Proceedings of the American Academy of Arts and Sciences. 

 Vol. XLV. No. 12. — April, 1910. 



CONTRIBUTIONS FROM THE JEFFERSON PHYSICAL 

 LABORATORY, HARVARD UNIVERSITY. 



THE CONCEPTION OF THE DERIVATIVE OF A 



SCALAR POINT FUNCTION WITH RESPECT 



TO ANOTHER SIMILAR FUNCTION. 



By B. Osgood Peirce. 



