1. See the extensive treatment of this topic in W. Böttger, Qualitative Analysis, Leipzig, 1925 and C. R. Fresenius, Qualitative Analysis, 17th edn., New York, 1921.
2. Eine Neue Methode Zur Massanalytischen Bestimmung Von Nitraten
3. Reversible chromatic thermosensitivity
4. F. Feigl, Proc. Int. Symp. on Reactions of Solids, Gothenburg, 1952, p. 115.
5. Compare Cl. Duval, Inorganic Thermogravimetric Analysis, Amsterdam, 1953, pp. 189, 211.