22 Trans. Acad. Sci. of St. Louis. 



ceased to be gaseous, it must be on account of the immense 

 pressure to which it is subjected. Its high temperature will 

 tend to preserve the gaseous state, but in the condensation of 

 a mass like the Sun, a time must at length arrive when the 

 influence of pressure will become predominant. Liquids will 

 then begin to form, though they cannot solidify while the 

 temperature is still very high. 



Accordingly, assuming in line with the best available evi- 

 dence that the body of the Sun is gaseous throughout, we 

 shall now treat of the theory of convective equilibrium, and 

 finally consider a very remarkable law of temperature, which 

 applies to all gaseous celestial bodies, and apparently throws 

 a new light on the processes by which the material universe 

 has reached its present condition. We have elsewhere* dis- 

 cussed the history of the discovery of this law, and as nothing 

 has since come to light to alter the statements then submitted, 

 we content ourselves with observing that considerable addi- 

 tional credit should be given to Ritter, with the contents of 

 whose researches the author was not acquainted at the time 

 of composing the former paper. Ritter appears to have been 

 the first investigator to arrive at the law treated in the con- 

 cluding part of this paper, but it received so little attention 

 from astronomers and other men of science that when the 

 present writer found the law independently and made it known 

 in the most learned circles, apparently no astronomer in this 

 country was acquainted with Ritter' s work. The importance 

 of his researches will be admitted by all who have read his 

 papers, but as some of his conclusions are contradicted by 

 well-established phenomena of the heavens, it is safe to assume 

 that a very cautious sifting of his results must be effected 

 before the truth can be arrived at. As the law of tempera- 

 ture announced in Astronomische Nachrichten, No. 3585, has 

 an important bearing on astro-physical theories, and yet to 

 some minds presents difficulties which are greater than could 

 have been anticipated, and on that account has been exten- 

 sively discussed by astronomers, some denying the existence 

 of such a physical law, others alleging that it was known 



* Astronomical Journal, No. 455. 



