Abernethy, in impressing any anatomical fact, would sometimes say that we carried about with us in our own bodies excellent means of refreshing our impressions on many points of anatomy; but we may say this in a much more extensive sense with regard to the interpretation of that for which anatomy is alone useful—namely, the _uses_ or _functions_ of the body. It would be very possible for any observant person, who was moderately versed in the ordinary principles of correct reasoning, to detect many defects in medical investigations and practice; in the correction of which many of Abernethy's practical contributions consisted; but the mind, restlessly impatient to arrive at conclusions, often overlooks the most important facts, and deduces inferences _directly_ from the evidence of the eye or other senses, without submitting it to such test as the intellectual faculty can alone supply. Nothing can exceed the mischief of this in serious matters, nor the absurdity of it, when we _think awhile_. We should hardly refrain from laughter if we saw a man try to see with the point of his nose, or endeavour to examine the odour of a rose by his ear, or to listen with his eye; yet this is not a whit more absurd than to try to deduce conclusions from the impressions furnished by the eye, which can alone be afforded by the rational faculty. Nothing is more common than this sort of fallacy, nothing more easy than its correction; but then people must bestow at least a little of that time on their highest faculties which they so lavishly expend on inferior powers. How much time we consume, for example, in the study of various languages—those instruments for the communication of ideas—as compared with that bestowed on the collecting and marshalling of ideas themselves; which is little better than grasping at the shadow, and losing the substance; or, to use a humorous illustration, like a friend of our own, who, having a new dog, sent his servant forthwith to purchase sundry articles for him, in the shape of kennel, chains, engraved collars and food; all of which, at some expense, he safely accomplished to his master's satisfaction, expressing his sorrow at the same time for having accidentally lost the dog!