272 



THE SOUTHERN PLANTER. 



and were to introduce within it any burn- 

 ing body, you would immediately see the 

 combustion increases to an enormous ex- 

 tent. I have got a little oxygen in a 

 glass on this table, and if it has stood the 

 journey from London you will see the ef- 

 fect which I have mentioned. [A piece 

 of ignited wood was here inserted in the 

 aperture of the glass, where it burnt with 

 greatly increased intensity.] The increas- 

 ed intensity is entirely owing to the oxy- 

 gen. This substance it is which serves to 

 burn up all our fuel. You can now un- 

 derstand why, if oxygen were not diluted 

 by four times its own volume we should 

 be incapable of existing. Everything 

 would then be burnt as quickly as a piece 

 of paper when put in the fire. Now let 

 me introduceinto ajar of oxygen a piece 

 of ignited charcoal or carbon, which I 

 was speaking of, in order that you may 

 see how t much more brilliantly it burns 

 there than it does iu ordinary atmosphere. 

 [Experiment performed.] The produce of 

 this union is called carbonic acid or char- 

 coal gas, and of its properties I shall 

 shortly speak. Well, now, gentlemen, af- 

 ter what you have just seen, you cannot 

 be surpised when I tell you that this sub- 

 stance, which is always found in the air, 

 is most active in the decomposition of ma- 

 nure-heads and of animal vegetable mat- 

 ter generally. To this point it is my in- 

 tention to allude further in an after-part 

 of the lecture. Well, now, oxygen is also 

 found in water. Water consists of hydro- 

 gen, one of the other elements of which 

 I spoke, and oxygen. You must bear in 

 mind the difference between these two 

 substances. Oxygen is the body which 

 consumes everything ; hydrogen is one of 

 the substances which is burnt. All tallow, 

 all oils, all wood, all things generally 

 which burn with a flame contain hydro- 

 gen. Hydrogen is, as I have just stated, 

 found in water, and it can be liberated 

 from water with perfect ease. Water, as 

 I have just told you, consists of oxygen 

 and hydrogen. 



# * # # # 



I have now spoken to you of oxygen, 

 which is the active burning principle of 

 the air, and one of the constituents of wa- 

 ter; and of hydrogen, which is the other 

 constituents. Let me now speak of nitro- 

 gen. Nitrogen exists in the air to the ex- 

 tent of four-fifths of the entire bulk. It 



is in itself very inert, having no particular 

 action by itself. Some of its combina- 

 tions are very curious. For instance, ni- 

 trogen and charcoal, with some hydrogen, 

 forms the powerful poison called prussic 

 acid. Saltpetre, which contains nitrogen, 

 mixed with sulphur and charcoal, forms 

 the gunpowder by means of which men 

 blow each other to pieces, and, in fact, 

 nitrogen is found in almost all our power- 

 ful explosive compounds, such as fulmi- 

 nating silver, gun cotton, &,c. Nitrogen, 

 existing in nitrate of soda and guano, is, 

 however, used for the far different purpose 

 of assisting in the growth of the farmer's 

 crops. So far, however, as the farmer is 

 concerned, what it is chiefly necessary for 

 him to know is the main constituent of 

 ammonia, and of nitrate of soda, and of 

 guano, which are all so very valuable to 

 the cultivator of the soil. I now come to 

 carbon or charcoal. I gave you just now 

 an example of the burning of charcoal, 

 but I did not point out the properties of 

 what was then produced by the burning of 

 the charcoal. Has it never struck you 

 that when coal or wood- is burnt, nothing 

 but the' ashes seem to remain ? What has 

 become of the bulk of the materials? It 

 has passed into the air in an invisible 

 form ; and, so far as the charcoal is con- 

 cerned, that portion has passed into the 

 air in the form of a' substance which is 

 commonly called carbonic-acid gas, but 

 which we will also call charcoal gas. — 

 Now carbonic-acid generally exists in the 

 form of a gas ; it comes out in the form 

 of an effervescence in bottled beer, in 

 champagne, or in soda-water; and it is 

 also given out in the' burning or decompo- 

 sition of any animal' or vegetable matter 

 containing carbon; and when I tell you 

 fhat it is this carbonic-acid gas that kills 

 so many men who incautiously descend 

 into wells or brewer's vats, and that it is, 

 in fact, identical with what is termed 

 choke-damp by miners, you will admit 

 that it is a most important agent wherever 

 it is found operating. Let me now ex- 

 hibit to you one of the effects of this gas. 

 It is a substance which has the power of 

 uniting with lime-water, and forming a 

 white sediment, which is, in fact, carbo- 

 nate of lime, or chalk. I will take the 

 bottle in which I burnt the charcoal in a 

 previous experiment, and will introduce 

 some lime water; on agitation you will 



