122 ACTION OF SALTS. 



evolve carbonic acid, by its carbon combining with 

 oxygen of air, and its second act is to decompose 

 water. Its oxygen combines with the carbon of the 

 seed, a single bean, produces many times its bulk of 

 carbonic acid gas ; and in the .soil would surround 

 itself with an atmosphere of carbonic acid. This 

 evolved, begins its action upon the silicates. The 

 living seed begins the electric action, and the plants 

 exert and keep up this influence. Salts act in a 

 similar way, but above all, over all, influencing all; 

 is the. living plant. This electric action induced, ex- 

 tends to undetermined distances ; hence there is a 

 transfer, as is usual in all cases of galvanic decom- 

 position, of substances remote from the plant, to its 

 root, where they are taken up.  It is not the potash 

 and lime, fee, immediately in contact with the root, 

 which alone supplies the plant, but under the galvan- 

 ic influence, an undetermined portion of soil is de- 

 composed. This decomposing agency of plants, 

 wholly destroys all confidence in experiments, un- 

 dertaken to prove that pure water alone, can nourish 

 plants. The containing vessel, that is the vessel in 

 which the experiment is made, is itself always de- 

 composed. If to guard against an error, glass is 

 used, it has already been shown, that this is only a 

 combination of silicates, and these will be transfer- 

 red from the glass to the plant. 



