474 [March 12, 



(6.) X=15-672-0-074045* + 0- 



corresponding to a percentage decrement of 36*010 per cent. 

 (7.) X=14-269-0-064133+0-0001456^, 



corresponding to a percentage decrement of 34' 7 '42 per cent. 

 (8.) X = 12-342-0-055894*+0-0001379# 2 , 



corresponding to a percentage decrement of 34'1 17 per cent. 

 (9.) Strip of iron, heated in a current of hydrogen at a red heat for 

 two hours. This, as well as Nos. 10, 11, 12, were hardened. 



X=14-673-0-067999-|-0-0001597* 2 , 

 corresponding to a percentage decrement of 35 '45 9 per cent. 

 (10.) As No. 9, heated for three hours under sugar charcoal in a 

 current of hydrogen; the carbon taken up was 0'99 per cent. 



X=10-654-0-044560+0-00009789* 2 , 

 corresponding to a percentage decrement of 32- 63 7 per cent. 

 (11.) As No. 9, heated for four hours under sugar charcoal in a 

 current of hydrogen; the carbon taken up was 0'933 per cent. 



X=9'925-0-040097*+0'00009168* 2 , 

 corresponding to a percentage decrement of 3 1 1 63 per cent. 

 (12.) As No. 9, heated for three hours under sugar charcoal in a 

 current of hydrogen ; the carbon taken up was 1*06 per cent. 



X=9-457-0-037573*+0-00008642* 2 , 

 corresponding to a percentage decrement of 30*592 per cent. 

 (13.) Thin music wire, melted with one quarter of its weight of 

 peroxide of iron under a flux of plate glass. 



X= 13-381 -0-056829*+0-0001230* 2 , 

 corresponding to a percentage decrement of 33 -278 per cent. 

 (14.) A piece of narrow watch-spring. 



X=8-565-0-029099*+0-00005383*', 

 corresponding to a percentage decrement of 27*689 per cent. 

 (15.) Commercial iron wire. 



X=13-772-0-058970* + 0-0001242* 2 , 

 corresponding to a percentage decrement of 33-801 per cent. 

 From the results obtained, it is obvious that the higher the con- 

 ducting power the higher the percentage decrement in the conducting 

 power between and 100. This has been proved to be the case with 

 about 100 alloys with which we have experimented. We have also 

 found that we may deduce the conducting power of a pure metal from 

 an impure one when the impurity does not reduce the conducting 



