RESPIRATION. 



culation. Before birth, only a very small proportion of the 

 blood is carried through the lungs ; but after birth, and 

 through life, the whole of it. The connection between the 

 action of the lungs and that of the heart is very close and 

 important. The functions they perform are mutually depend- 

 ent, and neither can go on alone. If the circulation cease 

 by the cessation of the action of the heart, respiration is im- 

 mediately interrupted. If, on the other hand, respiration be 

 impeded, the heart does not stop at once ; but as the dark, 

 venous blood is no longer changed in its properties, as usual, 

 in the lungs, it is returned to the heart in the same state, and 

 is then sent throughout the body ; and being totally unfit for 

 the purposes of life, destroys it, by cutting short the action of 

 all the organs. The effect of its contact upon the brain is 

 an immediate suspension of Jife ; and if the cause be long 

 continued, it is never restored. But in many cases of this 

 kind, as in persons apparently drowned, circulation and respi- 

 ration may be renewed, if they have not been too long inter- 

 rupted, by blowing air into the lungs, and by the application 

 of warmth and stimulating substances to the body. 



' Beside these uses of the function of respiration, it is made 

 subservient to a number of other important purposes. All 

 animals furnished with lungs, express their wants, their affec- 

 tions and aversions, their pleasures and pains, either by words, 

 or by sounds peculiar to each species. These are produced 

 by different changes in the windpipe or canal through which 

 the air is drawn into the lungs. The inferior animals are by 

 this means enabled to maintain some sort of communication 

 with others of the same species, and can, to a certain extent, 

 convey information and express their affections and wants. 

 But how far they are intelligible one to another, it is impos- 

 sible to ascertain.' On man alone, nature has bestowed the 

 faculty of speaking, or of expressing his various feelings and 

 ideas, by a regular, extensive, and established combination 

 of articulate sounds. To have extended this faculty to the 

 brute creation, would not, it is probable, have been of any 

 use to them j for, though some animals can be taught to 

 articulate, yet none of them seem to have any idea of the 

 proper meaning of the words they utter. Speech is performed 

 by a very various and complicated machinery. In speaking, 

 the tongue, the lips, the jaws, the whole palate, the nose, 

 the throat, together with the muscles, bones, &c., of which 

 these organs are composed, are all employed. This combi- 

 nation of organs we are taught to use when so young, that 



