48 



LOCALIZED ELECTRIZATION. 



electro-physiology and jDathology, especially that which concerns 

 the individual muscular action, and the treatment, by inter- 

 mittent currents, of paralyses of movement, particularly when the 

 treatment requires frequent applications. What I have before 

 stated in the preceding (first) chapter, renders it unnecessary to 

 dwell on this part of the subject. 



I. — Medical Batteries. 



A. — Batteries of large surface and with inconstant currents. 



For a long period, the only batteries employed in medicine were 

 those with inconstant currents, in which the electricity was pro- 

 duced by the action of sulphuric acid upon a plate of zinc ; while 

 a plate of copper was the collecting element. This was the pile 

 of Volta ; and it was tried in succession in many different forms. 



All these forms, although they were for a long time used exclu- 

 sively, have now been abandoned for medical purposes ; because 

 they lose their power after a short period, and 

 because they vary much during the course of even 

 a single experiment, although it may last only from 

 ten to fifteen minutes. I shall therefore content 

 myself by briefly recalling them by the aid of figures 

 and descrij)tions taken, for the most part, from the 

 admirable treatise of M. de la Eive.'* 



(a). The columnar pile of Volta (fig. 3) is cele- 

 brated as being the first form in which the illus- 

 trious inventor realized his conception. It was 

 speedily abandoned on account of the quick dessica- 

 F's- 3- tion of the circles of cloth or of paper which sepa- 



Columnar Pile of Volta. ^^^^^^ ^j^^ ^-^.^j,,,^ 



(fe). The wooden trough battery with fixed metallic divisions, 

 called after its inventor the Cruikshank battery (fig. 4), is the 



form in which the great battery was 

 made that was presented by Napoleon 

 to the Ecole Poly technique in 1806. It 

 was with this that Gay-Lussac and 

 Thenard made their experiments in 

 1808. This form has many inconveni- 

 ences, especially that it requires much 

 time to prepare ; and that, unless the partitions are very securely 

 fixed, they allow of communication between the fluid in the several 

 cells. 



Fig. 4. 

 Cruiksbank's Trougb Battery. 



"• De la Rive, Traite d' Electricity tMorique et pratique. Paris, 1854, t. i. 



