180 GEOLOGICAL RECONNOISSANCE 
matter to the solvent action of water; this extract contained 1.33 parts of 
anhydrous nitric acid, corresponding to 2.493 parts of nitre. 
The air-dried earth lost 7.59 per cent. of moisture at 212 deg. F. 
No. 42. Nitre-determination, in a nitre earth, labeled “red nitre earth 
above and below the laminated nitre earth, same cave.” 
The watery extract from 100 parts of air-dried earth contains 3.305 
parts of anhydrous nitric acid, corresponding to 6.195 parts of nitre. 
According to Dr. Owen, the air-dried earth lost 3.15 per cent. of mois- 
ture at 300 deg. F. 
This nitre-earth is by far the richest of the three, a ton yielding nearly 
124 ibs of nitre. 
WELL AND RIVER WATER. 
The examinations of these waters having been performed in the field, 
with comparatively limited means, only qualitative analyses could be 
made, and in these even, regard could only be paid to such constituents 
as occur in not inconsiderable quantities. I hope to be enabled to report 
at a future period full quantitative analyses of the water of the principal 
rivers and mineral springs. 
No. 48. Water of the St. Francis river, taken at Chalk Bluffs, Greene 
county. 
The ordinary reagents showed only the presence of 
Bi-carbonate of lime, and 
Bi-carbonate of magnesia. 
No. 44. Water from a well on A. L. Stuart’s farm, Greene county. 
This water is remarkably pure, containing no lime, and only a small 
quantity of 
Bi-carbonate of magnesia, and a trace of 
Chloride of magnesium, or an alkaline chloride. 
No. 45. Water from a well on Wm. Lane’s farm, Greene county. 
This is also a very pure water, containing only minute quantities of 
Bi-carbonate of lime, and 
Bi-carbonate of magnesia. 
