THE CARBONIFEROUS SYSTEM. 7 143 
area, the shields of diatomaces accumulated in beds of considerable thick- 
ness, and these, now blended and consolidated by solution, form our Coal 
Measure burr-stones. 
In this view, the wide diffusion of the silica and its blending with 
and shading into purer limestone as though deposited in the quieter 
nooks of the broad lagoon, its association with fossils and iron, are all 
harmonious and confirmatory facts. If hot springs had furnished the 
silica, we should be pretty certain to find it impregnating other strata 
than the limestone, and should probably find some masses or accumula- 
tions heaped up about the source of supply, but we have discovered 
nothing of the kind; and the careful observation of the facts in the 
case has convinced me that the silica, like the lime, is indigenous and 
not exotic, that is, that it accumulated particle by particle as a sediment 
at the bottom of water where it was slowly drawn from solution and fixed 
by some vital agency. 
ANALYSES oF Coat No. 4. 
No. 1. Sharples’s bank, Bedford township, Coshocton county ; cannel. 
“« 2. Lyman’s, Jefferson towhship, e *s 
“ 3. Trumbull Company’s shaft, Stark county ; bituminous. 
““ 4, Greentown, Summit county, 
‘“ 5. Porter’s coal, Hopewell township, Muskingum county; bituminous. 
‘* 6. Flint Ridge cannel. 
if 2. 3 
SPeCwicronravltyarececes cscs sceccce: 1.149 1.357 1.322 
IMPOISCUTCMseer cise cciseues eves seg wince 1.50 1.75 7.00 
Volatile combustible ......... 44.40 38.45 30.80 
JED CAVA OOI, Ghecosuce sobocaacoaS: 44,50 41.55 59.50 
PNG IMM eeeeweetivec heals cists tseaves ercsistioe 9.60 18.25 2.70 
100.00 | 100.00 | 100.00 
SUN erotics ie ssecs vewrioe'ss No 1.34 0.65 
Coat No. 5. 
In the western part of Holmes county the distance between the Putnam 
Hill limestone and its underlying coal (No. 4) and Coal No. 6—to be de- 
scribed further on—is little more than twenty feet, and no coal seam 
occurs in the interval. In going toward the east from this point this 
' interval rapidly expands, until in Tuscarawas county it becomes as much 
as one hundred feet, and one, sometimes two, coal seams are found in it. 
