VEGETABLE PHYSIOLOGY. 



supposed that light acts by decomposing the carbonic acid gas in the sap as it is 

 carried through the leaves, and thus enables the plant to appropriate the carbon 

 in building up its own structure. But is there any evidence in chemistry that 

 sunlight can decompose carbonic acid, or release oxygen from its compounds in 

 any case. Until this is shown, it would seem to be hardly proper to attribute to 

 it an effect without some proof of its power to produce such an effect. That such 

 an effect is produced, is no evidence that that was the agent in producing it ; more 

 particularly, as there is an agent in nature that is known to produce such an effect, 

 and one within reach of every plant. 



That agent is electricity, the power of which is perhaps not yet fully ascertained, 

 but enough is already known to consider it fully capable of performing all that 

 may l)e required of it in the growth of plants. The beautiful art of gilding by 

 galvanism is proof of this. In this case, the metal is dissolved in acid, the oxygen 

 here dissolving the metal, making it fluid and colorless. Now, if the object to be 

 gildeil is connected with the pole of a battery, and galvanism applied, the one 

 pole will attract the oxygen, and the metal in solution will be drawn to the other 

 pole, and will be distributed over the surface to be gilded. Now, as carbonic 

 acid gas is a union of carbon and oxygen (and it is from this that vegetable 

 physiologists generally consider wood is derived in its growth), and as carbon is 

 positive and oxygen is negative, it is fair to presume that the application of elec- 

 tricity in such case would release the oxygen and retain the carbon, and unite it 

 to the already fornjed wood of the plant. That carbonic acid gas is carried up by 

 the sap as well as imbibed by the leaves, is now generally admitted, and as this 

 gas is readily imbibed by water, and will unite with it in large proportion, we 

 have the exact condition necessary to effect the object desired, on the application 

 of electricity, without resorting to any supposed hypothesis. 



That electricity is present, in sufficient quantities, during the growing season, 

 we have reason to believe from experiments already made. In a work published 

 in New York, and styled " The Farmer's Guide to Scientific and Practical Agri- 

 culture," by Henry Stevens, of Edinburgh, and J. P. Norton, of Yale College, is 

 an article on "Electro-Culture." In this article, the author quotes the language 

 of William Sturgeon, of Manchester, who has bestowed much attention to the 

 subject of electricity in all its bearings, and who asserts that "this active element 

 of nature is so universally diffused through every part of the terrestrial creation, 

 that it becomes an occupant of every part of the earth's surface, and of the shell 

 of air that surrounds it ; that trees, shrubs, plants, flowers, and crops of every 

 kind, partake of this electric distribution ;" and then goes on to show that "each 

 individual object is requisitely susceptible of disturbance when the circumstances 

 vary," when they become "positive" and "negative" to each other. This con- 

 dition, "the various objects which constitute the vegetable clothing of the land 

 are now in precisely the same condition, being positive and negative with regard 

 to each other. A similar inequality of electric force occurs among growing 

 plants and their manures, and even amongst the various elements which constitute 

 the latter, no two of them being precisely alike at the same time." And after 

 describing the manner of electric action, the writer concludes : " From this train 

 of reasoning, we are led to some of the most interesting points in vegetable 

 physiology. The electro-polar condition of plants qualifies them in an eminent 

 degree for the performance of those operations which develop electro-chemical 

 phenomena ; and, what is very remarkable, the laws of this beautiful branch of 

 electricity are rigidly enforced, and admirably complied with, in the decomposition 

 of carbonic acid gas by their foliaceous parts; for, in this process, the elect 

 positive carbon is drawn to the electro-negative poles of the plants in pre'c 



