348 Researches on the Electrical Resistance of Bismuth. 



The differences, which I pointed out at the beginning', 

 between the results of other physicists are easily explained 

 by the rarity of pure bismuth. 



Unfortunately I had not enough of pure bismuth to be 

 able to study compressed electrolyzed bismuth and its alloys 

 with tin and lead. 



Considering the great influence of very small traces of 

 lead, it is allowable to. suppose that the presence of this 

 foreign metal modifies the molecular structure of the bismuth 

 to a considerable extent ; unfortunately a microscopic ex- 

 amination could hardly give any result here. 



Finally, if the results which we have obtained in this 

 treatise be compared with those which we published in our 

 " Preliminary Communication/' it will be seen how much the 

 conclusions deduced from the experiments may vary accord- 

 ing to the nature of the impurities contained in metal. Also, 

 the question of the variation of the electrical conductivity of 

 bismuth with the temperature presents a difficulty of a chemi- 

 cal nature, and we strongly recommend physicists to make 

 known in their works the method of preparation, and if 

 possible the results of the analysis of the different bismuths 

 which they have examined. 



By means of the two following Tables my results may be 

 easily compared with those of other physicists. Jt appears 

 by the results that the bismuths studied by Messrs. L. Lorenz 

 and Righi were pure. 





Slowly cooled. 



Tempered. 



Compressed. 













R . 



K* 



R . 



K. 



R . 



K 



Brommsdorff... 



10 3 x 109-90 



0-003-25 



10 3 x 139-86 



0-00199 







Classen I 





0-00076 



10 3 x246 91 



-0-000603 







Classen II. a . . . 



10 3 x 124-69 



000299 



10 3 x 166-66 



4-0-00106 



10 3 x 236-96 



-000049 



II. b ... 







10 3 x 157-48 



4-O-00128 



10 3 x 251-26 



-0-00083 



II. G ... 







10 3 x 163-40 



+0-00116 



10 3 x 268-10 



-0-00105 



Classen III. a... 



10 3 x 156-74 



oobi'32 



10 3 x 204-50 



+0-00009 







III. b... 





000101 



10 3 x 208-33 



+0-00005 







Classen IV. a... 



10 3 x 170-07 



0-00126 



10 3 x 207-47 



-0-00004 







IV. b... 



10 3 x 168-35 



000113 



10 3 x 212-94 



-000008 







Electrolyzed Bi. 



10 3 x 10799 



0-00429 



10 3 x 108-69 



+0-00422 







* It is to be observed that all the coefficients of K in this column are 



positive. 



