Page:Popular Science Monthly Volume 4.djvu/353

Rh decay, is the change of taste for mental food of various kinds. Every one must be conscious of the fact that books, and the subjects of thought, lose the interest they once had, making way for others of a different nature. The favorite author, whose words we read and reread with continually fresh enjoyment in youth, appears dull and uninteresting as the mind grows, and becomes unendurable in advanced years. And this is not merely the effect of familiarity. I knew one who was never tired of reading the works of a famous modern novelist until the age of twenty-five or thereabouts, when it chanced that he was placed in circumstances which caused novel-reading to be an unfrequent occupation, and in point of fact certain works of this author were not opened by him for ten or twelve years. He supposed, when at the end of that time he took up one of these works, that he should find even more than the pleasure he formerly had in reading it, since the story would now have something of novelty for him, and he had once thoroughly enjoyed reading it even when he almost knew the work by heart. But he no longer found the work in the least interesting; the humor seemed forced, the pathos affected, the eloquence false; in short, he had lost his taste for it. In the mean time the works of another equally famous humorist had acquired a new value in his estimation. They had formerly seemed rather heavy reading; now, every sentence gave enjoyment. They appeared now as books not to be merely tasted or swallowed, as Bacon hath it, but "to be chewed and digested." The change here described indicated (in accordance at least with the accepted estimates of the novelist and humorist in question) an increase of mental power. But a distaste for particular writings may imply the decay of mental power. And also, more generally, a tendency to disparagement is a very common indication of advancing mental age. "The old brain," says Wendell Holmes, "thinks the world grows worse, as the old retina thinks the eyes of needles and the fractions in the printed sales of stocks grow smaller."

Another singular effect of advancing years is shown by the tendency to repetition. It is worthy of notice that this peculiar mental phenomenon has been clearly associated with physical deterioration of the substance of the brain, because it may be brought about by a blow or by disease. Wendell Holmes, speaking of this peculiarity, remarks, "I have known an aged person repeat the same question five,