214 Transactions of the American Institute. 



"When anthracite coal was first introduced in Philadelphia, it could 

 not be burned. A man is said to have taken some hard coal from a 

 friend for trial, and after keeping it on his fire for a week to have 

 returned it as " fire proof." The man who sold the first wagon load 

 of anthracite in Philadelphia had to hurry out of the city to avoid 

 arrest for fraud. People had been accustomed to burn the soft coal, 

 and were not familiar with the method. of bringing anthracite coal 

 up to the proper heat. Dr. Nott of Schenectady was one of the first 

 to comprehend the difficulty and devise a remedy ; and the old Nott 

 stove will long be remembered, particularly in the neighborhood of 

 Union College. He made the first experiment to see whether anthra- 

 cite coal could be used under the boiler of a steamboat, on the Hud- 

 son river, by forcing air under the fire-grate; and it is hardly 

 necessary to say that the experiment was successful. 



Conditions Antagonistic to Combustion. 



Fire-extinguishing substances act sometimes by cooling the fire ; as 

 water cools the body below the burning point ; sometimes by covering 

 the burning body with something to impede the access of air, as a rug ; 

 and sometimes by surrounding it with an atmosphere containing but 

 little, if any, oxygen. The nitrogen in our atmosphere interferes 

 with combustion, very fortunately for us, for we find it rapid enough 

 even now. The reason the magnesium and phosphorus burned so 

 much more brightly in pure oxygen was that there was no nitrogen 

 present to take up the heat and reduce the temperature. 



I have here a jar of sulphurous acid. Sulphur is combustible, but 

 the acid produced by its combustion is no longer combustible. The 

 combustion is ended. It is a common practice, when a chimney takes 

 fire, to throw sulphur down. This seems rather a homoeopathic treat- 

 ment of the fire, but the explanation is very simple. The sulphur, 

 in burning, very quickly takes up the oxygen in the atmosphere, and 

 the combustion ceases because the air essential to combustion is 

 excluded by the sulphurous acid which does not support combustion. 

 I shall lower these candles into the jar, and you see that the moment 

 the flames come below the level of the sulphurous acid, they are 

 extinguished. Here, we have a jar of carbonic acid, which is equally 

 antagonistic to combustion. Even if there is as little as six per cent 

 of carbonic acid in the air, it is sufficient to extinguish the flame. If 

 we breathe the air from our lungs into a jar, a taper plunged in it 

 will be extinguished, as you now see. 



