CHAP. II.] FUNCTIONS. 73 



form its functions well." For example, the heart 

 is given for the purpose of sending the blood through 

 the arteries, all over the body ; but when the pulse 

 beats low or irregularly, that organ is said to " per- 

 form its function badly;" when it ceases to beat, 

 this function is lost or gone. So, certain of the 

 organs are said to secrete something or other that 

 is liquid ; the doing this is their function ; the 

 power of doing so, that of secretion, and the article 

 secreted or collected together, is called the secretion 

 of this or that organ. Thus, the kidneys secrete 

 urine, and it runs off (sect. 53.); the glands, under 

 the jaws, secrete spittle (saliva), which passes off 

 with the food by the intestines : therefore are they 

 properly considered as excretory also, seeing both 

 the secretions are drawn together for the express 

 purpose of being so sent away, this last by the 

 grand canal (or gut), as the first-mentioned is by 

 the bladder, and the perspiration is through the 

 pores of the skin. But some secretions are found 

 that have no outlet visible to us weak mortals, though 

 they find their way through the skin, sensibly 

 enough at times ; and this then becomes the sensible 

 perspiration or sweat, but when we do not see it, 

 this third species of evacuation is termed the in- 

 sensible perspiration ; and, in health, one of the two 

 is always in action, — in disease not so : we then 

 give sweats, or procure them by exercise. 



When, however, it happens, such functions are 

 obstructed, or, on the other hand, too much of either 

 secretion is furnished to the system, then disease 



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