192 



ECONOMIC GEOLOGY. 



[PT. III. 



The sole peculiarity in the above, affecting the manufacture of iron, 

 is the presence of the very appreciable proportions of phosphoric acid. * 

 For comparison the following analyses of ashes of coal may be taken. f 



Welsh Coal. 



Pont3'pool 



Bedwas 



Porthmaivr 



EbbwVale 



Coleshffl 



Scotch Coal. 



Fordel Splint 



Wallsend, Elgin .... 



Patent Fuel. 

 Warlich's 



Ash in 

 Coal. 



Fixed 

 Carbon 

 in Coal. 



5-52 



6-94 



14-72 



1-50 



8-92 



4-00 

 1070 



48-0 

 47-7 



Alumina 



and 

 Oxide of 



Iron. 



40-00 

 26-87 

 34-21 

 53-00 

 59-27 



37-60 

 61-66 



44-78 

 56-95 

 52-00 

 35-01 

 2909 



52-00 

 24-42 



57' 30 



12-00 

 5-10 

 6-199 

 394 

 6-02 



373 

 2-62 



Magne- 

 sia. 



trace. 

 1-19 

 0-659 

 220 

 1-35 



1-10 

 1-73 



Sulphu- 

 ric Acid 



Phospho- 

 ric Acid 



02-22 

 7-23 

 4-12 

 4-89 

 3-84 



4-14 

 8-38 



Percent- 

 age. 

 Total. 



99-75 



98-08 



97-821 



99-92 



99-97 



99-45 

 99-99 



It will be immediately seen that in Raniganj coal the proportion of 

 phosphoric acid in the ash is more than double that in any of the 

 above analyses, and as the ash is above the average percentage, the 

 amount of phosphoric acid in Damuda coal, judging from the above 

 analyses, obtained from two distinct seams, is considerable ; the 

 percentage of phosphorus being in Sirsol 0*172, and in Raniganj coal 

 0*139, the average amounting to 0-155, or between £ and \ per cent. 



If such coal were used in a blast furnace, a considerable portion of 

 the phosphorus would doubtless be found to combine with the iron 

 produced. 



The effect of phosphorus upon iron is to render the pig, or cast 

 iron produced very fluid, and slow in solidifying, 

 so that it is, if the quantity of phosphorus be 



Phosphorus. 



* In beds so completely destitute of animal organic remains, the presence of so much 

 phosphoric acid is curious. 



f First Report on the Coals, &c, suited to the Steam Navy. — Memoirs of the Geological 

 Survey of Great Britain, Vol. II., Part IL, pp. 550—629. 



