68 NEKVOUS SYSTEM. 



tions, should have stated that the posterior roots were motor 

 and the anterior roots sensory, precisely the reverse of the 

 truth, and should have advanced this view in a publication 

 as late as 1844. 1 In the work alluded to, which contains 

 some of the most extraordinary pseudo-scientific vagaries 

 ever published, it is curious to see how near Walker came to 

 the greatest discovery in physiology since the description of 

 the circulation of the blood. He gives an account of an ex- 

 periment as follows : " On opening the spinal canal of a 

 frog, accordingly, and performing the only operation on a 

 living animal which he ever has performed, or ever will per- 

 form, he found that, in perfect conformity with previous 

 reasoning, irritation of the anterior roots caused motion, 

 and irritation of the posterior roots caused little or none." ' 

 !N~ow, it does not appear in the work from which this quota- 

 tion is made at what time this experiment was performed ; 

 and we have not been able to ascertain that it w r as done be- 

 fore 1811 ; but, correctly interpreted, this observation had 

 been almost the great discovery. To conclude our review 

 of the claims of Walker, there can be no doubt of the fact 

 that he was the first to distinctly assign motion and sensa- 

 tion to the different roots of the spinal nerves, though he 

 incorrectly ascribed motor properties to the posterior roots 

 and sensory properties to the anterior, and brought forward 

 not one iota of proof in support of his theories. 



The claims of Mayo to the discovery of the distinct 

 properties of the roots of the spinal nerves are very indefi- 

 nite. He simply states, long after the publication of the 

 experiments of Magendie, that the "remarkable analogy 

 which exists between the fifth nerve and the spinal nerves 



1 WALKER, The Nervous System, anatomical and physiological : in which the 

 functions of the various parts of the brain are for the first time assigned, and to 

 which is prefixed some account of the author's earliest discoveries, of which the 

 more recent doctrine of Bell, Magendie, etc., is shown to be at once a plagiarism, an 

 inversion, and a blunder, associated with useless experiments, which they have nei- 

 ther understood nor explained, London, 1844, p. 50, et seg. 



* WALKER, op. cit., p. 18. 



