DETERMINATION OF THE CARBON IN SMOKE. l$$ 



lected. Pass a stream of cold water through a pipe in this 

 gas-current and a large quantity of black will be deposited. 

 On stopping the water flow and inclining the tube a little 

 the carbon disappears gradually, and when the temperature 

 of the tube attains that of the gas, no black will be deposited. 

 Cool it again, and more black forms immediately. 



Combustion gases meet with surfaces relatively cold in 

 the boiler sides or flues, or even in colder currents of gas or 

 air passing in through the grate. This produces a quick cool- 

 ing, and consequent formation of black. 



Experiments made at Mulhouse in 1859 by Burnat 

 showed an advantage gained in steaming by producing smoke, 

 rather than introducing too great excess of air. The experi- 

 ments showed that the loss in carbon was quite small, and 

 these results have been confirmed by others since. E. R. 

 Tatlock of Glasgow finds 60 per cent combustible matter in 

 soot, and obtained 51.46 grains per cubic foot of furnace 

 gases. 



To determine the amount of carbon in smoke, Scheurer- 

 Kestner used a glass organic analysis apparatus, the tube 

 having in the middle loosely packed asbestos for about 8 

 inches, which was kept in place by platinum spirals. One 

 end was drawn out to connect with the absorption apparatus, 

 and the other end placed in the flue. After igniting and 

 cooling the asbestos the small end is connected with an 

 aspirator and the gas drawn slowly through. The carbon is 

 all stopped by the asbestos, which becomes black for a short 

 distance. When sufficiently collected, dry the tube at 100 

 C., heat to redness, and pass a stream of oxygen through it, 

 collecting the carbonic acid formed. 



As an example Scheurer-Kestner gives the following: 



Waste gases, reduced to o and 760 mm. 86 litres. 

 Time of sampling I hour. 



