S6S ON THE ALKALINB METALLOIDS, 



gas is absorbed, and a solid compound of potassium Jlffd 

 hidrogen formed. These facts, as proving the existence of 

 an affinity between potassium and hidrogen, are favourable 

 to the supposition, that it may consist of a base combined 

 with a portion of hidrogen; especially as potassium is 

 Sodium has less never formed, where hidrogen is not present. Sodium is 

 affinity for hi- scarcely visibly soluble in hidrogen ; it appears therefore to 

 have a less strong affinity to it, and may be supposed to re- 

 tain a smaller quantity in combination with it. And from 

 this may arise, in conformity to the view I have given in 

 my former paper, the greater specific gravity of sodium, 

 and the inferior attraction of soda to water. 

 The two light- The lightness of the metalloids is probably owing, I have 



est of the com- stated, to the combination of real metals, which form their 



mon metals ' ^ ' 



combine with bases, with hidrogen; the lightest of them, ' potassium, 



bidrogen. probably containing the largest portion. It is a curious 



fact in conformity to this view, that the two lightest metals^ 

 tellurium and arsenic, are those which have the most pecu- 

 liar relation to hidrogen, and evidently exert an affinity to 

 it. Ritter observed the singular fact, that, when tellurium 

 is employed as the negative wire in decomposing water by 

 galvanism, hidrogen gas is not evolved, though oxigen i$ 

 given out at the positive side; at the negative a powder falls 

 down, which he found reason to conclude is a compound of 

 tellurium and hidrogen*. The observation is an important 

 one, as proving a combination to be established by galvanism 

 between a metal and hidrogen, though in this case the 

 quantity of hidrogen combined appears to be so large, as 

 to cause the metallic qualities to disappear; as happens too 

 in the combination of potassium with a large proportion of 

 hidrogen in the experiment of Gay-Lussac and Thenard 



Arsenic com- above quoted +. I have found, that, in decomposing water 



bines with hi- ^y g^jyanism, if arsenic be the metal immersed in the water 



drogen by gal- •' ^ ' 



vanic action, at the negative side, while platina is at the positive side, less 



. ■ rrr'") ■ ■ 



f , See Journal, atoI. xxiv, p. 3 1 8. 

 Hidrogen not t These facts with regard to the loss of metallic properties when 

 fin aeriform hidrogen in considerable proportion is combined with a metal are 

 laetal. unfavourable to the hypothesis, that it is a metallic body in the 



aerial form. The properties of its oxide, water, are equally ad- 

 verse to.this exposition. 



hidrogca 



