on the Electrical Resistance of Bismuth. 201 



There is, then, a notable difference, with regard to the 

 molecular structure, between bismuth prepared in a draw- 

 plate and that which, having been melted, has been allowed 

 to cool slowly. One may conceive in this latter case that the 

 crystals take up their own positions during the cooling, whilst 

 the metal prepared in a drawplate is formed of parallel fibres 

 of bismuth. 



More complete electrical researches might make clear this 

 important question of molecular physics. On e might especially 

 compare bismuth, compressed in an ordinary compressor, with 

 that prepared in a drawplate. 



VII. Conclusions. 



To sum up, the diminution of electrical resistance observed 

 in certain kinds of bismuth and in some alloys with lead 

 cannot as yet be explained. The molecular structure, which 

 we have modified by tempering and compression, has a great 

 influence on the action of the temperature. 



We hope that our further researches will lead us to an 

 explanation of the anomalies which we have pointed out. 



In the course of this paper we have never mentioned the 

 name of Prof. Ad. Wiillner, our learned and venerated 

 master ; we might well have done so at each step. We are 

 glad to be able here to express our thanks to him for the 

 facilities which he has procured for us for undertaking our 

 researches. 



LaTboratoire de Physique de l'Ecole 



Technique Superieure d'Aix-la»Chapelle. 



November 1887. 



Note. 

 M. Gr. P. Gf-rimaldi has recently * studied the influence of mag- 

 netism on the thermoelectric properties of bismuth. He denotes 

 by e the thermoelectric electromotive force of the bismuth-copper 

 couple, when it is out of the magnetic field ; by e' the electromotive 

 force of the same couple in the magnetic field ; and takes for a 



measure of the phenomenon the quantity £= . 



This physicist finds that I is positive for commercial bismuth and 

 negative for pure bismuth. 



One ought, perhaps, to compare this result with those we have 

 obtained relative to the influence of temperature on the electrical 

 resistance of different kinds of bismuth. — Edm. von Atjbel. 



* Journal de Physique, Dec. 1887, p. 569. This paper is a resumS 

 written by the author of a preliminary note presented to the R. Accademia 

 dei Lincei (Feb. 7, 1886) and of a memoir presented in June 1886 to the 

 Societa di Scienza naturali ed economiche di Palermo. 



See also Beiblatter zu den Annalen der Physik, 1887, no. 6, p. 472. 



