I860.] 



THE SOUTHERN PLANTER. 



469 



portions, multiples the one of the other, 

 and the quantity rarely surpasses the pro- 

 portion of five to one. Substances may be, 

 it is true, heterogeneously mixed in any pro- 

 portions, and these mixtures present endless 

 varieties, but are not chemical compounds, 

 and do not enter into the category ot which 

 we are speaking. 



Matter may be divided into that which 

 has life, and tliat which is without life. The 

 principal part of the substances which go 

 to compose organic beings exists around us, 

 in the air we breathe, (water, carbonic acid, 

 nitrogen). There are other substances not 

 less essential to organic life, but which are 

 found to enter their composition in infinitely 

 smaller quantities. These are found in the 

 ashes, after incineration of any vegetable or 

 animal matter. We shall learn their com- 

 position as we proceed. 



Those things which are endowed with vi- 

 tality are produced, then increase, and ma- 

 ture. Inorganic substances increase by the 

 juxtaposition of similar parts, and their form 

 is destroyed by forces exterior to themselves, 

 while organisms reproduce their like, and 

 have a period of existence determined by 

 laws, which fix their time of growth, decay, 

 and death. Of organic life there are two 

 distinct classes, one receiving its food through 

 a digestive canal, and is endowed with loco- 

 motion ; the other is fixed by roots to the 

 soil. This is not rigorously correct, but suf- 

 ficiently so for our present purpose. The 

 last, or vegetable productions, receive a por- 

 tion of their food through their roots, and 

 another through their leaves. The root an- 

 swers a double purpose, that of fixing the 

 plant in the earth, and drawing from it 

 nourishment. Vegetable anatomy informs 

 us that among the elements of their con- 

 struction there are cells, which are found in 

 all plants, whatever character they may 

 have, and those cells, by transformations and 

 successive development, form fibres, tubes, 

 or elongated canals. While the character- 

 istics of the animal and vegetable chsses 

 are thus marked, the qualitative chemical 

 composition of both is identical ; the prin- 

 cipal organic portions of which — I do not 

 allude to the mineral constituents, or ash, 

 and there is great similarity in that respect 

 — may be said to express the condensation 

 of the gases of which they are composed. 

 Oxygen, hydrogen, carbon and nitrogen, 

 form the volatile portions; and silex, lime, 

 potash, soda, magnesia, iron, sulphur and 



phosphorus, the mineral parts. It is mainly 

 with those substances that we have to deal 

 in connection with fertility or agriculture. 

 If we can turn a never-ceasing influx of 

 them into our fields, the problem of fertility 

 is solved, and it remains for us to consider 

 their properties, their history, their action 

 the one upon the other, and the means that 

 have heretofore been employed of making 

 them subservient to our wants. 



Plants are divided into two distinct class- 

 es, those that receive their increment from 

 within and those that receive their growth 

 on the exterior. The first are called endo- 

 gens, the latter exogens. All organized 

 bodies have forms and properties peculiar 

 and inherent to themselves, and those forms 

 and properties characterize the parts as well 

 as the whole ; and it is that particular form 

 and the properties of the parts that render 

 it what it is and make it a living thing. 

 Some plants go through the difi"erent stages 

 of germination, growth, fructification, and 

 death in one season; they are called annuals. 

 Others live through a succession of years, 

 and are called perennial. 



* >}: * >is * * 



It is through the roots that the ash or 

 mineral ingredient enters [a plant,] while 

 the leaves absorb from the atmosphere the 

 organic or combustible portion. The power 

 of assimilation appears to be dependent upon 

 the action of light. A plant placed in wa- 

 ter, containing carbonic acid, and exposed 

 to the light of the sun, absorbs the acid and 

 gives off oxygen. At night the action is 

 reversed, and carbonic acid is emitted, when 

 oxygen is assimilated. Every one has re- 

 marked the tendency of plants to lean to- 

 wards the sun, and wdiere they are kept in 

 cellars they wnll bend even several leet from 

 the perpendicular to receive the rays of 

 light that may enter through an aperture. 

 In the early stages of plant-life, the carbon 

 of the soil enters through the roots ; but 

 when the plant has risen above the ground, 

 and its leaves are formed, the carbon of the 

 soil is no longer needed, and it is probable that 

 what is required is entirely assimilated from 

 the carbonic acid of the atmosphere. 



The sap rises from the roots through the 

 internal vessels to the leaves, becomes car* 

 bonized by the decomposition of the car- 

 bonic acid of the atmosphere, and passes- 

 down into the plant, forming ligneous fiber, 

 &c. We shall not enter into the subject of 

 vegetable physiology; that would be foreign 



