590 APPENDIX 



per cent saline; and their shrinkage (crenatiori) in the concentrated 

 solution illustrate osmosis. 



Dialysis. Sausage casings make good dialyzing tubes, or special 

 tubes may be purchased from chemical supply houses. To illus- 

 trate the separation of crystalloids from colloids by dialysis make 

 a mixture of raw egg white with moderately concentrated sodium 

 chlorid solution. Place in the dialyzing tube; suspend the tube in 

 a beaker of distilled water. Stir the water frequently. After 

 a sufficient interval the presence of sodium chlorid in the water 

 can be demonstrated with silver nitrate, but the biuret test for 

 protein (a very delicate test) continues negative. 



THE SUPPORTING TISSUES 



Gross and microscopic studies of bones and cartilage, and micro- 

 scopic studies of various forms of connective tissue may be made 

 as the time and available material permit, and as the previous 

 training of the students requires. 



That bone consists of inorganic salts deposited in an organic 

 matrix may be shown by dissolving out the inorganic salts with 

 dilute hydrochloric acid. That calcium is an important constituent 

 of the inorganic portion may be shown by testing the hydrochloric 

 acid solution with sodium oxalate. 



Gelatin is a product obtained from bones by cooking them in 

 water heated above the normal boiling point by inclosing in 

 sealed vessel. The ordinary protein tests applied to gelatin shoi 

 that it is a member of the group of proteins. 



THE SKELETON 



The general arrangement of the bones of the skeleton, and d< 

 tails of selected regions, as the skull, may be studied. 



Joints. In connection with work on the skeleton the varioi 

 types of joints should be studied in detail. 



Typical joints are those at hip, knee, and ankle. 



Hip Joint. Observe on the outer surface of the innominate bon( 

 a deep depression, the acetabulum, into which fits the smooi 

 nearly spherical head of the femur, making a ball and socket joit 

 Study the possible movements of the joint. Note (1) flexion, simple 

 bending of the joint as in walking; (2) extension, the opposite of 



