(1) The catalytic action of Japanese acid earth on naphthalene is greatly promoted when it contains the “retained water”, designated temporarily by the present author. (2) The molecules of the “retained water” may be replaced by those of several other neutral substances containing oxygen in their molecules, the catalytic activity of the earth being thereby raised to a greater or smaller extent according to the nature of the substance. (3) The term “degree of promotion” has been introduced, and the relation between the degree of promotion and molecular affinity has been discussed. (4) The nitrogen-containing substances such as ammonia, methylamine, acetonitrile, and amyl nitrite have been found to be strong poisons to the catalysis, while the acidic substances such as hydrogen chloride and acetic acid have proved to be quite weak poisons. (5) Chloroform, carbon tetrachloride, chlorobenzene, and many hydrocarbons have been found indifferent to the catalytic action.
(1) In the reaction between chlorine and ethylene chloride in the liquid phase 1,1,2,-trichlorethane is the principal product and in the gaseous phase the formation of hexachlorethane predominates. (2) The reaction between gaseous chlorine and liquid ethylene chloride seems to occur mainly on the liquid gas interface. (3) Hydrogen chloride gas dissolved in the mixture catalytically accelerates the reaction. (4) There seems to exist an induction period in the reaction between ethylene chloride and chlorine possibly owing to catalytic acceleration by either hydrogen chloride or substituted product or both in later stage. (5) In the gaseous reaction between chlorine and ethylene chloride the formation of hexachlorethane predominates especially when chlorine exists largely in excess to ethylene chloride vapour. (6) A suggestion is made as to the method of study on chemical reactions, especially on chlorination reaction (substitution).