APPENDIX. 697 



Since 1869 the principal contributions to the subject have been 

 made by Bernhardt (' Archiv fur Psychiatric ', vol. iii., 1872), Weir 

 Mitchell ('Injuries of Nerves', 1872), Ferrier ('Functions of the 

 Brain', 1876), and G. H. Lewes (' Brain,' No. i., April, 1878). 



Bernhardt supports the intermediate view that our notions of 

 ' resistance ' and ' weight ' are derived principally from an appre- 

 hension of the degree of outgoing energy in the volitional centre, 

 though in part, also, from ordinary centripetal impressions. Weir 

 Mitchell also holds an intermediate doctrine: he admits the efficacy 

 of ordinary centripetal impressions from skin, joints, and muscle, 

 though he, in addition, relies upon an estimation of another kind, 

 more distinctly connected with the volitional act, either in the 

 manner suggested by Scaliger and Wundt, or else after the fashion 

 suggested by the present writer in 1869. His words are (loc. cit. 

 p. 358) : "Probably, then, a part of those ideas which we are pre- 

 sumed to obtain through the muscular sense are really coincident 

 with, and necessitated by, the originative act of will, or else are 

 messages sent to the sensorium from the spinal ganglia which every 

 act of motor volition excites." Weir Mitchell adduces many 

 extremely interesting facts in reference to the sensations in ques- 

 tion, and the power of recalling feelings of movement referred to 

 amputated limbs, which have a very interesting bearing upon this 

 subject. He thinks, and his facts seem to show, that something 

 more than mere ordinary centripetal impressions require to be 

 postulated; but he admits that these facts may be explained just 

 as well by impressions passing to the sensorium from spinal as 

 from cerebral motor centres. So far, therefore, Weir Mitchell's 

 views are closely in accord with those previously expressed by 

 the writer in 1869 though this was apparently unknown to 

 Mitchell at the time of the publication of his work. 



The reasons cited by the present writer in 1869 seemed quite 

 sufficient to entitle him absolutely to reject the notion that degrees 

 of 'resistance' and 'weight' were apprehended through the cerebral 

 motor centres, rather than from centripetal impressions. The 

 grounds for this rejection have been, however, very decidedly 

 strengthened by Ferrier. Experiments made by himself and 

 Lauder-Brunton show that muscular discrimination of weight is 

 independent of the volitional act, since it can be exercised when 

 the muscles are made to contract artificially by means of the 

 electric stimulus (loc. cit., p. 228). The facts furnished by certain 

 persons suffering from complete Hemi-ancesthesia also seem con- 



