i 33: Chcmico- Galvanic Observations. 



ment, and they were all plunged into one vessel containing 



water. 



The gas was abundantly liberated in the positive tube 

 during the whole time of the experiment* At first only 

 a few bubbles were seen upon the negative side, and they 

 soon disappeared. After 24 hours of galvanization the au- 

 thor found carbonate of soda in the water of the negative 

 pole. That of the positive tube, in which so much gas was 

 disengaged, appeared to contain only a few atoms of this 

 salt. 



On the positive side the charcoal preserved its surface 

 very black, but that of the negative charcoal was singularly 

 whitened by combining with the hydrogen as it was forming. 



It is the opinion of Kinvan (Phil. Trans. 1785.) and Ber- 

 thollet (Stat. Chim. t. ii.) that charcoal contains hydrogen, 

 because in certain circumstances it yields an inflammable gas : 

 but the author strongly suspects that the inflammable gas ob- 

 tained, in a close vessel, even from calcined charcoal, comes 

 from a little humidity attracted from the atmosphere in cool- 

 ing, and which is decomposed at the burning temperature; 

 or perhaps that it is only the gaseous oxide of carbon, so 

 well examined by Cruickshank. He founds this conjecture 

 upon the observation which he had made, that charcoal 

 scarcely beginning to be hydrogenated by Galvanism, changes 

 all at once the electrometer character, as gold does; and 

 from negative becomes positive, compared with other char- 

 coal, and tried with the frog, after the method of Galvani. 

 It is probable that upon thus giving the negative property 

 to 100 disks of charcoal, and by uniting them to 100 other 

 disks of pure carbon, we might form a solid and active ve- 

 getable pile, by placing, in the usual way, between the disks 

 united two and two, rounds of wet pasteboard. Thus we 

 might have a pile analogous to that of Ritter, which has 

 been called the charging pile. 



§ IX. 

 The Black Oxide of Manganese may he hydrogenated ly 

 Galvanism. — Character which distinguishes it. 

 The author remarked, in the course of all his experiments 



upon 



