_Observation._ Persons from the North, in travelling through the Southern States, are surprised to see the heavy burdens that the porters carry on their heads. It is not unusual to see them walking at a rapid pace, with one or two trunks, weighing fifty or eighty pounds each, upon their heads. Occasionally, we meet an itinerant toy-man, with his tray of fragile merchandise upon his head, walking with as much apparent security, as though his toys, or images, were in his hands. This is the easiest method of carrying burdens, because the position of the head and spinal column is erect. 144. _If the animal and earthy matter of the bones is not deposited in proper proportions, they are deficient in strength._ If the gelatin predominates, the bones are weak, and become distorted. When nutrition is defective in the cylindrical bones, the heads are generally enlarged, and the shafts crooked; if in the spinal column, it may be curved; or in the cranium, it may be enlarged. This disease is familiarly known by the name of rickets. It is most common among these who have poor and insufficient food, live in dark, damp rooms, and breathe a vitiated air. The prevention and remedies for this disease are cleanliness, regular exercise, pure air, and nutritious food. -=-=-=-=-=-=-=-=-=-=-=-= 142. What statement by eminent physicians respecting deformities of the spine? What caution to teachers and mothers? 143. Why should we stand and sit erect? How may slight deformities of the spine be prevented? What is frequently noticed in travelling South? 144. What is the effect upon the bones when the gelatin preponderates? -=-=-=-=-=-=-=-=-=-=-=-= 145. When a bone is broken, some days elapse before the substance that reunites it is thrown out from the blood. In young persons, it may be secreted during the second or third week, and in individuals advanced in life, usually during the third and fourth week. When the bone is uniting, during the second, third, or fourth week, the attention of a surgeon is more needed than during the first week. At this time, the ends of the bone should be placed together with accuracy, which requires the careful application of proper dressing. After the bones have united, it will take some weeks to consolidate the uniting material and render the "callus," or union, firm. During this time, the limb should be used with care.