GALVANIC INSTRUMENTS. 



339 



strument is contained in a case 

 two feet long, one foot wide, 

 and six inches in depth. 



Mode of using. The plates 

 being properly arranged in 

 the cells, the external glass 

 vessels are to be nearly filled 

 with sulphuric acid, previ- 

 ously diluted with from 12 

 to 15 times its bulk of wa- 

 ter, and the interior porcelain 

 cups with strong and pure 

 nitric acid. The wires are 

 to be secured in the brass 

 cups with screws at the poles 

 of the battery, and when 

 steel shavings, fine wires, 

 watch springs, etc., attached 

 to one of them, are brought 

 in contact with the other, 

 combustion, with brilliant 

 scintillations, will be exhibit- 

 ed. Gold, silver, or copper 

 leaves, interposed between 

 their extremities, will burn 

 with bright and varied colors. 

 Water, with a little sulphuric 

 acid or common salt added 

 to it, may be rapidly decom- 

 posed by employing the 

 wires tipped with platina, 

 and the gases collected in 

 the glass globe furnished 

 with the instrument. 



Charcoal points at- 

 tached to the wires can 

 be burned with a bril- 

 liant light. The coal 

 should be of hard 

 wood, and recently 

 burned. After using, 

 the whole should be 

 taken out of the case, 



Fig. 400. 



Fig. 401. 



