THE 



AMERICAN JOURNAL OF SCIENCE 



[FO URTH SERIES.] 



Art. XIX. — On the Effect of High Pressures on the Phys- 

 ical and Chemical Behavior of Solids ; by John Johnston 

 and L. H. Adams. 



Contents. 



Page 



Introductory 206 



Gen eral Effects of Uniform Pressure 207 



General, Effects of Non-Uniform Compression 210 



Influence of Unequal Pressure Upon the Melting Point 



of Crystalline Substances 212 



The Phenomenon of Regelation _. 215 



Influence of Unequal Pressure Upon the Solubility of 



Solid Substances ... 215 



Correlation of Mechanical Properties of Metals with 

 the (Unequal) Pressure required to Depress their 

 Melting Points to Ordinary Temperature _ 218 



Effect of Compression of One-Component Solid Systems 223 



A. The Flow of Solids under Compression 223 



Effect of (Non-Uniform) Compression on Solid 



Blocks' _• .. 226 



Effect of Pressure on Viscosity 229 



Residual Effect of Compression on the Density 

 of Solids ._ _ 231 



B. The Alleged Effect of Compression in Producing 



Crystalline Forms and in Effecting Transforma- 

 tions 232 



Effect of Compression in Promoting Chemical Reaction 



between Solids _ .._ 237 



A. The Formation of Sulphides and Arsenides by Com- 



pression . . . 238 



B. The Alleged Reaction between Solid Salts 240 



1. The Equilibrium — 



BaS0 4 + Na 2 C0 3 ^Z± BaC0 3 + Na 2 S0 4 240 



2. The Reaction between Potassium Nitrate and 



Sodium Acetate .. .. 243 



C. The Reputed Formation of Alloys by Compression.. 244 



The Work of G. Spezia 247 



The Interdiffusion of Solids _ 248 



General Remarks... 248 



Summary and Conclusion __. 251 



Am. Jour. Sci. -Fourth Series, Vol. XXXV, No. 207.— March, 1913. 

 15 



