Experimental Researches on Gravitation, 



491 



valued as null. We can suppose, in consequence of the 

 above stated hypothesis, that it would continually put forth 

 a certain flux, "proportional to dm, that is to say, kdm, 

 uniformly irradiated in all directions. Let us suppose the 

 particle to be in a vacuum ; across a solid angle subtending 

 the surface dco at the distance of 1, the flux would only be 



<£=/,• 



dm dco 

 Ait 



g in a vacuum is in a medium 



If the particle instead of bein 



of: true density B v , the flux that will have arrived at the 



distance x from the particle, will be expressed by 



7 dm dco _ Hx 

 k— - — e 



-±7T 



(1) 



This is equivalent to admitting a gradual absorption o£ the 

 flux, proportional to its value at every point, to the thickness 

 of the medium that has been crossed, and to the medium's 

 densit} r . It is supposed, in fact, that 



H = AS„ (2) 



H being the quenching factor for the density 8 V , and h the 

 quenching factor for density 1. 



We will now consider a massive sphere, with the uniform 

 density 8 V ; and determine the flux that emerges from it. 

 Let us call R its radius, its centre (fig. 1). I consider an 



inner point P of it, in which the mass dm would be concen- 

 trated. I trace the PO radius of the sphere passing through 

 P; and I trace QPB, an infinitesimal angle, with the vertex 

 at P ; I trace QA perpendicular to PQ. I say: OP— V ; 

 PQ = t i' ; QD=3/. I make the triangle QPA turn around 



2 K2 



