364 Mr. F. C. Thompson on the Electrical and 



of the components, and p and q the fractional volume of each, 

 then it was shown that the added resistance r 



273e 2 



k J£ 



p q 



a result which does not contain n. Now in a pure metal if p 

 is the fraction of the volume composed of the crystalline 

 material, and q that of the remaining amorphous metal, and 



if k and k! are of the same order of magnitude, then - 



V P 



is negligible compared with — , since the amount of the 



amorphous constituent is so small. Hence, approximately, 



273e 2 q 



Since q is directly proportional to ?i, the increased resistance 

 in a pure metal due to the intercrystalline films is also 

 dependent on the number of crystals per cm. The total 

 resistance of the metal is, therefore, expressed by an equation 

 of exactly the same type as equation (1). Unfortunately, 

 the data required for the comparison of this result with that 

 (2) already determined experimentally are wanting, but the 

 coincidence of the general type of the equation with that 

 found experimentally is of the greatest interest, and affoids 

 further confirmation of the truth of the, at first sight, 

 unlikely theory of the amorphous intercrystalline cement. 



(B) Magnetic Properties. . 



The magnetic properties of the same samples of heat- 

 treated iron were determined ballistically with the aid of 

 Hicks' yoke. No correction lias been applied for the 

 reluctance of the latter, since relative values are sufficient 

 for the present purpose of correlating crystalline size with 

 magnetic properties. The results are summarized in Table II., 

 and the hysteresis loops are reproduced in fig. 1. 



These results indicate that the maximum induction for a 

 field of 95 gauss and the remanent magnetism are both, to 

 all intents and purposes, independent of the size of the 

 constituent crystals. They depend, therefore, apparently on 

 the nature of the crystalline material rather than on the 

 nature and number of the crystalline boundaries. The co- 

 ercive force, however, increases regularly with the number 



