OF ARKANSAS. 175 
Carbonate of limes-+eeeseeeeeverevecee 50.075 
Carbonate of magnesia: +++-+sseeseeees 32,487 
POPASSAl es WS Oe ei Bee Se ose dae wes 0.136 
Organic matter, and loss. +++ +eeeeeeeee 4.985 
100.000 
The air-dried rock lost 0.16 per cent of moisture at 250 deg. F. 
No. 34. Dolomite, in which occur the zine and Jead ores at Wood’s 
mine, Marion county. . 
A grayish-white, fine-grained dolomite; lustre sub-resinous from minute | 
crystalline, shining particles dispersed through the rock; easily reduced to 
powder; powder grayish-white. 
Composition, dried at 230 deg. F: 
Silicia, with a trace of clay.-.+++-++> *+ 3.191 
Alumina, with trace of iron....-.+.++.. 8.023 
Carbonate of lime+ ++ ++eees cess ewes eens 50.041 
Carbonate of magnesia--+---+. bee eae 42.317 
Carbonate of zinc.-++-++s+e5- Cece n tenes 1.950 
Potassa, with trace of soda--+++eseeeass 0.435 
100.957 
The air-dried rock lost 0.23 per cent. of moisture at 230 deg. F. 
No. 35. Red clay, occurring in veins and pockets in dolomite and 
imbedding the zinc ore at the Bath mine, Lawrence county. 
A ferruginous clay of dirty yellowish-red color; soft; easily crumbling 
to powder between the fingers; when burnt, assumes a bright orange-red 
° color. 
Composition, dried at 250 deg. F: 
Silicates, insoluble in hydrochloric acid-- 84.616 
Sesquioxide of iron-++++++seeeeres seeee 4,308 
pis cara of manganese-++-++++essee+ 0.236 
Alumina: + se varsa caverns iwnt ites Mueriees Ale i anieneh one wee 3.515 
Carbonate SP AEenG miusuremeaatennen 0.380 
Carbonate of lime--s++eseeeeeeeeeeees 0.275 
Organic matter,’ and’ water--++ -++++++ 6.447 
99.772 
The air-dried clay lost 4.32 per cent. of moisture at 250 deg. F. 
On account of the bright color which the clay assumes on burning, it 
