abstracts: physical chemistry 47 



melting point and considerably affected by solid solution has been ob- 

 served in two forms. The ju-form (unstable) crystallizes from glass 

 at temperatures below about 950°, and transforms at somewhat higher 

 temperatures into the a-form (stable). The properties of both forms, 

 but especially the a-forms, are close to those of the mineral cordierite. 

 The effects of solid solution in flattening two of the boundary curvxs 

 of the field of this compound are discussed. The preparation and 

 properties of crystalline aggregates of substances which dissociate 

 when melting are considered. Crystals of natural cordierite dissociate 

 when melting. Brief consideration is given to the effects of FeO in 

 magnesian rocks and minerals. H. E. M. 



INORGANIC CUUMISTRY.— Solubility and fusion relations at high 

 temperatures and pressures. George W. Morey. Journ. Engin, 

 Club Phila. 35: 509-519. November, 1918. 



An address, giving a popular discussion of the principles underlying 

 the solubility relations of binary systems composed of both volatile 

 and nonvolatile components. In addition, some new compounds of 

 the alkalies with AI2O3 and Fe203 are described, as well as a new method 

 for determining solubilities under difficult experimental conditions. 



G. W. M. 



PHYSICAL CHEMISTRY.— r/z^ laws of chemical equilibrium. Ers- 

 KiNE D. Williamson and George W. Morey. Journ. Amer. 

 Chem. Soc. 40: 49-59. January, 191 8. 



In examining the complicated chemical systems which present 

 themselves in the study of geophysical problems it is found that the 

 approximate formulas used for dilute solutions break down and prove 

 worse than useless even for qualitative application. The monumental 

 work which the genius of Willard Gibbs evolved in 1876 remains the 

 safest guide and that to which reference must necessarily be made. 

 The extreme mathematical setting with which he surrounds his argu- 

 ments has militated against the general use of his results by chemists, 

 and a consequence of this is that much ink has been spilled in proving 

 by roundabout and far from rigid methods, theorems which are either 

 explicitly stated by Gibbs or are so readily deducible from his equa- 

 tions as to be implicit in his work. This paper has therefore been 

 written as an attempt to popularize, in so far as such a term can be 

 used in this connection, the derivation of the fundamental equations 

 and to deduce from them such additional formulas as are found neces- 



