IT is a very generally accepted fact that the phenomena of thought are at least connected with a physical basis, however difficult it may be at present to trace the connection. The dependence, however, of mental attributes and sensations upon brain-structure, is too notorious a fact to admit of doubt by competent judges. This view is illustrated well by a remark of Prof. Huxley's in his essay “On the Physical Basis of Life”, viz.: “And if so, it must be true in the same sense and to the same extent that the thoughts to which I am now giving utterance and your thoughts regarding them are the expression of molecular changes in that matter of life which is the source of our other vital phenomena” (Fortnightly Review, 1868).