152 SENSIBILITY OF BONES 



moter of their recovery. In such circumstances, 

 indeed, nothing can be more truly benevolent than 

 pain. It accompanies that inflammation and vascu- 

 lar activity without which the work of reunion of 

 the broken part cannot be accomplished ; and is the. 

 means of securing the repose and quietude which 

 are essential to the exact adaptation of the parts to 

 each other, and which can be effected only by caus- 

 ing great pain to follow even the slightest motion. 

 Of such utility is the inflammation on these occa- 

 sions, that when, as sometimes happens, the requi- 

 site degree of it, from want of nervous sensibility in 

 the part, does not take place, and the bone remains 

 disunited for many weeks, surgeons are in the habit 

 of using violence to produce the necessary stimulus. 

 In this case they either rub the broken ends rudely 

 against each other, or introduce an instrument be- 

 tween them, by which pain and irritation may be ex- 

 cited; and then reunion is accomplished. On the 

 other hand, if pain did not guard the limb from mo- 

 tion when the process of recovery was going on, 

 the union would be incessantly disturbed by every 

 heedless and unavoidable start altering the relative 

 positions of the parts. This, also, is occasionally 

 exemplified in practice. Looking at these facts, it 

 is impossible not to admire the wisdom and the be- 

 nevolence manifested in the adaptation of the struc- 

 ture of bones in every particular to the circumstances 

 and occurrences of life. 



Another advantage arising from the vitality of 

 bones is their susceptibility of change without in- 

 jury to life. Thus it frequently happens, that, in 

 infancy, water collects within the head in consider 

 able quantity : but, in consequence of the law, that 

 the form of the scull accommodates itself to the 

 form and dimensions of its soft contents, the bones 

 yield to the pressure from within, become larger, 

 and, by forming a larger cavity, enable the brain to 

 execute its functions, and life to go on ; whereas, 



