xl Trans. Acad. Sci. of St. Louis. 



The speaker read a letter addressed to him in criticism of this 

 paper by J. Willard Gibbs, in which the writer adduced certain gen- 

 eral objections to any atomic theory of energy. 



In conclusion, after commenting on Prof. Gibbs's views in the 

 light of later developments. Dr. Bostwick presented in abstract Poin- 

 care's discussion of Planck's theory, which is that a physical system 

 is susceptible only of a finite number of distinct states; it leaps from 

 one of these to the next without passing through any continuous 

 series of intermediate states. The universe leaps suddenly from one 

 state to another; but in the interval it must remain immovable, and 

 the divers instants during which it keeps in the same state can no 

 longer be discriminated from one another; wq thus reach a concep- 

 tion of the dis«ontinuous variations of time — the atom of time. 



Professor Wm. H. Eoever exhibited and explained '*A 

 Mechanism for Illustrating Lines of Force. ' ' 



The mechanism consisted essentially of two wheels with radial 

 spokes (about 8 inches in diameter) which could be made to rotate 

 in nearly coincident planes and thus render visible the loci of the 

 intersections of the spokes. In the Transactions of the Academy, Vol. 

 VII, No. 9, p. 201, Professor Roever has shown for what fields of force 

 the systems of curves exhibited by this mechanism are the lines of 

 force. 



May 6, 1912. 



President Engler in the chair ; attendance 45. 



The gift of a volume of ''Globus" and one of "Natur- 

 wissenschaftliche Rundschau" from Dr. Edward Evers 

 was announced. 



Professor James F. Abbott gave an interesting account 

 of "The Water Boatmen, an Unexplored Corner of the 

 Insect World." 



Mr. Chas. M. Gill gave an illustrated lecture on ' ' Rec- 

 reation Studies in Estes Park, Colorado." 



Mr. Frederick Hecker read a paper on "Microscopic 

 Studies of Living Organisms and Their Growth Rate." 



Dr. William Trelease was unanimously elected an 

 Honorary Member of the Academy. 



May 20, 1913. 



President Engler in the chair; attendance 62. 

 The following gifts to the museum were announced: 

 Dr. Joseph Grindon — Three Colubris from Guadeloupe, West In- 

 dies. 



