xxxii Trans. Acad. Sci. of St. Louis. 



Prof. F. E. Nipher made some informal remarks on some 

 properties of Radium, as compared with certain other bodies, 

 indicating, that much of the mystery, now connected with 

 radium, will probably soon be cleared, as we get better 

 acquainted with it, finding it subject probably to well-known 

 physical laws. His remarks were followed by a discussion. 



The Treasurer reported further voluntary contributions, 

 amounting to a total of $248.00. 



February 15, 1904. 



Dr. Wm. Trelease presiding; twenty-eight persons present. 



Rev. Martin S. Brennan delivered a popular lecture on the 

 " Nebular Hypothesis," illustrating same with lantern views. 

 He explained the theory of La Place, according to which the 

 heavenly bodies were formed by a condensation of gases into 

 nebular masses, these in turn condensing farther by the force 

 of gravity, the interior increasing in pressure, centrifugal 

 motion and heat, while the peripheric motion decreased and 

 gradually cooled the mass, until it formed a crust, growing 

 thicker in time ; this crust being at first surrounded chiefly 

 by carbon-dioxide gases, soon allowing the existence of plant 

 life, later followed bv animal Ufe. From this he deduced 

 the five geological eras, corresponding with the ages of 

 paleontology. 



Mr. Nipher remarked, that he had applied the equations for 

 gaseous nebulae, which had been deduced in his paper on the 

 Law of Contraction of Gaseous Nebulae, to the case of our 

 own planetary system. Introducing an integration constant 

 into the pressure formula, the pressure, — and as conse- 

 quence the temperature, — can be made zero at any radius 

 from the center. He had given the constant a value, which 

 made the mass of the nebula equal to that of the entire solar 

 system. When the nebula has reached such a stage, that the 

 mass external to Neptune's present orbit, is equal to Nep- 

 tune's mass, the density at Neptune's orbit will be 1.93 X 10~^* 

 grammes per cc, and the pressure will be 1.49 X 10~^® atmos- 

 phere. The outer limit of the nebula will be about half a 



