5S(i GALVANISM. 



of gas and oxyd disappear, but are renewed again 

 upon restoring the communication. 



In this experiment it would appear that the hy- 

 drogen is separated from the water, and is con- 

 verted into a gaseous state by the wire connected 

 with the negative extremity of the battery ; whilst 

 the oxygen unites with, and oxy dates the wire 

 connected with the positive end of the battery. 

 If you connect the positive end of the battery with 

 the lower wire of the tube, and the negative with 

 the upper, then the hydrogen proceeds from the 

 upper wire, and the lower wire is oxydated. 



If two wires of gold or platina be used, they are 

 not oxydable; then streams of gas issue from each j 

 the water is diminished ; and the collected gas is 

 found to be a mixture of hydrogen and oxygen, 

 and explodes violently on the approach of an ig- 

 nited body, or by the electric or the galvanic shock. 



To obtain these gases separately, let the two 

 ends of the gold wires be immersed in a vessel of 

 water (Fig. lo.), and be about one inch apart. 

 Then hang over them two w T ine-glasses, inverted, 

 and full of water. The gases will ascend into the 

 separate vessels. 



It is well known that hydrogen gas, in its nas- 

 cent state, reduces the oxyds of metals. Accord- 

 ingly, when the tube (Fig. 14.) is filled with a 

 solution of acetite of lead in distilled water, and a 

 communication is made with the battery as above 

 described, no gas is perceived to issue from the 

 wire which proceeds from the negative end of the 

 battery ; but in a few minutes, beautiful metallic 

 needles are perceived on the extremity of this 

 wire ; these soon increase, and assume a dendri- 

 tical appearance or the form of fern. The lead 

 thus separated is in its perfect metallic state, and 

 very brilliant. 





