ANALYSIS OF POSTURES. 177 



proof of their practical importance. Most of these 

 points are commonplace clinical considerations, but 

 principles vi. and vii. perhaps require further ex- 

 planation and defence. 



It may be readily admitted that it is desirable 

 and important to know what are the motor indica- 

 tions of excitement or over-action of a nerve-centre, 

 also to know the relative strength of the different 

 motor centres, and what are the outward physical 

 signs of widespread stimulation or weakness among 

 portions of the nerve-mechanism. In numerous 

 cases, where common experience has shown general 

 strength, weakness, or widespread stimulation, etc., 

 these principles of analysis have been applied, and 

 some general knowledge has thus been obtained, 

 but more exact knowledge is wanted. I trust by 

 an experimental method, described in the Journal 

 of Physiology* to be able to give hereafter a 

 much more precise and definite account of these 

 principles. 



These studies afford evidence that some parts of 

 the brain may be in a condition of weakness, while 

 others are in a state of strength or excitement, and 

 that one hemisphere may be weaker in action than 

 the other. Again, a change of posture may indicate 

 a change in the corresponding nerve-mechanism. 

 Thus in chorea, when the forearm is passively sup- 

 ported, we often see that the free hand passes from 

 the posture of rest to the convulsive posture, thus 

 indicating the change in the condition of the nerve- 

 mechanism, corresponding to the muscles of the 



* Vol. iv. No. 2, August, 1883 ; also see chap. xix. 



N 



