Nipher — The Law of Contraction of Gaseous Nebulae. 146 



SPECIFIC HEAT OF HYDROGEN. 



The values of the table which lie between those for constant 

 volume, and those for constant entropy, correspond to paths 

 on the surface of the figure, lying in the angle v^ m, k. In 

 these cases, pressure and temperature are increasing, volume 

 is diminishing and heat is being added to the gas. The spe- 

 cific heat is positive. The specific heat becomes zero on the 

 isentropic line m, ac, and between this line and the isothermal, 

 w, ^, the specific heat is negative. The temperature is rising. 



