548 



THE SOUTHERN PLANTER. 



nearly the whole of most plants, ashes 

 bearing but a small proportion to the whole. 

 Carbon constitutes about half the dry 

 weight of plants. Oxygen supports com- 

 bustion. It unites with many substances. 

 It is sometimes called vital air, because 

 necessary to respiration. Oxygen and 

 carbon form carbonic acid, and united with 

 hydrogen forms water. When united 

 with iron, the iron becomes rusty. This 

 rust is called oxide of iron. Oxygen united 

 with nitrogen forms nitric acid. The two 

 also compose atmospheric air ; and here 

 witness the wonderful adaptation of the 

 works of creation to each other ! If the 

 atmosphere was pure oxygen, every liv- 

 ing thing would soon decay of combus- 

 tion ; but adding to one part of oxygen 

 four parts of nitrogen, God has so diluted 

 the exhilarating gas, as that in its place we 

 have a delicious life-giving and life-pre- 

 serving nectar — so pure and palatable that 

 we never cease to thirst for it, yet the sup- 

 ply is ample. But there are other ele- 

 ments in the atmosphere which the lungs 

 of plants receive, and yet they are called 

 impurities. We have seen fartners, for 

 the want of proper knowledge, apply cer- 

 tain compositions to a soil, when, instead 

 of benefitting the plant, it drove away, 

 and dissipated all that w^as giving life to 

 it. We have seen ammonia, one of the 

 impuiities above alluded to, allowed to es- 

 cape from a manure heap, because of the 

 want of the proper application to fix it 

 there. Carbonic acid, water and ammonia 

 are all essential to the maturity of most 

 vegetables. Carbonic acid is the most im- 

 portant in its relations to plants, for from 

 this source alone is their carbon obtained. 

 It consists, as has been said, of carbon 

 and oxygen. It is remarkable as being the 

 first gaseous substance recognized after 

 atmospheric air. Dr. Black, in 1757, c^W- 

 Qdi \i fixed air, he CdiUSQ he found it fixed 

 in common limeslone and magnesia. 

 Plants, as we hav# before said, receive 

 ■nourishment through their roots, and by 

 their leaves. Carbon enters in the water 

 by the roots, and is absorbed from the air 

 by the leaves. Since carbonic acid is the 

 source of supply of carbon only, to the 

 plant, the oxygen must be separated from 

 the carbon, and sent off into the atmos- 

 phere. The gum portions of the plant 

 exhales the oxygen under the influence of 

 sunlight. Sunlight is essential to the de- 



I composition of carbonic acid, and to the 

 rapid growth of plants. When a plant 

 decays, the carbon in the plant unites with 

 the oxygen in the air, and becomes car- 

 bonic acid. The same is the result where 

 bodies burn. In the consumption of food 

 and respiration, you are manufacturing 

 and throwing off carbonic acid, which 

 goes to assist again the formations of food 

 for yourself or your dependants. Carbon, 

 then, is certainly in a transition state, and 

 though it constitutes so large a part of all 

 vegetable and animal matter, yet it is all 

 derived from the small amount of carbonic 

 acid in the atmosphere ; and but for this 

 constant change and exhalation of both 

 plants and animals, the supply would be 

 exhausted. The fire in your kitchen is 

 constantly supplying the trees and vege- 

 tables near your door with carbonic acid, 

 which if exposed to the sun decomposes 

 rapidly, and hence makes a rapid growth. 

 The tree near your dwelling, though no 

 better than the one planted at the same 

 time, in the same manner, and in equally 

 as good soil, in the orchard fifty yards dis- 

 tant, is far outstripping the orchard tree 

 in growth — simply because it is fed with 

 more carbon. Trees are necessary near 

 the house ; and in large cities, every man 

 who understands the laws of nature and 

 of health will provide these absorbents 

 for the extra amount of acid generated. 

 We frequently find in cities the leaves of 

 plants rapidly forming, while in the coun- 

 try the twigs are as bear of foliage as at 

 mid-winter. We should not be misun- 

 derstood. Carbon enters the plant in the 

 form of carbonic acid. The carbon is re- 

 tained until the plant decays but the oxy- 

 gen is thrown off to unite with carbon 

 again. Carbon is fixed in the plant until 

 decay commences. The blood of animals, 

 which contains carbon, unites with the 

 air, or the oxygen of the air, as it is in- 

 haled into the lungs, and forms carbonic 

 acid, without which process no animal 

 could live. This carbonic acid is thrown 

 off', and feeds plants, which in turn feed 

 animals again. 



We have said carbon is a solid, or, in 

 other words, charcoal is a solid. It is 

 light and porous, hence a good absorbent. 

 This is the secret of its value to the far- 

 mer. It absorbs gases that may escape 

 from plants or decomposing substances. 

 It separates from water any impurities, de- 



