Abernethy multiplied the illustrations by showing the various analogies which seemed to him to be presented in the velocity, the chemical, and other powers of Life and Electricity; and, with especial reference to the extraordinary discoveries of Sir Humphrey Davy, added such illustrations, as more recent achievements in chemical science had placed within his grasp; and thence concluding it as evident that some subtile, mobile, invisible substance seemed to pervade all nature, so it was not unreasonable to suppose that some similar substance or power pervaded animal bodies. He guarded himself, however, both in his first and again in his second Course of Lectures, from being supposed to identify Life with electricity, in a long paragraph especially devoted to that object. In his second Course, in 1815, he proceeded to enumerate John Hunter's various labours and contributions to science, as shown by the Museum; imparting great interest to every subject, and in so popular a form, that we wonder now, when (as we rejoice to see) there are some small beginnings of a popularization of physiology, that there is not a cheap reprint of these Lectures. Keeping, then, his object in view, we cannot see how, as a faithful interpreter of John Hunter, Abernethy could have done less; and if any theory of life at all is to be adopted, as _necessary to give an intelligible impression_ to phenomena, one can hardly quarrel with that which takes the phenomena of life on one hand, and those of death on the other, as the means of expressing our ideas. When we see a man dead, whom we had contemplated alive, it certainly seems that something has left him; and whether we say "something superadded,"—the "breath" or "Life," or by whatever term we call it,—we appear really to express in as simple a form as possible the facts before us. It seems to us that, after all, John Hunter did little more; for the illustration or similitude by which we endeavour to render an idea clear, has in strictness nothing _necessarily_ to do with the idea itself; any more than an analogy, however real the likeness, or a parallelism, however close, represents identity.