142 BRIDGMAN. 



coefficient, the resistance decreasing to only 3% of its initial value 

 under 120000 kg. In spite of this abnormally large effect, the relative 

 variation with pressure of the pressure coefficient is much less than 

 that of sodium or potassium. The figures have already been given. 

 There is a reversal of behavior with rising temperature. At 0° and 

 50° the instantaneous pressure coefficient increases with rising pres- 

 sure, which is not what we would expect, but at 100° the coefficient 

 falls with rising pressure. The temperature coefficient of black phos- 

 phorus is abnormal in sign, being negative. The coefficient decreases 

 numerically with rising pressure, at first slowly, but more and more 

 rapidly. From the table of resistance it may be found that the mean 

 temperature coefficient between 0° and 100° are — 0.00579, 554, and 

 299 at 0, 6000, and 12000 kg. respectively. The readings at the 

 higher pressures are not so accurate as the others, so that possibly 

 the rate of fall of the coefficient at high pressures may be too rapid. 



Abnormal solids. Previously there were measurements on only 

 two abnormal solids, bismuth and antimony. The results for anti- 

 mony were not sufficiently accurate to show the variation of pressure 

 coefficient with pressure, but except for this the two metals agreed 

 in that the pressure coefficient increases with increasing pressure and 

 falls with increasing temperature, and the temperature coefficient 

 falls with increasing pressure. 



The instantaneous pressvu'e coefficient of lithium increases with 

 rising pressure, having the following values at 0, 6000, and 12000 kg. 

 respectively; 0.0 568, 0.0 574, and 0.0 5796. The accuracy of the 

 measurements was not sufficient to establish variations of pressure 

 coefficient with temperature, or of temperature coefficient with pres- 

 sure within the range. So far as the results are certain, however, 

 the behavior of Li is like that of Bi and Sb. 



For calcium the following values may be found from the table of 

 resistance. The instantaneous pressure coefficients at 0° have at 0, 

 6000, and 12000 kg. the respective values O.O4IO6, O.O4I2I, and O.O4I35. 

 The corresponding values at 100° are O.O592, O.O4IO7, and O.O4II9. 

 The pressure coefficient therefore increases with increasing pressure, 

 and decreases with rising temperature. The average temperature 

 coefficients of resistance between 0° and 25° are 0.00299, 0.00291, and 

 0.00281 at 0, 6000, and 12000 kg. respectively, thus decreasing with 

 rising pressure. Within the limits of error the temperature coefficients 

 between 75° and 100° are the same as between 0° and 25°. It would be 

 normal for the temperature coefficients to decrease with rising tem- 

 perature. In all particulars of comparison, therefore, Ca is like Bi 

 and Sb. 



