CHEMICAL ANALYSES. 
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2. MARL, SAN PEDRO RIVER. 
Found. Calculated. 
Matter insoluble in hydrochloric acid......4.224 31.5 
Alumina and peroxide of iron. .844 6.3 
Carbonate of lime... 5.856 43.7 
Carbonate of magnesia... 703 5.2 
Soluble salts, as— 
Sulphate of lime, chloride of sodium.... .362 2.7 
Moisture.......... 1.411 10,5 
13.400 100.0 
A fresh water deposit. 
3. LIMESTONE, CHIRICAHUI MOUNTAIN. 
Color, blue. Specific gravity, 2.74. 
Found. Calculated. 
Silica and insoluble clay....... 5.020 35.30 
Alumina and peroxide of iron... 2.928 20.33 
Carbonate of lime. 4.864 33.77 
Carbonate of magnesia.. 324 2.22 
Alkaline salts. .270 1.35 
Moisture and traces of organic matter... 1.000 6.94 
14.388 99.90 
4. LIMESTONE, ORGAN MOUNTAINS. 
Physical characters same as 3. 
Insoluble silicates....... 38.00 
Alumina and peroxide of iron......... 12.17 
Carbonate of lime....... 37.65 
Carbonate of magnesia........ 3.16 
Alkaline salts............. ....... 1.75 
Moisture and organic matter.. 7.25 
99.98, in 100 parts. 
5. TRACHYTE, PELONCILLO HILLS. 
Specific gravity, 2.56. 
Silica.......... 69.470 
Alumina............ 22.600 
Peroxide of iron..... .720 
Carbonate of lime.......................... 2.154 
Carbonate of magnesia.. .300 
Alkalies ......... 4.666 
99.910, in 100 parts. 
