1. Lange's “Handbook of Chemistry”, 6th edit., 222 (Handbook Pub., Inc., Sandusky, Ohio). “Handbook of Chemistry and Physics”, 35th edit., 553 (Chemical Rubber Pub. Co., Cleveland, Ohio). Original source, Cusack, Proc. Roy. Irish. Acad., 4, 399 (1897).
2. Zelikman, A. N., and Belyaevskaya, L. V., Zh. Neorg. Khim., 1, 2239 (1956).
3. Joly, J., Phil. Mag., 27, 7 (1914).
4. See, for several examples of this rule, Gregg, “Active Solids”, “Surface Phenomena in Chemistry and Biology”, edit. by Danielli et al., 205 (Pergamon Press, 1958).