BATTERIES. 



63 



Fin. 4. 



MEIDINGER CELL. The Meidingor cell, constructed on the 

 same principles as the preceding one, is largely used in Russia* 

 Au-triu, and Germany. We represent it (Fig. 4) under its best 

 known form. The external vessel is larger at the top than at 

 tin- bottom. The sulphate of copper and the negative strip are 

 contained in a small conical 

 jar placed at the bottom of 

 the vessel. An inverted flask, 

 the neck of which reaches 

 into the above - mentioned 

 conical jar, is' filled with 

 crystals of sulphate of copper, 

 which, owing to the large 

 capacity reserved for the sul- 

 phate of zinc, allows the bat- 

 tery to be used for a long 

 time without rendering it 

 necessary to take the cells to 

 pieces and to put them to- 

 gether again. 



Under this perfected shape, M. Meidinger's cell may be 

 considered as one of the best forms of Daniell cell in use, and 

 as one of those which consume the least sulphate of copper 

 for the production of a given quantity of electricity ; but its 

 resistance is comparatively great. 



BUNSEN CELL. In his original cell M. JBunsen made use 

 of a cylinder of carbon dipping into the nitric acid contained 

 in an external jar, and a strip of zinc dipping in the acidulated 

 water contained in an internal porous jar. Without making 

 any change in the liquids, or in the electrodes, M. Archereau 

 placed the carbon in the centre ard the zinc outside, and it is 

 under that form (Fig. 5) that the Bunsen cell is used in 

 France.* This battery is the most generally used in industry, 

 notwithstanding the acid smell which it emits. It owes its 

 sustained success to its great electromotive force and its small 

 resistance. 



* We are not writing a treatise on electric batteries, or we should not fail to men- 

 tion the Grove cell as having preceded that of Bunsen in its general arrangement. 



