effect arising from them, we need not stop to examine, as this is, in the present state of our knowledge, a mere speculation. We have no evidence that electricity is an exciting power, but rather that it is one of those forces which tend to establish the equilibrium of matter. When disturbed--when its equilibrium is overset--it does, in its efforts to regain its stability, produce most remarkable effects. An electrical machine must be rubbed to exhibit any force. In all galvanic arrangements, even the most simple, dissimilar bodies are brought together, and the latent electricity of both is disturbed; and, even in the magnet, it is only when this takes place that its electrical powers are developed. In the _Gymnotus_, electricity appears to be dependent upon the power of the will of the animal; but even in this extraordinary fish, it is only under peculiar conditions that the electrical excitement takes place, and “what they inflict, they feel” during the restoration of that equilibrium which is necessary to their healthy state. In every case, therefore, we see that some power far superior to this is the ultimate cause; indeed, light and heat, and probably actinism, appear to stand superior to this principle; and on these, in some combined mode of action, in all probability, sensible electricity is dependent. Beyond even these elements, largely as they are engaged in the organic and inorganic changes of this world, there are occult powers which may never be understood by finite beings. We advance step by step from the most solid to the most ethereal of material creations, and we examine a series of extraordinary effects produced by powers which we know not whether to regard as material or immaterial, so subtile are they. On these, it appears, we may exhaust our inductive investigations--we may discover the laws by which these principles act upon the grosser elements, and develope phenomena of a very remarkable kind which have been unobserved or misunderstood. Whether light, heat, and electricity are modifications of one power, or different powers very closely united in action, is a problem we may possibly solve; but to know what they are, appears to be beyond the hopes of science; and it were idle to dream of elucidating the causes hidden beyond these forces, and by which they are regulated in all their actions on dead or living matter. M. Du Bois Raymond, from a series of researches remarkable alike for their difficulty and the delicacy with which they have been pursued, draws the following, amongst many others, as his conclusions as to the connection of electricity and vital phenomena. The muscles and nerves, including the brain and the spinal chord, are endowed during life with an electromotive power, which acts according to a definite law.