SCIENCE OF COMMON THINGS 



293 



Different forms of galvanic batteries. Light and beat produced by galvanism. 



tity of the liquid, we increase the intensity of the elec- 

 tricity developed. 



Fig. 88. 



Fig. 89. 



Figs. 88 and 80 represent some of the most common forms of galvanic 

 batteries. In Fig. 88 two plates of zinc, z z, inclosing a piece of silver 

 between them, are immersed in a glass cylinder, Gr, containing acid ; S 

 and A represent the poles of the battery. In Fig. 89 the battery con- 

 gists of two concentric cups or cylinders of copper, C, and a cylinder of 

 zinc, Z, fitting between. The acid solution is poured into the spaces be- 

 tween the cylinders. Another form consists of an earthenware trough, 

 containing acid, in which alternate plates of copper and zinc are arranged, 

 and connected together by wires rising from each end of the trough. 



19O3 What are the most ordinary effects produced by the developed 

 electricity of a large galvanic battery f 



The production of sparks and brilliant flashes of 

 light, the heating and fusing of metals, the deflagration 

 of gunpowder and other inflammable substances, and 

 the decomposition of water, saline compounds, and 

 metallic oxides. 



19 O3 How may the most splendid artificial light known be produced f 



By fixing pieces of pointed charcoal to the wires 

 connected with opposite poles of a powerful galvanic 

 battery, and bringing them into contact. 



19 O 4 Can intense heat be developed by the action of the galvanic bat- 

 tery as well as intense light ? 



The greatest artificial heat man has yet succeeded in 

 producing has been through the agency of the galvanic 

 oattery. 



19O5 What refractory substances c&n be fused by the aid of the gal' 



vanic battery f 



All the metals, including platinum, can be readily 



