Injuries or inflammations of the brain are attended immediately with derangement of organs, or the most destructive consequences; whereas injuries of other parts, essential to the powers of life, and therefore called vital, appear rather by indirect means to impair the bodily functions; necessary to the proper performance of which, there is a very delicate organization of the whole, existing in close dependence on the circulation, or (the tout ensemble) of organic life. We may also argue something from the tenacity of life possessed by the nerves. While other parts of the body, even bone, may be destroyed by pressure, the nerves resist its destructive influence, as is evinced in the ligature of the surgeon passed round them in awkward operation, for however tight it may be drawn; it only impairs the communication between the extremity and the sensorium commune, producing no slough or death, as in other parts. Again, Our evidence of life is most clearly evinced in an alternate state of contraction and relaxation of parts. To which effect a nervous influence appears essentially necessary, for destroy the continuity of their chords, and though all other circumstances may remain the same, the action is prevented from taking place. “When the recurrent nerve on one side of the larynx is cut, the voice becomes sensibly weaker, when both are cut it is entirely destroyed.” From whence it is plain that the moving power is intercepted. But it may be, and I am aware it has been objected, to this inference that muscles may be made to contract by the application of stimuli after excision from the body. Which fact in my estimation only serves to prove the great tenacity and subtilty of the nervous influence. Anatomical research has traced the ramification of the nerve through all the fibre entirely diffused even till lost in pulp, and no one I believe has reason to doubt the complete dependence of _sensibility_ on the presence of the nerves, yet there is no instrument, however sharp, that can touch a single point in a muscle without producing a sensation more or less acute; which circumstance shews the entire distribution of the nerves. And until every part be entirely removed, I presume they may communicate their influence; which upon the application of stimuli will be evinced, though in a feeble and irregular manner. I therefore conclude we can not concede the important vis nervae, the direct influence of which is supported by demonstration, in favour of an imaginary inherent, or any other property of muscular matter.