MEDICAL CATTERIES. 83 



to a distance, — to the incisor teeth, and sometimes to the base of 

 the orbit. 



Excitation of the frontal nerves, given off by the ophthalmic 

 nerve of Willis, produces pains \\ Inch radiate over the head ; and 

 it is for this reason that direct faradization of the frontal muscle, 

 which is crossed by these nerves, is very painful. The orbicuhir 

 niiiscles of the eyelids, the depressor alae nasi, the levator labii 

 superioris aloeque nasi, the quadratus menti, the levator menti, the 

 orbicularis oris, and the triangularis menti, are the most excitable. 

 Tiie order in which they have been enumerated indicates the 

 degree of their sensibility. Next come the zygomaticus major and 

 minor, the masseter, and the buccinator, which is comparatively 

 little excitable. 1 rarely fiiradize the levator anguli oris, for fear 

 of acting upon the infra-orbital nerve. 



In the neck the platysma is as excitable as the superior half of 

 the sternomastoid, and as the external border of the superior half 

 of the trapezius." The other muscles of the neck are much less 

 excitable. 



The pectoralis major, and the muscles of the infra-spinous fossa, 

 are moderately sensitive to electric excitation ; the deltoid, and 

 the muscles of the arm, a little less so. The muscles of the 

 anterior region of the forearm are much more sensitive than those 

 of the postei'ior region. 



The longissimus dorsi, and the sacrolumbal muscles, have very 

 little sensibility. 



The muscles of the buttocks, and the tensor vaginse femoris,'^ are 

 very sensitive to electric excitation ; as compared with the muscles 

 of the external and posterior regions of the thigh. Those of the 

 internal crural region are more sensitive than those of the external 

 crural region. 



The muscles of the posterior region of the leg have very little 

 sensibility, when compared with those of the interior and external 

 region. 



It is possible to express in numbers the degree of excitability 

 of each muscle and nerve ; and such investigations will be the 

 subject of a special work, I am so familiarised with the practice 

 of localized faradization that I am able, with, the help of my new 

 apparatus, to administer to each muscle or nerve the dose of 

 electricity required for the production of an energetic muscular 

 contraction, and that without causing much pain. It requires 



' The extreme sensitiveness of the I ^ Of the muscles of the lower limbs, 

 platysma leads me to suppose that it is i the tensor vaginae femoris is the most 

 supplied by the external branch of- the sensitive to electric excitation, 

 spinal nerve. 



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