1. The importance of demographic and material conditions for the development of science is argued in Harold Dorn, The Geography of Science (Baltimore: Johns Hopkins University Press, 1991). See also Norman J. G. Pounds, An Historical Geography of Europe 1800–1914 (Cambridge: Cambridge University Press, 1988), which includes much information relevant to chemical industry.
2. Walt W. Rostow, The Stages of Economic Growth, 2nd ed. (Cambridge: Cambridge University Press, 1971).
3. The lack of international significance is reflected in the standard histories of chemical industry. Thus no Danish companies or developments are mentioned in either L.F. Haber, The Chemical Industry, 1900–1930 (Oxford: Clarendon Press, 1971) or F.S. Taylor, A History of Chemical Industry (New York: Arno Press, 1972). Fred Aftalion, A History of the International Chemical Industry (Philadelphia: University of Pennsylvania Press, 1991) briefly treats Denmark and Norway as appendices to Sweden and singles out Nordisk Insulin and Novo, the two pioneering companies in insulin production, as noteworthy Danish enterprises in the interwar period (on p. 313).
4. Quoted in Helge Kragh and Hans J. Styhr Petersen, En Nyttig Videnskab: Episoder fra den Tekniske Kemis Historie i Danmark (Copenhagen: Gyldendal, 1995), p. 189.
5. Charles A. Thomas, “Chemical industry,” in Encyclopedia Britannica, vol. 5 (Chicago: Encyclopedia Britannica Inc., 1966), pp. 378–382, on p. 378.