102 STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 



introduced by wind or running water. When the deposit has been 

 protected from influx of silt, the ash may be less than 2 per cent, 

 of the dried material; but there is every gradation from that per- 

 centage to shale, clay, or sand with merely a trace of vegetable 

 matter. Such variations are commonplace in upland bogs and are 

 illustrated by one in Ohio, recorded by Dachnowski, which had 

 more than five times as much ash on the shallow border as in the 

 deeper portions. Analyses published in European works are too 

 commonly of material from localities where peat is dug, where it is 

 of proved economic value ; so that one is liable to suppose that peat 

 with less than 10 per cent, of ash predominates. It would appear, 

 however, that a much poorer grade of peat predominates, except 

 where, in lowland areas, checking of streams at the borders causes 

 dropping of the load or where a dense protecting fringe of plants, 

 like the "cane brakes" of the Mississippi delta, act as filters. The 

 analyses by Stanton in C. A. Davis's work are of samples from 

 many localities in 8 states. Practically all of them were taken 

 from previously unexplored deposits and, being collected according 

 to the official method, they represent the whole thickness. A com- 

 parsion of the results shows that the peat from 



24 localities has less than 5 per cent, of ash. 



74 localities has less than 10 per cent, of ash. 



28 locahties has less than 15 per cent, of ash. 



28 localities has less than 20 per cent, of ash. 



28 localities has less than 30 per cent, of ash. 



20 localities has less than 40 per cent, of ash. 



43 localities has more than 40 per cent, of ash. 



The lowest percentage is 1.53, which is less than that of the plants: 

 only 98 samples show less than 10 per cent., while 147 show more, 

 a vast preponderance of worthless material. The analyses, tabulated 

 by Dachnowski,"^ are from 61 localities in Ohio ; none is below 3 

 per cent., 14 are below 10 per cent., while 12 are above 20. When 

 one considers that the samples, in all cases cited, were taken because 

 the peat appeared to be such as might be utilized, it is evident that 

 good fuel peat is only a small part of whole now existing. 



151 A. Dachnowski, " Peat Deposits in Ohio," pp. 366, 367. 



