to realize the speculations of philosophers, and to verify the deductions of reason, by demonstrating the existence of a subtile, active, vital principle, pervading mized, and denominated the Anima Mundi. The opinions which in former times were a justifiable hypothesis, seem to me now to be converted into a rational theory." It is then, I think, manifest, that Mr. Hunter's Theory of Life, presents us with the most probable solution of the phæ nomena of irritability, of any that has hitherto been proposed. vikim r The human mind has been the same at all periods of the world; in all ages there have been men of a sceptical disposition, disinclined to believe any thing that was not directly an object of their senses. At allperiods there have been other men of a contem 1 plative, and perhaps more credulous charac-> ter, who have been disposed to believe that there were invisible causes, operating to produce the alterations which are visible, and who from much less numerous facts have drawn the same inferences that I have done. And many of these, from Pythagoras downwards, have expressed their sentiments, though with some variety, yet pretty much to the same effect. The Greek philosophers recognized in man, the Equa, xn, and Nus, the body, vital principle, and mind, whilst some used words significant of intellect, to express the energizing principle in nature, without apparently having any elear ideas of intelligence. What was called the Anima Mundi, was, however, by many considered as a distinct and active principle, and was not confounded with intelligence of any kind. I know not how I can better exhibit to my au 1 dience the subject I am alluding to, or better acquaint them with the general tenour and tendencies of these opinions, than by quoting that portion of these philosophical notions, which Virgil is said to have put into the mouth of Anchises, Spiritus intus alit, totamque infusa per artus And please to observe, gentlemen, it is Virgil says, it is Anchises speaks, that which I also this day have been saying; Inde hominum pecudumque genus, vitæque volantum Et quæ marmoreo fert monstra sub æquore pontus. I proceed to speak of the structure and functions of the nervous fibres. The nerves which we observe pervading the body, appear to be packets of very minute threads, seemingly distinct from each other. The nerves divide and subdivide, and in so doing a certain number of threads separate from the original packet, and appear as a distinct nerve. It is, therefore, possible to trace a minute nerve, up to its origin, from the toe or finger, by splitting it off from the various packets with which it has been conjoined. So far does anatomical fact concur with the physiological opinion, that every nervous filament communicates distinctly with the brain or some process of that organ. This apparent continuity is, however, lost, whenever we find those intumescences on nerves which are called ganglia, for in these there seems to be a mixture or consolidation of the nervous matter. It is also lost wherever various nerves unite together, and form a plexus; in which case the nervous fibrils either coalesce, or become inextricably interwoven with one another. 2 The nerve from which the thoracic and abdominal viscera are chiefly supplied, is beset with numerous ganglia and plexuses; and as we cannot by our will influence the actions of those viscera, and as the iris, the motions of which are also involuntary, is supplied with |