THE ROYAL INSTITUTION THE ARCHITECTURE OF THE HUMAN BODY PROFESSOR HUMPHRY, M.D., F.R.S., of Cambridge University, is now giving a course of six Tuesday morn ing lectures on the Architecture of the Human Body, and the fourth lecture of the series was delivered last Tuesday. He said that the several bones forming the spinal column or “ backbone,” are joined together at their outer edges by tough fibres, but the inner portion of the space between the bones is pulpy and not fibrous, so that the vertebrae are to all practical intents and purposes balanced upon fluid balls, tough outside and soft in the centre. These fluid balls prevent bad effects from jars. By pressure and by work, some of the in ternal fluid is squeezed out of the balls during the day, but the fibrous substance having a great attraction for moisture, the loss is soon replaced. So tightly are the bones joined together, that when the spinal column is broken, some of the bones themselves are almost sure to be broken also. All mammals, with a very few excep tions, have the same number of bones in the neck, and there are no more bones in the neck of the giraffe than in the neck of a man. The ribs are attached to the spinal column, and proceed from it in a curve ; they are inclined in a slightly downward direction, but in old people they become more horizontal. The points of the ribs are not directly joined to the breast-bone, but are connected with it by ligaments which slant slightly up wards, so that the downward slant of the ribs, and the upward slant of the ligaments, permit respiration to go on more easily than would otherwise be the case. The position of the heart, which is somewhat to the left of the centre of the chest, seems to give it a tendency to drive more blood to the right side, and to the right arm so may have something to do with right-handedness. Babies have very large skulls in proportion to the size of the rest of the body, and this is curious, because for many years the large brain enclosed in the skull has very little work to do. The lower jaw is moved by a very large and powerful muscle, which spreads upward and outwards like a fan, so as to reach to the temples and to cover a very large portion of the side of the skull; it is the presence of this muscle which makes it unpleasant to eat a hard biscuit while a tight hat is upon the head. The thigh-bone is the longest bone in the body it has a very shallow socket, so that it is kept in its place principally by atmospheric pressure, and moves to and fro, depending from the shallow socket, something like a pendulum. The knee is one of the most complicated joints in the whole body, and when it gets out of order does not readily get right again. The pelvis is an inch wider in woman than in man, therefore tends to make women walk with a waddle, but this defect is not seen unless they strive to keep pace with man; although women have this disadvantage, they have graces which man has not. After the age of twenty-five is past, exa mination of the bones will give very little clue to the age at death of the individual who owned them. Madder will colour growing bone a red colour, so that pigs fed on madder for a time, and then killed, will be found to have portions of their bones stained red. Anatomist have availed themselves of this plan of colouring bone to learn more of the method of growth of the substance.