G6 RECORDS 



induction of the circuit, and K is the coefficient of the term 

 consisting of products. Just what mechanical coordinate is to 

 be represented by x is partly a matter of choice. Maxwell 

 chose one whose velocity means a motion of the wire in the 

 direction of its length. There is one other coordinate which 

 seems to be geometrically possible, although it is not one that 

 is naturally suggested by the most satisfactory hypotheses now 

 in vogue as to the nature of an electric current. This other 

 coordinate is one such that its velocity means a rotation of the 

 wire carrying the current around its axis of figure. If x has 

 this meaning, then if the coefficient K is not zero, Lagrange's 

 equations of motion show that if a current is suddenly started 

 or stopped in a wire there would be an impulsive torque acting 

 on the wire. The experiment was performed to look for such 

 an effect, if it existed. A straight piece of aluminium wire 30 

 cm. long and 0.25 cm. in diameter was suspended by a quartz 

 fiber in such a way that it was free to rotate, and by means of 

 mercury cups, a current could be passed through it at pleasure. 

 No effect of the kind considered was detected. If the value of 

 /T expressed in C.G.S. electromagnetic units, and referred to a 

 centimeter of the wire, had been as great as 0.OOO02, it could 

 have been detected. 



S. A. Mitchell, 



Secretary. 



SECTION OF BIOLOGY. 



May 12, 1902. 



Section met at 8:15 P. M., Professor Dean presiding. The 

 minutes of the last meeting of Section were read and approved. 



The following program was then offered : 



Edmund B. Wilson, Cell-Lineage and the Study of 

 Homologies. 



Gary N. Calkins, Artificial Parthenogenesis in Para- 



MCECIUM. 



Francis B. Sumner, Further Experimental Studies upon 

 Fish Development. 



