,c}o 



or THE MUSCLES. 



with a variety, a compass, and precision, of which no other 

 musical instrument is capable. And, lastly, which in my 

 opinion crowns the whole as a piece of machinery, we have 

 a specific contrivance for dividing tlie pneumatic part from 

 the mechanical, and for preventing one set of actions in- 

 terfering with the other. Where various functions are 

 united, the difficulty is to guard against the inconvenien- 

 cies of a too great complexity. In no apparatus put togeth- 

 er by art, and for the purposes of art, do I know such mul- 

 tifarious uses so aptly combined, as in the natural organi- 

 zation of the human mouth ; or where the structure, com- 

 pared with the uses, is so simple. The mouth, with all 

 these intentions to serve, is a single cavity ; is one machine; 

 with its parts neither crowded nor confused, and each un- 

 embarrassed by the rest ; each at least at liberty in a de- 

 gree sufficient for the end to be attained. If we cannot 

 eat and sing at the same moment, we can eat one moment 

 and sing the next ; the respiration proceeding freely all the 

 while. 



There is one case, however, of this double office, and 

 that of the earliest necessity, which the mouth alone could 

 not perform ; and that is, carrying on together the two ac- 

 tions of sucking and breathing. Another rout, therefore, 

 is opened for the air, namely, through the nose, which lets 

 the breath pass backward and forward, whilst the lips, in 

 the act of sucking, are necessarily shut close upon the 

 body, from which the nutriment is drawn. This is a cir- 

 cumstance, which always appeared to me worthy of notice. 

 The nose would have been necessary, although it had not 

 been the organ of smelling. The making it the seat of a 

 sense, was superadding a new use to apart already wanted : 

 was taking a vise advantage of an antecedent and a con- 

 stitutional necessity. 



But to return to that which is the proper subject of the 

 present section, the celerity and precision of muscular mo- 

 tion. These qualities may be particularly observed in the 

 execution of many species of instrumental music, in which 

 the changes produced by the hand of the musician, are ex- 

 ceedingly rapid ; are exactly measured, even when most 

 minute; and display, on the part of the muscles, an obedi- 

 ence of action, alike wonderful for its quickness and its 

 correctness. 



