Quoted by Micheal Finn, 'The West Riding Lunatic Asylum and the making of the modern brain sciences in the nineteenth century', University of Leeds PhD thesis (2012).
Description:

'In elaborating [his view on the function of the cerebral hemispheres],... he [Carpenter] showed how he diverged from Ferrier's understanding in holding on to older ideas. He wrote:

I am disposed to believe that it is the augmented activity of the re-action between the Blood and the Nerve-substance, producing an excessive tension like that of an overcharged Leyden jar, rather than the direct stimulation of the nerve-substance itself, which causes the discharge of the Nerve-force that produces movement.

Carpenter did not think that the cerebral cortex directly stimulated the motor nerves, but rather that, in his words, it 'plays downwards on the motor centres contained within the Axial Cord; from which, and not from the Cerebral convolutions, the motor nerves take their real departure'. Stimulation merely excited a state of hyperaemia within a specific region of the cortex, which then acted upon the lower centres of the brain already known to be linked to muscular movements: his evidence was that when stimulated, some of Ferrier's dogs continued their purposive movements after the electrodes had been removed, but hyperaemia remained. As he put it, 'this could scarcely be the case if the stimulus acted directly on the nerve-substance. Whether the audience of the conversazione were convinced by this analysis is unknown, but Carpenter included it in revised versions of his Primciples of Mental Physiology - originally published in 1852 [sic] - with post-1874 editions including a 14-page appendix that almost directly replicated his.conversazione speech.' (146-148)

 

'If Carpenter questioned the novelty of Ferrier's findings, he was in no way uncertain of their validity, arguing that

the fact that other experimenters have not obtained the positive results which Dr. Ferrier has over and over again publicly exhibited, merely shows, in my opinion, that they have not succeeded in obtaining the precise conditions which are essential to the success of the experiments.

' (148)