366 on THE ALKALINE METALLOIDS, 



But this ac- hidrogen, connected with the formation of the metal. This, I 

 counted for by think, admits of a ditferent conclusion from that which is in- 



thedrcomi)osi- , j i , , i* . tit . • . 



tion of the wa- tended to be drawn trom it. Water is certainly more easy of 

 teriathepot- decomposition by galvanism than potash is ; when the gal- 

 vanic power therefore is sufficiently strong to decompose? 

 the latter, it must be able to decompose the former; and of 

 course, when common potash, containing water, is decom- 

 posed by a galvanic battery, this water can scarcely be sup- 

 posed to escape decomposition. And the hidrogen of such 

 a portion of water cannot be supposed to pass off unob. 

 served, for although the hidrogen in water is to the oxygen 

 only as 15 to 83 by weight, yet it is as 2 to 1 nearly by 

 volume : and hencd in the decomposition of water by galva- 

 nism, the disengagement of elastic fluid at the negative side 

 Farther argu- is much more abundant than at the positive. It is farther 

 existence of ^ to be considered, that, from the small quantity of oxygen 

 hidrogen in the which enters into the composition of potash, and the large 

 SiK:ed°* ^^^' quantity of it which exists in the composition of water, tha 

 quantity of it belonging to the water, which common fused 

 potash contains, supposing this to be only 13 per cent, is equal 

 to the quantity which is contained in the real alkali. If 

 both, therefore, are decomposed in the galvanic action, 

 half the quantity at least of the oxygen disengaged at the 

 positive wire must be from the water, a quantity of hidro- 

 gen double the quantity of this, that is equal in volume to 

 the whole oxigen evolved at the positive side, ought 

 to appear at the i^egative side; if an effervescence, there- 

 fore, is perceived at the former from the disengagement of 

 oxigen, an equal effervessence ought to be conspicuous at 

 the latter; and, since it is not, we can scarcely avoid the 

 conclusion, that the hidrogen, or at least much of it, enters 

 into the composition of the globules of metallic matter, 

 which appear at the negative side. With regard to the fact,, 

 that when the potash is under the action of a very powerful 

 battery, there is a violent effervescence, and production of 

 hidrogen, and potassuretted hidrogen, I suppose this must 

 arise from the intense heat excited at the point of decompo- 

 sition, by which an elastic combination of potassium and 

 hidrogen is established. If there is a certain degree of gal- 

 vanic ©nergyj at which hidrogen, pure, or not holding 



