On the Decomposition of Water. • 331 



is so fine or so interesting as this vegetation, presenting to 

 our view the image of a fine shrub, furnished with its foliage 

 and adorned with the most beautiful metallic brilliance. 



IV. Wollaston, the celebrated English chemist, has al- 

 ready noticed, that upon establishing a current of electricity 

 in the solution of a metal, the latter is revived at the extre- 

 mity of the conductor endued with negative electricity; but 

 I am ignorant whether or no he also perceived that this re- 

 vival is susceptible of assuming a symmetrical arrangement, 

 when the action has enough of energy and has lasted a suf- 

 ficient time. 



V. All the metals in solution are not equally decomposed 

 by Galvanic electricity. From nitrate of manganese I ob- 

 tained gaseous bubbles at the negative pole * in place of a 

 metallic deposit ; and it seems that when in similar circum- 

 stances, the metal, in solution has more affinity for oxygen 

 than hydrogen has for this principle, it is the water which 

 alone suffers the decomposition. 



VI. During the arborisation of the metals at the negative 

 pole, no gas is seen to be disengaged ; whence I conclude, 

 either that the hydrogen arising is combined with the oxy- 

 gen of the metallic oxide, or that the action is only exercised 

 upon this oxide and not upon the water. This last conclu- 

 sion ought to be a true one ; for we can scarcely admit that 

 the hydrogen is able to carry off completely the oxygen from 

 the oxides of zinc and iron, as well as from certain acids 

 their solvents, in which these two metals are not dissolved, 

 except after having produced an effect contrary to this ad- 

 mission, by decomposing water. 



VII. Of all the metallic salts which I submitted to the 

 action of the electrometer apparatus, the acetate of lead and 

 the muriate of tin f presented the most beautiful vegetation. 



* I shall in future make use of the phrase positive pok to express the extre- 

 mity of the wire communicating' with the disk of zinc, and of the term /•rga- 

 tive pole to express the extremity of the wire in contact with the disk of 

 copper. 



\ I have also obtained effects more or less remarkable from the nitro-mu- 

 riates of eold and plalina, from the nitrates of zinc, copper, mercury, and 

 cobalt; from the sulphates of zinc and iron, from the stannite of mun.itid 

 potash, and from muriate of iron. 



That 



