454 MUSCULAR MOTION. 



and ornamental processes of the arts. These processes require the 

 most accurate, quick, and combined movements of the muscles. How 

 quick, for example, is the motion of the hand in writing, and in execut- 

 ing the most rapid movements on the piano-forte ! How accurate the 

 muscular contraction, which stops the precise part of the violin-string 

 to bring out the note or semi-tone in allegro movements; and what a 

 multitude of combinations must be invoked in all these cases ! 



As an organ of touch, the advantages of the upper extremity have 

 already been depicted ; and much of what was then said applies to it 

 as an organ of prehension. "In this double respect," observes M. 

 Adelon, 1 "man is the best provided of animals. How much, in fact, 

 does he stand in need of an ingenious instrument of prehension! As 

 we have several times remarked, he has, in his organization, neither 

 the offensive nor defensive arms, that are bestowed on other animals. 

 Naked from birth, and exposed to the inclemencies of the atmosphere, 

 without means of attack or defence against animals, he must inces- 

 santly labour to procure what he requires. It was not, consequently, 

 enough that he should possess an intellect, capable of making him ac- 

 quainted with, and of appropriating to himself, the universe. He must 

 have an instrument adapted for the execution of all that his intellect 

 conceives. Such instrument is his upper extremity. In short, whilst 

 other animals find every thing in nature necessary for their different 

 wants more or less prepared ; man, alone, is obliged to labour to pro- 

 cure what he requires. He must make himself clothes, construct his 

 habitations, and prepare his food. He is the labouring and producing 

 animal par excellence; and hence needs not only an intellect to con- 

 ceive, but an instrument to execute." 



FUNCTION OF EXPRESSION OR LANGUAGE. 



Under this head will be included those varieties of muscular con- 

 traction, by which man and animals exhibit the feelings that impress 

 them, and communicate the knowledge of such feelings to each other. 

 It comprises two different sets of actions: those addressed to the ear 

 or phenomena of voice: and those appreciated by the senses of sight and 

 touch or gestures. Of these we shall treat consecutively. 



a. Of the Voice. 



By the term voice or phonation, a term proposed by Chaussier 

 is meant the sound produced in the larynx, whilst the air is passing 

 through it, either to enter, or issue from, the trachea. 



1. ANATOMY OF THE VOCAL APPARATUS. 



The apparatus, concerned in the production of voice, is composed, in 

 man, of the muscles concerned in respiration ; the larynx ; the mouth 

 and nasal fossae. The first are merely agents for propelling the air 

 through the instrument of voice. They will fall under consideration 

 under Respiration ; whilst the^anatomy of the mouth and nasal fossae 

 has been, or will have to be, described in other places. The larynx, 



1 Physiologie de 1'Homme, ii. 201, 2de edit,, Paris, 1839. 



