MEMOIR OF MAGENDIE. 113 



"Scientific discoveries have very diiFerent destinies. Some, accepted with 

 enthusiasm from their very origin, traverse the woi'ld, everywhere exciting ad- 

 miration. So vast and focile is their success that we are tempted to assign them 

 to [hat cLass of brilHant errors which spring up at periods only too frequent to 

 satisfy an imperious necessity of the human mind, that, namely, of being de- 

 ceived. Other discoveries remain in the obscurity in which they are produced, 

 imtil some fortunate circumstance occurs to throAV light upon them and confer 

 renown on their authors. Others still, which at first enjoy a certain lustre, foil 

 to surmount the ill-will of cotemporaries, and after having striven for recognition, 

 eventually vanish and sink into oblivion, if they do not meet in time with some 

 efficacious succor. A remark of some importance which I had the honor of 

 presenting to the academy in 1839, and which may be regarded, I think, as a 

 discovery, happens unfortunately to fall at this time within the last category. 



" I shall not here recount its vicissitudes ; I shall only say that it has been 

 twice condemned by committees of the academy, since these committees have 

 conferred a prize on two works in which my discovery is qualified as erroneous. 

 Sustained by such respectable authority, it is the right of every one to think 

 that I have labored under an illusion, (a thing in itself quite possible, for who- 

 ever investigates is liable to err.) 



" Another ground may have existed for the same conclusion. I was a member 

 of the two committees; I abstained from co-operating with them, as it was proper 

 that I should; but it was in my power to have protested, and yet I have main- 

 tained a silence which has been doubtless construed as a tacit acknowledgment 

 of my error, although, in truth, it had a wholly diff'ereut signification. Prob- 

 ably my honorable colleagues acted on this occasion upon the maxim , Amicus 

 Plato, sed magis arnica Veritas. I am myself a strong partisan of this wise 

 maxim, and I have more than once put it in practice, taking care, however, to 

 prefer to Plato nothing but truth. 



"Why did my honorable colleagues not consult me? Why not ask to see 

 my experiments, which I should have been only too ready to repeat before 

 them ? I can only explain it by a sentiment of benevolent discretion towards 

 a colleague whose position might appear to them embarrassing. However this 

 may be, to foreclose all discussion, I concede that those who have not seen my 

 experiments might well regard my discovery as seriously compromised; for un- 

 fortunately the physiologists who have thought proper to reproduce them have 

 done so in such a manner that it was impossible for them to verify the results. 

 Yet the fact in question is one which I regard as opening a new Avay to experi- 

 mental researches on the functions, still so obscure, of the nervous system. 

 There rests, then, on me an obligation to recur to this point of physiology, and 

 to put it in the power of every one to verify the exactness of the results which 

 I made known in 1839. 



"Let us first state in what consists the phenomenon which in the year just 

 mentioned I denominated sensibility en retour, but which at present 1 think it 

 preferable to call recurrent sensibility. 



" If we lay bare, with suitable precautions, a pair of the rachidian nerves, we 

 ghall recognize that the two roots are sensitive, but that they are so by very 

 different titles. In the posterior, the source of the sensibility is at the centre 

 , and diffuses itself to the circumference; in the anterior, on the contrary, the 

 origin of the sensibility is at the periphery and is propagated towards the centre. 

 It is for this reason that I give to the latter the name of recurrent sensibility. 



" To prove that the sensibility of the anterior root really proceeds from the 

 periphery, I divide it transversely towards the middle of its length, and of the 

 two ends which result from its section, that at the periphery remains sensitive, while 

 the central is insensible. To demonstrate that this sensibility of the anterior ra- 

 chidian root is acquired and that it takes its source in the corresponding poste- 

 rior root, I divide likewise this last, and instantly the anterior root loses all its 

 8 s66 



