A NEW SOLAR THEORY. 175 



;H)})roach('s ;i stsitc in which attfiiclioii is coiintcThiilaiict'd hy I'cpuisive 

 forces ])ot\V{HMi the inoJcculcs. When this state is reached the o-as 

 would appear to obey Boyh^'s law, because th(^ molecular forces, to 

 which a (le^•iatioll from the law is due, neutralize each other. !^)ut 

 from this behavior of the gases at low^ timiperatures we may not yet 

 conclude that an augmentation of temperature will more and more 

 approach the gas to its ideal state as a limiting condition, and that 

 conse([uently the incandescent gases in the sun must be in the perfect 

 condition which was assumed by Lane when he derived his remarkable 

 law. Such a conclusion would take no account of the possibility of an 

 increase in the repulsive molecular forces with rising temperature. 

 That indeed the perfect state is not the final state at w hich the gas 

 arrives when its temperature is raised is clearly shown in the case of 

 hydrog"en. 



The researches of Wroblewski havo demonstrated that at very low 

 temperatures hydrogen behaves liki^ the other gases, showing a pre- 

 ponderance of molecular attraction. But already at ' Celsius the 

 gas exhil)its the predominating influence of repulsive forces, which 

 become more and more pronounced when the temperature rises. In 

 a yet un]:)ublished paper I have investigated, for a number of gases, 

 the behavior of the molecular forces with changing temperature. By 

 a simple modification of the equation of van der Waals T have suc- 

 ceeded in representing the isothermal curves of these gases up to the 

 highest pressures hitherto attainable (3,000 atm.). The new equation 

 of state, which is in accordance with Clausius's equation of the virial, 

 enal)les us to study the influence of temperature on the attractive and 

 repulsive molecular forces. In all cases the atti'active forces have 

 been found to diminish with increasing temperature, a result in 

 accordance with the outcome of the researches of Clausius and van 

 der Waals. But the repulsive forces, or to us(^ Andrews's expression: 

 "The forces w'hich tend to produce a resistance to diminution of vol- 

 ume," appear to increase very rapidly when the temperature is raised. 

 The investigation leads to tho conclusion that at the temperature of 

 the sun the preponderance of repulsive forces between the molecules 

 of the gases must be very consideral)le. But it can be shown that 

 under such conditions Lane's law loses its validity, so that a celestial 

 body, although gaseous, may shrink under loss of temperature. This 

 would remove an objection to the solar theory hei'e advanced, which 

 otherwise might be urged on the ground of its being in opposition to 

 a theorem Indd by many to constitute one of the fundamental laws in 

 the evolution of stars. 



An objection may also bc^ rais(Hl against the assunqition that sohir 

 eruptions are real outbursts of mattei- into the higher regions of the 

 solar atmosphere. To many astrophysicists it appears difficult to 

 account for the erjormous velociti(\s exhibited l)y these phenomena on 



