ECKEL.] MISSISSIPPI. 219 
The analysis below, by Mr. G. T. Hetherington, was recently made 
on a -sample taken several miles south of Jackson, Hinds County: 
Analysis of Vicksburg limestone from near Jackson, Miss. 
Silica ( Si0 2 ) 9. 63 
Alumina (A1 2 3 ) 2. 73 
Iron oxide (Fe 2 3 ) 2.76 
Lime (CaO) 45. 95 
Magnesia ( MgO) 99 
Alkalies ( K 2 0, Na 2 ) • 95 
Sulphur trioxide ( S0 3 ) 35 
Carbon dioxide ( C0 2 ) ^ 
Water F°° 
This corresponds to a content of about 81 per cent lime carbonate; 
and as the rock is otherwise satisfactory, the addition of a little clay 
will make a suitable Portland cement mixture. 
The analyses below were published in the early reports of the 
Mississippi Geological Survey. The last two, and perhaps the other 
three also, were made by Dr. E. W. Hilgard. 
Analyses of Vicksburg limestones from Mississippi. 
Silica (Si0 2 ) 
Alumina (A1 2 3 ) 
Iron oxide (Fe 2 3 ) ... 
Lime (CaO) 
Magnesia (MgO) 
Alkalies (K 2 0, Na 2 0). 
Sulphur trioxide (S0 3 ) 
Carbon dioxide (C0 2 ) 
Water 
1 
2 
3 
4 
6.30 
15. 05 
9.20 
2.03 
| 7.20 
5. 35 
6.65 
2.12 
48.44 
44. 58 
47. 12 
52.47 
n. d. 
n. d. 
n.d. 
.67 
n.d. 
n.d. 
n.d. 
n.d. 
n.d. 
n.d. 
n.d. 
n.d. 
38. 06 
35.02 
37. 03 
41. 53 
n.d. 
n.d. 
n.d. 
1.10 
12.31 
2.70 
43.93 
1.69 
.79 
1.27 
34.72 
2.40 
1-3. Red Hills, Wayne County. Harper, Report on Geology of Mississippi, 1857, p. 166. 
4. Brandon, Rankin County. Hilgard, Report on Geology of Mississippi, 1860. 
5. Byram, Hinds County. Hilgard, Report on Geology of Mississippi, 1860. 
PORTLAND-CEMENT RESOURCES OF MISSOURI. 
PORTLAND-CEMENT MATERIALS. 
Two large Portland-cement plants are now in operation in Missouri, 
and it seems probable that this State will soon become an important 
factor in the cement production of the United States. This proba- 
bility of high rank as a cement producer is due to the fact that the 
thickest and purest limestones of the State outcrop along the banks 
of the Mississippi and Missouri rivers. Plants located on these lime- 
