112 FARADAY 



how it glows ! This is the glorious lime light, which rivals 

 the voltaic light, and which is almost equal to sunlight. I 

 have here a piece of carbon or charcoal, which will burn 

 and give us light exactly in the same manner as if it were 

 burnt as part of a candle. The heat that is in the flame of a 

 candle decomposes the vapor of the wax, and sets free the 

 carbon particles; they rise up heated and glowing as this 

 now glows, and then enter into the air. But the particles, 

 when burnt, never pass off from a candle in the form of car- 

 bon. They go off into the air as a perfectly invisible sub- 

 stance, about which we shall know hereafter. 



Is it not beautiful to think that such a process is going on, 

 and that such a dirty thing as charcoal can become so incan- 

 descent? You see it comes to this that all bright flames 

 contain these solid particles; all things that burn and pro- 

 duce solid particles, either during the time they are burning, 

 as in the candle, or immediately after being burnt, as in the 

 case of the gunpowder and iron filings all these things give 

 us this glorious and beautiful light. 



I will give you a few illustrations. Here is a piece of 

 phosphorus, which burns with a bright flame. Very well; 

 we may now conclude that phospho- 

 rus will produce, either at the mo- 

 ment that it is burning or after- 

 wards, these solid particles. Here 

 is the phosphorus lighted, and I 

 cover it over with this glass for the 

 purpose of keeping in what is pro- 

 duced. What is all that smoke? 

 That smoke consists of those very 

 particles which are produced by the 



combustion of the phosphorus. Here again are two sub- 

 stances. This is chlorate of potassa, and this other sulphuret 

 of antimony. I shall mix these together a little, and then 

 they may be burnt in many ways. I shall touch them with a 

 drop of sulphuric acid, for the purpose of giving you an illus- 

 tration of chemical action, and they will instantly burn.( 9 ) 



9 The following is the action of the sulphuric in inflaming the mixture of 

 sulphuret of antimony and chlorate of potassa. A portion of the latter is 

 decomposed by the sulphuric acid into oxide of chlorine, bisulphate of potassa. 



