2S OF LIFE, 



pain. Now, this sensibility is not the attribute of vege- 

 tables. 



Q. In what respects do organic and animal sensibility 

 resemble each other? 



Ji. They originate from the same principle, viz. that 

 of life; and they vary only in degree of exaltation. Hence 

 organic sensibility can, by irritation, be exalted into ani- 

 mal sensibility. 



Q. Does organic sensibility vary in its nature? 



Jl. It does not ; it varies in force. In disease it is in- 

 creased or diminished. In health, each organ has its pri- 

 mitive determinate quantum of sensibility, which places 

 it in relation to its appropriate stimulus, as the -urine to 

 the bladder, the air to the lungs. The organs in health 

 will admit no other than their appropriate stimuli. 



Q. Can you illustrate this more clearly? 



#. In the healthy state, serous exhalants carry serum 

 only, but let their organic sensibility be exalted into ani- 

 mal by irritation, and you will see them allowing the pas- 

 sage of blood. This change is often independent of the 

 healthy calibre of the vessels; for a vessel large enough in 

 health to convey a red globule, will, from its organic sen- 

 sibility, be in relation only to white fluids. 



Q. What effect has sudden death on these two kinds of 



sensibility? 



/?. It annihilates immediately the animal, but more 



slowly the organic sensibility. 



Q. How is contractility divided and subdivided? 



/?. It is divided into animal and organic contractility. 

 The last is subdivided into sensible and insensible organic 

 contractility. 



Q. What do you understand by the term contractility? 



