The agreeable influence of smiles is so well known that many are tempted to counterfeit them, and assume an expression in which the eye and lip are in unhappy conflict.[3] On the other hand, painful thoughts are inimical to mirth. No sally of humour will brighten the countenance of a man who has lately suffered a severe loss, and even mental reflection will extinguish every sparkle. But the bed of sickness can often be better cheered by some gay efflorescence, some happy turn of thought, than by expressions of condolence. Galen says that AEsculapius wrote comic songs to promote circulation in his patients; and Hippocrates tells us that "a physician should have a certain ready humour, for austerity is repulsive both to well and ill." The late Sir Charles Clark recognised this so far that one of his patients told me that his visits were like a bottle of Champagne; and Sir John Byles observes, "Cheerfulness eminently conduces to health both of body and mind; it is one of the great physicians of nature. "Il y a trois medecins qui ne se trompent pas, La gaite, le doux exercice, et le modeste repas. Every hour redeemed from despondency and melancholy, and bathed in the sunshine of cheerfulness, is an hour of true life gained." Our views with regard to the first appearance of laughter depend on whether we consider that man was gradually developed from the primeval oyster, or that he came into the world much in the same condition as that in which we find him now. If we adopt the former opinion, we must consider that no outward expressions of feeling originally existed; if the latter, that they were from the first almost as perfect as they are at present. But I think that we shall be on tolerably safe ground, and have the support of probability and history, if we say that, in his earliest condition, the mental endowments of man were of the very humblest description, but that he had always a tendency to progress and improve. This view obtains some little corroboration from the fact that the sounds animals utter in the early stages of their lives are not fully developed, and that the children of the poor are graver and more silent than those of the educated classes. But a certain predisposition to laughter there always was, for what animal has ever produced any but its own characteristic sound? Has not everyone its own natural mode of expression? Does not the dog show its pleasure by wagging its tail, and the cat by purring? We never find one animal adopting the vocal sounds of another--a bird never mews, and a cat never sings. Some men have been called cynics from their whelpish ill-temper, but none of them have ever adopted a real canine snarl, though it might express their feelings better than human language. Laughter, so far as we can judge, could not have been obtained by any mere mental exercise, nor would it have come from imitation, for it is only found in man, the yelping of a hyena