274 



THE SOUTHERN PLANTER. 



charcoal, which, when united with oxy- r 

 gen, forms carbonic-acid gas. With re- 

 gard to this last, I may add that it is found 

 in the air, in the proportion of one part 

 to every two or three thousand ; and from 

 this source it is that plants derive all their 

 carbon. It will perhaps be our best course 

 to direct our attention now to the nature 

 of plants. As I before remarked, vegeta- 

 bles have roots and leaves. Their rootlets 

 go down into the soil, and thence obtain 

 the nutriment in the soil ; their leaves go 

 out into the air, and there seek the nutri- 

 ment which is contained in the air. Now 

 it is a curious fact, that when the light of 

 the sun, or the diffused light of day, is 

 shining upon the leaves of plants, these 

 leaves have the power of taking in carbo- 

 nic acid gas from the air, of retaining the 

 charcoal or carbon of the carbonic acid, 

 and the hydrogen of the water, within 

 themselves, and of giving the other con- 

 stituent of these substances — viz: oxygen, 

 or vital air — back again to the atmosphere. 

 However strange this may seen, it is nev- 

 ertheless true. One single experiment 

 will suffice to prove this. If you intro- 

 duce a sprig of mint into a bottle of wa- 

 ter containing carbonic acid, you will, af- 

 ter exposing it for a time to ihe light of 

 the sun, find it covered with little globules; 

 and if you collect all these into one glo- 

 bule at the top, you will find pure oxygen 

 gas. Another experiment is that of a cel- 

 ebrated French chemist, who placed a liv- 

 ing branch of a vine in a glass tube, and 

 then covered the tube all over with black- 

 ened paper, so that no light could pene- 

 trate, and he sent a current of air through 

 it containing about five per cent, of car- 

 bonic acid gas. He sent this through the 

 tube, and did not expose it to the light. — 

 He found that the tube at the other end, 

 "which passed through lime water, gave an 

 abundant precipitate, showing that the 

 leaves had no action on the charcoal gas. 

 He then took off the paper and exposed 

 the tube and vine branch to the light of 

 the sun ; and on now sending the stream 

 of air and carbonic acid through the appa- 

 ratus, not a trace of carbonic acid was 

 found to pass through at the other end.-— 

 Another point which you have to remem- 

 ber is, that plants obtain the largest amount 

 of their nutriment from the air; You shall 

 plant a forest upon land which contains no 

 vegetable matter, I might say, upon Brown 



Willy or Rough Tod ; you, or some one 

 else coming after you,'may, at the end of, 

 say fifty years, remove cart load after 

 cart load of timber, and yet, at the expi- 

 ration of the period, the soil shall be richer 

 in vegetable matter than it was when the 

 trees were first planted. Where did all 

 this vegetable matter come from, if not 

 from the air ? Again, in the case of a 

 field of turnips, it is the action of the 

 leaves of the turnip upon the air that se- 

 cures the greatest amount of vegetable 

 matter. Bear in mind, then, that plants 

 are dependent in a far greater degree upon 

 the air than upon the land ; that so far as 

 the land is concerned, you can only, after 

 a due supply of mineral matter, assist the 

 plant in endeavoring to obtain more organ- 

 ic matter by its roots fromj the land than 

 it could naturally obtain by its leaves from 

 the air ; and in this consists the true prin- 

 ciple of manuring. I mujst now proceed 

 to speak to you about the production of 

 farm-yard dung. That is the sine qua non 

 of farmers, and I am afraid that some far- 

 mers attach too much importance to it, re- 

 garding it as if nothing else could possi- 

 bly equal it in value. Now, gentlemen, 

 what is farm-yard dung ? I am not about 

 to speak now of all the various modes of 

 manuring which are adopted, though I 

 have heard it stated that the decomposing 

 vegetable matter differs greatly in differ- 

 ent counties. Farm-yard dung is neither 

 more nor less than decomposed vegetable 

 matter, derived from plants which once 

 had life in the soil, and which, when re- 

 turned to the land, will furnish the neces- 

 sary elements for reproducing vegetable 

 life. The manner in which it is decom- 

 posed — the mode of reducing it to a prop- 

 er state for its application to the land — is 

 quite another question. Is what I have 

 heard stated true, that in Devonshire 

 and Cornwall there are parties who are in 

 the habit of strewing their straw on the 

 high roads and bye-roads ? Is it true that 

 in this county it is the practice to place 

 vegetable matter in a position in which 

 everything in it that is valuable is likely to 

 be washed away? If that is the mode of 

 making farm-yard manure w r hich is adopt- 

 ed in this district, or in other districts, all 

 I can say with regard to it is, that it is 

 not a mode which I should recommend for 

 imitation. Gentlemen, in considering the 

 subject of the decomposition of vegetable 



