302 



LOCALIZED ELECTRIZATION. 



times, serves to produce more or less rapid intermissions, at the 



pleasure of the operator. 



" At L is a movable and flexible lever, which serves to establish 



communication between the coil and the battery. For this purpose 



it carries a stem which proceeds to the platinum, I, that is fixed in 



the caibon of the battery. 



'• The battery (fig-. 85) is composed of a copper cylinder. A, lined 



by thick zinc, E, and within this a porous vase, C, containing a bar 

 of gas carbon, H. Within the porous vase 

 is put nitric acid or bichromate of potash, 

 and pure water outside it. A lid of gutta 

 percha, B, closes the whole system almost 

 hermetically. 



This battery presents the inconveniences 

 inseparable from the use of nitric acid, but 

 it has the advantage of yielding a notable 

 quantity of electricity, with that of being 

 prepared beforehand, of remaining many 

 hours in action, and of being dismantled at 

 leisure; while the small batteries of bisul- 

 phate of mercury should be prepared at the 

 bedside of the patient. 



" The apparatus of IMorin may be regarded 

 as arranged to furnish currents for purposes 

 in which quantity is one of the elements 

 to be regarded ; while most of the other 

 portable instruments have been constructed 

 chiefly with a view to tension, and in order 



Fig. 85.— Battery of Legendre and to attain thc mean limit of cffect fixcd by 



Morin's instrmnent. .-, -i 'Tj. i" m • i 



the sensibility oi our organs, the inventor 

 was desirous, according to his own expression, not mei-ely to con- 

 struct an apparatus for giving sho(^ks, but one that should be 

 truly physiological. 



" The apparatus gives the extra current, the induced current, 

 and the two together. M. Morin appears to have been the first to 

 employ this combination."^ 



(/). The instruments of M. Gaiffe. — This ingenious maker long 

 ago constructed a small and very portable apparatus, represented 

 at one-fourth of its natural size in fig. 86. 



" The battery and the induction coil occupy two separate com- 

 partments, opening independently of each other. The battery is 

 composed of two elements of zinc and bisulphate of mercury, con- 



* Le Ronx. p. 75. 



