LECTURE IV 



HYDROGEN IN THE CANDLE BURNS INTO 



WATER THE OTHER PART OF 



WATER OXYGEN 



I SEE you are not tired of the candle yet, or I am sure 

 you would not be interested in the subject in the way you 

 are. When our candle was burning we found it pro- 

 duced water exactly like the water we have around us ; and by 

 farther examination of this water we found in it that curious 

 body, hydrogen that light substance of which there is some 

 in this jar. We afterward saw the burning powers of that 

 hydrogen, and that it produced water. And I think I intro- 

 duced to your notice an apparatus which I very briefly said 

 was an arrangement of chemical force, or power, or energy, 

 so adjusted as to convey its power to us in these wires; and 

 I said I should use that force to pull the water to pieces, to 

 see what else there was in the water besides hydrogen; 

 because, you remember, when we passed the water through 

 the iron tube, we by no means got the weight of water back 

 which we put in in the form of steam, though we had a very 

 large quantity of gas evolved. We have now to see what is 

 the other substance present. That you may understand the 

 character and use of this instrument, let us make an experi- 

 ment or two. Let us put together, first of all, some sub- 

 stances, knowing what they are, and then see what that 

 instrument does to them. There is some copper (observe the 

 various changes which it can undergo), and here is some 

 nitric acid, and you will find that this, being a strong chemi- 

 cal agent, will act very powerfully when I add it to the 

 copper. It is now sending forth a beautiful red vapor; 

 but as we do not want that vapor, Mr. Anderson will hold it 

 near the chimney for a short time, that we may have the use 



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