Alkali Carbonate Solution, 107 



calcic sulphate. The puddling effect of dilute carbonate solu- 

 tions is so striking, so easily brought about, and so permanent 

 when once accomplished, that it should command serious atten- 

 tion as a means for the consolidation of earth dams and fortifi- 

 cations, whose tough resistance to the penetration, whether of 

 water or missiles, would render them effective under conditions 

 under which they would otherwise be altogether insecure. If 

 we imagine the amphoteric solution as imbuing a loose clay 

 deposit, which is then subjected to pressure such as constantly 

 occurs in the formation of geologic strata, the quick consolida- 

 tion resulting from the destruction of the flocculent structure, 

 and then the collapse by compression ; and the subsequent 

 deposition of calcic carbonate, dissolved silica or both, we can 

 easily conceive of the formation of a very substantial rock 

 within (geologically speaking) a very short period of time. 



It thus appears that whether viewed from the chemical or 

 physical standpoint, the ready formation of super-acid alkali 

 carbonate solutions by the mutual reaction of neutral alkali 

 salts, calcic, magnesic or generally earthy and metallic carbon- 

 ates, and free carbonic acid, is likely to throw light upon many 

 intricate problems in chemical geology ; so that the further 

 study of this reaction in its complex bearings upon other salts 

 and metallic compounds than those heretofore investigated by 

 us, offer a most promising field for farther research. 



A.M. Jour. Scl— Fourth Series, Yol. II, No. 8.— August, 1896. 

 8 



