802 



SCIENCE 



[N. S. Vol. XXXVI. No. 936 



SOCIETIES AND ACADEMIES 



THE ACADEMY OP SCIENCE OF ST. LOUIS 



The first meeting of the season was held at the 

 Academy Building on Monday evening, October 

 21, 1912; President Engler in the chair. 



Dr. G. O. James, of Washington University, 

 addressed the academy "On the Contingence of 

 the Physical Theory and the Problem of the 

 Geologic Past." 



After reviewing the theories of Helmholtz, Mach 

 and Enriques on the principle of causality, Dr. 

 James stated that as far as descriptive representa- 

 tion of the present is concerned, it makes no dif- 

 ference whether or not we admit that pushing the 

 precision of measurement further and further we 

 shall ultimately come to a point where there ceases 

 to be accord between observation and theory, and 

 beyond which it can not be again established. 



The postulate of causality builds the program 

 according to which we must envisage the geologic 

 past and prescribes the confines within which ex- 

 pectation places the future. Without it neither 

 would exist for us. In answer to whether a past 

 or future created in accordance with the postulate 

 of causality possesses reality, it was pointed out 

 that the older point of view, which regarded 

 empirical verification as a proof of reality, which 

 nevertheless did not cease to exist even when all 

 connection between the external world and its 

 representation was broken, has given way to a 

 modern conception of reality of which invariance 

 is the criterion, but regards this invariance as 

 relative and approximate. 



Dr. James also read an appreciation of the life 

 and work of Jules Henri Poincarg, who died 

 July 17. 



The academy met on Monday evening, Novem- 

 ber 4, 1912; President Engler in the chair. 



Professor Nipher, of Washington University, 

 gave a verbal account of work supplemental to 

 that published in his last paper.' This work has 

 reference to the longitudinal creeping of a copper 

 wire through which spark discharges are passed. 



In his latest work the wire is laid upon a strip 

 of plate glass having a length of 71 cm. 



The wire extends several centimeters beyond the 

 glass and the ends drop downwards about 8 or 

 10 centimeters. The discharges are sent into the 



' Trans. Acad, of Sc. of St. Louis, Vol. XXI., 

 No. 3. 



side of the wire from above, and just outside of 

 the glass support. Small brass cylinders are 

 placed between the wire and glass at the ends in 

 order to eliminate frictional contact at the edge 

 of the glass. The main portion of the wire rests 

 upon the glass. A condenser formed of tinfoil 

 and sheets of glass having the dimensions 26 X 26 

 inches was used. The total area of tinfoil in the 

 condenser was 2 X 15 square feet. 



The recent results were obtained when one of 

 the discharge terminals was grounded. When the 

 positive terminal is grounded a compression wave 

 is sent surging through the wire, and the wire is 

 driven in the direction of the corpuscular displace- 

 ment thus impressed upon the nebulous corpus- 

 cular column within the wire. 



When the negative terminal is grounded, a rare- 

 faction wave is sent through the wire in the op- 

 posite direction. The displacement is in the same 

 direction as before. The air-gap between the 

 positive terminal and the wire is then first con- 

 verted into a drainage or conduction channel, and 

 the discharge from the wire is drained into it. 

 The wire now creeps in a direction opposite to 

 that of the corpuscular displacement. In one case 

 an aluminum wire was made to creep over a dis- 

 tance of 18 cm. by the passage of about 1,200 

 sparks. 



When neither terminal is grounded the wire also 

 creeps in the same direction as when the negative 

 terminal is grounded. The surging effect of the 

 compression wave is then eliminated. This is the 

 condition discussed in Professor Nipher 's paper 

 forming No. 3 of Vol. XXI. of The Transactions 

 of the academy, to which reference is made in 

 Science, August 2, p. 153. 



When a short wire 4 or 5 cm. in length is placed 

 upon the glass plate, two or three cm. from the 

 creeping wire, it creeps in the direction in which 

 it is urged by the surging wave which is induced 

 in it. The direction is the same whether the wave 

 in the primary wire is one of compression or of 

 rarefaction, or whether both are simultaneously 

 imposed. The short wire is placed opposite the 

 middle of the primary wire. 



All of these creeping effects are reversed in 

 direction, when the direction of discharge through 

 the main wire is reversed. 



Mr. M. E. Hard also gave a brief talk on 

 "Mushrooms found in the Vicinity of St. Louis." 



George T. Moore, 

 Corresponding Secretary 



