ABSTRACT
Our goal in this paper is to understand the DC Branly effect by means of an experiment with a chain of metallic beads (Falcon et al. 2004; Falcon & Castaing 2005). Our focus is on the local properties (the contacts between grains). The second goal is to characterize and to explain the origin of the temporal fluctuations of resistance in a metallic powder submitted to a DC voltage in a 3D container (Falcon et al. 2004). In this second part, our focus is on the collective properties of the granular matter.
