FUNDAMENTAL PRINCIPLES. 



39 



2. If the two rheophores, one moist and the other dry, are 

 placed on two points of the surface, the person experimented upon 

 will feel, at the point where the dry rheophore has developed 

 only physical effects, a superficial and evidently cutaneous sensa- 

 tion. Tlie opposite electricities, in such a case, are recomposed at 

 the dry point ; hut after having traversed the dermis by the aid of 

 the moist rheophore. 



3. If the skin be very slightly moistened, on a part where tlie 

 epidermis is very thick, a sensation that is superficial, but stronger 

 than in the preceding case, and without either sparks or crackling, 

 is produced at the points where the dry metallic rheophores are 

 placed. Here the electric recomposition takes place in the thick- 

 ness of the skin. 



4. Lastly, if the skin and the rheophores are both thoroughly 

 moistened, the current produces neither sparks, nor crackling, nor 

 burning sensation, but very variable phenomena of contractility or 

 sensibility ; accordingly as we act upon a muscle, or muscular 

 fasciculus, a nerve, or an osseous surface. In the latter case an 

 acute pain of a very peculiar character is experienced ; insomuch 

 that we should carefully avoid placing moist rheophores over such 

 surfaces.'^ 



It follows from these experiments that we may, in faradization, 

 arrest at pleasure the power of electricity in the skin ; and that, 

 without puncture or incision, we may make the current traverse 

 the skin, and may limit its action to subcutaneous organs, tliat is, 

 to nerves, muscle, and even bone. 



It is difficult to conceive, however, that electricity will act upon 

 subcutaneous organs without, at the same time, physiologically 

 exciting the skin itself. One is apt to think that the sensations 

 produced by electrization of deep organs are due either to excita- 

 tion of the skin only, or of the skin and the deep organs together. 



2 I will attempt to generalize these 

 phenomena. It is well known that ten- 

 sion electricity has a great tendency to 

 escape by points. The same occurs with 

 dynamic electricity, when recompositions 

 occur between the epidermis and dry 

 rheophores. In fact, the epidermis and 

 the rlieophores present each a number of 

 asperities by which the fluids of oj^p'osite 

 denominations, proceeding from the bat- 

 tery or the induction apparatus and the 

 body, escape to be recomposed and neutra- 

 lized; producing crepitation and sparks. 

 If the skin lias been traversed, the exci- 

 tation is then superficia], and can only 

 produce cutaneous phenomena, that is, 

 cutaneous sensations. But if the aspe- 



rities are abolished by a film of water, 

 the electricity traverses the skin en masse 

 and is recomposed deeply, either in the 

 muscles or in bone, or in nerve ; the more 

 deeply the more intense the cm-rent. 

 There will then be no more sparks or crack- 

 ling, or cvitaneous sensations; but only 

 IDhysiological plieuomena in accordance 

 with the functions of ihe organs that are 

 excited. These latter jjhenomena display 

 a difference between the jjhysiological 

 effects of tension electricity and dynamic 

 electricity. The former always produces 

 electric recomposition between the rheo- 

 ]5hore and the epidermis, in whatever 

 manner the operation is performed. 



