BONE. 



Bone consists of an organic matrix, ossein, which is identi- 

 cal with collagen obtained from the white fibrous connective 

 tissue. This matrix is impregnated with insoluble inorganic 

 salts, which serve to give strength and stability to the tissue. 

 Ossein when hydrated with weak acids is converted into 

 gelatin. 



MINERAL CONSTITUENTS. 



Incinerate 10 grms. of bone under the hood. Extract the 

 grayish residue with 25 c.c. of hot dilute HN0 3 , filter, and 

 use the filtrate for the following tests: 



(a) Phosphoric Acid. To 10 c.c. of the solution add 10 c.c. 

 of the molybdic solution and warm in the water-bath at 75 

 C. until a canary-colored precipitate settles out. What is 

 this? Filter it off on a small filter, wash once with very 

 dilute HN0 3 , and then dissolve the precipitate upon the 

 filter by adding dilute NH 4 OH,' drop by drop. To the fil- 

 trate add a few c.c. of magnesium mixture. What is this 

 precipitate? Write the equations for all the reactions in 

 this procedure. 



(6) Chlorides. To a few c.c. of the solution add a few 

 drops of AgN0 3 . What results? 



(c) Calcium. Make 10 c.c. of the solution alkaline with 

 NH 4 OH. What is the precipitate? Filter, and to the filtrate 

 add ammonium oxalate. The white precipitate of calcium 



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