loS THEPHILOSOPHY 



Refpiration commences Inftantly after birth, and is inftindlively 

 continued during life. In the foetus ftate, as formerly mentioned *, 

 refpiration is unneceflary, becaufe the circulation of the general mafs 

 of blood is carried on through a different channel. In the a£l of 

 infpiration, we are confcious of making a certain effort ; but in the 

 aft of expiration we fcarcely perceive any exertion whatever. 



Befide the circulation of the blood, and the continuation of the 

 vital warmth, refpiration gives rife to many other important func- 

 tions in the animal oeconomy. All animals who refpire, befide a 

 watery vapor, exhale great quantities of mephytic or corrupted ef- 

 fluvia, which, if retained in the lungs, or breathed by other animals, 

 would foon prove fatal. The muicles of refpiration, of which we 

 have the command, are employed In many other operations of the 

 body, befide the mere adl of breathing air. All animals furnifhed 

 with lungs exprefs their wants, their affedions and averfions, their 

 pleafures and pains, either by words, or by founds peculiar to each 

 fpecies. Thefe different founds are produced by ftraitening or 

 widening the glottis and wind-pipe, or, in general, the paflage 

 through which the air palTes In refpiration. The inferior animals 

 are by this means enabled to exprefs themfelves, though not by ar- 

 ticulate founda, in fuch a manner as to be perfedlly intelligible to 

 every individual of a fpecies. On man alone. Nature has beftowed 

 the faculty of fpeaking, or of expreffing his various feelings and 

 ideas, by a regular, extenfive, and eftabliflied combination of arti- 

 culate founds. To have extended this faculty to the brute creation, 

 would not, it is probable, have been of any ufe to them; for, though 

 fome animals can be taught to articulate, yet, from a defedt In their 

 intellea, none of them feem to have any idea of the proper mean- 

 ing of the words they utter. Speech is performed by a very various 



and 



* See aboTC, page 66. 



