366 PALEOZOIC TIME. 



1*14 to 17 per cent, (the last in Cladonia), but mostly between 1*14 and 4 , 30 per cent. 

 In Lycopodium dendroideum, Hawes, in his analyses (p. 362), found 3-25 per cent, of 

 ash; in L. complanatum, 5-47 per cent., and in Equiselum hyemale, 11-82 per cent-. 



Lycopodium cha.mcecyparissus afforded Aderholt 5185 per cent, of alumina; or, when 

 without spores, 57-36 per cent. ; while Ritthausen obtained 39-07 alumina for this species, 

 and 37-87 for L. complanatum. In Lycopods, the silica constitutes 10 to 14 per cent, of 

 the ash. In the ash of Mosses have been found 8 to 23 - 58 per cent, of potash, 4 to 16 

 of silica, l - 06 to 6-56 of phosphoric acid, 4-9 to 10-7 of magnesia. Among Ferns, the 

 amount of ash, so far as determined, varies from 5 to 8 per cent. 



The ash of Fungi affords 21 to 54 per cent, of potash, 0-36 to 11-8 of soda, 1*27 to 8 

 of magnesia, 15 to 60 of phosphoric acid, and to 15-4 of silica. Among Lichens, the 

 ash of Cladonia rangiferina contains 70*34 percent, of silica; of other species, less, 

 down to 0*9 per cent. 



Trapa nalans, of bogs, in Europe, affords 13 to 25 per cent, of ash ; and 25 per cent, 

 of this are oxyd of iron (Fe 2 3 ) with a little oxyd of manganese. Of the ash of the 

 fruit scales, over 60 per cent, are oxyd of iron. 



Since, according to the average composition of Lycopods, the dried 

 plant affords 5 pounds of ash to 100 of the plant, and 40 per cent, 

 of this is alumina and silica (27 alumina and 13 silica), these two 

 ingredients make up 2 per cent, of the plants. Ferns, with the same 

 amount of ash, afford, as the average, 27 per cent, of silica, with no 

 alumina. Equiseta afford, on an average, 20 per cent, of ash, and 50 

 per cent, of this may be silica. Supposing, now, that Lycopods {Lepi- 

 dodendrids, etc.) afforded one half the material of the coal-beds, and 

 the other plants the rest, and that the silica and alumina of the former 

 averaged 40 per cent., and of the latter only 27 per cent., this being 

 all silica, then the amount of these ingredients afforded by the vegeta- 

 tion would be 1-66 per cent, of the whole weight when dried. This 

 would make the amount of silica and alumina, in the bituminous coal 

 made from such plants (supposing three fifths of the material of the 

 wood lost in making the coal, as estimated on page 363), 4 percent. ; 

 and the whole amount of ash about 4*75 per cent. At the same time, 

 the ratio of silica to alumina would be nearly 3 to 2. 



Now many analyses of the bituminous coal of the Interior basin 

 have obtained not over 3 per cent, of ash, or impurity, although the 

 general average, excluding obviously impure kinds, reaches 4-5 to 6 

 per cent.; being, for the coals of the northern half of Ohio, 5*12, and 

 for the southern half 4.72. 



It hence follows that (1) the whole of the impurity in the best coals 

 may have been derived from the plants ; (2) the amount of ash in the 

 plants was less than the average in modern species of the same tribes ; 

 (3) the winds and waters for long periods contributed almost no dust 

 or detritus to the marshes ; and (4) the ash, or else the detritus, was 

 greatest in amount toward the borders of the Interior marsh-region. 

 In that era of moist climate and universal forests, there was almost no 

 chance for the winds to gather dust or sand for transportation. 



