An equation for the viscosity of a liquid in terms of the energy of vaporization and the molal volume is developed from the reaction rate theory of viscosity due to Eyring. The degree of freedom corresponding to flow is assumed to be a translational one, and the energy of activation for the elementary flow process is assumed to be some fraction, 1/n, of the energy of vaporization. On applying this equation to a large number of normal liquids it is found that molecules possessing spherical symmetry have n = 3, while nonspherical molecules have n greater than 3, usually about 4. It is shown that the ratio ΔEvap/ΔEvis,  where  ΔEvis=R(d ln η)/(d(1/T)),can be taken as an index of the size and shape of the molecule, or more precisely, of the unit of flow in the liquid. The activation energy for flow in liquid metals is a very small fraction of the energy of vaporization, ranging from 1/10 to 1/25, leading to the conclusion that the metal ions flow without their valence electrons. Viscosity data confirm the S8 ring structure for sulfur below 160° and lead to the conclusion that above 250° sulfur probably consists of long chains containing as a rough average about 36 sulfur atoms. In the long chain hydrocarbons the activated configuration for flow is probably a curled up molecule. The structure activation energy of flow in associated liquids due to the hydrogen bond structure is discussed, and viscosity data are used to compute the degree of coordination in liquid water. At high pressures the energy of vaporization in the equation must be replaced by V(pinternal+pexternal). This yields an equation for computing either the internal pressure of a liquid or the viscosity under pressure, if either is known. Using Bridgman's viscosity data, values of the internal pressures of some liquids are calculated from this equation which agree with internal pressures calculated from compressibility data.

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Kaolinite was synthesized by heating coprecipitated AJ20 3-Si02 gels and mixtures of Al20 3 and Si02 with water in a pressure bomb at 310 0 C. Similarly dickite was prepared by treating coprecipitated Ah03-Si02 gels at 350 0 C and 365 0 C, beidellite from mixtures of Ab03 and Si02 at 350 0 C and 390 0 C, and also from co precipitated gels and kaolinite at 390 0 C. Nontronite was madc by treating a coprecipitated Fe203-2Si02 gel at 350 0 C. Beidellite was formed in these experiments in the presence of soda by transport of Si02 in solution to the Alz03 and reaction with Al20 3 in situ.The products were identified by X-ray patterns. Their optical properties were also consistent with those of the natural minerals. The stability ranges of kaolinite, dickite, and beidellite probably occur in the order named, with increasing temperature. This relation between kaolinite and dickite is consistent with geological evidence as to their formation in nature.

When minerals of the kaolin group are heated at constant rates there are two principal heat effects, a broad, pronounced endothermic effect near 5.'50 0 C and a sharp, intense exothermic effect near 950 0 C. New evidence, based largely on X-ray patterns of the kaolin minerals and of artificial alumina-silica gels after various heat treatments, leads to the following conclusions: (1) The endothermic effect is due to the dissociation of the kaolin m inerals into water vapor and an intimate mixture of amorphous Ah03 and amorphous Si02; (2) The exothermic effect is caused by the crystallization of /,-Al,03 from amorphous AI. Oa; (3) The delay in the crystallization of /,-AhOa until higher temperatures are Teached and the resultant intensity of the effect produced are due to the restraining action of the rigid amorphous SiOz network with which the AhOa is closely a~~ociated.

THEquantitative study of vapor-liquid equilibria in ternary systems has been a neglected field, largely because of the difficulty of