THEORY OF ELECTRODYNAMICS L ACTION. 24!) 



grce in which the force is affected by the obliquity of the elements. 

 One of the general causes of equilibrium, of which we have spoken, 

 gave a relation between these two quantities ; a and as the power was 

 naturally, and, as it afterwards appeared, rightly conjectured to be the 

 inverse square, the other quantity also was determined ; and the 

 general problem of electrodynamical action was fully solved. 



If Ampere had not been an accomplished analyst, he would not 

 have been able to discover the condition on which the nullity of the 

 integral in this case depended. 3 And throughout his labors, we find 

 reason to admire, both his mathematical skill, and his steadiness of 

 thought ; although these excellences are by no means accompanied 

 throughout with corresponding clearness and elegance of exposition in 

 his writings. 



Reception of Ampere's Theory. Clear mathematical conceptions, 

 and some familiarity with mathematical operations, were needed by 

 readers also, in order to appreciate the evidence of the theory ; and, 

 therefore, we need not feel any surprise if it was, on its publication 

 and establishment, hailed with far less enthusiasm than so remarkable 

 a triumph of generalizing power might appear to deserve. For some 

 time, indeed, the greater portion of the public were naturally held in 

 suspense by the opposing weight of rival names. The Amperian 

 theory did not make its way without contention and competition. 

 The electro-magnetic experiments, from their first appearance, gave a 

 clear promise of some new and wide generalization ; and held out a 

 prize of honor and fame to him who should be first in giving the 

 right interpretation of the riddle. In France, the emulation for such 

 reputation is perhaps more vigilant and anxious than it is elsewhere ; 

 and we see, on this as on other occasions, the scientific host of Paris 

 springing upon a new subject with an impetuosity which, in a short 

 time, runs into controversies for priority or for victory. In this case, 

 M. Biot, as well as Ampere, endeavored to reduce tlie electro-magnetic 

 phenomena to general laws. t The discussion between him and Am- 

 pere turned on some points which are curious. M. Biot was disposed 

 to consider as an elementary action, the force which an element of a 

 voltaic wire exerts upon a magnetic particle, and which is, as we have 

 seen, at right angles to their mutual distance ; and he conceived that 



* Communication to the Acad. Sc., June 10, 1822. See Ampere, Recueil, p 

 292. 



1 Recueil, p. 314. 



