OV THE DECOMrOSITION OF THE EAETH?. 



silcx; but without gaining distinct evidences of their haring 

 undergone any change in the processes. 



Obliged to seek for other means of acting upon them, it 

 was necessary to consider minutely their relations to other 

 bodies, and to search for analogies, by which the principles 

 of research might be guided. 



Aluminc very slowly finds its point of rest at the negative 

 pole, in the electrical circuit ; but silex, even when diffused 

 in its gelatinous state through water, rests indifferently at 

 the negative or positive poles. 



From this indifference to positive and negative elecrical 

 attractions, following the general order of facts, it might be 

 inferred, that if these bodies be compounds, th^ electrical 

 energies of their elements are nearly in equilibrium ; and that 

 thcirstatc is either analogous to that of insoluble neutral salts, 

 or of oxides nearly saturated with oxigen. 



The combinations of silex and alumine with acids and al- 

 kalis, as well as their electrical powers, were not inconsistent 

 M ith either of these ideas ; for in some respects they resem- 

 ble in physical characters fluate and phosphate of lime, as 

 much as in others they approach to the oxides of zinc and 

 tin. 



Oa the idea that silex might be an insoluble neutrosaline 

 resolve sdex, compound, containing an unknown acid or earth, or both, 



Nearly indif- 

 ferent to the 

 iwo electrici- 

 ties. 



Analogous to 

 insoluble neu- 

 tral salts, 



or saturated 

 oxides. 



Experiments to 

 resolve silex, 

 if neutrosaline. 



Exposed to 

 electricity in 

 •water. 



and capable of being resolved into its secondary elementsj 

 in the same manner as sulphate of barytes, or fluate of lime, 

 I made the following experiments. 



Two gold cones *, connected by moistened amianthus, 

 were filled with pure water, and placed in the electrical cir- 

 cuit, a small quantity of carcftilly prepared and well washed 

 silex was introduced into the positive cone; the action was 

 kept up from a battery of two hundred plates, for some 

 hours, till nearly half of the fluid in each cone was ex- 

 hausted; the remainders were examined; the fluid in the 

 One vessel acid, cone Containing the silex was strongly acid : that in the op- 

 tte other alka- posite cone was strongly all(:aline; the two fluids were 

 disbolveU. *' ''passed through bibulous paper, qnd mixed together, wjien a 

 precipitate fell down, which proved to be silex. 



* The same as thos? dcspribed in Phil. Trans. 18Q7, p. 6; or 



Joiu-rjal, vol. xviii, p. 325. 



Oft 



1 



