Growth produces in the species a somewhat remarkable change in the mechanical qualities of the bones. This important part of our organism consists of three constituents--fibre, cartilage, and the earthy matter already mentioned called _phosphate of lime_. From the fibre they derive their toughness; from the cartilage their elasticity; and from the lime their hardness and firmness. Nothing can be more admirable in the economy of our body than the manner in which the proportion of these constituents adapts itself to the habitudes of age. The helpless infant, exposed by a thousand incidents to external shocks, has bones, the chief constituents of which being gristly and cartilaginous, are yielding and elastic, and incur little danger of fracture. Those of the youth, whose augmented weight and increased activity demand greater strength, have a larger proportion of the calcareous and fibrous elements, but still enough of the cartilaginous to confer upon the solid framework of his body the greatest firmness, toughness, and elasticity. As age advances, prudence and tranquil habits increasing, as well as the weight which the bones have to sustain, the proportion of the calcareous constituent increases, giving the requisite hardness and strength, but diminishing the toughness and elasticity. While the bones thus change their mechanical qualities as age advances, they diminish in number, the frame consequently having fewer joints and less flexibility. The bones of a child, whose habits require greater bodily pliability, are more numerous than those of an adult, several of the articulations becoming ossified between infancy and maturity. In like manner, the bones at maturity are more numerous than in advanced age, the same progressive ossification of the joints being continued. It has been ascertained by anatomists that, on attaining the adult state, the number of bones constituting the framework of the human body is 198; of which 52 belong to the trunk, 22 to the head, 64 to the arms, and 60 to the legs. TOWER OF THE THUNDERING WINDS. [Illustration: [++] Tower of the Thundering Winds.] The Great Wall is certainly a wonderful monument of ancient times; but it is almost the only one that we read of in China, except a famous Temple, or Tower, partly in ruins, which stands on an eminence in the neighbourhood of Hang-chow-foo. It is called the "Tower of the Thundering Winds," and is supposed to have been built about 2,500 years ago. DR. MONSEY BEQUEATHS HIS OWN BODY. This eccentric person died at the great age of 96, and was for half a century, physician to Chelsea Hospital. He left his body for dissection, and a few days before he died, wrote to Mr. Cruikshanks, the Anatomist, begging him to know, whether it would suit his convenience to do it, as he felt he could not live many hours, and Mr. Forster, his surgeon, was then out of town. He died as he predicted, and his wishes with respect to his body, were strictly attended to. TEA.