OF LIFE. 31 



J3.. Sensible organic contractility is involuntary, animal 

 contractility in its ordinary condition involves volition. 



Q. Be more particular in distinguishing sensible and in- 

 sensible organic contractility from each other. 



Ji. Uterine contraction, the heart's action, and vomit- 

 ing, are instances of sensible organic contractility; they 

 can be felt. The action of the biliary vessels, indeed 

 of the capillaries generally, are examples of insensible 

 organic contractility; they cannot be felt. Yet organic 

 contractility, whether sensible or insensible, is the same 

 principle in different degrees of exaltation. The fact that 

 insensible organic contractility is without the sphere of 

 volition distinguishes it from animal contractility. 



Q. There yet remains a difference between organic con- 

 tractility and organic sensibility, yet to be stated; it is 

 singular and important, what is it? 



ft. You have seen that a mere exaltation of organic sen- 

 sibility from disease, will convert it into animal sensibility 

 or pain ; now organic contractility, sensible or insensible, 

 cannot be converted or exalted to animal contractility. 



Q. Should contractility be considered as exclusively 

 attached to the muscular tissue ? 



#. It should not it is a property of all the tissues to 

 a greater or less extent. 



Q. What do the two forms of organic contractility re- 

 present? 



#. The sensible organic contractility is the irritability, 

 and the insensible organic contractility is the tonicity of 

 writers. 



