Charm of Mystery--Complication--Poetry and Humour compared--Exaggeration. All who are accustomed to novel reading or writing, are aware of the fascinating power of mystery. They even consider it a principal test of a good story that the plot should be impenetrable, and the final result concealed up to the last page. Tension and excitement are agreeable, even when the subject itself is somewhat painful. We observe this in a tragedy, and it is a common saying some people are never happy except when they are miserable. Such is the constitution of the mind; and the fact that enjoyment can be obtained when we should expect the reverse, is noteworthy with reference to the ludicrous. All mystery causes a certain disquietude, but if the problem seems to us capable of being solved, it begets an agreeable curiosity. On its resolution the excitement ceases, and we only feel a kind of satisfaction, which, though more unalloyed, gives less enjoyment than mystery, inasmuch as it produces less mental and physical commotion. This tendency in the mind to find pleasure in complexity was observed even by Aristotle. Experience teaches us that no literary style is attractive without a certain interlacing of thoughts and feelings. The sentiments which are most treasured and survive longest, are those which are conveyed rather in a complex than simple form--emotion is thus most quickened, and memory impressed. The beauty and charm of form lie greatly in its bringing ideas closer together, and succinctness implies fulness of thought. Thus a vast number of paradoxical expressions have been generated, which are far more agreeable than plain language. We speak of "blushing honours," "liquid music," "dry wine," "loud" or "tender colours," "round flavour," "cold hearts," "trembling stars," "storms in tea-cups," and a thousand similar combinations, putting the abstract for the concrete, transferring the perception of one sense to another, intermingling the nomenclature of arts, and using a great variety of metaphorical and even ungrammatical phrases. Poets owe much of their power to such combinations, and we find that allusions, which are confessedly the reverse of true, are often the most beautiful, touch the heart deepest, and live longest in the memory. Thus the lover delights to sing-- "Why does azure deck the sky? 'Tis to be like thine eyes of blue."