Phil. Trans. R. Soc., (1828) 79.