POLYMORPHISM AT HIGH PRESSURES. 

 By p. W. Bridgman. 



Received, January 13, 1916. 



TABLE OF CONTENTS. 



Page. 



Introduction 91 



New Data for Individual Substances 92 



Acetic Acid 92 



Acetamide 97 



Carbamide 106 



Camphor 110 



Potassium Acid Sulfate 119 



Ammonium Acid Sulfate 125 



Cuprous Iodide 130 



Ammonium Iodide 133 



Ammonium Bromide 135 



Ammonium Chloride 138 



The Antimony Sulfides 139 



Zinc Potassium Double Sulfate 142 



Thallium 143 



Ammonium Potassium Phosphate 144 



Potassium Binoxalate 146 



General Survey of All Substances Examined 146 



This includes all those substances which do not show new modifica- 

 tions in the range of this work. 



Discussion 165 



Summary 187 



Introduction. 



In a number of preceding papers ^ the phase diagrams and the other 

 thermodynamic data have been given for a number of polymorphic 

 transitions under high pressures. In this paper complete data are 

 given for ten new transitions, and incomplete data for five or six 

 others. This brings the total number of polymorphic substances 



. 1 P. W. Bridgman, (A) Proc. Amer. Acad., 47, 439-558 (1912). 



(B) Jour. Amer. Chem. Soc, 36, 1344-1366 (1914). 



(C) Phys. Rev., 3, 126-141 and 153-203 (1914). 



(D) Phys. Rev., 6, 1-33 and 94-112 (1915). 



(E) Proc. Amer. Acad., 51, 53-124 (1915). 



(F) Proc. Nat. Acad., 1, 513-516 (1915). 



(G) Proc. Amer. Acad., 49, 4-114 (1913). 

 (H) Proc. Amer. Acad., 51, 579-625 (1916). 

 (I) Proc. Amer. Acad., 52, 57-88 (1916). 



Throughout the rest of this paper reference to these papers will be made by 

 letter. 



