Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: 2. Study of longitudinal section of a long bone. a. Identify all the structures seen in cross- section, viz., hard bone, spongy bone, marrow. b. What additional facts in regard to the structure of a long bone do you learn from the longitudinal section ? c. Make a drawing of the longitudinal sec tion, labelling as in the previous drawing. B. Structure of a rib (tabular bone). 1. Can you distinguish in the cross-section of the rib the hard bone, spongy bone, and marrow ? 2. How do long bones and tabular bones differ in plan of structure ? 3. Make a diagrammatic drawing of the cross- section of the rib (X 2), labelling all the parts. 2. Composition Of Bones. Materials: Two clean ribs ; the two halves of the soup-bone used in 1 ; diluted hydrochloric acid (6 parts water to 1 part acid); weighing balances ; a piece of wire. A. Action of acid on bone. Compare the two ribs as to form and size; place one of them in a bottle of diluted muriatic acid. Allow the bone to remain in the acid for a few days and then compare the two ribs again. This exercise may be performed by the pupil at home. 1. Has the acid changed the form of the bone ? 2. Has it changed the size of the bone ? 3. What change do you observe to have taken place ? 4. Pour some of the liquid in which the bone has been soaking into an evaporating-dish and heat over an alcohol-lamp or over a gas-flame until the liquid has disappeared. What kind of substance is left in the dish ? (This substance is a kind of mineral matter formed from the mineral matter of the bone by the action of the acid.) 5. What properties of bone are due to the pres ence of mineral matter? B. Effect of burning bone. Weigh half of the long bone used in 1. Tie a piece of wire about ...