Experiments with Vollas Galvanic jlpparafus, ^25 



tilre of turnfol, did not become red when placbd very near the 

 acid in tlic water. 1'he wires c and //were of goki ; a the zinc, 

 and b the filver, of the apparatus ; when brought into contat^t 

 he received in tlie tube next the zinc oxygen gas, and in that 

 towards the fiber, hydrogen gas. • ' . 



Exp, XII. lie obtained tlic fame refult by fcparating the 

 two tubes: fee fig. 6. The two tubes wesre fdled. half with 

 acid and half with water, and one of tlie gold wires was in 

 the acid and the other in tlie water. Thefe two wires im- 

 merfed in the acid conninuiicatcd with a third wire, and the 

 other two with the zinc and filver of the battery. When 

 the apparatus began to operate, oxvgcn gas was feen to rife 

 in the one tube, and hydrogen gas in the olher. 



To jiroduce a contrary elfecl, nothing was neceflTary but to 

 turn the zinc towards a, 



Kxp, XIIL M. Ricluer combined feveral tubes in this 

 manner. (Fig. 6.) All the wires which produced oxygen 

 were in the water, and all thofe which produced hydrogen 

 in the acid. The wires in the water in con taft with the zinc 

 of the battery gave immediately oxygen gas 5 and when the 

 zinc was a^ipiied on the contrary fide they gave hydrogen gas. 



Such are the experiments, from which M. Richter concludes 

 that the two airs cannot be conlidered as conftituent parts of 

 water, but as two matters produced by a part of the water 

 combined with the galvanic fluid, and that the generation of 

 one is in no manner depepdcnt ou the production of the other* 



Exp.Xir. M. Richter filled the tube of fig. 1. with nitric 

 acid mixed with water: he employed two wires of ditferent 

 metals, p e, being of copper. The metal began to be dif- 

 folved ; but, when he brought the tube into contaft with his 

 galvanic battery in fuch a manner that they formed a chain, 

 the wire of zinc towards a dilTolved much fooner^ whereas 

 that of copper towards b ceafed \o be diflblved. 



Exp. XF. M. Richter filled the tube with a folution of 

 copper in fulphuric acid. The two wires were of iron. The 

 precipitation was as uiual ; but when he brought the tube 

 into the galvanic chain the precipitation was increafcd to- 

 wards a, while it decreafed towards the filver. 



Bv putting copper w^ircs into the folution every tiling re- 

 \'oL. IX. F f mained 



