222 PHYSICAL EXPRESSION. 



eyes is maintained till that stimulus is removed, or 

 some stronger stimulus excites the nerve-centres. 

 While the eyes are thus fixed by the sight of an 

 object, or other visual stimulus, they are not alto- 

 gether free or disengaged to express emotions ; 

 their nerve-centres are engaged as much as those 

 of a hand while digging. 



A sufficiently strong visual stimulus may direct 

 the eyes towards the object, or repel them; that 

 is, direct them away from the object. In these 

 varying effects of the sight of an object we have 

 one of the most interesting modes of expression. 

 A glass of water placed within the field of vision 

 of a thirsty man causes his eyes to turn towards 

 it ; the glass of water, if placed within the field 

 of vision of a man suffering from hydrophobia, 

 causes repulsion of the eyes. Some explanation 

 of these phenomena may be seen on referring to 

 Ferrier's experiments. 



When a patient is under the influence of chloro- 

 form, a number of facts show that he is less 

 impressionable to outward stimuli. Touching the 

 cornea does not excite reflex movement ; speaking 

 to the patient does not excite movement. The 

 movements that do occur in this condition are 

 then probably spontaneous (automatic). It has 

 been already stated that in this condition spon- 

 taneous movements of the eyes are seen, and they 

 are mostly in the horizontal plane. We have in 

 these facts evidence that horizontal movements 

 are more likely to be spontaneous than those in 

 the vertical direction ; this also makes it probable 



