THE LAW OF CONTKACTION OF GASEOUS 

 NEBULAE. 



Francis E. Nipher. 



In the discussion which follows it will be assumed that a 

 nebulous mass of spherical form, is gravitating towards a 

 central nucleus, and that the gas follows the law 



Pv=CT. (1) 



At any point in the mass, the heat dQ^ added to unit mass 

 of volume r, under increasing pressure is, 



dQ=C,dT+Pdv (2) 



Let it be assumed that when thus subject to compression 

 due to gravitation, the relation between pressure and specific; 

 volume is represented by the equation 



P." = f„=^. (3) 



It is required to find the value of n. Eliminating P in (1) 

 and (3), 



C 



By differentiation 



C 



dv = V''-ry-f .dT 



A{2 — n) 

 Combining this equation with (3) 



^'^^ = j&n<^'^- (4) 



Hence if this quantity be expressed in heat units, the spe- 

 cific heat of the gas will be 



(143) 



