SECTIONS OF BONE 



75 



PIG. 51. DEVELOPING BONE, FROM THE PIG (PRUDDEN). 



Fig. 46 lias been drawn from a section of dry bone which has 

 been sawn as thin as possible, and afterward rubbed down on a 

 hone with water. It is a tedious process, and shows little but the 

 osseous matrix. Bone should be decalcified for microscopical 

 work, and it may then be readily cut in thin sections with a razor. 

 The process* is as follows: 



To 100 c.c. of the dilute chromic acid solution add 3 c.c. of 

 0. P. nitric acid. The bone, previously divided into slices not 

 over one -half centimeter in thickness, is then placed in the fluid, 

 and should be completely decalcified in a week or ten days. 

 Examine the pieces after twenty -four hours by puncturing with a 

 needle. Should the action proceed too slowly, add a few drops 

 more of the nitric acid from time to time. The bone eventually 

 takes on a green color. After complete decalcification, wash the 

 pieces for twenty-four hours in clean water, and preserve them, 

 until required, in 80 per cent, alcohol. Small pieces of young 

 bone may be decalcified in a saturated aqueous solution of picric 



