HIGH PRESSURE BRIDGMAN. 195 



tion from the unstable to the stable, or ordinary ice, runs very slowly 

 indeed, so that there was time enough to examine the contents of the 

 cylinder, after opening it, before all the unstable variety had disap- 

 peared. It was found that the new substance was indeed a solid, 

 and that as it changed into ordinary ice it increased greatly in vol- 

 ume. Tammann performed this experiment for both the varieties II 

 and III. It might perhaps be possible to repeat the experiment for 

 the other two varieties, V and VI, but the chances of success are very 

 much less, because atmospheric pressure is so much further removed 

 from the equilibrium pressure for these two varieties that the reac- 

 tion would be expected to run very much more rapidly. What is 

 more, the behavior of these new varieties is in all respects like that of 

 the two varieties which we know to be solid ; that is, under some con- 

 ditions the reaction velocity is much greater than it ever is when a 

 liquid passes to a solid. Also, in some cases when one variety changes 

 to another, enough pressure is exerted on the thin steel vessel contain- 

 ing the ice to rupture it. It is difficult to conceive how a liquid would 

 develop enough pressure to rupture a steel vessel; one would expect 

 instead that it would flow away, relieving the pressure as fast as it 

 was formed. The overwhelming probability from all the evidence is, 

 therefore, that the other two varieties, V and VI, are solid also. 

 THE COAGULATION OF ALBUMEN BY PRESSURE. 1 



If the white of an egg is subjected to hydrostatic pressure at room 

 temperature it becomes coagulated, presenting an appearance much 

 like that of a hard-boiled egg. In my experiments the albumen was 

 inclosed in a nickel-steel case and pressure transmitted to it by mer- 

 cury. Pressure may be applied so slowly that the rise of temperature 

 due to the compression is inappreciable. At room temperature (20°) 

 the limits of pressure necessary to produce the coagulation were 

 fairly well marked. A pressure of 5,000 atmospheres (T5.000 pounds 

 per square inch) applied for 30 minutes produced a perceptible stif- 

 fening of the white, but little more ; 6,000 atmosphere for 30 minutes 

 produced a coagulation in appearance like curdled milk ; while 7,000 

 for 30 minutes resulted in apparently complete coagulation, the white 

 being capable of standing under its own weight. 



I have made no attempt to determine whether the nature of the 

 coagulation produced by pressure is the same as that produced by 

 heat. If one can judge by appearances the two may be different. -In 

 the course of 21 hours there separates from the pressure-coagulated 

 white a small quantity of some watery fluid, in which the coagulated 

 part remains insoluble. 



TWO NEW MODIFICATIONS OF PHOSPHORUS. 2 



The two modifications of phosphorus to be described here were 

 obtained during an investigation of the effect of high pressure on the 



1 Abstracted from the Journal of Biological Chemistry, Vol. XIX, No. 4, 1914. 



2 Extracted from the Journal of the American Chemical Society, Vol. XXXVI. No. 7. 

 July, 1914. 



