174 RESULTS OF RESPIRATION. 





The control possessed by the will over the introduction of air stands 

 Respiration in a close relation to the production of articulate or other 

 tar^and^art- soun ^ s an ^ therefore to intercommunication between indi- 

 ly automatic, viduals by speech. This involves not merely a general con- 

 trol alone, but also a particular one, which is reached by regulating the 

 movements of the glottis by the agency of the superior and inferior laryn- 

 geal nerves. But though the will for these important purposes exercises 

 so marked a power of regulation, it is to be looked upon as superadded 

 or incidental, and during sleep, coma, and that larger portion of life which 

 is spent in total inattention to the carrying on of this function, it is dis- 

 charged in a purely automatic way. 



The mechanism which accomplishes the surprising results of respira- 

 Results of res- tion may therefore well challenge our admiration. As a 

 piration. self-acting or automatic contrivance, over which we have not 

 a necessary control, it originates in a single year nearly nine millions of 

 separate motions of breathing. It never fatigues us ; indeed, we are 

 never conscious of its action. In the same time, a hundred thousand 

 cubic feet of air have been introduced and expelled, and more than thir- 

 ty-five hundred tons of blood have been aerated. In a future page we 

 shall have to present the wonderful mechanism by which aerial currents, 

 as they pass in and out of the respiratory apparatus, are incidentally em- 

 ployed as a means of producing musical notes or articulate sounds, and 

 of thus establishing a relation and communication between different in- 

 dividuals. By these the feelings and thoughts are diffused, and in a 

 mechanical origin commence those bonds which hold society together. 



