G4 



LOCAL! ZKD ELECTRIZATION. 



is thus a happy modification of the voltaic pile, has been prin- 

 cipally intended to be employtd as a topical application; and the 

 electro-cntaneous excitation that it produces has been found useful 

 in the treatment of obstinate rheumatoid or neuralgic pains. But 

 the continued interruptions due to its mobility and its rapid 

 polarisation render i"t an apparatus ill suited for muscular electri- 

 zation, and especially for the application of continuous currents. 



[Pulvermacher has recently effected a considerable improyeroent in the 

 construction of his chain battery. He has discarded the cylinder of wood, and 

 substituted for tlie wire thin zinc and copper plate. The dimensions of the 

 elements of the different sized chains remain the same, but each segment 

 is formed of a cylinder of copper plate, pei'forated with longitudinal open- 

 ings ; and within the copper cylinder is a cylinder of zinc without perfora- 

 tions. The zinc is sejjarated from immediate contact with the copper by 

 a few stout threads. An unbroken link, which forms part of the copper 

 cylinder, serves as the means for joining the several segments. This construc- 

 tion permits the withdrawal and renewal of the zinc cylinder when neces- 

 sary. — //. 2'.] 



(d). Bihbon hattery of DucJienne. — To avoid the inconvenience of 

 mobility of the elements, I constructed a small voltaic apparatus, 

 resting also on the principle of the multiplication of elements 

 with diminution of their surfaces. It was formed of little cubes, a 

 centimetre and a half in height, each composed of a band of zinc 

 and a band of copper, folded repeatedly upon tliemselves, and 

 separated by a small diaphragm of linen, or, better still, of gold- 

 beater's skin. These little cubes, connected by soldering, and so 

 adapted that the bands of copper communicate with the bands of 

 of zinc, were fixed in a wooden frame (fig. 22). 



Fig. 22. — The Ribbon battery of Pucbenne. 



One hundred and fifty of these little elements were arranged 

 in a frame, having a surface of sixteen centimetres by twelve. I 

 called the apparatus the ribbon battery. In order to put it in 

 action, it was i)laced for a few minutes in a vessel of vinegar. A 



