IMPORTANCE OF THE STUDY OF MOVEMENTS. 49 



and functions of the subject that is particularly 

 worthy of extended and accurate study. Move- 

 ment itself is a physical mode of expression, 

 capable of very accurate observation both in time 

 and in quantity ; it is capable of being easily noted 

 by more than one observer at the same time, and 

 can be recorded by various adaptations of the 

 graphic method. Such records can be preserved, 

 and submitted to analysis by mathematical pro- 

 cedures. Observations of this kind have been 

 largely employed by physiological experimenters, 

 and much accurate knowledge has been thus 

 obtained, elucidating processes of circulation, re- 

 spiration, reflex action, etc. Movement, however 

 produced, whether by vital action, nutrition, or 

 otherwise, can always be shown to be correctable 

 with other modes of force. It is surely reasonable 

 to observe, record, and study, movements result- 

 ing from vital action as an expression of that vital 

 process, and not to confine observation to histo- 

 logical or structural (trophic) effects of vital action. 

 It will be granted by the reader, that movement 

 always indicates some force antecedent to that 

 movement ; it follows that movement in a body is 

 expressive of a force acting upon, or in, that body 

 coincident with the observation of the movement, 

 or antecedent to it. 



Movements may, then, be studied as modes of 

 expression. In the common experiences of life, 

 movements are accepted as expressive of conditions 

 in the subject, as is easily shown by the analysis 

 of examples. Let us look and inquire, then, whether 



