90 Lessons in Nature Study. 



slender at middle. Why ? Call attention to the marrow- 

 cavity, the delicate fibres of bone at its ends. Describe 

 the cavity. Is it lined with periosteum ? etc., etc. Draw 

 figure of the interior of bone. 



III. Exhibit the burnt bone. The animal matter is 

 burnt out ; what kind of matter remains ? Exhibit the 

 chicken bone. The mineral matter is dissolved out ; what 

 kind remains ? Bone, then, consists of two kinds of matter, 

 animal and mineral. 



The above is sufficient for young children. More exten- 

 sive lessons may be made by calling attention to the end of 

 a freshly broken piece of burnt bone, where the ends of fine 

 pores (canals) may be seen. The effects of weather and 

 soil on bones may be brought out by samples of bone picked 

 up on the ground. Uses of bones as levers, and as organs 

 for protection of delicate parts. Their use as a fertilizer, 

 and their employment in arts, may also be brought out. 

 The pupils may then write what they can of bones. 



BONES. II. 



SOME EASY AND USEFUL DEVICES FOR TEACHING THEM. 



It is a fully determined principle that the way to teach 

 things is to bring the things themselves into the class-room. 

 This is opposed to the usual way, which gives the pupil a 

 book to study what some one else has seen. 



This principle is well established in the teaching of 

 physics and chemistry. It is no less applicable to physiology 

 and kindred subjects. 



How much clearer is the knowledge possessed by a child 

 of the turbinal bone after he has seen one and noted its 

 convolutions. How much clearer is his knowledge of a joint 

 when he has himself put one together. 



The memorizing of the names of bones, the classifying 

 of various species of joints, is proper when it follows the 

 observation of the things memorized. But when taught, as 

 is usually the case, purely from the text, it results in a most 



