THE LAW OF CONTEACTION 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 v, 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 



Pv- = j,,=A. (3) 



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

 and (3), 



C 



By differentiation 



C 



dv = v'* ~m X dT 



A{1 — n) 



Combining this equation with (3) 



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

 cific heat of the gas will be 



(143) 



