THE SOUTHERN PLANTER. 



271 



substance to be used occasionally, and not 

 in place of a proper and continual supply 

 of manure. I have mentioned this matter 

 thus minutely because I know there is in 

 many places a very great want of a proper 

 understanding with regard to the use of 

 lime. If you have enough lime already, 

 to apply more is like sending coals to New- 

 castle, or throwing them into the sea: the 

 addition of more will produce no effect. — 

 I know that many of the farmers in the 

 southern and western parts of Cornwall 

 have declared that ihey do not like using 

 shell-sand, because they do not find it to 

 act in the land. I have discovered by 

 analysis that this view, at least in some 

 instances, is correct — that many farms 

 have got enough of this extraneous matter 

 already. When such a substance has been 

 carted on the land year after year for per- 

 haps two or three hundred years, it is but 

 natural to suppose that there is now suffi- 

 cient calcareous or limy matter for the 

 purposes of cultivation, and that the pe- 

 riod has now arrived when, if other sub- 

 stances are applied, the land will, in con- 

 sequence of the presence of lime in ade- 

 quate quantities, be perfectly prepared to 

 make the best use of them. I must now 

 speak to you, gentlemen, of vegetables, or 

 the various crops which you grow. What 

 are they, and what do they contain ? — 

 Without speaking of the vegetables which 

 grow in the sea, and which only require 

 roots for the purpose of being attached to 

 rocks, and having a hold there, f may ob- 

 serve that the vegetables which are culti- 

 vated on the farm are found to have a root 

 and a stem, or at all events to have a por- 

 tion which grows in the land and a portion 

 which grows out of the land. That por- 

 tion which grows in the land, and which 

 is called the root, serves two purposes : it 

 serves as a holdfast for the plant in the 

 land, and it also serves, by means of the 

 little pores which are found throughout 

 the root, to absorb those matters from the 

 soil which the plant requires for its devel- 

 opment. The plant also sends leaves into 

 the air, and these act by absorption upon 

 any materials contained in the air which 

 may be essential to the plant. Now, gen- 

 tlemen, if you have been in the habit of 

 considering that plants derive all their 

 materials from the soil, you have been in 

 the habit of considering wrongly ; for 

 they derive on the average nine- tenths of 



their weight from the air, into which the 

 leaves shoot, and about one-tenth — and 

 many of them very much less than that — 

 from the soil in which they grow. It is 

 on this point that I wish now especially to 

 address you, If I burn this piece of pa- 

 per (holding it up,) paper in fact a vegeta- 

 ble, the ash which is left behind is what 

 came from the soil : that is called the 

 mineral or inorganic matter, consisting of 

 the phosphate of lime and the potash, and 

 the other materials which the plant may 

 happen to have derived from the soil. — 

 All that which burns off and goes into the 

 air was derived originally from the air. — 

 So that this analysis is exceedingly sim- 

 ple. That which does not burn off, viz : 

 the ashes, originally came from the soil; 

 that which burnt off, came from the air. — 

 Now, gentlemen, I wish to speak to you 

 of those materials which plants derive 

 from the air, and from the water which 

 comes down from the air. There are only 

 four substances which plants derive from 

 the air, and, though I am very much afraid 

 of introducing too much chemistry, I must 

 give you some account of each of them. 

 One is called oxygen another is called ni- 

 trogen, another hydrogen, and another 

 carbon or charcoal. I must, I say, endea- 

 vour to convey to you some idea what 

 these four substances really are. I am 

 probably addressing many persons who 

 are as "well acquainted with these sab- 

 stances as myself ; but I think it best to 

 go to the bottom, in order that none may 

 be without the requisite information.- — 

 Here we have, then, oxygen, nitrogen, hy- 

 drogen, and carbon. Now let us begin 

 with oxygen. Oxygen, gentlemen, used 

 to be called vital-air, because animals are 

 absolutely dependent upon it for their life: 

 they cannot exist without it. If we were 

 deprived of the oxygen which is found in 

 the air, we should all die by suffocation. 

 Death by drowning is nothing else than 

 the cessation of breathing for want of the 

 vital power in the air. Common air con- 

 tains oxygen in the proportion of one-fifth, 

 that is to say, five bushels of air contain 

 one bushel of oxygen. This substance in 

 air is diluted by another substance, called 

 nitrogen ; and if it were not so diluted, 

 we should be placed in considerable diffi- 

 culty, because it is so powerful a burner, 

 so strong in its action; that it would burn 

 everything up. If I had a jar of oxygen, 



