206 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



We have, then, 



Carbon - - - - - • - - 28*350 



Hydrogen ---_-._ 0*926 



.Oxygen*?! _ 



Nitrogen J 



Ash 68-569 



100-000 



I also incinerated another portion, which evidently contained a much larger 

 quantity of rock. Dried at 120° Centig. 



28*70 grains gave of Ash, 24*21, or 84-35 per 100. 



We have, then, 15*65 per 100 of carbon, etc. The incineration was conducted 

 during 21 hours. The colour of the ash was reddish-brown, due evidently to 

 oxide of iron. 



In the combustion I employed as much heat as I could obtain by wafting 

 the charcoal with a piece of paste-board, The gas ceased to be disengaged 

 completely, and the caustic ley rose rapidly in the bulb, and continued to rise 

 after breaking off the drawn-out extremity of the combustion-tube. I imme- 

 diately removed the charcoal. On cooling, the tube, as I expected, cracked 

 slightly, the ley in the large bulb descended, and I was enabled to draw air 

 through effectually in the usual way. After removing the sheet of copper, with 

 which the tube had been enveloped, I found the glass melted in several places, 

 and in one spot, about two inches from the drawn-out end, the glass had sunk 

 down to the chromate of lead, and so intercepted the passage of air from the 

 drawn-out point. Only a very minute quantity of carbonic acid could possibly 

 have escaped absorption. I am thus particular in relating details, that you may 

 exactly know what value to attach to the analysis, which I think must be very 

 near the truth. 



Postscript. — Feb. 26. 1845. 



1 subjoin the following analysis of Anthracite from the Lehigh Summit Mine, 

 Pennsylvania. The ash is in very small proportion : — 



1st Analysis. 

 6*93 grains gave of 



Water, 1 -717 = 0*1907 Hydrogen, or 2*75 per 100. 



Carbonic Acid, 23*57 =6*428 Carbon, or 92*756 do. 



2c? Analysis. 

 6*854 grains of coal gave of 



Water, 1*55 = 0*172 Hydrogen, or 2*509 per 100. 



Carbonic Acid, 23*23 = 6*335 Carbon, or 92*427 do. 



Nitrogen Analysis. 

 7 '01 4 grains gave of 



Metallic Platinum, 0*46=0*0652 Nitrogen, or 0*921 per 100. 



Incineration. 



33*73 grains gave of Ash, 0*75, or 2*223 per 100. 

 16*89 do. 0*385, or 2*280 do. 



Mean - 2*251. 



* I presume oxygen to have been present. Its presence, however, could only 

 have been demonstrated by determining the proportion of nitrogen. 



