PROPERTIES OP ANIMAL BODIES. 97 



we have no proof of its existence in our own feelings and 

 consciousness, as we have of the other kinds of sensibility. 



11. p5y organic sensibility, we mean that the stomach is 

 sensible to food, the heart to the blood, ice. ; and that this 

 feeling is confined to the organ and not transmitted to the 

 brain. It presides over the process of digestion, circulation, 

 secretion, absorption, and nutrition. 



12. Although the internal organs of the body are not 

 sensible to the presence of the fluids or solids with which 

 they are usually in contact, yet if foreign bodies are brought 

 in contact with them, or substances calculated to injure 

 them, we are immediately made sensible of it. Thus let a 

 person drink a quantity of brandy, or spirits, to which he 

 is not accustomed, and he will at once feel a sensation of 

 heat in the region of the stomach, altogether unnatural to 

 that organ. This proves that ardent spirits are not designed 

 for the drink of man, and are therefore hurtful. 



13. Certain parts of the body, which, in a healthy state, 

 are nearly insensible ; yet, by disease,{become the seats of 

 acute pain) This is particularly the case with the bones, 

 cartilages, and ligaments parts usually wholly destitute of 

 feeling. 



14. ^Contractility, or the property of contracting, is the chief 

 motive power of the system^ It exists in various degrees, in 

 different kinds of animal matter. {That element which pos- 

 sesses it in the greatest degree is Jibrin p and those tissues 

 which have the most fibrin, have the greatest degree of con- 

 tractility. The same is true of muscles, for the heart, which 

 is in constant motion, is almost pure fibrin. 



15. It is supposed that the coagulation of the blood is 

 owing to this contractile power of fibrin. In the living 

 vessels, the blood is kept fluid by the vital influence of the 

 walls of the vessels themselves ; but as soon as it is with- 

 drawn from this influence, the particles of fibrin immediately 

 rush together and form a solid mass. 



16. Those tissues which contain but little fibrin and are 



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